// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "lib/jxl/base/status.h"
#ifndef FJXL_SELF_INCLUDE
#include <assert.h>
#include <stdint.h>
#include <string.h>
#include <algorithm>
#include <array>
#include <limits>
#include <memory>
#include <vector>
#include "lib/jxl/enc_fast_lossless.h"
#if FJXL_STANDALONE
#if defined(_MSC_VER)
using ssize_t = intptr_t;
#endif
#else // FJXL_STANDALONE
#include "lib/jxl/encode_internal.h"
#endif // FJXL_STANDALONE
#if defined(__x86_64__) ||
defined(_M_X64)
#define FJXL_ARCH_IS_X86_64 1
#else
#define FJXL_ARCH_IS_X86_64 0
#endif
#if defined(__i386__) ||
defined(_M_IX86) || FJXL_ARCH_IS_X86_64
#define FJXL_ARCH_IS_X86 1
#else
#define FJXL_ARCH_IS_X86 0
#endif
#if FJXL_ARCH_IS_X86
#if defined(_MSC_VER)
#include <intrin.h>
#else // _MSC_VER
#include <cpuid.h>
#endif // _MSC_VER
#endif // FJXL_ARCH_IS_X86
// Enable NEON and AVX2/AVX512 if not asked to do otherwise and the compilers
// support it.
#if defined(__aarch64__) ||
defined(_M_ARM64)
// ARCH
#include <arm_neon.h>
#if !
defined(FJXL_ENABLE_NEON)
#define FJXL_ENABLE_NEON 1
#endif // !defined(FJXL_ENABLE_NEON)
#elif FJXL_ARCH_IS_X86_64 && !
defined(_MSC_VER)
// ARCH
#include <immintrin.h>
// manually add _mm512_cvtsi512_si32 definition if missing
// (e.g. with Xcode on macOS Mojave)
// copied from gcc 11.1.0 include/avx512fintrin.h line 14367-14373
#if defined(__clang__) && \
((!
defined(__apple_build_version__) && __clang_major__ < 10) || \
(
defined(__apple_build_version__) && __apple_build_version__ < 12000032))
inline int __attribute__((__gnu_inline__, __always_inline__, __artificial__))
_mm512_cvtsi512_si32(__m512i __A) {
__v16si __B = (__v16si)__A;
return __B[0];
}
#endif
#if !
defined(FJXL_ENABLE_AVX2)
#define FJXL_ENABLE_AVX2 1
#endif // !defined(FJXL_ENABLE_AVX2)
#if !
defined(FJXL_ENABLE_AVX512)
// On clang-7 or earlier, and gcc-10 or earlier, AVX512 seems broken.
#if (
defined(__clang__) && \
(!
defined(__apple_build_version__) && __clang_major__ > 7) || \
(
defined(__apple_build_version__) && \
__apple_build_version__ > 10010046)) || \
(
defined(__GNUC__) && __GNUC__ > 10)
#define FJXL_ENABLE_AVX512 1
#endif
#endif // !defined(FJXL_ENABLE_AVX512)
#endif // ARCH
#ifndef FJXL_ENABLE_NEON
#define FJXL_ENABLE_NEON 0
#endif
#ifndef FJXL_ENABLE_AVX2
#define FJXL_ENABLE_AVX2 0
#endif
#ifndef FJXL_ENABLE_AVX512
#define FJXL_ENABLE_AVX512 0
#endif
namespace {
enum class CpuFeature : uint32_t {
kAVX2 = 0,
kAVX512F,
kAVX512VL,
kAVX512CD,
kAVX512BW,
kVBMI,
kVBMI2
};
constexpr uint32_t CpuFeatureBit(CpuFeature feature) {
return 1u <<
static_cast<uint32_t>(feature);
}
#if FJXL_ARCH_IS_X86
#if defined(_MSC_VER)
void Cpuid(
const uint32_t level,
const uint32_t count,
std::array<uint32_t, 4>& abcd) {
int regs[4];
__cpuidex(regs, level, count);
for (
int i = 0; i < 4; ++i) {
abcd[i] = regs[i];
}
}
uint32_t ReadXCR0() {
return static_cast<uint32_t>(_xgetbv(0)); }
#else // _MSC_VER
void Cpuid(
const uint32_t level,
const uint32_t count,
std::array<uint32_t, 4>& abcd) {
uint32_t a;
uint32_t b;
uint32_t c;
uint32_t d;
__cpuid_count(level, count, a, b, c, d);
abcd[0] = a;
abcd[1] = b;
abcd[2] = c;
abcd[3] = d;
}
uint32_t ReadXCR0() {
uint32_t xcr0;
uint32_t xcr0_high;
const uint32_t index = 0;
asm volatile(
".byte 0x0F, 0x01, 0xD0"
:
"=a"(xcr0),
"=d"(xcr0_high)
:
"c"(index));
return xcr0;
}
#endif // _MSC_VER
uint32_t DetectCpuFeatures() {
uint32_t flags = 0;
// return value
std::array<uint32_t, 4> abcd;
Cpuid(0, 0, abcd);
const uint32_t max_level = abcd[0];
const auto check_bit = [](uint32_t v, uint32_t idx) ->
bool {
return (v & (1U << idx)) != 0;
};
// Extended features
if (max_level >= 7) {
Cpuid(7, 0, abcd);
flags |= check_bit(abcd[1], 5) ? CpuFeatureBit(CpuFeature::kAVX2) : 0;
flags |= check_bit(abcd[1], 16) ? CpuFeatureBit(CpuFeature::kAVX512F) : 0;
flags |= check_bit(abcd[1], 28) ? CpuFeatureBit(CpuFeature::kAVX512CD) : 0;
flags |= check_bit(abcd[1], 30) ? CpuFeatureBit(CpuFeature::kAVX512BW) : 0;
flags |= check_bit(abcd[1], 31) ? CpuFeatureBit(CpuFeature::kAVX512VL) : 0;
flags |= check_bit(abcd[2], 1) ? CpuFeatureBit(CpuFeature::kVBMI) : 0;
flags |= check_bit(abcd[2], 6) ? CpuFeatureBit(CpuFeature::kVBMI2) : 0;
}
Cpuid(1, 0, abcd);
const bool os_has_xsave = check_bit(abcd[2], 27);
if (os_has_xsave) {
const uint32_t xcr0 = ReadXCR0();
if (!check_bit(xcr0, 1) || !check_bit(xcr0, 2) || !check_bit(xcr0, 5) ||
!check_bit(xcr0, 6) || !check_bit(xcr0, 7)) {
flags = 0;
// TODO(eustas): be more selective?
}
}
return flags;
}
#else // FJXL_ARCH_IS_X86
uint32_t DetectCpuFeatures() {
return 0; }
#endif // FJXL_ARCH_IS_X86
#if defined(_MSC_VER)
#define FJXL_UNUSED
#else
#define FJXL_UNUSED __attribute__((unused))
#endif
FJXL_UNUSED
bool HasCpuFeature(CpuFeature feature) {
static uint32_t cpu_features = DetectCpuFeatures();
return (cpu_features & CpuFeatureBit(feature)) != 0;
}
#if defined(_MSC_VER) && !
defined(__clang__)
#define FJXL_INLINE __forceinline
FJXL_INLINE uint32_t FloorLog2(uint32_t v) {
unsigned long index;
_BitScanReverse(&index, v);
return index;
}
FJXL_INLINE uint32_t CtzNonZero(uint64_t v) {
unsigned long index;
_BitScanForward(&index, v);
return index;
}
#else
#define FJXL_INLINE
inline __attribute__((always_inline))
FJXL_INLINE uint32_t FloorLog2(uint32_t v) {
return v ? 31 - __builtin_clz(v) : 0;
}
FJXL_UNUSED FJXL_INLINE uint32_t CtzNonZero(uint64_t v) {
return __builtin_ctzll(v);
}
#endif
// Compiles to a memcpy on little-endian systems.
FJXL_INLINE
void StoreLE64(uint8_t* tgt, uint64_t data) {
#if (!
defined(__BYTE_ORDER__) || (__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__))
for (
int i = 0; i < 8; i++) {
tgt[i] = (data >> (i * 8)) & 0xFF;
}
#else
memcpy(tgt, &data, 8);
#endif
}
FJXL_INLINE size_t AddBits(uint32_t count, uint64_t bits, uint8_t* data_buf,
size_t& bits_in_buffer, uint64_t& bit_buffer) {
bit_buffer |= bits << bits_in_buffer;
bits_in_buffer += count;
StoreLE64(data_buf, bit_buffer);
size_t bytes_in_buffer = bits_in_buffer / 8;
bits_in_buffer -= bytes_in_buffer * 8;
bit_buffer >>= bytes_in_buffer * 8;
return bytes_in_buffer;
}
struct BitWriter {
void Allocate(size_t maximum_bit_size) {
assert(data == nullptr);
// Leave some padding.
data.reset(
static_cast<uint8_t*>(malloc(maximum_bit_size / 8 + 64)));
}
void Write(uint32_t count, uint64_t bits) {
bytes_written += AddBits(count, bits, data.get() + bytes_written,
bits_in_buffer, buffer);
}
void ZeroPadToByte() {
if (bits_in_buffer != 0) {
Write(8 - bits_in_buffer, 0);
}
}
FJXL_INLINE
void WriteMultiple(
const uint64_t* nbits,
const uint64_t* bits,
size_t n) {
// Necessary because Write() is only guaranteed to work with <=56 bits.
// Trying to SIMD-fy this code results in lower speed (and definitely less
// clarity).
{
for (size_t i = 0; i < n; i++) {
this->buffer |= bits[i] << this->bits_in_buffer;
memcpy(this->data.get() + this->bytes_written, &this->buffer, 8);
uint64_t shift = 64 - this->bits_in_buffer;
this->bits_in_buffer += nbits[i];
// This `if` seems to be faster than using ternaries.
if (this->bits_in_buffer >= 64) {
uint64_t next_buffer = bits[i] >> shift;
this->buffer = next_buffer;
this->bits_in_buffer -= 64;
this->bytes_written += 8;
}
}
memcpy(this->data.get() + this->bytes_written, &this->buffer, 8);
size_t bytes_in_buffer = this->bits_in_buffer / 8;
this->bits_in_buffer -= bytes_in_buffer * 8;
this->buffer >>= bytes_in_buffer * 8;
this->bytes_written += bytes_in_buffer;
}
}
std::unique_ptr<uint8_t[],
void (*)(
void*)> data = {nullptr, free};
size_t bytes_written = 0;
size_t bits_in_buffer = 0;
uint64_t buffer = 0;
};
size_t SectionSize(
const std::array<BitWriter, 4>& group_data) {
size_t sz = 0;
for (size_t j = 0; j < 4; j++) {
const auto& writer = group_data[j];
sz += writer.bytes_written * 8 + writer.bits_in_buffer;
}
sz = (sz + 7) / 8;
return sz;
}
constexpr size_t kMaxFrameHeaderSize = 5;
constexpr size_t kGroupSizeOffset[4] = {
static_cast<size_t>(0),
static_cast<size_t>(1024),
static_cast<size_t>(17408),
static_cast<size_t>(4211712),
};
constexpr size_t kTOCBits[4] = {12, 16, 24, 32};
size_t TOCBucket(size_t group_size) {
size_t bucket = 0;
while (bucket < 3 && group_size >= kGroupSizeOffset[bucket + 1]) ++bucket;
return bucket;
}
#if !FJXL_STANDALONE
size_t TOCSize(
const std::vector<size_t>& group_sizes) {
size_t toc_bits = 0;
for (size_t group_size : group_sizes) {
toc_bits += kTOCBits[TOCBucket(group_size)];
}
return (toc_bits + 7) / 8;
}
size_t FrameHeaderSize(
bool have_alpha,
bool is_last) {
size_t nbits = 28 + (have_alpha ? 4 : 0) + (is_last ? 0 : 2);
return (nbits + 7) / 8;
}
#endif
void ComputeAcGroupDataOffset(size_t dc_global_size, size_t num_dc_groups,
size_t num_ac_groups, size_t& min_dc_global_size,
size_t& ac_group_offset) {
// Max AC group size is 768 kB, so max AC group TOC bits is 24.
size_t ac_toc_max_bits = num_ac_groups * 24;
size_t ac_toc_min_bits = num_ac_groups * 12;
size_t max_padding = 1 + (ac_toc_max_bits - ac_toc_min_bits + 7) / 8;
min_dc_global_size = dc_global_size;
size_t dc_global_bucket = TOCBucket(min_dc_global_size);
while (TOCBucket(min_dc_global_size + max_padding) > dc_global_bucket) {
dc_global_bucket = TOCBucket(min_dc_global_size + max_padding);
min_dc_global_size = kGroupSizeOffset[dc_global_bucket];
}
assert(TOCBucket(min_dc_global_size) == dc_global_bucket);
assert(TOCBucket(min_dc_global_size + max_padding) == dc_global_bucket);
size_t max_toc_bits =
kTOCBits[dc_global_bucket] + 12 * (1 + num_dc_groups) + ac_toc_max_bits;
size_t max_toc_size = (max_toc_bits + 7) / 8;
ac_group_offset = kMaxFrameHeaderSize + max_toc_size + min_dc_global_size;
}
#if !FJXL_STANDALONE
size_t ComputeDcGlobalPadding(
const std::vector<size_t>& group_sizes,
size_t ac_group_data_offset,
size_t min_dc_global_size,
bool have_alpha,
bool is_last) {
std::vector<size_t> new_group_sizes = group_sizes;
new_group_sizes[0] = min_dc_global_size;
size_t toc_size = TOCSize(new_group_sizes);
size_t actual_offset =
FrameHeaderSize(have_alpha, is_last) + toc_size + group_sizes[0];
return ac_group_data_offset - actual_offset;
}
#endif
constexpr size_t kNumRawSymbols = 19;
constexpr size_t kNumLZ77 = 33;
constexpr size_t kLZ77CacheSize = 32;
constexpr size_t kLZ77Offset = 224;
constexpr size_t kLZ77MinLength = 7;
void EncodeHybridUintLZ77(uint32_t value, uint32_t* token, uint32_t* nbits,
uint32_t* bits) {
// 400 config
uint32_t n = FloorLog2(value);
*token = value < 16 ? value : 16 + n - 4;
*nbits = value < 16 ? 0 : n;
*bits = value < 16 ? 0 : value - (1 << *nbits);
}
struct PrefixCode {
uint8_t raw_nbits[kNumRawSymbols] = {};
uint8_t raw_bits[kNumRawSymbols] = {};
uint8_t lz77_nbits[kNumLZ77] = {};
uint16_t lz77_bits[kNumLZ77] = {};
uint64_t lz77_cache_bits[kLZ77CacheSize] = {};
uint8_t lz77_cache_nbits[kLZ77CacheSize] = {};
size_t numraw;
static uint16_t BitReverse(size_t nbits, uint16_t bits) {
constexpr uint16_t kNibbleLookup[16] = {
0b0000, 0b1000, 0b0100, 0b1100, 0b0010, 0b1010, 0b0110, 0b1110,
0b0001, 0b1001, 0b0101, 0b1101, 0b0011, 0b1011, 0b0111, 0b1111,
};
uint16_t rev16 = (kNibbleLookup[bits & 0xF] << 12) |
(kNibbleLookup[(bits >> 4) & 0xF] << 8) |
(kNibbleLookup[(bits >> 8) & 0xF] << 4) |
(kNibbleLookup[bits >> 12]);
return rev16 >> (16 - nbits);
}
// Create the prefix codes given the code lengths.
// Supports the code lengths being split into two halves.
static void ComputeCanonicalCode(
const uint8_t* first_chunk_nbits,
uint8_t* first_chunk_bits,
size_t first_chunk_size,
const uint8_t* second_chunk_nbits,
uint16_t* second_chunk_bits,
size_t second_chunk_size) {
constexpr size_t kMaxCodeLength = 15;
uint8_t code_length_counts[kMaxCodeLength + 1] = {};
for (size_t i = 0; i < first_chunk_size; i++) {
code_length_counts[first_chunk_nbits[i]]++;
assert(first_chunk_nbits[i] <= kMaxCodeLength);
assert(first_chunk_nbits[i] <= 8);
assert(first_chunk_nbits[i] > 0);
}
for (size_t i = 0; i < second_chunk_size; i++) {
code_length_counts[second_chunk_nbits[i]]++;
assert(second_chunk_nbits[i] <= kMaxCodeLength);
}
uint16_t next_code[kMaxCodeLength + 1] = {};
uint16_t code = 0;
for (size_t i = 1; i < kMaxCodeLength + 1; i++) {
code = (code + code_length_counts[i - 1]) << 1;
next_code[i] = code;
}
for (size_t i = 0; i < first_chunk_size; i++) {
first_chunk_bits[i] =
BitReverse(first_chunk_nbits[i], next_code[first_chunk_nbits[i]]++);
}
for (size_t i = 0; i < second_chunk_size; i++) {
second_chunk_bits[i] =
BitReverse(second_chunk_nbits[i], next_code[second_chunk_nbits[i]]++);
}
}
template <
typename T>
static void ComputeCodeLengthsNonZeroImpl(
const uint64_t* freqs, size_t n,
size_t precision, T infty,
const uint8_t* min_limit,
const uint8_t* max_limit,
uint8_t* nbits) {
assert(precision < 15);
assert(n <= kMaxNumSymbols);
std::vector<T> dynp(((1U << precision) + 1) * (n + 1), infty);
auto d = [&](size_t sym, size_t off) -> T& {
return dynp[sym * ((1 << precision) + 1) + off];
};
d(0, 0) = 0;
for (size_t sym = 0; sym < n; sym++) {
for (T bits = min_limit[sym]; bits <= max_limit[sym]; bits++) {
size_t off_delta = 1U << (precision - bits);
for (size_t off = 0; off + off_delta <= (1U << precision); off++) {
d(sym + 1, off + off_delta) =
std::min(d(sym, off) +
static_cast<T>(freqs[sym]) * bits,
d(sym + 1, off + off_delta));
}
}
}
size_t sym = n;
size_t off = 1U << precision;
assert(d(sym, off) != infty);
while (sym-- > 0) {
assert(off > 0);
for (size_t bits = min_limit[sym]; bits <= max_limit[sym]; bits++) {
size_t off_delta = 1U << (precision - bits);
if (off_delta <= off &&
d(sym + 1, off) == d(sym, off - off_delta) + freqs[sym] * bits) {
off -= off_delta;
nbits[sym] = bits;
break;
}
}
}
}
// Computes nbits[i] for i <= n, subject to min_limit[i] <= nbits[i] <=
// max_limit[i] and sum 2**-nbits[i] == 1, so to minimize sum(nbits[i] *
// freqs[i]).
static void ComputeCodeLengthsNonZero(
const uint64_t* freqs, size_t n,
uint8_t* min_limit, uint8_t* max_limit,
uint8_t* nbits) {
size_t precision = 0;
size_t shortest_length = 255;
uint64_t freqsum = 0;
for (size_t i = 0; i < n; i++) {
assert(freqs[i] != 0);
freqsum += freqs[i];
if (min_limit[i] < 1) min_limit[i] = 1;
assert(min_limit[i] <= max_limit[i]);
precision = std::max<size_t>(max_limit[i], precision);
shortest_length = std::min<size_t>(min_limit[i], shortest_length);
}
// If all the minimum limits are greater than 1, shift precision so that we
// behave as if the shortest was 1.
precision -= shortest_length - 1;
uint64_t infty = freqsum * precision;
if (infty < std::numeric_limits<uint32_t>::max() / 2) {
ComputeCodeLengthsNonZeroImpl(freqs, n, precision,
static_cast<uint32_t>(infty), min_limit,
max_limit, nbits);
}
else {
ComputeCodeLengthsNonZeroImpl(freqs, n, precision, infty, min_limit,
max_limit, nbits);
}
}
static constexpr size_t kMaxNumSymbols =
kNumRawSymbols + 1 < kNumLZ77 ? kNumLZ77 : kNumRawSymbols + 1;
static void ComputeCodeLengths(
const uint64_t* freqs, size_t n,
const uint8_t* min_limit_in,
const uint8_t* max_limit_in, uint8_t* nbits) {
assert(n <= kMaxNumSymbols);
uint64_t compact_freqs[kMaxNumSymbols];
uint8_t min_limit[kMaxNumSymbols];
uint8_t max_limit[kMaxNumSymbols];
size_t ni = 0;
for (size_t i = 0; i < n; i++) {
if (freqs[i]) {
compact_freqs[ni] = freqs[i];
min_limit[ni] = min_limit_in[i];
max_limit[ni] = max_limit_in[i];
ni++;
}
}
uint8_t num_bits[kMaxNumSymbols] = {};
ComputeCodeLengthsNonZero(compact_freqs, ni, min_limit, max_limit,
num_bits);
ni = 0;
for (size_t i = 0; i < n; i++) {
nbits[i] = 0;
if (freqs[i]) {
nbits[i] = num_bits[ni++];
}
}
}
// Invalid code, used to construct arrays.
PrefixCode() =
default;
template <
typename BitDepth>
PrefixCode(BitDepth
/* bitdepth */, uint64_t* raw_counts,
uint64_t* lz77_counts) {
// "merge" together all the lz77 counts in a single symbol for the level 1
// table (containing just the raw symbols, up to length 7).
uint64_t level1_counts[kNumRawSymbols + 1];
memcpy(level1_counts, raw_counts, kNumRawSymbols *
sizeof(uint64_t));
numraw = kNumRawSymbols;
while (numraw > 0 && level1_counts[numraw - 1] == 0) numraw--;
level1_counts[numraw] = 0;
for (size_t i = 0; i < kNumLZ77; i++) {
level1_counts[numraw] += lz77_counts[i];
}
uint8_t level1_nbits[kNumRawSymbols + 1] = {};
ComputeCodeLengths(level1_counts, numraw + 1, BitDepth::kMinRawLength,
BitDepth::kMaxRawLength, level1_nbits);
uint8_t level2_nbits[kNumLZ77] = {};
uint8_t min_lengths[kNumLZ77] = {};
uint8_t l = 15 - level1_nbits[numraw];
uint8_t max_lengths[kNumLZ77];
for (uint8_t& max_length : max_lengths) {
max_length = l;
}
size_t num_lz77 = kNumLZ77;
while (num_lz77 > 0 && lz77_counts[num_lz77 - 1] == 0) num_lz77--;
ComputeCodeLengths(lz77_counts, num_lz77, min_lengths, max_lengths,
level2_nbits);
for (size_t i = 0; i < numraw; i++) {
raw_nbits[i] = level1_nbits[i];
}
for (size_t i = 0; i < num_lz77; i++) {
lz77_nbits[i] =
level2_nbits[i] ? level1_nbits[numraw] + level2_nbits[i] : 0;
}
ComputeCanonicalCode(raw_nbits, raw_bits, numraw, lz77_nbits, lz77_bits,
kNumLZ77);
// Prepare lz77 cache
for (size_t count = 0; count < kLZ77CacheSize; count++) {
unsigned token, nbits, bits;
EncodeHybridUintLZ77(count, &token, &nbits, &bits);
lz77_cache_nbits[count] = lz77_nbits[token] + nbits + raw_nbits[0];
lz77_cache_bits[count] =
(((bits << lz77_nbits[token]) | lz77_bits[token]) << raw_nbits[0]) |
raw_bits[0];
}
}
// Max bits written: 2 + 72 + 95 + 24 + 165 = 286
void WriteTo(BitWriter* writer)
const {
uint64_t code_length_counts[18] = {};
code_length_counts[17] = 3 + 2 * (kNumLZ77 - 1);
for (uint8_t raw_nbit : raw_nbits) {
code_length_counts[raw_nbit]++;
}
for (uint8_t lz77_nbit : lz77_nbits) {
code_length_counts[lz77_nbit]++;
}
uint8_t code_length_nbits[18] = {};
uint8_t code_length_nbits_min[18] = {};
uint8_t code_length_nbits_max[18] = {
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
};
ComputeCodeLengths(code_length_counts, 18, code_length_nbits_min,
code_length_nbits_max, code_length_nbits);
writer->Write(2, 0b00);
// HSKIP = 0, i.e. don't skip code lengths.
