/*
* Copyright (c) 2020, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <arm_neon.h>
#include <assert.h>
#include "aom_dsp/arm/aom_convolve8_neon.h"
#include "aom_dsp/arm/mem_neon.h"
#include "aom_dsp/arm/transpose_neon.h"
#include "config/aom_dsp_rtcd.h"
static inline void scaled_convolve_horiz_neon(
const uint8_t *src,
const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride,
const InterpKernel *
const x_filter,
const int x0_q4,
const int x_step_q4,
int w,
int h) {
DECLARE_ALIGNED(16, uint8_t, temp[8 * 8]);
if (w == 4) {
do {
int x_q4 = x0_q4;
// Process a 4x4 tile.
for (
int r = 0; r < 4; ++r) {
const uint8_t *s = &src[x_q4 >> SUBPEL_BITS];
if (x_q4 & SUBPEL_MASK) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int16x8_t filter =
vshrq_n_s16(vld1q_s16(x_filter[x_q4 & SUBPEL_MASK]), 1);
uint8x8_t t0, t1, t2, t3;
load_u8_8x4(s, src_stride, &t0, &t1, &t2, &t3);
transpose_elems_inplace_u8_8x4(&t0, &t1, &t2, &t3);
int16x4_t s0 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t0)));
int16x4_t s1 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t1)));
int16x4_t s2 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t2)));
int16x4_t s3 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t3)));
int16x4_t s4 = vget_high_s16(vreinterpretq_s16_u16(vmovl_u8(t0)));
int16x4_t s5 = vget_high_s16(vreinterpretq_s16_u16(vmovl_u8(t1)));
int16x4_t s6 = vget_high_s16(vreinterpretq_s16_u16(vmovl_u8(t2)));
int16x4_t s7 = vget_high_s16(vreinterpretq_s16_u16(vmovl_u8(t3)));
int16x4_t dd0 = convolve8_4(s0, s1, s2, s3, s4, s5, s6, s7, filter);
// We halved the filter values so -1 from right shift.
uint8x8_t d0 =
vqrshrun_n_s16(vcombine_s16(dd0, vdup_n_s16(0)), FILTER_BITS - 1);
store_u8_4x1(&temp[4 * r], d0);
}
else {
// Memcpy for non-subpel locations.
s += SUBPEL_TAPS / 2 - 1;
for (
int c = 0; c < 4; ++c) {
temp[r * 4 + c] = s[c * src_stride];
}
}
x_q4 += x_step_q4;
}
// Transpose the 4x4 result tile and store.
uint8x8_t d01 = vld1_u8(temp + 0);
uint8x8_t d23 = vld1_u8(temp + 8);
transpose_elems_inplace_u8_4x4(&d01, &d23);
store_u8x4_strided_x2(dst + 0 * dst_stride, 2 * dst_stride, d01);
store_u8x4_strided_x2(dst + 1 * dst_stride, 2 * dst_stride, d23);
src += 4 * src_stride;
dst += 4 * dst_stride;
h -= 4;
}
while (h > 0);
return;
}
// w >= 8
do {
int x_q4 = x0_q4;
uint8_t *d = dst;
int width = w;
do {
// Process an 8x8 tile.
for (
int r = 0; r < 8; ++r) {
const uint8_t *s = &src[x_q4 >> SUBPEL_BITS];
if (x_q4 & SUBPEL_MASK) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int16x8_t filter =
vshrq_n_s16(vld1q_s16(x_filter[x_q4 & SUBPEL_MASK]), 1);
uint8x8_t t0, t1, t2, t3, t4, t5, t6, t7;
load_u8_8x8(s, src_stride, &t0, &t1, &t2, &t3, &t4, &t5, &t6, &t7);
transpose_elems_inplace_u8_8x8(&t0, &t1, &t2, &t3, &t4, &t5, &t6,
&t7);
int16x8_t s0 = vreinterpretq_s16_u16(vmovl_u8(t0));
int16x8_t s1 = vreinterpretq_s16_u16(vmovl_u8(t1));
int16x8_t s2 = vreinterpretq_s16_u16(vmovl_u8(t2));
int16x8_t s3 = vreinterpretq_s16_u16(vmovl_u8(t3));
int16x8_t s4 = vreinterpretq_s16_u16(vmovl_u8(t4));
int16x8_t s5 = vreinterpretq_s16_u16(vmovl_u8(t5));
int16x8_t s6 = vreinterpretq_s16_u16(vmovl_u8(t6));
int16x8_t s7 = vreinterpretq_s16_u16(vmovl_u8(t7));
uint8x8_t d0 = convolve8_8(s0, s1, s2, s3, s4, s5, s6, s7, filter);
vst1_u8(&temp[r * 8], d0);
}
else {
// Memcpy for non-subpel locations.