// As per Brotli RFC.
uint8_t code_length_order[18] = {1, 2, 3, 4, 0, 5, 17, 6, 16,
7, 8, 9, 10, 11, 12, 13, 14, 15};
uint8_t code_length_length_nbits[] = {2, 4, 3, 2, 2, 4};
uint8_t code_length_length_bits[] = {0, 7, 3, 2, 1, 15};
// Encode lengths of code lengths.
size_t num_code_lengths = 18;
while (code_length_nbits[code_length_order[num_code_lengths - 1]] == 0) {
num_code_lengths--;
}
// Max bits written in this loop: 18 * 4 = 72
for (size_t i = 0; i < num_code_lengths; i++) {
int symbol = code_length_nbits[code_length_order[i]];
writer->Write(code_length_length_nbits[symbol],
code_length_length_bits[symbol]);
}
// Compute the canonical codes for the codes that represent the lengths of
// the actual codes for data.
uint16_t code_length_bits[18] = {};
ComputeCanonicalCode(nullptr, nullptr, 0, code_length_nbits,
code_length_bits, 18);
// Encode raw bit code lengths.
// Max bits written in this loop: 19 * 5 = 95
for (uint8_t raw_nbit : raw_nbits) {
writer->Write(code_length_nbits[raw_nbit], code_length_bits[raw_nbit]);
}
size_t num_lz77 = kNumLZ77;
while (lz77_nbits[num_lz77 - 1] == 0) {
num_lz77--;
}
// Encode 0s until 224 (start of LZ77 symbols). This is in total 224-19 =
// 205.
static_assert(kLZ77Offset == 224);
static_assert(kNumRawSymbols == 19);
{
// Max bits in this block: 24
writer->Write(code_length_nbits[17], code_length_bits[17]);
writer->Write(3, 0b010);
// 5
writer->Write(code_length_nbits[17], code_length_bits[17]);
writer->Write(3, 0b000);
// (5-2)*8 + 3 = 27
writer->Write(code_length_nbits[17], code_length_bits[17]);
writer->Write(3, 0b010);
// (27-2)*8 + 5 = 205
}
// Encode LZ77 symbols, with values 224+i.
// Max bits written in this loop: 33 * 5 = 165
for (size_t i = 0; i < num_lz77; i++) {
writer->Write(code_length_nbits[lz77_nbits[i]],
code_length_bits[lz77_nbits[i]]);
}
}
};
}
// namespace
extern "C" {
struct JxlFastLosslessFrameState {
JxlChunkedFrameInputSource input;
size_t width;
size_t height;
size_t num_groups_x;
size_t num_groups_y;
size_t num_dc_groups_x;
size_t num_dc_groups_y;
size_t nb_chans;
size_t bitdepth;
int big_endian;
int effort;
bool collided;
PrefixCode hcode[4];
std::vector<int16_t> lookup;
BitWriter header;
std::vector<std::array<BitWriter, 4>> group_data;
std::vector<size_t> group_sizes;
size_t ac_group_data_offset = 0;
size_t min_dc_global_size = 0;
size_t current_bit_writer = 0;
size_t bit_writer_byte_pos = 0;
size_t bits_in_buffer = 0;
uint64_t bit_buffer = 0;
bool process_done =
false;
};
size_t JxlFastLosslessOutputSize(
const JxlFastLosslessFrameState* frame) {
size_t total_size_groups = 0;
for (
const auto& section : frame->group_data) {
total_size_groups += SectionSize(section);
}
return frame->header.bytes_written + total_size_groups;
}
size_t JxlFastLosslessMaxRequiredOutput(
const JxlFastLosslessFrameState* frame) {
return JxlFastLosslessOutputSize(frame) + 32;
}
void JxlFastLosslessPrepareHeader(JxlFastLosslessFrameState* frame,
int add_image_header,
int is_last) {
BitWriter* output = &frame->header;
output->Allocate(1000 + frame->group_sizes.size() * 32);
bool have_alpha = (frame->nb_chans == 2 || frame->nb_chans == 4);
#if FJXL_STANDALONE
if (add_image_header) {
// Signature
output->Write(16, 0x0AFF);
// Size header, hand-crafted.
// Not small
output->Write(1, 0);
auto wsz = [output](size_t size) {
if (size - 1 < (1 << 9)) {
output->Write(2, 0b00);
output->Write(9, size - 1);
}
else if (size - 1 < (1 << 13)) {
output->Write(2, 0b01);
output->Write(13, size - 1);
}
else if (size - 1 < (1 << 18)) {
output->Write(2, 0b10);
output->Write(18, size - 1);
}
else {
output->Write(2, 0b11);
output->Write(30, size - 1);
}
};
wsz(frame->height);
// No special ratio.
output->Write(3, 0);
wsz(frame->width);
// Hand-crafted ImageMetadata.
output->Write(1, 0);
// all_default
output->Write(1, 0);
// extra_fields
output->Write(1, 0);
// bit_depth.floating_point_sample
if (frame->bitdepth == 8) {
output->Write(2, 0b00);
// bit_depth.bits_per_sample = 8
}
else if (frame->bitdepth == 10) {
output->Write(2, 0b01);
// bit_depth.bits_per_sample = 10
}
else if (frame->bitdepth == 12) {
output->Write(2, 0b10);
// bit_depth.bits_per_sample = 12
}
else {
output->Write(2, 0b11);
// 1 + u(6)
output->Write(6, frame->bitdepth - 1);
}
if (frame->bitdepth <= 14) {
output->Write(1, 1);
// 16-bit-buffer sufficient
}
else {
output->Write(1, 0);
// 16-bit-buffer NOT sufficient
}
if (have_alpha) {
output->Write(2, 0b01);
// One extra channel
output->Write(1, 1);
// ... all_default (ie. 8-bit alpha)
}
else {
output->Write(2, 0b00);
// No extra channel
}
output->Write(1, 0);
// Not XYB
if (frame->nb_chans > 2) {
output->Write(1, 1);
// color_encoding.all_default (sRGB)
}
else {
output->Write(1, 0);
// color_encoding.all_default false
output->Write(1, 0);
// color_encoding.want_icc false
output->Write(2, 1);
// grayscale
output->Write(2, 1);
// D65
output->Write(1, 0);
// no gamma transfer function
output->Write(2, 0b10);
// tf: 2 + u(4)
output->Write(4, 11);
// tf of sRGB
output->Write(2, 1);
// relative rendering intent
}
output->Write(2, 0b00);
// No extensions.
output->Write(1, 1);
// all_default transform data
// No ICC, no preview. Frame should start at byte boundary.
output->ZeroPadToByte();
}
#else
assert(!add_image_header);
#endif
// Handcrafted frame header.
output->Write(1, 0);
// all_default
output->Write(2, 0b00);
// regular frame
output->Write(1, 1);
// modular
output->Write(2, 0b00);
// default flags
output->Write(1, 0);
// not YCbCr
output->Write(2, 0b00);
// no upsampling
if (have_alpha) {
output->Write(2, 0b00);
// no alpha upsampling
}
output->Write(2, 0b01);
// default group size
output->Write(2, 0b00);
// exactly one pass
output->Write(1, 0);
// no custom size or origin
output->Write(2, 0b00);
// kReplace blending mode
if (have_alpha) {
output->Write(2, 0b00);
// kReplace blending mode for alpha channel
}
output->Write(1, is_last);
// is_last
if (!is_last) {
output->Write(2, 0b00);
// can not be saved as reference
}
output->Write(2, 0b00);
// a frame has no name
output->Write(1, 0);
// loop filter is not all_default
output->Write(1, 0);
// no gaborish
output->Write(2, 0);
// 0 EPF iters
output->Write(2, 0b00);
// No LF extensions
output->Write(2, 0b00);
// No FH extensions
output->Write(1, 0);
// No TOC permutation
output->ZeroPadToByte();
// TOC is byte-aligned.
assert(add_image_header || output->bytes_written <= kMaxFrameHeaderSize);
for (size_t group_size : frame->group_sizes) {
size_t bucket = TOCBucket(group_size);
output->Write(2, bucket);
output->Write(kTOCBits[bucket] - 2, group_size - kGroupSizeOffset[bucket]);
}
output->ZeroPadToByte();
// Groups are byte-aligned.
}
#if !FJXL_STANDALONE
bool JxlFastLosslessOutputAlignedSection(
const BitWriter& bw, JxlEncoderOutputProcessorWrapper* output_processor) {
assert(bw.bits_in_buffer == 0);
const uint8_t* data = bw.data.get();
size_t remaining_len = bw.bytes_written;
while (remaining_len > 0) {
JXL_ASSIGN_OR_RETURN(
auto buffer,
output_processor->GetBuffer(1, remaining_len));
size_t n = std::min(buffer.size(), remaining_len);
if (n == 0)
break;
memcpy(buffer.data(), data, n);
JXL_RETURN_IF_ERROR(buffer.advance(n));
data += n;
remaining_len -= n;
};
return true;
}
bool JxlFastLosslessOutputHeaders(
JxlFastLosslessFrameState* frame_state,
JxlEncoderOutputProcessorWrapper* output_processor) {
JXL_RETURN_IF_ERROR(JxlFastLosslessOutputAlignedSection(frame_state->header,
output_processor));
JXL_RETURN_IF_ERROR(JxlFastLosslessOutputAlignedSection(
frame_state->group_data[0][0], output_processor));
return true;
}
#endif
#if FJXL_ENABLE_AVX512
__attribute__((target(
"avx512vbmi2")))
static size_t AppendBytesWithBitOffset(
const uint8_t* data, size_t n, size_t bit_buffer_nbits,
unsigned char* output, uint64_t& bit_buffer) {
if (n < 128) {
return 0;
}
size_t i = 0;
__m512i shift = _mm512_set1_epi64(64 - bit_buffer_nbits);
__m512i carry = _mm512_set1_epi64(bit_buffer << (64 - bit_buffer_nbits));
for (; i + 64 <= n; i += 64) {
__m512i current = _mm512_loadu_si512(data + i);
__m512i previous_u64 = _mm512_alignr_epi64(current, carry, 7);
carry = current;
__m512i out = _mm512_shrdv_epi64(previous_u64, current, shift);
_mm512_storeu_si512(output + i, out);
}
bit_buffer = data[i - 1] >> (8 - bit_buffer_nbits);
return i;
}
#endif
size_t JxlFastLosslessWriteOutput(JxlFastLosslessFrameState* frame,
unsigned char* output, size_t output_size) {
assert(output_size >= 32);
unsigned char* initial_output = output;
size_t (*append_bytes_with_bit_offset)(
const uint8_t*, size_t, size_t,
unsigned char*, uint64_t&) = nullptr;
#if FJXL_ENABLE_AVX512
if (HasCpuFeature(CpuFeature::kVBMI2)) {
append_bytes_with_bit_offset = AppendBytesWithBitOffset;
}
#endif
while (
true) {
size_t& cur = frame->current_bit_writer;
size_t& bw_pos = frame->bit_writer_byte_pos;
if (cur >= 1 + frame->group_data.size() * frame->nb_chans) {
return output - initial_output;
}
if (output_size <= 9) {
return output - initial_output;
}
size_t nbc = frame->nb_chans;
const BitWriter& writer =
cur == 0 ? frame->header
: frame->group_data[(cur - 1) / nbc][(cur - 1) % nbc];
size_t full_byte_count =
std::min(output_size - 9, writer.bytes_written - bw_pos);
if (frame->bits_in_buffer == 0) {
memcpy(output, writer.data.get() + bw_pos, full_byte_count);
}
else {
size_t i = 0;
if (append_bytes_with_bit_offset) {
i += append_bytes_with_bit_offset(
writer.data.get() + bw_pos, full_byte_count, frame->bits_in_buffer,
output, frame->bit_buffer);
}
#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
// Copy 8 bytes at a time until we reach the border.
for (; i + 8 < full_byte_count; i += 8) {
uint64_t chunk;
memcpy(&chunk, writer.data.get() + bw_pos + i, 8);
uint64_t out = frame->bit_buffer | (chunk << frame->bits_in_buffer);
memcpy(output + i, &out, 8);
frame->bit_buffer = chunk >> (64 - frame->bits_in_buffer);
}
#endif
for (; i < full_byte_count; i++) {
AddBits(8, writer.data.get()[bw_pos + i], output + i,
frame->bits_in_buffer, frame->bit_buffer);
}
}
output += full_byte_count;
output_size -= full_byte_count;
bw_pos += full_byte_count;
if (bw_pos == writer.bytes_written) {
auto write = [&](size_t num, uint64_t bits) {
size_t n = AddBits(num, bits, output, frame->bits_in_buffer,
frame->bit_buffer);
output += n;
output_size -= n;
};
if (writer.bits_in_buffer) {
write(writer.bits_in_buffer, writer.buffer);
}
bw_pos = 0;
cur++;
if ((cur - 1) % nbc == 0 && frame->bits_in_buffer != 0) {
write(8 - frame->bits_in_buffer, 0);
}
}
}
}
void JxlFastLosslessFreeFrameState(JxlFastLosslessFrameState* frame) {
delete frame;
}
}
// extern "C"
#endif
#ifdef FJXL_SELF_INCLUDE
namespace {
template <
typename T>
struct VecPair {
T low;
T hi;
};
#ifdef FJXL_GENERIC_SIMD
#undef FJXL_GENERIC_SIMD
#endif
#ifdef FJXL_AVX512
#define FJXL_GENERIC_SIMD
struct SIMDVec32;
struct Mask32 {
__mmask16 mask;
SIMDVec32 IfThenElse(
const SIMDVec32& if_true,
const SIMDVec32& if_false);
size_t CountPrefix()
const {
return CtzNonZero(~uint64_t{_cvtmask16_u32(mask)});
}
};
struct SIMDVec32 {
__m512i vec;
static constexpr size_t kLanes = 16;
FJXL_INLINE
static SIMDVec32 Load(
const uint32_t* data) {
return SIMDVec32{_mm512_loadu_si512((__m512i*)data)};
}
FJXL_INLINE
void Store(uint32_t* data) {
_mm512_storeu_si512((__m512i*)data, vec);
}
FJXL_INLINE
static SIMDVec32 Val(uint32_t v) {
return SIMDVec32{_mm512_set1_epi32(v)};
}
FJXL_INLINE SIMDVec32 ValToToken()
const {
return SIMDVec32{
_mm512_sub_epi32(_mm512_set1_epi32(32), _mm512_lzcnt_epi32(vec))};
}
FJXL_INLINE SIMDVec32 SatSubU(
const SIMDVec32& to_subtract)
const {
return SIMDVec32{_mm512_sub_epi32(_mm512_max_epu32(vec, to_subtract.vec),
to_subtract.vec)};
}
FJXL_INLINE SIMDVec32 Sub(
const SIMDVec32& to_subtract)
const {
return SIMDVec32{_mm512_sub_epi32(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec32 Add(
const SIMDVec32& oth)
const {
return SIMDVec32{_mm512_add_epi32(vec, oth.vec)};
}
FJXL_INLINE SIMDVec32
Xor(
const SIMDVec32& oth)
const {
return SIMDVec32{_mm512_xor_epi32(vec, oth.vec)};
}
FJXL_INLINE Mask32 Eq(
const SIMDVec32& oth)
const {
return Mask32{_mm512_cmpeq_epi32_mask(vec, oth.vec)};
}
FJXL_INLINE Mask32 Gt(
const SIMDVec32& oth)
const {
return Mask32{_mm512_cmpgt_epi32_mask(vec, oth.vec)};
}
FJXL_INLINE SIMDVec32 Pow2()
const {
return SIMDVec32{_mm512_sllv_epi32(_mm512_set1_epi32(1), vec)};
}
template <size_t i>
FJXL_INLINE SIMDVec32 SignedShiftRight()
const {
return SIMDVec32{_mm512_srai_epi32(vec, i)};
}
};
struct SIMDVec16;
struct Mask16 {
__mmask32 mask;
SIMDVec16 IfThenElse(
const SIMDVec16& if_true,
const SIMDVec16& if_false);
Mask16
And(
const Mask16& oth)
const {
return Mask16{_kand_mask32(mask, oth.mask)};
}
size_t CountPrefix()
const {
return CtzNonZero(~uint64_t{_cvtmask32_u32(mask)});
}
};
struct SIMDVec16 {
__m512i vec;
static constexpr size_t kLanes = 32;
FJXL_INLINE
static SIMDVec16 Load(
const uint16_t* data) {
return SIMDVec16{_mm512_loadu_si512((__m512i*)data)};
}
FJXL_INLINE
void Store(uint16_t* data) {
_mm512_storeu_si512((__m512i*)data, vec);
}
FJXL_INLINE
static SIMDVec16 Val(uint16_t v) {
return SIMDVec16{_mm512_set1_epi16(v)};
}
FJXL_INLINE
static SIMDVec16 FromTwo32(
const SIMDVec32& lo,
const SIMDVec32& hi) {
auto tmp = _mm512_packus_epi32(lo.vec, hi.vec);
alignas(64) uint64_t perm[8] = {0, 2, 4, 6, 1, 3, 5, 7};
return SIMDVec16{
_mm512_permutex2var_epi64(tmp, _mm512_load_si512((__m512i*)perm), tmp)};
}
FJXL_INLINE SIMDVec16 ValToToken()
const {
auto c16 = _mm512_set1_epi32(16);
auto c32 = _mm512_set1_epi32(32);
auto low16bit = _mm512_set1_epi32(0x0000FFFF);
auto lzhi =
_mm512_sub_epi32(c16, _mm512_min_epu32(c16, _mm512_lzcnt_epi32(vec)));
auto lzlo = _mm512_sub_epi32(
c32, _mm512_lzcnt_epi32(_mm512_and_si512(low16bit, vec)));
return SIMDVec16{_mm512_or_si512(lzlo, _mm512_slli_epi32(lzhi, 16))};
}
FJXL_INLINE SIMDVec16 SatSubU(
const SIMDVec16& to_subtract)
const {
return SIMDVec16{_mm512_subs_epu16(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec16 Sub(
const SIMDVec16& to_subtract)
const {
return SIMDVec16{_mm512_sub_epi16(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec16 Add(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm512_add_epi16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 Min(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm512_min_epu16(vec, oth.vec)};
}
FJXL_INLINE Mask16 Eq(
const SIMDVec16& oth)
const {
return Mask16{_mm512_cmpeq_epi16_mask(vec, oth.vec)};
}
FJXL_INLINE Mask16 Gt(
const SIMDVec16& oth)
const {
return Mask16{_mm512_cmpgt_epi16_mask(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 Pow2()
const {
return SIMDVec16{_mm512_sllv_epi16(_mm512_set1_epi16(1), vec)};
}
FJXL_INLINE SIMDVec16
Or(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm512_or_si512(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16
Xor(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm512_xor_si512(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16
And(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm512_and_si512(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 HAdd(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm512_srai_epi16(_mm512_add_epi16(vec, oth.vec), 1)};
}
FJXL_INLINE SIMDVec16 PrepareForU8Lookup()
const {
return SIMDVec16{_mm512_or_si512(vec, _mm512_set1_epi16(0xFF00))};
}
FJXL_INLINE SIMDVec16 U8Lookup(
const uint8_t* table)
const {
return SIMDVec16{_mm512_shuffle_epi8(
_mm512_broadcast_i32x4(_mm_loadu_si128((__m128i*)table)), vec)};
}
FJXL_INLINE VecPair<SIMDVec16> Interleave(
const SIMDVec16& low)
const {
auto lo = _mm512_unpacklo_epi16(low.vec, vec);
auto hi = _mm512_unpackhi_epi16(low.vec, vec);
alignas(64) uint64_t perm1[8] = {0, 1, 8, 9, 2, 3, 10, 11};
alignas(64) uint64_t perm2[8] = {4, 5, 12, 13, 6, 7, 14, 15};
return {SIMDVec16{_mm512_permutex2var_epi64(
lo, _mm512_load_si512((__m512i*)perm1), hi)},
SIMDVec16{_mm512_permutex2var_epi64(
lo, _mm512_load_si512((__m512i*)perm2), hi)}};
}
FJXL_INLINE VecPair<SIMDVec32> Upcast()
const {
auto lo = _mm512_unpacklo_epi16(vec, _mm512_setzero_si512());
auto hi = _mm512_unpackhi_epi16(vec, _mm512_setzero_si512());
alignas(64) uint64_t perm1[8] = {0, 1, 8, 9, 2, 3, 10, 11};
alignas(64) uint64_t perm2[8] = {4, 5, 12, 13, 6, 7, 14, 15};
return {SIMDVec32{_mm512_permutex2var_epi64(
lo, _mm512_load_si512((__m512i*)perm1), hi)},
SIMDVec32{_mm512_permutex2var_epi64(
lo, _mm512_load_si512((__m512i*)perm2), hi)}};
}
template <size_t i>
FJXL_INLINE SIMDVec16 SignedShiftRight()
const {
return SIMDVec16{_mm512_srai_epi16(vec, i)};
}
static std::array<SIMDVec16, 1> LoadG8(
const unsigned char* data) {
__m256i bytes = _mm256_loadu_si256((__m256i*)data);
return {SIMDVec16{_mm512_cvtepu8_epi16(bytes)}};
}
static std::array<SIMDVec16, 1> LoadG16(
const unsigned char* data) {
return {Load((
const uint16_t*)data)};
}
static std::array<SIMDVec16, 2> LoadGA8(
const unsigned char* data) {
__m512i bytes = _mm512_loadu_si512((__m512i*)data);
__m512i gray = _mm512_and_si512(bytes, _mm512_set1_epi16(0xFF));
__m512i alpha = _mm512_srli_epi16(bytes, 8);
return {SIMDVec16{gray}, SIMDVec16{alpha}};
}
static std::array<SIMDVec16, 2> LoadGA16(
const unsigned char* data) {
__m512i bytes1 = _mm512_loadu_si512((__m512i*)data);
__m512i bytes2 = _mm512_loadu_si512((__m512i*)(data + 64));
__m512i g_mask = _mm512_set1_epi32(0xFFFF);
__m512i permuteidx = _mm512_set_epi64(7, 5, 3, 1, 6, 4, 2, 0);
__m512i g = _mm512_permutexvar_epi64(
permuteidx, _mm512_packus_epi32(_mm512_and_si512(bytes1, g_mask),
_mm512_and_si512(bytes2, g_mask)));
__m512i a = _mm512_permutexvar_epi64(
permuteidx, _mm512_packus_epi32(_mm512_srli_epi32(bytes1, 16),
_mm512_srli_epi32(bytes2, 16)));
return {SIMDVec16{g}, SIMDVec16{a}};
}
static std::array<SIMDVec16, 3> LoadRGB8(
const unsigned char* data) {
__m512i bytes0 = _mm512_loadu_si512((__m512i*)data);
__m512i bytes1 =
_mm512_zextsi256_si512(_mm256_loadu_si256((__m256i*)(data + 64)));
// 0x7A = element of upper half of second vector = 0 after lookup; still in
// the upper half once we add 1 or 2.
uint8_t z = 0x7A;
__m512i ridx =
_mm512_set_epi8(z, 93, z, 90, z, 87, z, 84, z, 81, z, 78, z, 75, z, 72,
z, 69, z, 66, z, 63, z, 60, z, 57, z, 54, z, 51, z, 48,
z, 45, z, 42, z, 39, z, 36, z, 33, z, 30, z, 27, z, 24,
z, 21, z, 18, z, 15, z, 12, z, 9, z, 6, z, 3, z, 0);
__m512i gidx = _mm512_add_epi8(ridx, _mm512_set1_epi8(1));
__m512i bidx = _mm512_add_epi8(gidx, _mm512_set1_epi8(1));
__m512i r = _mm512_permutex2var_epi8(bytes0, ridx, bytes1);
__m512i g = _mm512_permutex2var_epi8(bytes0, gidx, bytes1);
__m512i b = _mm512_permutex2var_epi8(bytes0, bidx, bytes1);
return {SIMDVec16{r}, SIMDVec16{g}, SIMDVec16{b}};
}
static std::array<SIMDVec16, 3> LoadRGB16(
const unsigned char* data) {
__m512i bytes0 = _mm512_loadu_si512((__m512i*)data);
__m512i bytes1 = _mm512_loadu_si512((__m512i*)(data + 64));
__m512i bytes2 = _mm512_loadu_si512((__m512i*)(data + 128));
__m512i ridx_lo = _mm512_set_epi16(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 63, 60, 57,
54, 51, 48, 45, 42, 39, 36, 33, 30, 27,
24, 21, 18, 15, 12, 9, 6, 3, 0);
// -1 is such that when adding 1 or 2, we get the correct index for
// green/blue.
__m512i ridx_hi =
_mm512_set_epi16(29, 26, 23, 20, 17, 14, 11, 8, 5, 2, -1, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
__m512i gidx_lo = _mm512_add_epi16(ridx_lo, _mm512_set1_epi16(1));
__m512i gidx_hi = _mm512_add_epi16(ridx_hi, _mm512_set1_epi16(1));
__m512i bidx_lo = _mm512_add_epi16(gidx_lo, _mm512_set1_epi16(1));
__m512i bidx_hi = _mm512_add_epi16(gidx_hi, _mm512_set1_epi16(1));
__mmask32 rmask = _cvtu32_mask32(0b11111111110000000000000000000000);
__mmask32 gbmask = _cvtu32_mask32(0b11111111111000000000000000000000);
__m512i rlo = _mm512_permutex2var_epi16(bytes0, ridx_lo, bytes1);
__m512i glo = _mm512_permutex2var_epi16(bytes0, gidx_lo, bytes1);
__m512i blo = _mm512_permutex2var_epi16(bytes0, bidx_lo, bytes1);
__m512i r = _mm512_mask_permutexvar_epi16(rlo, rmask, ridx_hi, bytes2);
__m512i g = _mm512_mask_permutexvar_epi16(glo, gbmask, gidx_hi, bytes2);
__m512i b = _mm512_mask_permutexvar_epi16(blo, gbmask, bidx_hi, bytes2);
return {SIMDVec16{r}, SIMDVec16{g}, SIMDVec16{b}};
}
static std::array<SIMDVec16, 4> LoadRGBA8(
const unsigned char* data) {
__m512i bytes1 = _mm512_loadu_si512((__m512i*)data);
__m512i bytes2 = _mm512_loadu_si512((__m512i*)(data + 64));
__m512i rg_mask = _mm512_set1_epi32(0xFFFF);
__m512i permuteidx = _mm512_set_epi64(7, 5, 3, 1, 6, 4, 2, 0);
__m512i rg = _mm512_permutexvar_epi64(
permuteidx, _mm512_packus_epi32(_mm512_and_si512(bytes1, rg_mask),
_mm512_and_si512(bytes2, rg_mask)));
__m512i b_a = _mm512_permutexvar_epi64(
permuteidx, _mm512_packus_epi32(_mm512_srli_epi32(bytes1, 16),
_mm512_srli_epi32(bytes2, 16)));
__m512i r = _mm512_and_si512(rg, _mm512_set1_epi16(0xFF));
__m512i g = _mm512_srli_epi16(rg, 8);
__m512i b = _mm512_and_si512(b_a, _mm512_set1_epi16(0xFF));
__m512i a = _mm512_srli_epi16(b_a, 8);
return {SIMDVec16{r}, SIMDVec16{g}, SIMDVec16{b}, SIMDVec16{a}};
}
static std::array<SIMDVec16, 4> LoadRGBA16(
const unsigned char* data) {
__m512i bytes0 = _mm512_loadu_si512((__m512i*)data);
__m512i bytes1 = _mm512_loadu_si512((__m512i*)(data + 64));
__m512i bytes2 = _mm512_loadu_si512((__m512i*)(data + 128));
__m512i bytes3 = _mm512_loadu_si512((__m512i*)(data + 192));
auto pack32 = [](__m512i a, __m512i b) {
__m512i permuteidx = _mm512_set_epi64(7, 5, 3, 1, 6, 4, 2, 0);
return _mm512_permutexvar_epi64(permuteidx, _mm512_packus_epi32(a, b));
};
auto packlow32 = [&pack32](__m512i a, __m512i b) {
__m512i mask = _mm512_set1_epi32(0xFFFF);
return pack32(_mm512_and_si512(a, mask), _mm512_and_si512(b, mask));
};
auto packhi32 = [&pack32](__m512i a, __m512i b) {
return pack32(_mm512_srli_epi32(a, 16), _mm512_srli_epi32(b, 16));
};
__m512i rb0 = packlow32(bytes0, bytes1);
__m512i rb1 = packlow32(bytes2, bytes3);
__m512i ga0 = packhi32(bytes0, bytes1);
__m512i ga1 = packhi32(bytes2, bytes3);
__m512i r = packlow32(rb0, rb1);
__m512i g = packlow32(ga0, ga1);
__m512i b = packhi32(rb0, rb1);
__m512i a = packhi32(ga0, ga1);
return {SIMDVec16{r}, SIMDVec16{g}, SIMDVec16{b}, SIMDVec16{a}};
}
void SwapEndian() {
auto indices = _mm512_broadcast_i32x4(
_mm_setr_epi8(1, 0, 3, 2, 5, 4, 7, 6, 9, 8, 11, 10, 13, 12, 15, 14));
vec = _mm512_shuffle_epi8(vec, indices);
}
};
SIMDVec16 Mask16::IfThenElse(
const SIMDVec16& if_true,
const SIMDVec16& if_false) {
return SIMDVec16{_mm512_mask_blend_epi16(mask, if_false.vec, if_true.vec)};
}
SIMDVec32 Mask32::IfThenElse(
const SIMDVec32& if_true,
const SIMDVec32& if_false) {
return SIMDVec32{_mm512_mask_blend_epi32(mask, if_false.vec, if_true.vec)};
}
struct Bits64 {
static constexpr size_t kLanes = 8;
__m512i nbits;
__m512i bits;
FJXL_INLINE
void Store(uint64_t* nbits_out, uint64_t* bits_out) {
_mm512_storeu_si512((__m512i*)nbits_out, nbits);
_mm512_storeu_si512((__m512i*)bits_out, bits);
}
};
struct Bits32 {
__m512i nbits;
__m512i bits;
static Bits32 FromRaw(SIMDVec32 nbits, SIMDVec32 bits) {
return Bits32{nbits.vec, bits.vec};
}
Bits64 Merge()
const {
auto nbits_hi32 = _mm512_srli_epi64(nbits, 32);
auto nbits_lo32 = _mm512_and_si512(nbits, _mm512_set1_epi64(0xFFFFFFFF));
auto bits_hi32 = _mm512_srli_epi64(bits, 32);
auto bits_lo32 = _mm512_and_si512(bits, _mm512_set1_epi64(0xFFFFFFFF));
auto nbits64 = _mm512_add_epi64(nbits_hi32, nbits_lo32);
auto bits64 =
_mm512_or_si512(_mm512_sllv_epi64(bits_hi32, nbits_lo32), bits_lo32);
return Bits64{nbits64, bits64};
}
void Interleave(
const Bits32& low) {
bits = _mm512_or_si512(_mm512_sllv_epi32(bits, low.nbits), low.bits);
nbits = _mm512_add_epi32(nbits, low.nbits);
}
void ClipTo(size_t n) {
n = std::min<size_t>(n, 16);
constexpr uint32_t kMask[32] = {
~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u,
~0u, ~0u, ~0u, ~0u, ~0u, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
};
__m512i mask = _mm512_loadu_si512((__m512i*)(kMask + 16 - n));
nbits = _mm512_and_si512(mask, nbits);
bits = _mm512_and_si512(mask, bits);
}
void Skip(size_t n) {
n = std::min<size_t>(n, 16);
constexpr uint32_t kMask[32] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u,
~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u,
};
__m512i mask = _mm512_loadu_si512((__m512i*)(kMask + 16 - n));
nbits = _mm512_and_si512(mask, nbits);
bits = _mm512_and_si512(mask, bits);
}
};
struct Bits16 {
__m512i nbits;
__m512i bits;
static Bits16 FromRaw(SIMDVec16 nbits, SIMDVec16 bits) {
return Bits16{nbits.vec, bits.vec};
}
Bits32 Merge()
const {
auto nbits_hi16 = _mm512_srli_epi32(nbits, 16);
auto nbits_lo16 = _mm512_and_si512(nbits, _mm512_set1_epi32(0xFFFF));
auto bits_hi16 = _mm512_srli_epi32(bits, 16);
auto bits_lo16 = _mm512_and_si512(bits, _mm512_set1_epi32(0xFFFF));
auto nbits32 = _mm512_add_epi32(nbits_hi16, nbits_lo16);
auto bits32 =
_mm512_or_si512(_mm512_sllv_epi32(bits_hi16, nbits_lo16), bits_lo16);
return Bits32{nbits32, bits32};
}
void Interleave(
const Bits16& low) {
bits = _mm512_or_si512(_mm512_sllv_epi16(bits, low.nbits), low.bits);
nbits = _mm512_add_epi16(nbits, low.nbits);
}
void ClipTo(size_t n) {
n = std::min<size_t>(n, 32);
constexpr uint16_t kMask[64] = {
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
};
__m512i mask = _mm512_loadu_si512((__m512i*)(kMask + 32 - n));
nbits = _mm512_and_si512(mask, nbits);
bits = _mm512_and_si512(mask, bits);
}
void Skip(size_t n) {
n = std::min<size_t>(n, 32);
constexpr uint16_t kMask[64] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
};
__m512i mask = _mm512_loadu_si512((__m512i*)(kMask + 32 - n));
nbits = _mm512_and_si512(mask, nbits);
bits = _mm512_and_si512(mask, bits);
}
};
#endif
#ifdef FJXL_AVX2
#define FJXL_GENERIC_SIMD
struct SIMDVec32;
struct Mask32 {
__m256i mask;
SIMDVec32 IfThenElse(
const SIMDVec32& if_true,
const SIMDVec32& if_false);
size_t CountPrefix()
const {
return CtzNonZero(~
static_cast<uint64_t>(
static_cast<uint8_t>(_mm256_movemask_ps(_mm256_castsi256_ps(mask)))));
}
};
struct SIMDVec32 {
__m256i vec;
static constexpr size_t kLanes = 8;
FJXL_INLINE
static SIMDVec32 Load(
const uint32_t* data) {
return SIMDVec32{_mm256_loadu_si256((__m256i*)data)};
}
FJXL_INLINE
void Store(uint32_t* data) {
_mm256_storeu_si256((__m256i*)data, vec);
}
FJXL_INLINE
static SIMDVec32 Val(uint32_t v) {
return SIMDVec32{_mm256_set1_epi32(v)};
}
FJXL_INLINE SIMDVec32 ValToToken()
const {
auto f32 = _mm256_castps_si256(_mm256_cvtepi32_ps(vec));
return SIMDVec32{_mm256_max_epi32(
_mm256_setzero_si256(),
_mm256_sub_epi32(_mm256_srli_epi32(f32, 23), _mm256_set1_epi32(126)))};
}
FJXL_INLINE SIMDVec32 SatSubU(
const SIMDVec32& to_subtract)
const {
return SIMDVec32{_mm256_sub_epi32(_mm256_max_epu32(vec, to_subtract.vec),
to_subtract.vec)};
}
FJXL_INLINE SIMDVec32 Sub(
const SIMDVec32& to_subtract)
const {
return SIMDVec32{_mm256_sub_epi32(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec32 Add(
const SIMDVec32& oth)
const {
return SIMDVec32{_mm256_add_epi32(vec, oth.vec)};
}
FJXL_INLINE SIMDVec32
Xor(
const SIMDVec32& oth)
const {
return SIMDVec32{_mm256_xor_si256(vec, oth.vec)};
}
FJXL_INLINE SIMDVec32 Pow2()
const {
return SIMDVec32{_mm256_sllv_epi32(_mm256_set1_epi32(1), vec)};
}
FJXL_INLINE Mask32 Eq(
const SIMDVec32& oth)
const {
return Mask32{_mm256_cmpeq_epi32(vec, oth.vec)};
}
FJXL_INLINE Mask32 Gt(
const SIMDVec32& oth)
const {
return Mask32{_mm256_cmpgt_epi32(vec, oth.vec)};
}
template <size_t i>
FJXL_INLINE SIMDVec32 SignedShiftRight()
const {
return SIMDVec32{_mm256_srai_epi32(vec, i)};
}
};
struct SIMDVec16;
struct Mask16 {
__m256i mask;
SIMDVec16 IfThenElse(
const SIMDVec16& if_true,
const SIMDVec16& if_false);
Mask16
And(
const Mask16& oth)
const {
return Mask16{_mm256_and_si256(mask, oth.mask)};
}
size_t CountPrefix()
const {
return CtzNonZero(~
static_cast<uint64_t>(
static_cast<uint32_t>(_mm256_movemask_epi8(mask)))) /
2;
}
};
struct SIMDVec16 {
__m256i vec;
static constexpr size_t kLanes = 16;
FJXL_INLINE
static SIMDVec16 Load(
const uint16_t* data) {
return SIMDVec16{_mm256_loadu_si256((__m256i*)data)};
}
FJXL_INLINE
void Store(uint16_t* data) {
_mm256_storeu_si256((__m256i*)data, vec);
}
FJXL_INLINE
static SIMDVec16 Val(uint16_t v) {
return SIMDVec16{_mm256_set1_epi16(v)};
}
FJXL_INLINE
static SIMDVec16 FromTwo32(
const SIMDVec32& lo,
const SIMDVec32& hi) {
auto tmp = _mm256_packus_epi32(lo.vec, hi.vec);
return SIMDVec16{_mm256_permute4x64_epi64(tmp, 0b11011000)};
}
FJXL_INLINE SIMDVec16 ValToToken()
const {
auto nibble0 =
_mm256_or_si256(_mm256_and_si256(vec, _mm256_set1_epi16(0xF)),
_mm256_set1_epi16(0xFF00));
auto nibble1 = _mm256_or_si256(
_mm256_and_si256(_mm256_srli_epi16(vec, 4), _mm256_set1_epi16(0xF)),
_mm256_set1_epi16(0xFF00));
auto nibble2 = _mm256_or_si256(
_mm256_and_si256(_mm256_srli_epi16(vec, 8), _mm256_set1_epi16(0xF)),
_mm256_set1_epi16(0xFF00));
auto nibble3 =
_mm256_or_si256(_mm256_srli_epi16(vec, 12), _mm256_set1_epi16(0xFF00));
auto lut0 = _mm256_broadcastsi128_si256(
_mm_setr_epi8(0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4));
auto lut1 = _mm256_broadcastsi128_si256(
_mm_setr_epi8(0, 5, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8));
auto lut2 = _mm256_broadcastsi128_si256(_mm_setr_epi8(
0, 9, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12));
auto lut3 = _mm256_broadcastsi128_si256(_mm_setr_epi8(
0, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16));
auto token0 = _mm256_shuffle_epi8(lut0, nibble0);
auto token1 = _mm256_shuffle_epi8(lut1, nibble1);
auto token2 = _mm256_shuffle_epi8(lut2, nibble2);
auto token3 = _mm256_shuffle_epi8(lut3, nibble3);
auto token = _mm256_max_epi16(_mm256_max_epi16(token0, token1),
_mm256_max_epi16(token2, token3));
return SIMDVec16{token};
}
FJXL_INLINE SIMDVec16 SatSubU(
const SIMDVec16& to_subtract)
const {
return SIMDVec16{_mm256_subs_epu16(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec16 Sub(
const SIMDVec16& to_subtract)
const {
return SIMDVec16{_mm256_sub_epi16(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec16 Add(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm256_add_epi16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 Min(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm256_min_epu16(vec, oth.vec)};
}
FJXL_INLINE Mask16 Eq(
const SIMDVec16& oth)
const {
return Mask16{_mm256_cmpeq_epi16(vec, oth.vec)};
}
FJXL_INLINE Mask16 Gt(
const SIMDVec16& oth)
const {
return Mask16{_mm256_cmpgt_epi16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 Pow2()
const {
auto pow2_lo_lut = _mm256_broadcastsi128_si256(
_mm_setr_epi8(1 << 0, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6,
1u << 7, 0, 0, 0, 0, 0, 0, 0, 0));
auto pow2_hi_lut = _mm256_broadcastsi128_si256(
_mm_setr_epi8(0, 0, 0, 0, 0, 0, 0, 0, 1 << 0, 1 << 1, 1 << 2, 1 << 3,
1 << 4, 1 << 5, 1 << 6, 1u << 7));
auto masked = _mm256_or_si256(vec, _mm256_set1_epi16(0xFF00));
auto pow2_lo = _mm256_shuffle_epi8(pow2_lo_lut, masked);
auto pow2_hi = _mm256_shuffle_epi8(pow2_hi_lut, masked);
auto pow2 = _mm256_or_si256(_mm256_slli_epi16(pow2_hi, 8), pow2_lo);
return SIMDVec16{pow2};
}
FJXL_INLINE SIMDVec16
Or(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm256_or_si256(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16
Xor(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm256_xor_si256(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16
And(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm256_and_si256(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 HAdd(
const SIMDVec16& oth)
const {
return SIMDVec16{_mm256_srai_epi16(_mm256_add_epi16(vec, oth.vec), 1)};
}
FJXL_INLINE SIMDVec16 PrepareForU8Lookup()
const {
return SIMDVec16{_mm256_or_si256(vec, _mm256_set1_epi16(0xFF00))};
}
FJXL_INLINE SIMDVec16 U8Lookup(
const uint8_t* table)
const {
return SIMDVec16{_mm256_shuffle_epi8(
_mm256_broadcastsi128_si256(_mm_loadu_si128((__m128i*)table)), vec)};
}
FJXL_INLINE VecPair<SIMDVec16> Interleave(
const SIMDVec16& low)
const {
auto v02 = _mm256_unpacklo_epi16(low.vec, vec);
auto v13 = _mm256_unpackhi_epi16(low.vec, vec);
return {SIMDVec16{_mm256_permute2x128_si256(v02, v13, 0x20)},
SIMDVec16{_mm256_permute2x128_si256(v02, v13, 0x31)}};
}
FJXL_INLINE VecPair<SIMDVec32> Upcast()
const {
auto v02 = _mm256_unpacklo_epi16(vec, _mm256_setzero_si256());
auto v13 = _mm256_unpackhi_epi16(vec, _mm256_setzero_si256());
return {SIMDVec32{_mm256_permute2x128_si256(v02, v13, 0x20)},
SIMDVec32{_mm256_permute2x128_si256(v02, v13, 0x31)}};
}
template <size_t i>
FJXL_INLINE SIMDVec16 SignedShiftRight()
const {
return SIMDVec16{_mm256_srai_epi16(vec, i)};
}
static std::array<SIMDVec16, 1> LoadG8(
const unsigned char* data) {
__m128i bytes = _mm_loadu_si128((__m128i*)data);
return {SIMDVec16{_mm256_cvtepu8_epi16(bytes)}};
}
static std::array<SIMDVec16, 1> LoadG16(
const unsigned char* data) {
return {Load((
const uint16_t*)data)};
}
static std::array<SIMDVec16, 2> LoadGA8(
const unsigned char* data) {
__m256i bytes = _mm256_loadu_si256((__m256i*)data);
__m256i gray = _mm256_and_si256(bytes, _mm256_set1_epi16(0xFF));
__m256i alpha = _mm256_srli_epi16(bytes, 8);
return {SIMDVec16{gray}, SIMDVec16{alpha}};
}
static std::array<SIMDVec16, 2> LoadGA16(
const unsigned char* data) {
__m256i bytes1 = _mm256_loadu_si256((__m256i*)data);
__m256i bytes2 = _mm256_loadu_si256((__m256i*)(data + 32));
__m256i g_mask = _mm256_set1_epi32(0xFFFF);
__m256i g = _mm256_permute4x64_epi64(
_mm256_packus_epi32(_mm256_and_si256(bytes1, g_mask),
_mm256_and_si256(bytes2, g_mask)),
0b11011000);
__m256i a = _mm256_permute4x64_epi64(
_mm256_packus_epi32(_mm256_srli_epi32(bytes1, 16),
_mm256_srli_epi32(bytes2, 16)),
0b11011000);
return {SIMDVec16{g}, SIMDVec16{a}};
}
static std::array<SIMDVec16, 3> LoadRGB8(
const unsigned char* data) {
__m128i bytes0 = _mm_loadu_si128((__m128i*)data);
__m128i bytes1 = _mm_loadu_si128((__m128i*)(data + 16));
__m128i bytes2 = _mm_loadu_si128((__m128i*)(data + 32));
__m128i idx =
_mm_setr_epi8(0, 3, 6, 9, 12, 15, 2, 5, 8, 11, 14, 1, 4, 7, 10, 13);
__m128i r6b5g5_0 = _mm_shuffle_epi8(bytes0, idx);
__m128i g6r5b5_1 = _mm_shuffle_epi8(bytes1, idx);
__m128i b6g5r5_2 = _mm_shuffle_epi8(bytes2, idx);
__m128i mask010 = _mm_setr_epi8(0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0, 0, 0, 0, 0);
__m128i mask001 = _mm_setr_epi8(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF);
__m128i b2g2b1 = _mm_blendv_epi8(b6g5r5_2, g6r5b5_1, mask001);
__m128i b2b0b1 = _mm_blendv_epi8(b2g2b1, r6b5g5_0, mask010);
__m128i r0r1b1 = _mm_blendv_epi8(r6b5g5_0, g6r5b5_1, mask010);
__m128i r0r1r2 = _mm_blendv_epi8(r0r1b1, b6g5r5_2, mask001);
__m128i g1r1g0 = _mm_blendv_epi8(g6r5b5_1, r6b5g5_0, mask001);
__m128i g1g2g0 = _mm_blendv_epi8(g1r1g0, b6g5r5_2, mask010);
__m128i g0g1g2 = _mm_alignr_epi8(g1g2g0, g1g2g0, 11);
__m128i b0b1b2 = _mm_alignr_epi8(b2b0b1, b2b0b1, 6);
return {SIMDVec16{_mm256_cvtepu8_epi16(r0r1r2)},
SIMDVec16{_mm256_cvtepu8_epi16(g0g1g2)},
SIMDVec16{_mm256_cvtepu8_epi16(b0b1b2)}};
}
static std::array<SIMDVec16, 3> LoadRGB16(
const unsigned char* data) {
auto load_and_split_lohi = [](
const unsigned char* data) {
// LHLHLH...