s += SUBPEL_TAPS / 2 - 1;
for (
int c = 0; c < 8; ++c) {
temp[r * 8 + c] = s[c * src_stride];
}
}
x_q4 += x_step_q4;
}
// Transpose the 8x8 result tile and store.
uint8x8_t d0, d1, d2, d3, d4, d5, d6, d7;
load_u8_8x8(temp, 8, &d0, &d1, &d2, &d3, &d4, &d5, &d6, &d7);
transpose_elems_inplace_u8_8x8(&d0, &d1, &d2, &d3, &d4, &d5, &d6, &d7);
store_u8_8x8(d, dst_stride, d0, d1, d2, d3, d4, d5, d6, d7);
d += 8;
width -= 8;
}
while (width != 0);
src += 8 * src_stride;
dst += 8 * dst_stride;
h -= 8;
}
while (h > 0);
}
static inline void scaled_convolve_vert_neon(
const uint8_t *src,
const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride,
const InterpKernel *
const y_filter,
const int y0_q4,
const int y_step_q4,
int w,
int h) {
int y_q4 = y0_q4;
if (w == 4) {
do {
const uint8_t *s = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
if (y_q4 & SUBPEL_MASK) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int16x8_t filter =
vshrq_n_s16(vld1q_s16(y_filter[y_q4 & SUBPEL_MASK]), 1);
uint8x8_t t0, t1, t2, t3, t4, t5, t6, t7;
load_u8_8x8(s, src_stride, &t0, &t1, &t2, &t3, &t4, &t5, &t6, &t7);
int16x4_t s0 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t0)));
int16x4_t s1 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t1)));
int16x4_t s2 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t2)));
int16x4_t s3 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t3)));
int16x4_t s4 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t4)));
int16x4_t s5 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t5)));
int16x4_t s6 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t6)));
int16x4_t s7 = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(t7)));
int16x4_t dd0 = convolve8_4(s0, s1, s2, s3, s4, s5, s6, s7, filter);
// We halved the filter values so -1 from right shift.
uint8x8_t d0 =
vqrshrun_n_s16(vcombine_s16(dd0, vdup_n_s16(0)), FILTER_BITS - 1);
store_u8_4x1(dst, d0);
}
else {
// Memcpy for non-subpel locations.
memcpy(dst, &s[(SUBPEL_TAPS / 2 - 1) * src_stride], 4);
}
y_q4 += y_step_q4;
dst += dst_stride;
}
while (--h != 0);
return;
}
if (w == 8) {
do {
const uint8_t *s = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
if (y_q4 & SUBPEL_MASK) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int16x8_t filter =
vshrq_n_s16(vld1q_s16(y_filter[y_q4 & SUBPEL_MASK]), 1);
uint8x8_t t0, t1, t2, t3, t4, t5, t6, t7;
load_u8_8x8(s, src_stride, &t0, &t1, &t2, &t3, &t4, &t5, &t6, &t7);
int16x8_t s0 = vreinterpretq_s16_u16(vmovl_u8(t0));
int16x8_t s1 = vreinterpretq_s16_u16(vmovl_u8(t1));
int16x8_t s2 = vreinterpretq_s16_u16(vmovl_u8(t2));
int16x8_t s3 = vreinterpretq_s16_u16(vmovl_u8(t3));
int16x8_t s4 = vreinterpretq_s16_u16(vmovl_u8(t4));
int16x8_t s5 = vreinterpretq_s16_u16(vmovl_u8(t5));
int16x8_t s6 = vreinterpretq_s16_u16(vmovl_u8(t6));
int16x8_t s7 = vreinterpretq_s16_u16(vmovl_u8(t7));
uint8x8_t d0 = convolve8_8(s0, s1, s2, s3, s4, s5, s6, s7, filter);
vst1_u8(dst, d0);
}
else {
// Memcpy for non-subpel locations.