__m256i bytes = _mm256_loadu_si256((__m256i*)data);
// L0L0L0...
__m256i lo = _mm256_and_si256(bytes, _mm256_set1_epi16(0xFF));
// H0H0H0...
__m256i hi = _mm256_srli_epi16(bytes, 8);
// LLLLLLLLHHHHHHHHLLLLLLLLHHHHHHHH
__m256i packed = _mm256_packus_epi16(lo, hi);
return _mm256_permute4x64_epi64(packed, 0b11011000);
};
__m256i bytes0 = load_and_split_lohi(data);
__m256i bytes1 = load_and_split_lohi(data + 32);
__m256i bytes2 = load_and_split_lohi(data + 64);
__m256i idx = _mm256_broadcastsi128_si256(
_mm_setr_epi8(0, 3, 6, 9, 12, 15, 2, 5, 8, 11, 14, 1, 4, 7, 10, 13));
__m256i r6b5g5_0 = _mm256_shuffle_epi8(bytes0, idx);
__m256i g6r5b5_1 = _mm256_shuffle_epi8(bytes1, idx);
__m256i b6g5r5_2 = _mm256_shuffle_epi8(bytes2, idx);
__m256i mask010 = _mm256_broadcastsi128_si256(_mm_setr_epi8(
0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0));
__m256i mask001 = _mm256_broadcastsi128_si256(_mm_setr_epi8(
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF));
__m256i b2g2b1 = _mm256_blendv_epi8(b6g5r5_2, g6r5b5_1, mask001);
__m256i b2b0b1 = _mm256_blendv_epi8(b2g2b1, r6b5g5_0, mask010);
__m256i r0r1b1 = _mm256_blendv_epi8(r6b5g5_0, g6r5b5_1, mask010);
__m256i r0r1r2 = _mm256_blendv_epi8(r0r1b1, b6g5r5_2, mask001);
__m256i g1r1g0 = _mm256_blendv_epi8(g6r5b5_1, r6b5g5_0, mask001);
__m256i g1g2g0 = _mm256_blendv_epi8(g1r1g0, b6g5r5_2, mask010);
__m256i g0g1g2 = _mm256_alignr_epi8(g1g2g0, g1g2g0, 11);
__m256i b0b1b2 = _mm256_alignr_epi8(b2b0b1, b2b0b1, 6);
// Now r0r1r2, g0g1g2, b0b1b2 have the low bytes of the RGB pixels in their
// lower half, and the high bytes in their upper half.
auto combine_low_hi = [](__m256i v) {
__m128i low = _mm256_extracti128_si256(v, 0);
__m128i hi = _mm256_extracti128_si256(v, 1);
__m256i low16 = _mm256_cvtepu8_epi16(low);
__m256i hi16 = _mm256_cvtepu8_epi16(hi);
return _mm256_or_si256(_mm256_slli_epi16(hi16, 8), low16);
};
return {SIMDVec16{combine_low_hi(r0r1r2)},
SIMDVec16{combine_low_hi(g0g1g2)},
SIMDVec16{combine_low_hi(b0b1b2)}};
}
static std::array<SIMDVec16, 4> LoadRGBA8(
const unsigned char* data) {
__m256i bytes1 = _mm256_loadu_si256((__m256i*)data);
__m256i bytes2 = _mm256_loadu_si256((__m256i*)(data + 32));
__m256i rg_mask = _mm256_set1_epi32(0xFFFF);
__m256i rg = _mm256_permute4x64_epi64(
_mm256_packus_epi32(_mm256_and_si256(bytes1, rg_mask),
_mm256_and_si256(bytes2, rg_mask)),
0b11011000);
__m256i b_a = _mm256_permute4x64_epi64(
_mm256_packus_epi32(_mm256_srli_epi32(bytes1, 16),
_mm256_srli_epi32(bytes2, 16)),
0b11011000);
__m256i r = _mm256_and_si256(rg, _mm256_set1_epi16(0xFF));
__m256i g = _mm256_srli_epi16(rg, 8);
__m256i b = _mm256_and_si256(b_a, _mm256_set1_epi16(0xFF));
__m256i a = _mm256_srli_epi16(b_a, 8);
return {SIMDVec16{r}, SIMDVec16{g}, SIMDVec16{b}, SIMDVec16{a}};
}
static std::array<SIMDVec16, 4> LoadRGBA16(
const unsigned char* data) {
__m256i bytes0 = _mm256_loadu_si256((__m256i*)data);
__m256i bytes1 = _mm256_loadu_si256((__m256i*)(data + 32));
__m256i bytes2 = _mm256_loadu_si256((__m256i*)(data + 64));
__m256i bytes3 = _mm256_loadu_si256((__m256i*)(data + 96));
auto pack32 = [](__m256i a, __m256i b) {
return _mm256_permute4x64_epi64(_mm256_packus_epi32(a, b), 0b11011000);
};
auto packlow32 = [&pack32](__m256i a, __m256i b) {
__m256i mask = _mm256_set1_epi32(0xFFFF);
return pack32(_mm256_and_si256(a, mask), _mm256_and_si256(b, mask));
};
auto packhi32 = [&pack32](__m256i a, __m256i b) {
return pack32(_mm256_srli_epi32(a, 16), _mm256_srli_epi32(b, 16));
};
__m256i rb0 = packlow32(bytes0, bytes1);
__m256i rb1 = packlow32(bytes2, bytes3);
__m256i ga0 = packhi32(bytes0, bytes1);
__m256i ga1 = packhi32(bytes2, bytes3);
__m256i r = packlow32(rb0, rb1);
__m256i g = packlow32(ga0, ga1);
__m256i b = packhi32(rb0, rb1);
__m256i a = packhi32(ga0, ga1);
return {SIMDVec16{r}, SIMDVec16{g}, SIMDVec16{b}, SIMDVec16{a}};
}
void SwapEndian() {
auto indices = _mm256_broadcastsi128_si256(
_mm_setr_epi8(1, 0, 3, 2, 5, 4, 7, 6, 9, 8, 11, 10, 13, 12, 15, 14));
vec = _mm256_shuffle_epi8(vec, indices);
}
};
SIMDVec16 Mask16::IfThenElse(
const SIMDVec16& if_true,
const SIMDVec16& if_false) {
return SIMDVec16{_mm256_blendv_epi8(if_false.vec, if_true.vec, mask)};
}
SIMDVec32 Mask32::IfThenElse(
const SIMDVec32& if_true,
const SIMDVec32& if_false) {
return SIMDVec32{_mm256_blendv_epi8(if_false.vec, if_true.vec, mask)};
}
struct Bits64 {
static constexpr size_t kLanes = 4;
__m256i nbits;
__m256i bits;
FJXL_INLINE
void Store(uint64_t* nbits_out, uint64_t* bits_out) {
_mm256_storeu_si256((__m256i*)nbits_out, nbits);
_mm256_storeu_si256((__m256i*)bits_out, bits);
}
};
struct Bits32 {
__m256i nbits;
__m256i bits;
static Bits32 FromRaw(SIMDVec32 nbits, SIMDVec32 bits) {
return Bits32{nbits.vec, bits.vec};
}
Bits64 Merge()
const {
auto nbits_hi32 = _mm256_srli_epi64(nbits, 32);
auto nbits_lo32 = _mm256_and_si256(nbits, _mm256_set1_epi64x(0xFFFFFFFF));
auto bits_hi32 = _mm256_srli_epi64(bits, 32);
auto bits_lo32 = _mm256_and_si256(bits, _mm256_set1_epi64x(0xFFFFFFFF));
auto nbits64 = _mm256_add_epi64(nbits_hi32, nbits_lo32);
auto bits64 =
_mm256_or_si256(_mm256_sllv_epi64(bits_hi32, nbits_lo32), bits_lo32);
return Bits64{nbits64, bits64};
}
void Interleave(
const Bits32& low) {
bits = _mm256_or_si256(_mm256_sllv_epi32(bits, low.nbits), low.bits);
nbits = _mm256_add_epi32(nbits, low.nbits);
}
void ClipTo(size_t n) {
n = std::min<size_t>(n, 8);
constexpr uint32_t kMask[16] = {
~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, 0, 0, 0, 0, 0, 0, 0, 0,
};
__m256i mask = _mm256_loadu_si256((__m256i*)(kMask + 8 - n));
nbits = _mm256_and_si256(mask, nbits);
bits = _mm256_and_si256(mask, bits);
}
void Skip(size_t n) {
n = std::min<size_t>(n, 8);
constexpr uint32_t kMask[16] = {
0, 0, 0, 0, 0, 0, 0, 0, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u, ~0u,
};
__m256i mask = _mm256_loadu_si256((__m256i*)(kMask + 8 - n));
nbits = _mm256_and_si256(mask, nbits);
bits = _mm256_and_si256(mask, bits);
}
};
struct Bits16 {
__m256i nbits;
__m256i bits;
static Bits16 FromRaw(SIMDVec16 nbits, SIMDVec16 bits) {
return Bits16{nbits.vec, bits.vec};
}
Bits32 Merge()
const {
auto nbits_hi16 = _mm256_srli_epi32(nbits, 16);
auto nbits_lo16 = _mm256_and_si256(nbits, _mm256_set1_epi32(0xFFFF));
auto bits_hi16 = _mm256_srli_epi32(bits, 16);
auto bits_lo16 = _mm256_and_si256(bits, _mm256_set1_epi32(0xFFFF));
auto nbits32 = _mm256_add_epi32(nbits_hi16, nbits_lo16);
auto bits32 =
_mm256_or_si256(_mm256_sllv_epi32(bits_hi16, nbits_lo16), bits_lo16);
return Bits32{nbits32, bits32};
}
void Interleave(
const Bits16& low) {
auto pow2_lo_lut = _mm256_broadcastsi128_si256(
_mm_setr_epi8(1 << 0, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6,
1u << 7, 0, 0, 0, 0, 0, 0, 0, 0));
auto low_nbits_masked =
_mm256_or_si256(low.nbits, _mm256_set1_epi16(0xFF00));
auto bits_shifted = _mm256_mullo_epi16(
bits, _mm256_shuffle_epi8(pow2_lo_lut, low_nbits_masked));
nbits = _mm256_add_epi16(nbits, low.nbits);
bits = _mm256_or_si256(bits_shifted, low.bits);
}
void ClipTo(size_t n) {
n = std::min<size_t>(n, 16);
constexpr uint16_t kMask[32] = {
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
};
__m256i mask = _mm256_loadu_si256((__m256i*)(kMask + 16 - n));
nbits = _mm256_and_si256(mask, nbits);
bits = _mm256_and_si256(mask, bits);
}
void Skip(size_t n) {
n = std::min<size_t>(n, 16);
constexpr uint16_t kMask[32] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
};
__m256i mask = _mm256_loadu_si256((__m256i*)(kMask + 16 - n));
nbits = _mm256_and_si256(mask, nbits);
bits = _mm256_and_si256(mask, bits);
}
};
#endif
#ifdef FJXL_NEON
#define FJXL_GENERIC_SIMD
struct SIMDVec32;
struct Mask32 {
uint32x4_t mask;
SIMDVec32 IfThenElse(
const SIMDVec32& if_true,
const SIMDVec32& if_false);
Mask32
And(
const Mask32& oth)
const {
return Mask32{vandq_u32(mask, oth.mask)};
}
size_t CountPrefix()
const {
uint32_t val_unset[4] = {0, 1, 2, 3};
uint32_t val_set[4] = {4, 4, 4, 4};
uint32x4_t val = vbslq_u32(mask, vld1q_u32(val_set), vld1q_u32(val_unset));
return vminvq_u32(val);
}
};
struct SIMDVec32 {
uint32x4_t vec;
static constexpr size_t kLanes = 4;
FJXL_INLINE
static SIMDVec32 Load(
const uint32_t* data) {
return SIMDVec32{vld1q_u32(data)};
}
FJXL_INLINE
void Store(uint32_t* data) { vst1q_u32(data, vec); }
FJXL_INLINE
static SIMDVec32 Val(uint32_t v) {
return SIMDVec32{vdupq_n_u32(v)};
}
FJXL_INLINE SIMDVec32 ValToToken()
const {
return SIMDVec32{vsubq_u32(vdupq_n_u32(32), vclzq_u32(vec))};
}
FJXL_INLINE SIMDVec32 SatSubU(
const SIMDVec32& to_subtract)
const {
return SIMDVec32{vqsubq_u32(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec32 Sub(
const SIMDVec32& to_subtract)
const {
return SIMDVec32{vsubq_u32(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec32 Add(
const SIMDVec32& oth)
const {
return SIMDVec32{vaddq_u32(vec, oth.vec)};
}
FJXL_INLINE SIMDVec32
Xor(
const SIMDVec32& oth)
const {
return SIMDVec32{veorq_u32(vec, oth.vec)};
}
FJXL_INLINE SIMDVec32 Pow2()
const {
return SIMDVec32{vshlq_u32(vdupq_n_u32(1), vreinterpretq_s32_u32(vec))};
}
FJXL_INLINE Mask32 Eq(
const SIMDVec32& oth)
const {
return Mask32{vceqq_u32(vec, oth.vec)};
}
FJXL_INLINE Mask32 Gt(
const SIMDVec32& oth)
const {
return Mask32{
vcgtq_s32(vreinterpretq_s32_u32(vec), vreinterpretq_s32_u32(oth.vec))};
}
template <size_t i>
FJXL_INLINE SIMDVec32 SignedShiftRight()
const {
return SIMDVec32{
vreinterpretq_u32_s32(vshrq_n_s32(vreinterpretq_s32_u32(vec), i))};
}
};
struct SIMDVec16;
struct Mask16 {
uint16x8_t mask;
SIMDVec16 IfThenElse(
const SIMDVec16& if_true,
const SIMDVec16& if_false);
Mask16
And(
const Mask16& oth)
const {
return Mask16{vandq_u16(mask, oth.mask)};
}
size_t CountPrefix()
const {
uint16_t val_unset[8] = {0, 1, 2, 3, 4, 5, 6, 7};
uint16_t val_set[8] = {8, 8, 8, 8, 8, 8, 8, 8};
uint16x8_t val = vbslq_u16(mask, vld1q_u16(val_set), vld1q_u16(val_unset));
return vminvq_u16(val);
}
};
struct SIMDVec16 {
uint16x8_t vec;
static constexpr size_t kLanes = 8;
FJXL_INLINE
static SIMDVec16 Load(
const uint16_t* data) {
return SIMDVec16{vld1q_u16(data)};
}
FJXL_INLINE
void Store(uint16_t* data) { vst1q_u16(data, vec); }
FJXL_INLINE
static SIMDVec16 Val(uint16_t v) {
return SIMDVec16{vdupq_n_u16(v)};
}
FJXL_INLINE
static SIMDVec16 FromTwo32(
const SIMDVec32& lo,
const SIMDVec32& hi) {
return SIMDVec16{vmovn_high_u32(vmovn_u32(lo.vec), hi.vec)};
}
FJXL_INLINE SIMDVec16 ValToToken()
const {
return SIMDVec16{vsubq_u16(vdupq_n_u16(16), vclzq_u16(vec))};
}
FJXL_INLINE SIMDVec16 SatSubU(
const SIMDVec16& to_subtract)
const {
return SIMDVec16{vqsubq_u16(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec16 Sub(
const SIMDVec16& to_subtract)
const {
return SIMDVec16{vsubq_u16(vec, to_subtract.vec)};
}
FJXL_INLINE SIMDVec16 Add(
const SIMDVec16& oth)
const {
return SIMDVec16{vaddq_u16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 Min(
const SIMDVec16& oth)
const {
return SIMDVec16{vminq_u16(vec, oth.vec)};
}
FJXL_INLINE Mask16 Eq(
const SIMDVec16& oth)
const {
return Mask16{vceqq_u16(vec, oth.vec)};
}
FJXL_INLINE Mask16 Gt(
const SIMDVec16& oth)
const {
return Mask16{
vcgtq_s16(vreinterpretq_s16_u16(vec), vreinterpretq_s16_u16(oth.vec))};
}
FJXL_INLINE SIMDVec16 Pow2()
const {
return SIMDVec16{vshlq_u16(vdupq_n_u16(1), vreinterpretq_s16_u16(vec))};
}
FJXL_INLINE SIMDVec16
Or(
const SIMDVec16& oth)
const {
return SIMDVec16{vorrq_u16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16
Xor(
const SIMDVec16& oth)
const {
return SIMDVec16{veorq_u16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16
And(
const SIMDVec16& oth)
const {
return SIMDVec16{vandq_u16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 HAdd(
const SIMDVec16& oth)
const {
return SIMDVec16{vhaddq_u16(vec, oth.vec)};
}
FJXL_INLINE SIMDVec16 PrepareForU8Lookup()
const {
return SIMDVec16{vorrq_u16(vec, vdupq_n_u16(0xFF00))};
}
FJXL_INLINE SIMDVec16 U8Lookup(
const uint8_t* table)
const {
uint8x16_t tbl = vld1q_u8(table);
uint8x16_t indices = vreinterpretq_u8_u16(vec);
return SIMDVec16{vreinterpretq_u16_u8(vqtbl1q_u8(tbl, indices))};
}
FJXL_INLINE VecPair<SIMDVec16> Interleave(
const SIMDVec16& low)
const {
return {SIMDVec16{vzip1q_u16(low.vec, vec)},
SIMDVec16{vzip2q_u16(low.vec, vec)}};
}
FJXL_INLINE VecPair<SIMDVec32> Upcast()
const {
uint32x4_t lo = vmovl_u16(vget_low_u16(vec));
uint32x4_t hi = vmovl_high_u16(vec);
return {SIMDVec32{lo}, SIMDVec32{hi}};
}
template <size_t i>
FJXL_INLINE SIMDVec16 SignedShiftRight()
const {
return SIMDVec16{
vreinterpretq_u16_s16(vshrq_n_s16(vreinterpretq_s16_u16(vec), i))};
}
static std::array<SIMDVec16, 1> LoadG8(
const unsigned char* data) {
uint8x8_t v = vld1_u8(data);
return {SIMDVec16{vmovl_u8(v)}};
}
static std::array<SIMDVec16, 1> LoadG16(
const unsigned char* data) {
return {Load((
const uint16_t*)data)};
}
static std::array<SIMDVec16, 2> LoadGA8(
const unsigned char* data) {
uint8x8x2_t v = vld2_u8(data);
return {SIMDVec16{vmovl_u8(v.val[0])}, SIMDVec16{vmovl_u8(v.val[1])}};
}
static std::array<SIMDVec16, 2> LoadGA16(
const unsigned char* data) {
uint16x8x2_t v = vld2q_u16((
const uint16_t*)data);
return {SIMDVec16{v.val[0]}, SIMDVec16{v.val[1]}};
}
static std::array<SIMDVec16, 3> LoadRGB8(
const unsigned char* data) {
uint8x8x3_t v = vld3_u8(data);
return {SIMDVec16{vmovl_u8(v.val[0])}, SIMDVec16{vmovl_u8(v.val[1])},
SIMDVec16{vmovl_u8(v.val[2])}};
}
static std::array<SIMDVec16, 3> LoadRGB16(
const unsigned char* data) {
uint16x8x3_t v = vld3q_u16((
const uint16_t*)data);
return {SIMDVec16{v.val[0]}, SIMDVec16{v.val[1]}, SIMDVec16{v.val[2]}};
}
static std::array<SIMDVec16, 4> LoadRGBA8(
const unsigned char* data) {
uint8x8x4_t v = vld4_u8(data);
return {SIMDVec16{vmovl_u8(v.val[0])}, SIMDVec16{vmovl_u8(v.val[1])},
SIMDVec16{vmovl_u8(v.val[2])}, SIMDVec16{vmovl_u8(v.val[3])}};
}
static std::array<SIMDVec16, 4> LoadRGBA16(
const unsigned char* data) {
uint16x8x4_t v = vld4q_u16((
const uint16_t*)data);
return {SIMDVec16{v.val[0]}, SIMDVec16{v.val[1]}, SIMDVec16{v.val[2]},
SIMDVec16{v.val[3]}};
}
void SwapEndian() {
vec = vreinterpretq_u16_u8(vrev16q_u8(vreinterpretq_u8_u16(vec)));
}
};
SIMDVec16 Mask16::IfThenElse(
const SIMDVec16& if_true,
const SIMDVec16& if_false) {
return SIMDVec16{vbslq_u16(mask, if_true.vec, if_false.vec)};
}
SIMDVec32 Mask32::IfThenElse(
const SIMDVec32& if_true,
const SIMDVec32& if_false) {
return SIMDVec32{vbslq_u32(mask, if_true.vec, if_false.vec)};
}
struct Bits64 {
static constexpr size_t kLanes = 2;
uint64x2_t nbits;
uint64x2_t bits;
FJXL_INLINE
void Store(uint64_t* nbits_out, uint64_t* bits_out) {
vst1q_u64(nbits_out, nbits);
vst1q_u64(bits_out, bits);
}
};
struct Bits32 {
uint32x4_t nbits;
uint32x4_t bits;
static Bits32 FromRaw(SIMDVec32 nbits, SIMDVec32 bits) {
return Bits32{nbits.vec, bits.vec};
}
Bits64 Merge()
const {
// TODO(veluca): can probably be optimized.
uint64x2_t nbits_lo32 =
vandq_u64(vreinterpretq_u64_u32(nbits), vdupq_n_u64(0xFFFFFFFF));
uint64x2_t bits_hi32 =
vshlq_u64(vshrq_n_u64(vreinterpretq_u64_u32(bits), 32),
vreinterpretq_s64_u64(nbits_lo32));
uint64x2_t bits_lo32 =
vandq_u64(vreinterpretq_u64_u32(bits), vdupq_n_u64(0xFFFFFFFF));
uint64x2_t nbits64 =
vsraq_n_u64(nbits_lo32, vreinterpretq_u64_u32(nbits), 32);
uint64x2_t bits64 = vorrq_u64(bits_hi32, bits_lo32);
return Bits64{nbits64, bits64};
}
void Interleave(
const Bits32& low) {
bits =
vorrq_u32(vshlq_u32(bits, vreinterpretq_s32_u32(low.nbits)), low.bits);
nbits = vaddq_u32(nbits, low.nbits);
}
void ClipTo(size_t n) {
n = std::min<size_t>(n, 4);
constexpr uint32_t kMask[8] = {
~0u, ~0u, ~0u, ~0u, 0, 0, 0, 0,
};
uint32x4_t mask = vld1q_u32(kMask + 4 - n);
nbits = vandq_u32(mask, nbits);
bits = vandq_u32(mask, bits);
}
void Skip(size_t n) {
n = std::min<size_t>(n, 4);
constexpr uint32_t kMask[8] = {
0, 0, 0, 0, ~0u, ~0u, ~0u, ~0u,
};
uint32x4_t mask = vld1q_u32(kMask + 4 - n);
nbits = vandq_u32(mask, nbits);
bits = vandq_u32(mask, bits);
}
};
struct Bits16 {
uint16x8_t nbits;
uint16x8_t bits;
static Bits16 FromRaw(SIMDVec16 nbits, SIMDVec16 bits) {
return Bits16{nbits.vec, bits.vec};
}
Bits32 Merge()
const {
// TODO(veluca): can probably be optimized.
uint32x4_t nbits_lo16 =
vandq_u32(vreinterpretq_u32_u16(nbits), vdupq_n_u32(0xFFFF));
uint32x4_t bits_hi16 =
vshlq_u32(vshrq_n_u32(vreinterpretq_u32_u16(bits), 16),
vreinterpretq_s32_u32(nbits_lo16));
uint32x4_t bits_lo16 =
vandq_u32(vreinterpretq_u32_u16(bits), vdupq_n_u32(0xFFFF));
uint32x4_t nbits32 =
vsraq_n_u32(nbits_lo16, vreinterpretq_u32_u16(nbits), 16);
uint32x4_t bits32 = vorrq_u32(bits_hi16, bits_lo16);
return Bits32{nbits32, bits32};
}
void Interleave(
const Bits16& low) {
bits =
vorrq_u16(vshlq_u16(bits, vreinterpretq_s16_u16(low.nbits)), low.bits);
nbits = vaddq_u16(nbits, low.nbits);
}
void ClipTo(size_t n) {
n = std::min<size_t>(n, 8);
constexpr uint16_t kMask[16] = {
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0, 0, 0, 0, 0, 0, 0, 0,
};
uint16x8_t mask = vld1q_u16(kMask + 8 - n);
nbits = vandq_u16(mask, nbits);
bits = vandq_u16(mask, bits);
}
void Skip(size_t n) {
n = std::min<size_t>(n, 8);
constexpr uint16_t kMask[16] = {
0, 0, 0, 0, 0, 0, 0, 0,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
};
uint16x8_t mask = vld1q_u16(kMask + 8 - n);
nbits = vandq_u16(mask, nbits);
bits = vandq_u16(mask, bits);
}
};
#endif
#ifdef FJXL_GENERIC_SIMD
constexpr size_t SIMDVec32::kLanes;
constexpr size_t SIMDVec16::kLanes;
// Each of these functions will process SIMDVec16::kLanes worth of values.
FJXL_INLINE
void TokenizeSIMD(
const uint16_t* residuals, uint16_t* token_out,
uint16_t* nbits_out, uint16_t* bits_out) {
SIMDVec16 res = SIMDVec16::Load(residuals);
SIMDVec16 token = res.ValToToken();
SIMDVec16 nbits = token.SatSubU(SIMDVec16::Val(1));
SIMDVec16 bits = res.SatSubU(nbits.Pow2());
token.Store(token_out);
nbits.Store(nbits_out);
bits.Store(bits_out);
}
FJXL_INLINE
void TokenizeSIMD(
const uint32_t* residuals, uint16_t* token_out,
uint32_t* nbits_out, uint32_t* bits_out) {
static_assert(SIMDVec16::kLanes == 2 * SIMDVec32::kLanes,
"");
SIMDVec32 res_lo = SIMDVec32::Load(residuals);
SIMDVec32 res_hi = SIMDVec32::Load(residuals + SIMDVec32::kLanes);
SIMDVec32 token_lo = res_lo.ValToToken();
SIMDVec32 token_hi = res_hi.ValToToken();
SIMDVec32 nbits_lo = token_lo.SatSubU(SIMDVec32::Val(1));
SIMDVec32 nbits_hi = token_hi.SatSubU(SIMDVec32::Val(1));
SIMDVec32 bits_lo = res_lo.SatSubU(nbits_lo.Pow2());
SIMDVec32 bits_hi = res_hi.SatSubU(nbits_hi.Pow2());
SIMDVec16 token = SIMDVec16::FromTwo32(token_lo, token_hi);
token.Store(token_out);
nbits_lo.Store(nbits_out);
nbits_hi.Store(nbits_out + SIMDVec32::kLanes);
bits_lo.Store(bits_out);
bits_hi.Store(bits_out + SIMDVec32::kLanes);
}
FJXL_INLINE
void HuffmanSIMDUpTo13(
const uint16_t* tokens,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd,
uint16_t* nbits_out, uint16_t* bits_out) {
SIMDVec16 tok = SIMDVec16::Load(tokens).PrepareForU8Lookup();
tok.U8Lookup(raw_nbits_simd).Store(nbits_out);
tok.U8Lookup(raw_bits_simd).Store(bits_out);
}
FJXL_INLINE
void HuffmanSIMD14(
const uint16_t* tokens,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd,
uint16_t* nbits_out, uint16_t* bits_out) {
SIMDVec16 token_cap = SIMDVec16::Val(15);
SIMDVec16 tok = SIMDVec16::Load(tokens);
SIMDVec16 tok_index = tok.Min(token_cap).PrepareForU8Lookup();
SIMDVec16 huff_bits_pre = tok_index.U8Lookup(raw_bits_simd);
// Set the highest bit when token == 16; the Huffman code is constructed in
// such a way that the code for token 15 is the same as the code for 16,
// except for the highest bit.
Mask16 needs_high_bit = tok.Eq(SIMDVec16::Val(16));
SIMDVec16 huff_bits = needs_high_bit.IfThenElse(
huff_bits_pre.
Or(SIMDVec16::Val(128)), huff_bits_pre);
huff_bits.Store(bits_out);
tok_index.U8Lookup(raw_nbits_simd).Store(nbits_out);
}
FJXL_INLINE
void HuffmanSIMDAbove14(
const uint16_t* tokens,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd,
uint16_t* nbits_out, uint16_t* bits_out) {
SIMDVec16 tok = SIMDVec16::Load(tokens);
// We assume `tok` fits in a *signed* 16-bit integer.
Mask16 above = tok.Gt(SIMDVec16::Val(12));
// 13, 14 -> 13
// 15, 16 -> 14
// 17, 18 -> 15
SIMDVec16 remap_tok = above.IfThenElse(tok.HAdd(SIMDVec16::Val(13)), tok);
SIMDVec16 tok_index = remap_tok.PrepareForU8Lookup();
SIMDVec16 huff_bits_pre = tok_index.U8Lookup(raw_bits_simd);
// Set the highest bit when token == 14, 16, 18.
Mask16 needs_high_bit = above.
And(tok.Eq(tok.
And(SIMDVec16::Val(0xFFFE))));
SIMDVec16 huff_bits = needs_high_bit.IfThenElse(
huff_bits_pre.
Or(SIMDVec16::Val(128)), huff_bits_pre);
huff_bits.Store(bits_out);
tok_index.U8Lookup(raw_nbits_simd).Store(nbits_out);
}
FJXL_INLINE
void StoreSIMDUpTo8(
const uint16_t* nbits_tok,
const uint16_t* bits_tok,
const uint16_t* nbits_huff,
const uint16_t* bits_huff, size_t n,
size_t skip, Bits32* bits_out) {
Bits16 bits =
Bits16::FromRaw(SIMDVec16::Load(nbits_tok), SIMDVec16::Load(bits_tok));
Bits16 huff_bits =
Bits16::FromRaw(SIMDVec16::Load(nbits_huff), SIMDVec16::Load(bits_huff));
bits.Interleave(huff_bits);
bits.ClipTo(n);
bits.Skip(skip);
bits_out[0] = bits.Merge();
}
// Huffman and raw bits don't necessarily fit in a single u16 here.
FJXL_INLINE
void StoreSIMDUpTo14(
const uint16_t* nbits_tok,
const uint16_t* bits_tok,
const uint16_t* nbits_huff,
const uint16_t* bits_huff, size_t n,
size_t skip, Bits32* bits_out) {
VecPair<SIMDVec16> bits =
SIMDVec16::Load(bits_tok).Interleave(SIMDVec16::Load(bits_huff));
VecPair<SIMDVec16> nbits =
SIMDVec16::Load(nbits_tok).Interleave(SIMDVec16::Load(nbits_huff));
Bits16 low = Bits16::FromRaw(nbits.low, bits.low);
Bits16 hi = Bits16::FromRaw(nbits.hi, bits.hi);
low.ClipTo(2 * n);
low.Skip(2 * skip);
hi.ClipTo(std::max(2 * n, SIMDVec16::kLanes) - SIMDVec16::kLanes);
hi.Skip(std::max(2 * skip, SIMDVec16::kLanes) - SIMDVec16::kLanes);
bits_out[0] = low.Merge();
bits_out[1] = hi.Merge();
}
FJXL_INLINE
void StoreSIMDAbove14(
const uint32_t* nbits_tok,
const uint32_t* bits_tok,
const uint16_t* nbits_huff,
const uint16_t* bits_huff, size_t n,
size_t skip, Bits32* bits_out) {
static_assert(SIMDVec16::kLanes == 2 * SIMDVec32::kLanes,
"");
Bits32 bits_low =
Bits32::FromRaw(SIMDVec32::Load(nbits_tok), SIMDVec32::Load(bits_tok));
Bits32 bits_hi =
Bits32::FromRaw(SIMDVec32::Load(nbits_tok + SIMDVec32::kLanes),
SIMDVec32::Load(bits_tok + SIMDVec32::kLanes));
VecPair<SIMDVec32> huff_bits = SIMDVec16::Load(bits_huff).Upcast();
VecPair<SIMDVec32> huff_nbits = SIMDVec16::Load(nbits_huff).Upcast();
Bits32 huff_low = Bits32::FromRaw(huff_nbits.low, huff_bits.low);
Bits32 huff_hi = Bits32::FromRaw(huff_nbits.hi, huff_bits.hi);
bits_low.Interleave(huff_low);
bits_low.ClipTo(n);
bits_low.Skip(skip);
bits_out[0] = bits_low;
bits_hi.Interleave(huff_hi);
bits_hi.ClipTo(std::max(n, SIMDVec32::kLanes) - SIMDVec32::kLanes);
bits_hi.Skip(std::max(skip, SIMDVec32::kLanes) - SIMDVec32::kLanes);
bits_out[1] = bits_hi;
}
#ifdef FJXL_AVX512
FJXL_INLINE
void StoreToWriterAVX512(
const Bits32& bits32, BitWriter& output) {
__m512i bits = bits32.bits;
__m512i nbits = bits32.nbits;
// Insert the leftover bits from the bit buffer at the bottom of the vector
// and extract the top of the vector.
uint64_t trail_bits =
_mm512_cvtsi512_si32(_mm512_alignr_epi32(bits, bits, 15));
uint64_t trail_nbits =
_mm512_cvtsi512_si32(_mm512_alignr_epi32(nbits, nbits, 15));
__m512i lead_bits = _mm512_set1_epi32(output.buffer);
__m512i lead_nbits = _mm512_set1_epi32(output.bits_in_buffer);
bits = _mm512_alignr_epi32(bits, lead_bits, 15);
nbits = _mm512_alignr_epi32(nbits, lead_nbits, 15);
// Merge 32 -> 64 bits.
Bits32 b{nbits, bits};
Bits64 b64 = b.Merge();
bits = b64.bits;
nbits = b64.nbits;
__m512i zero = _mm512_setzero_si512();
auto sh1 = [zero](__m512i vec) {
return _mm512_alignr_epi64(vec, zero, 7); };
auto sh2 = [zero](__m512i vec) {
return _mm512_alignr_epi64(vec, zero, 6); };
auto sh4 = [zero](__m512i vec) {
return _mm512_alignr_epi64(vec, zero, 4); };
// Compute first-past-end-bit-position.
__m512i end_intermediate0 = _mm512_add_epi64(nbits, sh1(nbits));
__m512i end_intermediate1 =
_mm512_add_epi64(end_intermediate0, sh2(end_intermediate0));
__m512i end = _mm512_add_epi64(end_intermediate1, sh4(end_intermediate1));
uint64_t simd_nbits = _mm512_cvtsi512_si32(_mm512_alignr_epi64(end, end, 7));
// Compute begin-bit-position.
__m512i begin = _mm512_sub_epi64(end, nbits);
// Index of the last bit in the chunk, or the end bit if nbits==0.
__m512i last = _mm512_mask_sub_epi64(
end, _mm512_cmpneq_epi64_mask(nbits, zero), end, _mm512_set1_epi64(1));
__m512i lane_offset_mask = _mm512_set1_epi64(63);
// Starting position of the chunk that each lane will ultimately belong to.
__m512i chunk_start = _mm512_andnot_si512(lane_offset_mask, last);
// For all lanes that contain bits belonging to two different 64-bit chunks,
// compute the number of bits that belong to the first chunk.
// total # of bits fit in a u16, so we can satsub_u16 here.
__m512i first_chunk_nbits = _mm512_subs_epu16(chunk_start, begin);
// Move all the previous-chunk-bits to the previous lane.
__m512i negnbits = _mm512_sub_epi64(_mm512_set1_epi64(64), first_chunk_nbits);
__m512i first_chunk_bits =
_mm512_srlv_epi64(_mm512_sllv_epi64(bits, negnbits), negnbits);
__m512i first_chunk_bits_down =
_mm512_alignr_epi32(zero, first_chunk_bits, 2);
bits = _mm512_srlv_epi64(bits, first_chunk_nbits);
nbits = _mm512_sub_epi64(nbits, first_chunk_nbits);
bits = _mm512_or_si512(bits, _mm512_sllv_epi64(first_chunk_bits_down, nbits));
begin = _mm512_add_epi64(begin, first_chunk_nbits);
// We now know that every lane should give bits to only one chunk. We can
// shift the bits and then horizontally-or-reduce them within the same chunk.
__m512i offset = _mm512_and_si512(begin, lane_offset_mask);
__m512i aligned_bits = _mm512_sllv_epi64(bits, offset);
// h-or-reduce within same chunk
__m512i red0 = _mm512_mask_or_epi64(
aligned_bits, _mm512_cmpeq_epi64_mask(sh1(chunk_start), chunk_start),
sh1(aligned_bits), aligned_bits);
__m512i red1 = _mm512_mask_or_epi64(
red0, _mm512_cmpeq_epi64_mask(sh2(chunk_start), chunk_start), sh2(red0),
red0);
__m512i reduced = _mm512_mask_or_epi64(
red1, _mm512_cmpeq_epi64_mask(sh4(chunk_start), chunk_start), sh4(red1),
red1);
// Extract the highest lane that belongs to each chunk (the lane that ends up
// with the OR-ed value of all the other lanes of that chunk).
__m512i next_chunk_start =
_mm512_alignr_epi32(_mm512_set1_epi64(~0), chunk_start, 2);
__m512i result = _mm512_maskz_compress_epi64(
_mm512_cmpneq_epi64_mask(chunk_start, next_chunk_start), reduced);
_mm512_storeu_si512((__m512i*)(output.data.get() + output.bytes_written),
result);
// Update the bit writer and add the last 32-bit lane.
// Note that since trail_nbits was at most 32 to begin with, operating on
// trail_bits does not risk overflowing.
output.bytes_written += simd_nbits / 8;
// Here we are implicitly relying on the fact that simd_nbits < 512 to know
// that the byte of bitreader data we access is initialized. This is
// guaranteed because the remaining bits in the bitreader buffer are at most
// 7, so simd_nbits <= 505 always.
trail_bits = (trail_bits << (simd_nbits % 8)) +
output.data.get()[output.bytes_written];
trail_nbits += simd_nbits % 8;
StoreLE64(output.data.get() + output.bytes_written, trail_bits);
size_t trail_bytes = trail_nbits / 8;
output.bits_in_buffer = trail_nbits % 8;
output.buffer = trail_bits >> (trail_bytes * 8);
output.bytes_written += trail_bytes;
}
#endif
template <size_t n>
FJXL_INLINE
void StoreToWriter(
const Bits32* bits, BitWriter& output) {
#ifdef FJXL_AVX512
static_assert(n <= 2,
"");
StoreToWriterAVX512(bits[0], output);
if (n == 2) {
StoreToWriterAVX512(bits[1], output);
}
return;
#endif
static_assert(n <= 4,
"");
alignas(64) uint64_t nbits64[Bits64::kLanes * n];
alignas(64) uint64_t bits64[Bits64::kLanes * n];
bits[0].Merge().Store(nbits64, bits64);
if (n > 1) {
bits[1].Merge().Store(nbits64 + Bits64::kLanes, bits64 + Bits64::kLanes);
}
if (n > 2) {
bits[2].Merge().Store(nbits64 + 2 * Bits64::kLanes,
bits64 + 2 * Bits64::kLanes);
}
if (n > 3) {
bits[3].Merge().Store(nbits64 + 3 * Bits64::kLanes,
bits64 + 3 * Bits64::kLanes);
}
output.WriteMultiple(nbits64, bits64, Bits64::kLanes * n);
}
namespace detail {
template <
typename T>
struct IntegerTypes;
template <>
struct IntegerTypes<SIMDVec16> {
using signed_ = int16_t;
using unsigned_ = uint16_t;
};
template <>
struct IntegerTypes<SIMDVec32> {
using signed_ = int32_t;
using unsigned_ = uint32_t;
};
template <
typename T>
struct SIMDType;
template <>
struct SIMDType<int16_t> {
using type = SIMDVec16;
};
template <>
struct SIMDType<int32_t> {
using type = SIMDVec32;
};
}
// namespace detail
template <
typename T>
using signed_t =
typename detail::IntegerTypes<T>::signed_;
template <
typename T>
using unsigned_t =
typename detail::IntegerTypes<T>::unsigned_;
template <
typename T>
using simd_t =
typename detail::SIMDType<T>::type;
// This function will process exactly one vector worth of pixels.
template <
typename T>
size_t PredictPixels(
const signed_t<T>* pixels,
const signed_t<T>* pixels_left,
const signed_t<T>* pixels_top,
const signed_t<T>* pixels_topleft,
unsigned_t<T>* residuals) {
T px = T::Load((unsigned_t<T>*)pixels);
T left = T::Load((unsigned_t<T>*)pixels_left);
T top = T::Load((unsigned_t<T>*)pixels_top);
T topleft = T::Load((unsigned_t<T>*)pixels_topleft);
T ac = left.Sub(topleft);
T ab = left.Sub(top);
T bc = top.Sub(topleft);
T grad = ac.Add(top);
T d = ab.
Xor(bc);
T zero = T::Val(0);
T clamp = zero.Gt(d).IfThenElse(top, left);
T s = ac.
Xor(bc);
T pred = zero.Gt(s).IfThenElse(grad, clamp);
T res = px.Sub(pred);
T res_times_2 = res.Add(res);
res = zero.Gt(res).IfThenElse(T::Val(-1).Sub(res_times_2), res_times_2);
res.Store(residuals);
return res.Eq(T::Val(0)).CountPrefix();
}
#endif
void EncodeHybridUint000(uint32_t value, uint32_t* token, uint32_t* nbits,
uint32_t* bits) {
uint32_t n = FloorLog2(value);
*token = value ? n + 1 : 0;
*nbits = value ? n : 0;
*bits = value ? value - (1 << n) : 0;
}
#ifdef FJXL_AVX512
constexpr
static size_t kLogChunkSize = 5;
#elif defined(FJXL_AVX2) ||
defined(FJXL_NEON)
// Even if NEON only has 128-bit lanes, it is still significantly (~1.3x) faster
// to process two vectors at a time.
constexpr
static size_t kLogChunkSize = 4;
#else
constexpr
static size_t kLogChunkSize = 3;
#endif
constexpr
static size_t kChunkSize = 1 << kLogChunkSize;
template <
typename Residual>
void GenericEncodeChunk(
const Residual* residuals, size_t n, size_t skip,
const PrefixCode& code, BitWriter& output) {
for (size_t ix = skip; ix < n; ix++) {
unsigned token, nbits, bits;
EncodeHybridUint000(residuals[ix], &token, &nbits, &bits);
output.Write(code.raw_nbits[token] + nbits,
code.raw_bits[token] | bits << code.raw_nbits[token]);
}
}
struct UpTo8Bits {
size_t bitdepth;
explicit UpTo8Bits(size_t bitdepth) : bitdepth(bitdepth) {
assert(bitdepth <= 8);
}
// Here we can fit up to 9 extra bits + 7 Huffman bits in a u16; for all other
// symbols, we could actually go up to 8 Huffman bits as we have at most 8
// extra bits; however, the SIMD bit merging logic for AVX2 assumes that no
// Huffman length is 8 or more, so we cap at 8 anyway. Last symbol is used for
// LZ77 lengths and has no limitations except allowing to represent 32 symbols
// in total.
static constexpr uint8_t kMinRawLength[12] = {};
static constexpr uint8_t kMaxRawLength[12] = {
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 10,
};
static size_t MaxEncodedBitsPerSample() {
return 16; }
static constexpr size_t kInputBytes = 1;
using pixel_t = int16_t;
using upixel_t = uint16_t;
static void PrepareForSimd(
const uint8_t* nbits,
const uint8_t* bits,
size_t n, uint8_t* nbits_simd,
uint8_t* bits_simd) {
assert(n <= 16);
memcpy(nbits_simd, nbits, 16);
memcpy(bits_simd, bits, 16);
}
#ifdef FJXL_GENERIC_SIMD
static void EncodeChunkSimd(upixel_t* residuals, size_t n, size_t skip,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd, BitWriter& output) {
Bits32 bits32[kChunkSize / SIMDVec16::kLanes];
alignas(64) uint16_t bits[SIMDVec16::kLanes];
alignas(64) uint16_t nbits[SIMDVec16::kLanes];
alignas(64) uint16_t bits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t nbits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t token[SIMDVec16::kLanes];
for (size_t i = 0; i < kChunkSize; i += SIMDVec16::kLanes) {
TokenizeSIMD(residuals + i, token, nbits, bits);
HuffmanSIMDUpTo13(token, raw_nbits_simd, raw_bits_simd, nbits_huff,
bits_huff);
StoreSIMDUpTo8(nbits, bits, nbits_huff, bits_huff, std::max(n, i) - i,
std::max(skip, i) - i, bits32 + i / SIMDVec16::kLanes);
}
StoreToWriter<kChunkSize / SIMDVec16::kLanes>(bits32, output);
}
#endif
size_t NumSymbols(
bool doing_ycocg_or_large_palette)
const {
// values gain 1 bit for YCoCg, 1 bit for prediction.
// Maximum symbol is 1 + effective bit depth of residuals.
if (doing_ycocg_or_large_palette) {
return bitdepth + 3;
}
else {
return bitdepth + 2;
}
}
};
constexpr uint8_t UpTo8Bits::kMinRawLength[];
constexpr uint8_t UpTo8Bits::kMaxRawLength[];
struct From9To13Bits {
size_t bitdepth;
explicit From9To13Bits(size_t bitdepth) : bitdepth(bitdepth) {
assert(bitdepth <= 13 && bitdepth >= 9);
}
// Last symbol is used for LZ77 lengths and has no limitations except allowing
// to represent 32 symbols in total.
// We cannot fit all the bits in a u16, so do not even try and use up to 8
// bits per raw symbol.
// There are at most 16 raw symbols, so Huffman coding can be SIMDfied without
// any special tricks.
static constexpr uint8_t kMinRawLength[17] = {};
static constexpr uint8_t kMaxRawLength[17] = {
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 10,
};
static size_t MaxEncodedBitsPerSample() {
return 21; }
static constexpr size_t kInputBytes = 2;
using pixel_t = int16_t;
using upixel_t = uint16_t;
static void PrepareForSimd(
const uint8_t* nbits,
const uint8_t* bits,
size_t n, uint8_t* nbits_simd,
uint8_t* bits_simd) {
assert(n <= 16);
memcpy(nbits_simd, nbits, 16);
memcpy(bits_simd, bits, 16);
}
#ifdef FJXL_GENERIC_SIMD
static void EncodeChunkSimd(upixel_t* residuals, size_t n, size_t skip,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd, BitWriter& output) {
Bits32 bits32[2 * kChunkSize / SIMDVec16::kLanes];
alignas(64) uint16_t bits[SIMDVec16::kLanes];
alignas(64) uint16_t nbits[SIMDVec16::kLanes];
alignas(64) uint16_t bits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t nbits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t token[SIMDVec16::kLanes];
for (size_t i = 0; i < kChunkSize; i += SIMDVec16::kLanes) {
TokenizeSIMD(residuals + i, token, nbits, bits);
HuffmanSIMDUpTo13(token, raw_nbits_simd, raw_bits_simd, nbits_huff,
bits_huff);
StoreSIMDUpTo14(nbits, bits, nbits_huff, bits_huff, std::max(n, i) - i,
std::max(skip, i) - i,
bits32 + 2 * i / SIMDVec16::kLanes);
}
StoreToWriter<2 * kChunkSize / SIMDVec16::kLanes>(bits32, output);
}
#endif
size_t NumSymbols(
bool doing_ycocg_or_large_palette)
const {
// values gain 1 bit for YCoCg, 1 bit for prediction.
// Maximum symbol is 1 + effective bit depth of residuals.
if (doing_ycocg_or_large_palette) {
return bitdepth + 3;
}
else {
return bitdepth + 2;
}
}
};
constexpr uint8_t From9To13Bits::kMinRawLength[];
constexpr uint8_t From9To13Bits::kMaxRawLength[];
void CheckHuffmanBitsSIMD(
int bits1,
int nbits1,
int bits2,
int nbits2) {
assert(nbits1 == 8);
assert(nbits2 == 8);
assert(bits2 == (bits1 | 128));
}
struct Exactly14Bits {
explicit Exactly14Bits(size_t bitdepth) { assert(bitdepth == 14); }
// Force LZ77 symbols to have at least 8 bits, and raw symbols 15 and 16 to
// have exactly 8, and no other symbol to have 8 or more. This ensures that
// the representation for 15 and 16 is identical up to one bit.
static constexpr uint8_t kMinRawLength[18] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 7,
};
static constexpr uint8_t kMaxRawLength[18] = {
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 10,
};
static constexpr size_t bitdepth = 14;
static size_t MaxEncodedBitsPerSample() {
return 22; }
static constexpr size_t kInputBytes = 2;
using pixel_t = int16_t;
using upixel_t = uint16_t;
static void PrepareForSimd(
const uint8_t* nbits,
const uint8_t* bits,
size_t n, uint8_t* nbits_simd,
uint8_t* bits_simd) {
assert(n == 17);
CheckHuffmanBitsSIMD(bits[15], nbits[15], bits[16], nbits[16]);
memcpy(nbits_simd, nbits, 16);
memcpy(bits_simd, bits, 16);
}
#ifdef FJXL_GENERIC_SIMD
static void EncodeChunkSimd(upixel_t* residuals, size_t n, size_t skip,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd, BitWriter& output) {
Bits32 bits32[2 * kChunkSize / SIMDVec16::kLanes];
alignas(64) uint16_t bits[SIMDVec16::kLanes];
alignas(64) uint16_t nbits[SIMDVec16::kLanes];
alignas(64) uint16_t bits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t nbits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t token[SIMDVec16::kLanes];
for (size_t i = 0; i < kChunkSize; i += SIMDVec16::kLanes) {
TokenizeSIMD(residuals + i, token, nbits, bits);
HuffmanSIMD14(token, raw_nbits_simd, raw_bits_simd, nbits_huff,
bits_huff);
StoreSIMDUpTo14(nbits, bits, nbits_huff, bits_huff, std::max(n, i) - i,
std::max(skip, i) - i,
bits32 + 2 * i / SIMDVec16::kLanes);
}
StoreToWriter<2 * kChunkSize / SIMDVec16::kLanes>(bits32, output);
}
#endif
size_t NumSymbols(
bool)
const {
return 17; }
};
constexpr uint8_t Exactly14Bits::kMinRawLength[];
constexpr uint8_t Exactly14Bits::kMaxRawLength[];
struct MoreThan14Bits {
size_t bitdepth;
explicit MoreThan14Bits(size_t bitdepth) : bitdepth(bitdepth) {
assert(bitdepth > 14);
assert(bitdepth <= 16);
}
// Force LZ77 symbols to have at least 8 bits, and raw symbols 13 to 18 to
// have exactly 8, and no other symbol to have 8 or more. This ensures that
// the representation for (13, 14), (15, 16), (17, 18) is identical up to one
// bit.
static constexpr uint8_t kMinRawLength[20] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 8, 8, 8, 8, 7,
};
static constexpr uint8_t kMaxRawLength[20] = {
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 10,
};
static size_t MaxEncodedBitsPerSample() {
return 24; }
static constexpr size_t kInputBytes = 2;
using pixel_t = int32_t;
using upixel_t = uint32_t;
static void PrepareForSimd(
const uint8_t* nbits,
const uint8_t* bits,
size_t n, uint8_t* nbits_simd,
uint8_t* bits_simd) {
assert(n == 19);
CheckHuffmanBitsSIMD(bits[13], nbits[13], bits[14], nbits[14]);
CheckHuffmanBitsSIMD(bits[15], nbits[15], bits[16], nbits[16]);
CheckHuffmanBitsSIMD(bits[17], nbits[17], bits[18], nbits[18]);
for (size_t i = 0; i < 14; i++) {
nbits_simd[i] = nbits[i];
bits_simd[i] = bits[i];
}
nbits_simd[14] = nbits[15];
bits_simd[14] = bits[15];
nbits_simd[15] = nbits[17];
bits_simd[15] = bits[17];
}
#ifdef FJXL_GENERIC_SIMD
static void EncodeChunkSimd(upixel_t* residuals, size_t n, size_t skip,
const uint8_t* raw_nbits_simd,
const uint8_t* raw_bits_simd, BitWriter& output) {
Bits32 bits32[2 * kChunkSize / SIMDVec16::kLanes];
alignas(64) uint32_t bits[SIMDVec16::kLanes];
alignas(64) uint32_t nbits[SIMDVec16::kLanes];
alignas(64) uint16_t bits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t nbits_huff[SIMDVec16::kLanes];
alignas(64) uint16_t token[SIMDVec16::kLanes];
for (size_t i = 0; i < kChunkSize; i += SIMDVec16::kLanes) {
TokenizeSIMD(residuals + i, token, nbits, bits);
HuffmanSIMDAbove14(token, raw_nbits_simd, raw_bits_simd, nbits_huff,
bits_huff);
StoreSIMDAbove14(nbits, bits, nbits_huff, bits_huff, std::max(n, i) - i,
std::max(skip, i) - i,
bits32 + 2 * i / SIMDVec16::kLanes);
}
StoreToWriter<2 * kChunkSize / SIMDVec16::kLanes>(bits32, output);
}
#endif
size_t NumSymbols(
bool)
const {
return 19; }
};
constexpr uint8_t MoreThan14Bits::kMinRawLength[];
constexpr uint8_t MoreThan14Bits::kMaxRawLength[];
void PrepareDCGlobalCommon(
bool is_single_group, size_t width, size_t height,
const PrefixCode code[4], BitWriter* output) {
output->Allocate(100000 + (is_single_group ? width * height * 16 : 0));
// No patches, spline or noise.
output->Write(1, 1);
// default DC dequantization factors (?)
output->Write(1, 1);
// use global tree / histograms
output->Write(1, 0);
// no lz77 for the tree
output->Write(1, 1);
// simple code for the tree's context map
output->Write(2, 0);
// all contexts clustered together
output->Write(1, 1);
// use prefix code for tree
output->Write(4, 0);
// 000 hybrid uint
output->Write(6, 0b100011);
// Alphabet size is 4 (var16)
output->Write(2, 1);
// simple prefix code
output->Write(2, 3);
// with 4 symbols
output->Write(2, 0);
output->Write(2, 1);
output->Write(2, 2);
output->Write(2, 3);
output->Write(1, 0);
// First tree encoding option
// Huffman table + extra bits for the tree.
uint8_t symbol_bits[6] = {0b00, 0b10, 0b001, 0b101, 0b0011, 0b0111};
uint8_t symbol_nbits[6] = {2, 2, 3, 3, 4, 4};
// Write a tree with a leaf per channel, and gradient predictor for every
// leaf.
for (
auto v : {1, 2, 1, 4, 1, 0, 0, 5, 0, 0, 0, 0, 5,
0, 0, 0, 0, 5, 0, 0, 0, 0, 5, 0, 0, 0}) {
output->Write(symbol_nbits[v], symbol_bits[v]);
}
output->Write(1, 1);
// Enable lz77 for the main bitstream
output->Write(2, 0b00);
// lz77 offset 224
static_assert(kLZ77Offset == 224,
"");
output->Write(4, 0b1010);
// lz77 min length 7
// 400 hybrid uint config for lz77
output->Write(4, 4);
output->Write(3, 0);
output->Write(3, 0);
output->Write(1, 1);
// simple code for the context map
output->Write(2, 3);
// 3 bits per entry
output->Write(3, 4);
// channel 3
output->Write(3, 3);
// channel 2
output->Write(3, 2);
// channel 1
output->Write(3, 1);
// channel 0
output->Write(3, 0);
// distance histogram first
output->Write(1, 1);
// use prefix codes
output->Write(4, 0);
// 000 hybrid uint config for distances (only need 0)
for (size_t i = 0; i < 4; i++) {
output->Write(4, 0);
// 000 hybrid uint config for symbols (only <= 10)
}
// Distance alphabet size:
output->Write(5, 0b00001);
// 2: just need 1 for RLE (i.e. distance 1)
// Symbol + LZ77 alphabet size:
for (size_t i = 0; i < 4; i++) {
output->Write(1, 1);
// > 1
output->Write(4, 8);
// <= 512
output->Write(8, 256);
// == 512
}
// Distance histogram:
output->Write(2, 1);
// simple prefix code
output->Write(2, 0);
// with one symbol
output->Write(1, 1);
// 1
// Symbol + lz77 histogram:
for (size_t i = 0; i < 4; i++) {
code[i].WriteTo(output);
}
// Group header for global modular image.
output->Write(1, 1);
// Global tree
output->Write(1, 1);
// All default wp
}
void PrepareDCGlobal(
bool is_single_group, size_t width, size_t height,
size_t nb_chans,
const PrefixCode code[4],
BitWriter* output) {
PrepareDCGlobalCommon(is_single_group, width, height, code, output);
if (nb_chans > 2) {
output->Write(2, 0b01);
// 1 transform
output->Write(2, 0b00);
// RCT
output->Write(5, 0b00000);
// Starting from ch 0
output->Write(2, 0b00);
// YCoCg
}
else {
output->Write(2, 0b00);
// no transforms
}
if (!is_single_group) {
output->ZeroPadToByte();
}
}
template <
typename BitDepth>
struct ChunkEncoder {
void PrepareForSimd() {
BitDepth::PrepareForSimd(code->raw_nbits, code->raw_bits, code->numraw,
raw_nbits_simd, raw_bits_simd);
}
FJXL_INLINE
static void EncodeRle(size_t count,
const PrefixCode& code,
BitWriter& output) {
if (count == 0)
return;
count -= kLZ77MinLength + 1;
if (count < kLZ77CacheSize) {
output.Write(code.lz77_cache_nbits[count], code.lz77_cache_bits[count]);
}
else {
unsigned token, nbits, bits;
EncodeHybridUintLZ77(count, &token, &nbits, &bits);
uint64_t wbits = bits;
wbits = (wbits << code.lz77_nbits[token]) | code.lz77_bits[token];
wbits = (wbits << code.raw_nbits[0]) | code.raw_bits[0];
output.Write(code.lz77_nbits[token] + nbits + code.raw_nbits[0], wbits);
}
}
FJXL_INLINE
void Chunk(size_t run,
typename BitDepth::upixel_t* residuals,
size_t skip, size_t n) {
EncodeRle(run, *code, *output);
#ifdef FJXL_GENERIC_SIMD
BitDepth::EncodeChunkSimd(residuals, n, skip, raw_nbits_simd, raw_bits_simd,
*output);
#else
GenericEncodeChunk(residuals, n, skip, *code, *output);
#endif
}
inline void Finalize(size_t run) { EncodeRle(run, *code, *output); }
const PrefixCode* code;
BitWriter* output;
alignas(64) uint8_t raw_nbits_simd[16] = {};
alignas(64) uint8_t raw_bits_simd[16] = {};
};
template <
typename BitDepth>
struct ChunkSampleCollector {
FJXL_INLINE
void Rle(size_t count, uint64_t* lz77_counts) {
if (count == 0)
return;
raw_counts[0] += 1;
count -= kLZ77MinLength + 1;
unsigned token, nbits, bits;
EncodeHybridUintLZ77(count, &token, &nbits, &bits);
lz77_counts[token]++;
}
FJXL_INLINE
void Chunk(size_t run,
typename BitDepth::upixel_t* residuals,
size_t skip, size_t n) {
// Run is broken. Encode the run and encode the individual vector.
Rle(run, lz77_counts);
for (size_t ix = skip; ix < n; ix++) {
unsigned token, nbits, bits;
EncodeHybridUint000(residuals[ix], &token, &nbits, &bits);
raw_counts[token]++;
}
}
// don't count final run since we don't know how long it really is
void Finalize(size_t run) {}
uint64_t* raw_counts;
uint64_t* lz77_counts;
};
constexpr uint32_t PackSigned(int32_t value) {
return (
static_cast<uint32_t>(value) << 1) ^
((
static_cast<uint32_t>(~value) >> 31) - 1);
}
template <
typename T,
typename BitDepth>
struct ChannelRowProcessor {
using upixel_t =
typename BitDepth::upixel_t;
using pixel_t =
typename BitDepth::pixel_t;
T* t;
void ProcessChunk(
const pixel_t* row,
const pixel_t* row_left,
const pixel_t* row_top,
const pixel_t* row_topleft,
size_t n) {
alignas(64) upixel_t residuals[kChunkSize] = {};
size_t prefix_size = 0;
size_t required_prefix_size = 0;
#ifdef FJXL_GENERIC_SIMD
constexpr size_t kNum =
sizeof(pixel_t) == 2 ? SIMDVec16::kLanes : SIMDVec32::kLanes;
for (size_t ix = 0; ix < kChunkSize; ix += kNum) {
size_t c =
PredictPixels<simd_t<pixel_t>>(row + ix, row_left + ix, row_top + ix,
row_topleft + ix, residuals + ix);
prefix_size =
prefix_size == required_prefix_size ? prefix_size + c : prefix_size;
required_prefix_size += kNum;
}
#else
for (size_t ix = 0; ix < kChunkSize; ix++) {
pixel_t px = row[ix];
pixel_t left = row_left[ix];
pixel_t top = row_top[ix];
pixel_t topleft = row_topleft[ix];
pixel_t ac = left - topleft;
pixel_t ab = left - top;
pixel_t bc = top - topleft;
pixel_t grad =
static_cast<pixel_t>(
static_cast<upixel_t>(ac) +
static_cast<upixel_t>(top));
pixel_t d = ab ^ bc;
pixel_t clamp = d < 0 ? top : left;
pixel_t s = ac ^ bc;
pixel_t pred = s < 0 ? grad : clamp;
residuals[ix] = PackSigned(px - pred);
prefix_size = prefix_size == required_prefix_size
? prefix_size + (residuals[ix] == 0)
: prefix_size;
required_prefix_size += 1;
}
#endif
prefix_size = std::min(n, prefix_size);
if (prefix_size == n && (run > 0 || prefix_size > kLZ77MinLength)) {
// Run continues, nothing to do.
run += prefix_size;
}
else if (prefix_size + run > kLZ77MinLength) {
// Run is broken. Encode the run and encode the individual vector.
t->Chunk(run + prefix_size, residuals, prefix_size, n);
run = 0;
}
else {
// There was no run to begin with.
t->Chunk(0, residuals, 0, n);
}
}
void ProcessRow(
const pixel_t* row,
const pixel_t* row_left,
const pixel_t* row_top,
const pixel_t* row_topleft,
size_t xs) {
for (size_t x = 0; x < xs; x += kChunkSize) {
ProcessChunk(row + x, row_left + x, row_top + x, row_topleft + x,
std::min(kChunkSize, xs - x));
}
}
void Finalize() { t->Finalize(run); }
// Invariant: run == 0 or run > kLZ77MinLength.
size_t run = 0;
};
uint16_t LoadLE16(
const unsigned char* ptr) {
return uint16_t{ptr[0]} | (uint16_t{ptr[1]} << 8);
}
uint16_t SwapEndian(uint16_t in) {
return (in >> 8) | (in << 8); }
#ifdef FJXL_GENERIC_SIMD
void StorePixels(SIMDVec16 p, int16_t* dest) { p.Store((uint16_t*)dest); }
void StorePixels(SIMDVec16 p, int32_t* dest) {
VecPair<SIMDVec32> p_up = p.Upcast();
p_up.low.Store((uint32_t*)dest);
p_up.hi.Store((uint32_t*)dest + SIMDVec32::kLanes);
}
#endif
template <
typename pixel_t>
void FillRowG8(
const unsigned char* rgba, size_t oxs, pixel_t* luma) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadG8(rgba + x);
StorePixels(rgb[0], luma + x);
}
#endif
for (; x < oxs; x++) {
luma[x] = rgba[x];
}
}
template <
bool big_endian,
typename pixel_t>
void FillRowG16(
const unsigned char* rgba, size_t oxs, pixel_t* luma) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadG16(rgba + 2 * x);
if (big_endian) {
rgb[0].SwapEndian();
}
StorePixels(rgb[0], luma + x);
}
#endif
for (; x < oxs; x++) {
uint16_t val = LoadLE16(rgba + 2 * x);
if (big_endian) {
val = SwapEndian(val);
}
luma[x] = val;
}
}
template <
typename pixel_t>
void FillRowGA8(
const unsigned char* rgba, size_t oxs, pixel_t* luma,
pixel_t* alpha) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadGA8(rgba + 2 * x);
StorePixels(rgb[0], luma + x);
StorePixels(rgb[1], alpha + x);
}
#endif
for (; x < oxs; x++) {
luma[x] = rgba[2 * x];
alpha[x] = rgba[2 * x + 1];
}
}
template <
bool big_endian,
typename pixel_t>
void FillRowGA16(
const unsigned char* rgba, size_t oxs, pixel_t* luma,
pixel_t* alpha) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadGA16(rgba + 4 * x);
if (big_endian) {
rgb[0].SwapEndian();
rgb[1].SwapEndian();
}
StorePixels(rgb[0], luma + x);
StorePixels(rgb[1], alpha + x);
}
#endif
for (; x < oxs; x++) {
uint16_t l = LoadLE16(rgba + 4 * x);
uint16_t a = LoadLE16(rgba + 4 * x + 2);
if (big_endian) {
l = SwapEndian(l);
a = SwapEndian(a);
}
luma[x] = l;
alpha[x] = a;
}
}
template <
typename pixel_t>
void StoreYCoCg(pixel_t r, pixel_t g, pixel_t b, pixel_t* y, pixel_t* co,
pixel_t* cg) {
*co = r - b;
pixel_t tmp = b + (*co >> 1);
*cg = g - tmp;
*y = tmp + (*cg >> 1);
}
#ifdef FJXL_GENERIC_SIMD
void StoreYCoCg(SIMDVec16 r, SIMDVec16 g, SIMDVec16 b, int16_t* y, int16_t* co,
int16_t* cg) {
SIMDVec16 co_v = r.Sub(b);
SIMDVec16 tmp = b.Add(co_v.SignedShiftRight<1>());
SIMDVec16 cg_v = g.Sub(tmp);
SIMDVec16 y_v = tmp.Add(cg_v.SignedShiftRight<1>());
y_v.Store(
reinterpret_cast<uint16_t*>(y));
co_v.Store(
reinterpret_cast<uint16_t*>(co));
cg_v.Store(
reinterpret_cast<uint16_t*>(cg));
}
void StoreYCoCg(SIMDVec16 r, SIMDVec16 g, SIMDVec16 b, int32_t* y, int32_t* co,
int32_t* cg) {
VecPair<SIMDVec32> r_up = r.Upcast();
VecPair<SIMDVec32> g_up = g.Upcast();
VecPair<SIMDVec32> b_up = b.Upcast();
SIMDVec32 co_lo_v = r_up.low.Sub(b_up.low);
SIMDVec32 tmp_lo = b_up.low.Add(co_lo_v.SignedShiftRight<1>());
SIMDVec32 cg_lo_v = g_up.low.Sub(tmp_lo);
SIMDVec32 y_lo_v = tmp_lo.Add(cg_lo_v.SignedShiftRight<1>());
SIMDVec32 co_hi_v = r_up.hi.Sub(b_up.hi);
SIMDVec32 tmp_hi = b_up.hi.Add(co_hi_v.SignedShiftRight<1>());
SIMDVec32 cg_hi_v = g_up.hi.Sub(tmp_hi);
SIMDVec32 y_hi_v = tmp_hi.Add(cg_hi_v.SignedShiftRight<1>());
y_lo_v.Store(
reinterpret_cast<uint32_t*>(y));
co_lo_v.Store(
reinterpret_cast<uint32_t*>(co));
cg_lo_v.Store(
reinterpret_cast<uint32_t*>(cg));
y_hi_v.Store(
reinterpret_cast<uint32_t*>(y) + SIMDVec32::kLanes);
co_hi_v.Store(
reinterpret_cast<uint32_t*>(co) + SIMDVec32::kLanes);
cg_hi_v.Store(
reinterpret_cast<uint32_t*>(cg) + SIMDVec32::kLanes);
}
#endif
template <
typename pixel_t>
void FillRowRGB8(
const unsigned char* rgba, size_t oxs, pixel_t* y, pixel_t* co,
pixel_t* cg) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadRGB8(rgba + 3 * x);
StoreYCoCg(rgb[0], rgb[1], rgb[2], y + x, co + x, cg + x);
}
#endif
for (; x < oxs; x++) {
uint16_t r = rgba[3 * x];
uint16_t g = rgba[3 * x + 1];
uint16_t b = rgba[3 * x + 2];
StoreYCoCg<pixel_t>(r, g, b, y + x, co + x, cg + x);
}
}
template <
bool big_endian,
typename pixel_t>
void FillRowRGB16(
const unsigned char* rgba, size_t oxs, pixel_t* y,
pixel_t* co, pixel_t* cg) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadRGB16(rgba + 6 * x);
if (big_endian) {
rgb[0].SwapEndian();
rgb[1].SwapEndian();
rgb[2].SwapEndian();
}
StoreYCoCg(rgb[0], rgb[1], rgb[2], y + x, co + x, cg + x);
}
#endif
for (; x < oxs; x++) {
uint16_t r = LoadLE16(rgba + 6 * x);
uint16_t g = LoadLE16(rgba + 6 * x + 2);
uint16_t b = LoadLE16(rgba + 6 * x + 4);
if (big_endian) {
r = SwapEndian(r);
g = SwapEndian(g);
b = SwapEndian(b);
}
StoreYCoCg<pixel_t>(r, g, b, y + x, co + x, cg + x);
}
}
template <
typename pixel_t>
void FillRowRGBA8(
const unsigned char* rgba, size_t oxs, pixel_t* y,
pixel_t* co, pixel_t* cg, pixel_t* alpha) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadRGBA8(rgba + 4 * x);
StoreYCoCg(rgb[0], rgb[1], rgb[2], y + x, co + x, cg + x);
StorePixels(rgb[3], alpha + x);
}
#endif
for (; x < oxs; x++) {
uint16_t r = rgba[4 * x];
uint16_t g = rgba[4 * x + 1];
uint16_t b = rgba[4 * x + 2];
uint16_t a = rgba[4 * x + 3];
StoreYCoCg<pixel_t>(r, g, b, y + x, co + x, cg + x);
alpha[x] = a;
}
}
template <
bool big_endian,
typename pixel_t>
void FillRowRGBA16(
const unsigned char* rgba, size_t oxs, pixel_t* y,
pixel_t* co, pixel_t* cg, pixel_t* alpha) {
size_t x = 0;
#ifdef FJXL_GENERIC_SIMD
for (; x + SIMDVec16::kLanes <= oxs; x += SIMDVec16::kLanes) {
auto rgb = SIMDVec16::LoadRGBA16(rgba + 8 * x);
if (big_endian) {
rgb[0].SwapEndian();
rgb[1].SwapEndian();
rgb[2].SwapEndian();
rgb[3].SwapEndian();
}
StoreYCoCg(rgb[0], rgb[1], rgb[2], y + x, co + x, cg + x);
StorePixels(rgb[3], alpha + x);
}
#endif
for (; x < oxs; x++) {
uint16_t r = LoadLE16(rgba + 8 * x);
uint16_t g = LoadLE16(rgba + 8 * x + 2);
uint16_t b = LoadLE16(rgba + 8 * x + 4);
uint16_t a = LoadLE16(rgba + 8 * x + 6);
if (big_endian) {
r = SwapEndian(r);
g = SwapEndian(g);
b = SwapEndian(b);
a = SwapEndian(a);
}
StoreYCoCg<pixel_t>(r, g, b, y + x, co + x, cg + x);
alpha[x] = a;
}
}
template <
typename Processor,
typename BitDepth>
void ProcessImageArea(
const unsigned char* rgba, size_t x0, size_t y0,
size_t xs, size_t yskip, size_t ys, size_t row_stride,
BitDepth bitdepth, size_t nb_chans,
bool big_endian,
Processor* processors) {
constexpr size_t kPadding = 32;
using pixel_t =
typename BitDepth::pixel_t;
constexpr size_t kAlign = 64;
constexpr size_t kAlignPixels = kAlign /
sizeof(pixel_t);
auto align = [=](pixel_t* ptr) {
size_t offset =
reinterpret_cast<uintptr_t>(ptr) % kAlign;
if (offset) {
ptr += offset /
sizeof(pixel_t);
}
return ptr;
};
constexpr size_t kNumPx =
(256 + kPadding * 2 + kAlignPixels + kAlignPixels - 1) / kAlignPixels *
kAlignPixels;
std::vector<std::array<std::array<pixel_t, kNumPx>, 2>> group_data(nb_chans);
for (size_t y = 0; y < ys; y++) {
const auto rgba_row =
rgba + row_stride * (y0 + y) + x0 * nb_chans * BitDepth::kInputBytes;
pixel_t* crow[4] = {};
pixel_t* prow[4] = {};
for (size_t i = 0; i < nb_chans; i++) {
crow[i] = align(&group_data[i][y & 1][kPadding]);
prow[i] = align(&group_data[i][(y - 1) & 1][kPadding]);
}
// Pre-fill rows with YCoCg converted pixels.
if (nb_chans == 1) {
if (BitDepth::kInputBytes == 1) {
FillRowG8(rgba_row, xs, crow[0]);
}
else if (big_endian) {
FillRowG16<
/*big_endian=*/true>(rgba_row, xs, crow[0]);
}
else {
FillRowG16<
/*big_endian=*/false>(rgba_row, xs, crow[0]);
}
}
else if (nb_chans == 2) {
if (BitDepth::kInputBytes == 1) {
FillRowGA8(rgba_row, xs, crow[0], crow[1]);
}
else if (big_endian) {
FillRowGA16<
/*big_endian=*/true>(rgba_row, xs, crow[0], crow[1]);
}
else {
FillRowGA16<
/*big_endian=*/false>(rgba_row, xs, crow[0], crow[1]);
}
}
else if (nb_chans == 3) {
if (BitDepth::kInputBytes == 1) {
FillRowRGB8(rgba_row, xs, crow[0], crow[1], crow[2]);
}
else if (big_endian) {
FillRowRGB16<
/*big_endian=*/true>(rgba_row, xs, crow[0], crow[1],
crow[2]);
}
else {
FillRowRGB16<
/*big_endian=*/false>(rgba_row, xs, crow[0], crow[1],
crow[2]);
}
}
else {
if (BitDepth::kInputBytes == 1) {
FillRowRGBA8(rgba_row, xs, crow[0], crow[1], crow[2], crow[3]);
}
else if (big_endian) {
FillRowRGBA16<
/*big_endian=*/true>(rgba_row, xs, crow[0], crow[1],
crow[2], crow[3]);
}
else {
FillRowRGBA16<
/*big_endian=*/false>(rgba_row, xs, crow[0], crow[1],
crow[2], crow[3]);
}
}
// Deal with x == 0.
for (size_t c = 0; c < nb_chans; c++) {
*(crow[c] - 1) = y > 0 ? *(prow[c]) : 0;
// Fix topleft.
*(prow[c] - 1) = y > 0 ? *(prow[c]) : 0;
}
if (y < yskip)
continue;
for (size_t c = 0; c < nb_chans; c++) {
// Get pointers to px/left/top/topleft data to speedup loop.
const pixel_t* row = crow[c];
const pixel_t* row_left = crow[c] - 1;
const pixel_t* row_top = y == 0 ? row_left : prow[c];
const pixel_t* row_topleft = y == 0 ? row_left : prow[c] - 1;
processors[c].ProcessRow(row, row_left, row_top, row_topleft, xs);
}
}
for (size_t c = 0; c < nb_chans; c++) {
processors[c].Finalize();
}
}
template <
typename BitDepth>
void WriteACSection(
const unsigned char* rgba, size_t x0, size_t y0, size_t xs,
size_t ys, size_t row_stride,
bool is_single_group,
BitDepth bitdepth, size_t nb_chans,
bool big_endian,
const PrefixCode code[4],
std::array<BitWriter, 4>& output) {
for (size_t i = 0; i < nb_chans; i++) {
if (is_single_group && i == 0)
continue;
output[i].Allocate(xs * ys * bitdepth.MaxEncodedBitsPerSample() + 4);
}
if (!is_single_group) {
// Group header for modular image.
// When the image is single-group, the global modular image is the one
// that contains the pixel data, and there is no group header.
output[0].Write(1, 1);
// Global tree
output[0].Write(1, 1);
// All default wp
output[0].Write(2, 0b00);
// 0 transforms
}
ChunkEncoder<BitDepth> encoders[4];
ChannelRowProcessor<ChunkEncoder<BitDepth>, BitDepth> row_encoders[4];
for (size_t c = 0; c < nb_chans; c++) {
row_encoders[c].t = &encoders[c];
encoders[c].output = &output[c];
encoders[c].code = &code[c];
encoders[c].PrepareForSimd();
}
ProcessImageArea<ChannelRowProcessor<ChunkEncoder<BitDepth>, BitDepth>>(
rgba, x0, y0, xs, 0, ys, row_stride, bitdepth, nb_chans, big_endian,
row_encoders);
}
constexpr
int kHashExp = 16;
constexpr uint32_t kHashSize = 1 << kHashExp;
constexpr uint32_t kHashMultiplier = 2654435761;
constexpr
int kMaxColors = 512;
// can be any function that returns a value in 0 .. kHashSize-1
// has to map 0 to 0
inline uint32_t pixel_hash(uint32_t p) {
return (p * kHashMultiplier) >> (32 - kHashExp);
}
template <size_t nb_chans>
void FillRowPalette(
const unsigned char* inrow, size_t xs,
const int16_t* lookup, int16_t* out) {
for (size_t x = 0; x < xs; x++) {
uint32_t p = 0;
for (size_t i = 0; i < nb_chans; ++i) {
p |= inrow[x * nb_chans + i] << (8 * i);
}
out[x] = lookup[pixel_hash(p)];
}
}
template <
typename Processor>
void ProcessImageAreaPalette(
const unsigned char* rgba, size_t x0, size_t y0,
size_t xs, size_t yskip, size_t ys,
size_t row_stride,
const int16_t* lookup,
size_t nb_chans, Processor* processors) {
constexpr size_t kPadding = 32;
std::vector<std::array<int16_t, 256 + kPadding * 2>> group_data(2);
Processor& row_encoder = processors[0];
for (size_t y = 0; y < ys; y++) {
// Pre-fill rows with palette converted pixels.
const unsigned char* inrow = rgba + row_stride * (y0 + y) + x0 * nb_chans;
int16_t* outrow = &group_data[y & 1][kPadding];
if (nb_chans == 1) {
FillRowPalette<1>(inrow, xs, lookup, outrow);
}
else if (nb_chans == 2) {
FillRowPalette<2>(inrow, xs, lookup, outrow);
}
else if (nb_chans == 3) {
FillRowPalette<3>(inrow, xs, lookup, outrow);
}
else if (nb_chans == 4) {
FillRowPalette<4>(inrow, xs, lookup, outrow);
}
// Deal with x == 0.
group_data[y & 1][kPadding - 1] =
y > 0 ? group_data[(y - 1) & 1][kPadding] : 0;
// Fix topleft.
group_data[(y - 1) & 1][kPadding - 1] =
y > 0 ? group_data[(y - 1) & 1][kPadding] : 0;
// Get pointers to px/left/top/topleft data to speedup loop.
const int16_t* row = &group_data[y & 1][kPadding];
const int16_t* row_left = &group_data[y & 1][kPadding - 1];
const int16_t* row_top =
y == 0 ? row_left : &group_data[(y - 1) & 1][kPadding];
const int16_t* row_topleft =
y == 0 ? row_left : &group_data[(y - 1) & 1][kPadding - 1];
row_encoder.ProcessRow(row, row_left, row_top, row_topleft, xs);
}
row_encoder.Finalize();
}
void WriteACSectionPalette(
const unsigned char* rgba, size_t x0, size_t y0,
size_t xs, size_t ys, size_t row_stride,
bool is_single_group,
const PrefixCode code[4],
const int16_t* lookup, size_t nb_chans,
BitWriter& output) {
if (!is_single_group) {
output.Allocate(16 * xs * ys + 4);
// Group header for modular image.
// When the image is single-group, the global modular image is the one
// that contains the pixel data, and there is no group header.
output.Write(1, 1);
// Global tree
output.Write(1, 1);
// All default wp
output.Write(2, 0b00);
// 0 transforms
}
ChunkEncoder<UpTo8Bits> encoder;
ChannelRowProcessor<ChunkEncoder<UpTo8Bits>, UpTo8Bits> row_encoder;
row_encoder.t = &encoder;
encoder.output = &output;
encoder.code = &code[is_single_group ? 1 : 0];
encoder.PrepareForSimd();
ProcessImageAreaPalette<
ChannelRowProcessor<ChunkEncoder<UpTo8Bits>, UpTo8Bits>>(
rgba, x0, y0, xs, 0, ys, row_stride, lookup, nb_chans, &row_encoder);
}
template <
typename BitDepth>
void CollectSamples(
const unsigned char* rgba, size_t x0, size_t y0, size_t xs,
size_t row_stride, size_t row_count,
uint64_t raw_counts[4][kNumRawSymbols],
uint64_t lz77_counts[4][kNumLZ77],
bool is_single_group,
bool palette, BitDepth bitdepth, size_t nb_chans,
bool big_endian,
const int16_t* lookup) {
if (palette) {
ChunkSampleCollector<UpTo8Bits> sample_collectors[4];
ChannelRowProcessor<ChunkSampleCollector<UpTo8Bits>, UpTo8Bits>
row_sample_collectors[4];
for (size_t c = 0; c < nb_chans; c++) {
row_sample_collectors[c].t = &sample_collectors[c];
sample_collectors[c].raw_counts = raw_counts[is_single_group ? 1 : 0];
sample_collectors[c].lz77_counts = lz77_counts[is_single_group ? 1 : 0];
}
ProcessImageAreaPalette<
ChannelRowProcessor<ChunkSampleCollector<UpTo8Bits>, UpTo8Bits>>(
rgba, x0, y0, xs, 1, 1 + row_count, row_stride, lookup, nb_chans,
row_sample_collectors);
}
else {
ChunkSampleCollector<BitDepth> sample_collectors[4];
ChannelRowProcessor<ChunkSampleCollector<BitDepth>, BitDepth>
row_sample_collectors[4];
for (size_t c = 0; c < nb_chans; c++) {
row_sample_collectors[c].t = &sample_collectors[c];
sample_collectors[c].raw_counts = raw_counts[c];
sample_collectors[c].lz77_counts = lz77_counts[c];
}
ProcessImageArea<
ChannelRowProcessor<ChunkSampleCollector<BitDepth>, BitDepth>>(
rgba, x0, y0, xs, 1, 1 + row_count, row_stride, bitdepth, nb_chans,
big_endian, row_sample_collectors);
}
}
void PrepareDCGlobalPalette(
bool is_single_group, size_t width, size_t height,
size_t nb_chans,
const PrefixCode code[4],
const std::vector<uint32_t>& palette,
size_t pcolors, BitWriter* output) {
PrepareDCGlobalCommon(is_single_group, width, height, code, output);
output->Write(2, 0b01);
// 1 transform
output->Write(2, 0b01);
// Palette
output->Write(5, 0b00000);
// Starting from ch 0
if (nb_chans == 1) {
output->Write(2, 0b00);
// 1-channel palette (Gray)
}
else if (nb_chans == 3) {
output->Write(2, 0b01);
// 3-channel palette (RGB)
}
else if (nb_chans == 4) {
output->Write(2, 0b10);
// 4-channel palette (RGBA)
}
else {
output->Write(2, 0b11);
output->Write(13, nb_chans - 1);
}
// pcolors <= kMaxColors + kChunkSize - 1
static_assert(kMaxColors + kChunkSize < 1281,
"add code to signal larger palette sizes");
if (pcolors < 256) {
output->Write(2, 0b00);
output->Write(8, pcolors);
}
else {
output->Write(2, 0b01);
output->Write(10, pcolors - 256);
}
output->Write(2, 0b00);
// nb_deltas == 0
output->Write(4, 0);
// Zero predictor for delta palette
// Encode palette
ChunkEncoder<UpTo8Bits> encoder;
ChannelRowProcessor<ChunkEncoder<UpTo8Bits>, UpTo8Bits> row_encoder;
row_encoder.t = &encoder;
encoder.output = output;
encoder.code = &code[0];
encoder.PrepareForSimd();
int16_t p[4][32 + 1024] = {};
size_t i = 0;
size_t have_zero = 1;
for (; i < pcolors; i++) {
p[0][16 + i + have_zero] = palette[i] & 0xFF;
p[1][16 + i + have_zero] = (palette[i] >> 8) & 0xFF;
p[2][16 + i + have_zero] = (palette[i] >> 16) & 0xFF;
p[3][16 + i + have_zero] = (palette[i] >> 24) & 0xFF;
}
p[0][15] = 0;
row_encoder.ProcessRow(p[0] + 16, p[0] + 15, p[0] + 15, p[0] + 15, pcolors);
p[1][15] = p[0][16];
p[0][15] = p[0][16];
if (nb_chans > 1) {
row_encoder.ProcessRow(p[1] + 16, p[1] + 15, p[0] + 16, p[0] + 15, pcolors);
}
p[2][15] = p[1][16];
p[1][15] = p[1][16];
if (nb_chans > 2) {
row_encoder.ProcessRow(p[2] + 16, p[2] + 15, p[1] + 16, p[1] + 15, pcolors);
}
p[3][15] = p[2][16];
p[2][15] = p[2][16];
if (nb_chans > 3) {
row_encoder.ProcessRow(p[3] + 16, p[3] + 15, p[2] + 16, p[2] + 15, pcolors);
}
row_encoder.Finalize();
if (!is_single_group) {
output->ZeroPadToByte();
}
}
template <size_t nb_chans>
bool detect_palette(
const unsigned char* r, size_t width,
std::vector<uint32_t>& palette) {
size_t x = 0;
bool collided =
false;
// this is just an unrolling of the next loop
size_t look_ahead = 7 + ((nb_chans == 1) ? 3 : ((nb_chans < 4) ? 1 : 0));
for (; x + look_ahead < width; x += 8) {
uint32_t p[8] = {}, index[8];
for (
int i = 0; i < 8; i++) {
for (
int j = 0; j < 4; ++j) {
p[i] |= r[(x + i) * nb_chans + j] << (8 * j);
}
}
for (
int i = 0; i < 8; i++) p[i] &= ((1llu << (8 * nb_chans)) - 1);
for (
int i = 0; i < 8; i++) index[i] = pixel_hash(p[i]);
for (
int i = 0; i < 8; i++) {
collided |= (palette[index[i]] != 0 && p[i] != palette[index[i]]);
}
for (
int i = 0; i < 8; i++) palette[index[i]] = p[i];
}
for (; x < width; x++) {
uint32_t p = 0;
for (size_t i = 0; i < nb_chans; ++i) {
p |= r[x * nb_chans + i] << (8 * i);
}
uint32_t index = pixel_hash(p);
collided |= (palette[index] != 0 && p != palette[index]);
palette[index] = p;
}
return collided;
}
template <
typename BitDepth>
JxlFastLosslessFrameState* LLPrepare(JxlChunkedFrameInputSource input,
size_t width, size_t height,
BitDepth bitdepth, size_t nb_chans,
bool big_endian,
int effort,
int oneshot) {
assert(width != 0);
assert(height != 0);
// Count colors to try palette
std::vector<uint32_t> palette(kHashSize);
std::vector<int16_t> lookup(kHashSize);
lookup[0] = 0;
int pcolors = 0;
bool collided = effort < 2 || bitdepth.bitdepth != 8 || !oneshot;
for (size_t y0 = 0; y0 < height && !collided; y0 += 256) {
size_t ys = std::min<size_t>(height - y0, 256);
for (size_t x0 = 0; x0 < width && !collided; x0 += 256) {
size_t xs = std::min<size_t>(width - x0, 256);
size_t stride;
// TODO(szabadka): Add RAII wrapper around this.
const void* buffer = input.get_color_channel_data_at(input.opaque, x0, y0,
xs, ys, &stride);
auto rgba =
reinterpret_cast<
const unsigned char*>(buffer);
for (size_t y = 0; y < ys && !collided; y++) {
const unsigned char* r = rgba + stride * y;
if (nb_chans == 1) collided = detect_palette<1>(r, xs, palette);
if (nb_chans == 2) collided = detect_palette<2>(r, xs, palette);
if (nb_chans == 3) collided = detect_palette<3>(r, xs, palette);
if (nb_chans == 4) collided = detect_palette<4>(r, xs, palette);
}
input.release_buffer(input.opaque, buffer);
}
}
int nb_entries = 0;
if (!collided) {
pcolors = 1;
// always have all-zero as a palette color
bool have_color =
false;
uint8_t minG = 255, maxG = 0;
for (uint32_t k = 0; k < kHashSize; k++) {
if (palette[k] == 0)
continue;
uint8_t p[4];
for (
int i = 0; i < 4; ++i) {
p[i] = (palette[k] >> (8 * i)) & 0xFF;
}
// move entries to front so sort has less work
palette[nb_entries] = palette[k];
if (p[0] != p[1] || p[0] != p[2]) have_color =
true;
if (p[1] < minG) minG = p[1];
if (p[1] > maxG) maxG = p[1];
nb_entries++;
// don't do palette if too many colors are needed
if (nb_entries + pcolors > kMaxColors) {
collided =
true;
break;
}
}
if (!have_color) {
// don't do palette if it's just grayscale without many holes
if (maxG - minG < nb_entries * 1.4f) collided =
true;
}
}
if (!collided) {
std::sort(
palette.begin(), palette.begin() + nb_entries,
[&nb_chans](uint32_t ap, uint32_t bp) {
if (ap == 0)
return false;
if (bp == 0)
return true;
uint8_t a[4], b[4];
for (
int i = 0; i < 4; ++i) {
a[i] = (ap >> (8 * i)) & 0xFF;
b[i] = (bp >> (8 * i)) & 0xFF;
}
float ay, by;
if (nb_chans == 4) {
ay = (0.299f * a[0] + 0.587f * a[1] + 0.114f * a[2] + 0.01f) * a[3];
by = (0.299f * b[0] + 0.587f * b[1] + 0.114f * b[2] + 0.01f) * b[3];
}
else {
ay = (0.299f * a[0] + 0.587f * a[1] + 0.114f * a[2] + 0.01f);
by = (0.299f * b[0] + 0.587f * b[1] + 0.114f * b[2] + 0.01f);
}
return ay < by;
// sort on alpha*luma
});
for (
int k = 0; k < nb_entries; k++) {
if (palette[k] == 0)
break;
lookup[pixel_hash(palette[k])] = pcolors++;
}
}
size_t num_groups_x = (width + 255) / 256;
size_t num_groups_y = (height + 255) / 256;
size_t num_dc_groups_x = (width + 2047) / 2048;
size_t num_dc_groups_y = (height + 2047) / 2048;
uint64_t raw_counts[4][kNumRawSymbols] = {};
uint64_t lz77_counts[4][kNumLZ77] = {};
bool onegroup = num_groups_x == 1 && num_groups_y == 1;
auto sample_rows = [&](size_t xg, size_t yg, size_t num_rows) {
size_t y0 = yg * 256;
size_t x0 = xg * 256;
size_t ys = std::min<size_t>(height - y0, 256);
size_t xs = std::min<size_t>(width - x0, 256);
size_t stride;
const void* buffer =
input.get_color_channel_data_at(input.opaque, x0, y0, xs, ys, &stride);
auto rgba =
reinterpret_cast<
const unsigned char*>(buffer);
int y_begin_group =
std::max<ssize_t>(
0,
static_cast<ssize_t>(ys) -
static_cast<ssize_t>(num_rows)) /
2;
int y_count = std::min<
int>(num_rows, ys - y_begin_group);
int x_max = xs / kChunkSize * kChunkSize;
CollectSamples(rgba, 0, y_begin_group, x_max, stride, y_count, raw_counts,
lz77_counts, onegroup, !collided, bitdepth, nb_chans,
big_endian, lookup.data());
input.release_buffer(input.opaque, buffer);
};
// TODO(veluca): that `64` is an arbitrary constant, meant to correspond to
// the point where the number of processed rows is large enough that loading
// the entire image is cost-effective.
if (oneshot || effort >= 64) {
for (size_t g = 0; g < num_groups_y * num_groups_x; g++) {
size_t xg = g % num_groups_x;
size_t yg = g / num_groups_x;
size_t y0 = yg * 256;
size_t ys = std::min<size_t>(height - y0, 256);
size_t num_rows = 2 * effort * ys / 256;
sample_rows(xg, yg, num_rows);
}
}
else {
// sample the middle (effort * 2 * num_groups) rows of the center group
// (possibly all of them).
sample_rows((num_groups_x - 1) / 2, (num_groups_y - 1) / 2,
2 * effort * num_groups_x * num_groups_y);
}
// TODO(veluca): can probably improve this and make it bitdepth-dependent.
uint64_t base_raw_counts[kNumRawSymbols] = {
3843, 852, 1270, 1214, 1014, 727, 481, 300, 159, 51,
5, 1, 1, 1, 1, 1, 1, 1, 1};
bool doing_ycocg = nb_chans > 2 && collided;
bool large_palette = !collided || pcolors >= 256;
for (size_t i = bitdepth.NumSymbols(doing_ycocg || large_palette);
i < kNumRawSymbols; i++) {
base_raw_counts[i] = 0;
}
for (size_t c = 0; c < 4; c++) {
for (size_t i = 0; i < kNumRawSymbols; i++) {
raw_counts[c][i] = (raw_counts[c][i] << 8) + base_raw_counts[i];
}
}
if (!collided) {
unsigned token, nbits, bits;
EncodeHybridUint000(PackSigned(pcolors - 1), &token, &nbits, &bits);
// ensure all palette indices can actually be encoded
for (size_t i = 0; i < token + 1; i++)
raw_counts[0][i] = std::max<uint64_t>(raw_counts[0][i], 1);
// these tokens are only used for the palette itself so they can get a bad
// code
for (size_t i = token + 1; i < 10; i++) raw_counts[0][i] = 1;
}
uint64_t base_lz77_counts[kNumLZ77] = {
29, 27, 25, 23, 21, 21, 19, 18, 21, 17, 16, 15, 15, 14,
13, 13, 137, 98, 61, 34, 1, 1, 1, 1, 1, 1, 1, 1,
};
for (size_t c = 0; c < 4; c++) {
for (size_t i = 0; i < kNumLZ77; i++) {
lz77_counts[c][i] = (lz77_counts[c][i] << 8) + base_lz77_counts[i];
}
}
JxlFastLosslessFrameState* frame_state =
new JxlFastLosslessFrameState();
for (size_t i = 0; i < 4; i++) {
frame_state->hcode[i] = PrefixCode(bitdepth, raw_counts[i], lz77_counts[i]);
}
size_t num_dc_groups = num_dc_groups_x * num_dc_groups_y;
size_t num_ac_groups = num_groups_x * num_groups_y;
size_t num_groups = onegroup ? 1 : (2 + num_dc_groups + num_ac_groups);
frame_state->input = input;
frame_state->width = width;
frame_state->height = height;
frame_state->num_groups_x = num_groups_x;
frame_state->num_groups_y = num_groups_y;
frame_state->num_dc_groups_x = num_dc_groups_x;
frame_state->num_dc_groups_y = num_dc_groups_y;
frame_state->nb_chans = nb_chans;
frame_state->bitdepth = bitdepth.bitdepth;
frame_state->big_endian = big_endian;
frame_state->effort = effort;
frame_state->collided = collided;
frame_state->lookup = lookup;
frame_state->group_data = std::vector<std::array<BitWriter, 4>>(num_groups);
frame_state->group_sizes.resize(num_groups);
if (collided) {
PrepareDCGlobal(onegroup, width, height, nb_chans, frame_state->hcode,
&frame_state->group_data[0][0]);
}
else {
PrepareDCGlobalPalette(onegroup, width, height, nb_chans,
frame_state->hcode, palette, pcolors,
&frame_state->group_data[0][0]);
}
frame_state->group_sizes[0] = SectionSize(frame_state->group_data[0]);
if (!onegroup) {
ComputeAcGroupDataOffset(frame_state->group_sizes[0], num_dc_groups,
num_ac_groups, frame_state->min_dc_global_size,
frame_state->ac_group_data_offset);
}
return frame_state;
}
template <
typename BitDepth>
jxl::Status LLProcess(JxlFastLosslessFrameState* frame_state,
bool is_last,
BitDepth bitdepth,
void* runner_opaque,
FJxlParallelRunner runner,
JxlEncoderOutputProcessorWrapper* output_processor) {
#if !FJXL_STANDALONE
if (frame_state->process_done) {
JxlFastLosslessPrepareHeader(frame_state,
/*add_image_header=*/0, is_last);
if (output_processor) {
JXL_RETURN_IF_ERROR(
JxlFastLosslessOutputFrame(frame_state, output_processor));
}
return true;
}
#endif
// The maximum number of groups that we process concurrently here.
// TODO(szabadka) Use the number of threads or some outside parameter for the
// maximum memory usage instead.
constexpr size_t kMaxLocalGroups = 16;
bool onegroup = frame_state->group_sizes.size() == 1;
bool streaming = !onegroup && output_processor;
size_t total_groups = frame_state->num_groups_x * frame_state->num_groups_y;
size_t max_groups = streaming ? kMaxLocalGroups : total_groups;
#if !FJXL_STANDALONE
size_t start_pos = 0;
if (streaming) {
start_pos = output_processor->CurrentPosition();
JXL_RETURN_IF_ERROR(
output_processor->Seek(start_pos + frame_state->ac_group_data_offset));
}
#endif
for (size_t offset = 0; offset < total_groups; offset += max_groups) {
size_t num_groups = std::min(max_groups, total_groups - offset);
JxlFastLosslessFrameState local_frame_state;
if (streaming) {
local_frame_state.group_data =
std::vector<std::array<BitWriter, 4>>(num_groups);
}
auto run_one = [&](size_t i) {
size_t g = offset + i;
size_t xg = g % frame_state->num_groups_x;
size_t yg = g / frame_state->num_groups_x;
size_t num_dc_groups =
frame_state->num_dc_groups_x * frame_state->num_dc_groups_y;
size_t group_id = onegroup ? 0 : (2 + num_dc_groups + g);
size_t xs = std::min<size_t>(frame_state->width - xg * 256, 256);
size_t ys = std::min<size_t>(frame_state->height - yg * 256, 256);
size_t x0 = xg * 256;
size_t y0 = yg * 256;
size_t stride;
JxlChunkedFrameInputSource input = frame_state->input;
const void* buffer = input.get_color_channel_data_at(input.opaque, x0, y0,
xs, ys, &stride);
const unsigned char* rgba =
reinterpret_cast<
const unsigned char*>(buffer);
auto& gd = streaming ? local_frame_state.group_data[i]
: frame_state->group_data[group_id];
if (frame_state->collided) {
WriteACSection(rgba, 0, 0, xs, ys, stride, onegroup, bitdepth,
frame_state->nb_chans, frame_state->big_endian,
frame_state->hcode, gd);
}
else {
WriteACSectionPalette(rgba, 0, 0, xs, ys, stride, onegroup,
frame_state->hcode, frame_state->lookup.data(),
frame_state->nb_chans, gd[0]);
}
frame_state->group_sizes[group_id] = SectionSize(gd);
input.release_buffer(input.opaque, buffer);
};
runner(
runner_opaque, &run_one,
+[](
void* r, size_t i) {
(*
reinterpret_cast<decltype(&run_one)>(r))(i);
},
num_groups);
#if !FJXL_STANDALONE
if (streaming) {
local_frame_state.nb_chans = frame_state->nb_chans;
local_frame_state.current_bit_writer = 1;
JXL_RETURN_IF_ERROR(
JxlFastLosslessOutputFrame(&local_frame_state, output_processor));
}
#endif
}
#if !FJXL_STANDALONE
if (streaming) {
size_t end_pos = output_processor->CurrentPosition();
JXL_RETURN_IF_ERROR(output_processor->Seek(start_pos));
frame_state->group_data.resize(1);
bool have_alpha = frame_state->nb_chans == 2 || frame_state->nb_chans == 4;
size_t padding = ComputeDcGlobalPadding(
frame_state->group_sizes, frame_state->ac_group_data_offset,
frame_state->min_dc_global_size, have_alpha, is_last);
for (size_t i = 0; i < padding; ++i) {
frame_state->group_data[0][0].Write(8, 0);
}
frame_state->group_sizes[0] += padding;
JxlFastLosslessPrepareHeader(frame_state,
/*add_image_header=*/0, is_last);
assert(frame_state->ac_group_data_offset ==
JxlFastLosslessOutputSize(frame_state));
JXL_RETURN_IF_ERROR(
JxlFastLosslessOutputHeaders(frame_state, output_processor));
JXL_RETURN_IF_ERROR(output_processor->Seek(end_pos));
}
else if (output_processor) {
assert(onegroup);
JxlFastLosslessPrepareHeader(frame_state,
/*add_image_header=*/0, is_last);
if (output_processor) {
JXL_RETURN_IF_ERROR(
JxlFastLosslessOutputFrame(frame_state, output_processor));
}
}
frame_state->process_done =
true;
#endif
return true;
}
JxlFastLosslessFrameState* JxlFastLosslessPrepareImpl(
JxlChunkedFrameInputSource input, size_t width, size_t height,
size_t nb_chans, size_t bitdepth,
bool big_endian,
int effort,
int oneshot) {
assert(bitdepth > 0);
assert(nb_chans <= 4);
assert(nb_chans != 0);
if (bitdepth <= 8) {
return LLPrepare(input, width, height, UpTo8Bits(bitdepth), nb_chans,
big_endian, effort, oneshot);
}
if (bitdepth <= 13) {
return LLPrepare(input, width, height, From9To13Bits(bitdepth), nb_chans,
big_endian, effort, oneshot);
}
if (bitdepth == 14) {
return LLPrepare(input, width, height, Exactly14Bits(bitdepth), nb_chans,
big_endian, effort, oneshot);
}
return LLPrepare(input, width, height, MoreThan14Bits(bitdepth), nb_chans,
big_endian, effort, oneshot);
}
jxl::Status JxlFastLosslessProcessFrameImpl(
JxlFastLosslessFrameState* frame_state,
bool is_last,
void* runner_opaque,
FJxlParallelRunner runner,
JxlEncoderOutputProcessorWrapper* output_processor) {
const size_t bitdepth = frame_state->bitdepth;
if (bitdepth <= 8) {
JXL_RETURN_IF_ERROR(LLProcess(frame_state, is_last, UpTo8Bits(bitdepth),
runner_opaque, runner, output_processor));
}
else if (bitdepth <= 13) {
JXL_RETURN_IF_ERROR(LLProcess(frame_state, is_last, From9To13Bits(bitdepth),
runner_opaque, runner, output_processor));
}
else if (bitdepth == 14) {
JXL_RETURN_IF_ERROR(LLProcess(frame_state, is_last, Exactly14Bits(bitdepth),
runner_opaque, runner, output_processor));
}
else {
JXL_RETURN_IF_ERROR(LLProcess(frame_state, is_last,
MoreThan14Bits(bitdepth), runner_opaque,
runner, output_processor));
}
return true;
}
}
// namespace
#endif // FJXL_SELF_INCLUDE
#ifndef FJXL_SELF_INCLUDE
#define FJXL_SELF_INCLUDE
// If we have NEON enabled, it is the default target.
#if FJXL_ENABLE_NEON
namespace default_implementation {
#define FJXL_NEON
#include "lib/jxl/enc_fast_lossless.cc"
#undef FJXL_NEON
}
// namespace default_implementation
#else // FJXL_ENABLE_NEON
namespace default_implementation {
#include "lib/jxl/enc_fast_lossless.cc" // NOLINT
}
#if FJXL_ENABLE_AVX2
#ifdef __clang__
#pragma clang attribute push(__attribute__((target(
"avx,avx2"))), \
apply_to = function)
// Causes spurious warnings on clang5.
#pragma clang diagnostic push
#pragma clang diagnostic ignored
"-Wmissing-braces"
#elif defined(__GNUC__)
#pragma GCC push_options
// Seems to cause spurious errors on GCC8.
#pragma GCC diagnostic ignored
"-Wpsabi"
#pragma GCC target
"avx,avx2"
#endif
namespace AVX2 {
#define FJXL_AVX2
#include "lib/jxl/enc_fast_lossless.cc" // NOLINT
#undef FJXL_AVX2
}
// namespace AVX2
#ifdef __clang__
#pragma clang attribute pop
#pragma clang diagnostic pop
#elif defined(__GNUC__)
#pragma GCC pop_options
#endif
#endif // FJXL_ENABLE_AVX2
#if FJXL_ENABLE_AVX512
#ifdef __clang__
#pragma clang attribute push( \
__attribute__((target(
"avx512cd,avx512bw,avx512vl,avx512f,avx512vbmi"))), \
apply_to = function)
#elif defined(__GNUC__)
#pragma GCC push_options
#pragma GCC target
"avx512cd,avx512bw,avx512vl,avx512f,avx512vbmi"
#endif
namespace AVX512 {
#define FJXL_AVX512
#include "lib/jxl/enc_fast_lossless.cc"
#undef FJXL_AVX512
}
// namespace AVX512
#ifdef __clang__
#pragma clang attribute pop
#elif defined(__GNUC__)
#pragma GCC pop_options
#endif
#endif // FJXL_ENABLE_AVX512
#endif
extern "C" {
#if FJXL_STANDALONE
class FJxlFrameInput {
public:
FJxlFrameInput(
const unsigned char* rgba, size_t row_stride, size_t nb_chans,
size_t bitdepth)
: rgba_(rgba),
row_stride_(row_stride),
bytes_per_pixel_(bitdepth <= 8 ? nb_chans : 2 * nb_chans) {}
JxlChunkedFrameInputSource GetInputSource() {
return JxlChunkedFrameInputSource{
this, GetDataAt,
[](
void*,
const void*) {}};
}
private:
static const void* GetDataAt(
void* opaque, size_t xpos, size_t ypos,
size_t xsize, size_t ysize, size_t* row_offset) {
FJxlFrameInput* self =
static_cast<FJxlFrameInput*>(opaque);
*row_offset = self->row_stride_;
return self->rgba_ + ypos * (*row_offset) + xpos * self->bytes_per_pixel_;
}
const uint8_t* rgba_;
size_t row_stride_;
size_t bytes_per_pixel_;
};
size_t JxlFastLosslessEncode(
const unsigned char* rgba, size_t width,
size_t row_stride, size_t height, size_t nb_chans,
size_t bitdepth,
bool big_endian,
int effort,
unsigned char** output,
void* runner_opaque,
FJxlParallelRunner runner) {
FJxlFrameInput input(rgba, row_stride, nb_chans, bitdepth);
auto frame_state = JxlFastLosslessPrepareFrame(
input.GetInputSource(), width, height, nb_chans, bitdepth, big_endian,
effort,
/*oneshot=*/true);
if (!JxlFastLosslessProcessFrame(frame_state,
/*is_last=*/true, runner_opaque,
runner, nullptr)) {
return 0;
}
JxlFastLosslessPrepareHeader(frame_state,
/*add_image_header=*/1,
/*is_last=*/1);
size_t output_size = JxlFastLosslessMaxRequiredOutput(frame_state);
*output = (
unsigned char*)malloc(output_size);
size_t written = 0;
size_t total = 0;
while ((written = JxlFastLosslessWriteOutput(frame_state, *output + total,
output_size - total)) != 0) {
total += written;
}
JxlFastLosslessFreeFrameState(frame_state);
return total;
}
#endif
JxlFastLosslessFrameState* JxlFastLosslessPrepareFrame(
JxlChunkedFrameInputSource input, size_t width, size_t height,
size_t nb_chans, size_t bitdepth,
bool big_endian,
int effort,
int oneshot) {
#if FJXL_ENABLE_AVX512
if (HasCpuFeature(CpuFeature::kAVX512CD) &&
HasCpuFeature(CpuFeature::kVBMI) &&
HasCpuFeature(CpuFeature::kAVX512BW) &&
HasCpuFeature(CpuFeature::kAVX512F) &&
HasCpuFeature(CpuFeature::kAVX512VL)) {
return AVX512::JxlFastLosslessPrepareImpl(
input, width, height, nb_chans, bitdepth, big_endian, effort, oneshot);
}
#endif
#if FJXL_ENABLE_AVX2
if (HasCpuFeature(CpuFeature::kAVX2)) {
return AVX2::JxlFastLosslessPrepareImpl(
input, width, height, nb_chans, bitdepth, big_endian, effort, oneshot);
}
#endif
return default_implementation::JxlFastLosslessPrepareImpl(
input, width, height, nb_chans, bitdepth, big_endian, effort, oneshot);
}
bool JxlFastLosslessProcessFrame(
JxlFastLosslessFrameState* frame_state,
bool is_last,
void* runner_opaque,
FJxlParallelRunner runner,
JxlEncoderOutputProcessorWrapper* output_processor) {
auto trivial_runner =
+[](
void*,
void* opaque,
void fun(
void*, size_t), size_t count) {
for (size_t i = 0; i < count; i++) {
fun(opaque, i);
}
};
if (runner == nullptr) {
runner = trivial_runner;
}
#if FJXL_ENABLE_AVX512
if (HasCpuFeature(CpuFeature::kAVX512CD) &&
HasCpuFeature(CpuFeature::kVBMI) &&
HasCpuFeature(CpuFeature::kAVX512BW) &&
HasCpuFeature(CpuFeature::kAVX512F) &&
HasCpuFeature(CpuFeature::kAVX512VL)) {
JXL_RETURN_IF_ERROR(AVX512::JxlFastLosslessProcessFrameImpl(
frame_state, is_last, runner_opaque, runner, output_processor));
return true;
}
#endif
#if FJXL_ENABLE_AVX2
if (HasCpuFeature(CpuFeature::kAVX2)) {
JXL_RETURN_IF_ERROR(AVX2::JxlFastLosslessProcessFrameImpl(
frame_state, is_last, runner_opaque, runner, output_processor));
return true;
}
#endif
JXL_RETURN_IF_ERROR(default_implementation::JxlFastLosslessProcessFrameImpl(
frame_state, is_last, runner_opaque, runner, output_processor));
return true;
}
}
// extern "C"
#if !FJXL_STANDALONE
bool JxlFastLosslessOutputFrame(
JxlFastLosslessFrameState* frame_state,
JxlEncoderOutputProcessorWrapper* output_processor) {
size_t fl_size = JxlFastLosslessOutputSize(frame_state);
size_t written = 0;
while (written < fl_size) {
JXL_ASSIGN_OR_RETURN(
auto buffer,
output_processor->GetBuffer(32, fl_size - written));
size_t n =
JxlFastLosslessWriteOutput(frame_state, buffer.data(), buffer.size());
if (n == 0)
break;
JXL_RETURN_IF_ERROR(buffer.advance(n));
written += n;
};
return true;
}
#endif
#endif // FJXL_SELF_INCLUDE