memcpy(dst, &s[(SUBPEL_TAPS / 2 - 1) * src_stride], 8);
}
y_q4 += y_step_q4;
dst += dst_stride;
}
while (--h != 0);
return;
}
// w >= 16
do {
const uint8_t *s = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
uint8_t *d = dst;
int width = w;
if (y_q4 & SUBPEL_MASK) {
do {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int16x8_t filter =
vshrq_n_s16(vld1q_s16(y_filter[y_q4 & SUBPEL_MASK]), 1);
uint8x16_t t0, t1, t2, t3, t4, t5, t6, t7;
load_u8_16x8(s, src_stride, &t0, &t1, &t2, &t3, &t4, &t5, &t6, &t7);
int16x8_t s0[2], s1[2], s2[2], s3[2], s4[2], s5[2], s6[2], s7[2];
s0[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t0)));
s1[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t1)));
s2[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t2)));
s3[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t3)));
s4[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t4)));
s5[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t5)));
s6[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t6)));
s7[0] = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(t7)));
s0[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t0)));
s1[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t1)));
s2[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t2)));
s3[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t3)));
s4[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t4)));
s5[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t5)));
s6[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t6)));
s7[1] = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(t7)));
uint8x8_t d0 = convolve8_8(s0[0], s1[0], s2[0], s3[0], s4[0], s5[0],
s6[0], s7[0], filter);
uint8x8_t d1 = convolve8_8(s0[1], s1[1], s2[1], s3[1], s4[1], s5[1],
s6[1], s7[1], filter);
vst1q_u8(d, vcombine_u8(d0, d1));
s += 16;
d += 16;
width -= 16;
}
while (width != 0);
}
else {
// Memcpy for non-subpel locations.
s += (SUBPEL_TAPS / 2 - 1) * src_stride;
do {
uint8x16_t s0 = vld1q_u8(s);
vst1q_u8(d, s0);
s += 16;
d += 16;
width -= 16;
}
while (width != 0);
}
y_q4 += y_step_q4;
dst += dst_stride;
}
while (--h != 0);
}
void aom_scaled_2d_neon(
const uint8_t *src, ptrdiff_t src_stride, uint8_t *dst,
ptrdiff_t dst_stride,
const InterpKernel *filter,
int x0_q4,
int x_step_q4,
int y0_q4,
int y_step_q4,
int w,
int h) {
// Fixed size intermediate buffer, im_block, places limits on parameters.
// 2d filtering proceeds in 2 steps:
// (1) Interpolate horizontally into an intermediate buffer, temp.
// (2) Interpolate temp vertically to derive the sub-pixel result.
// Deriving the maximum number of rows in the im_block buffer (135):
// --Smallest scaling factor is x1/2 ==> y_step_q4 = 32 (Normative).
// --Largest block size is 64x64 pixels.
// --64 rows in the downscaled frame span a distance of (64 - 1) * 32 in the
// original frame (in 1/16th pixel units).
// --Must round-up because block may be located at sub-pixel position.
// --Require an additional SUBPEL_TAPS rows for the 8-tap filter tails.
// --((64 - 1) * 32 + 15) >> 4 + 8 = 135.
// --Require an additional 8 rows for the horiz_w8 transpose tail.
// When calling in frame scaling function, the smallest scaling factor is x1/4
// ==> y_step_q4 = 64. Since w and h are at most 16, the temp buffer is still
// big enough.
DECLARE_ALIGNED(16, uint8_t, im_block[(135 + 8) * 64]);
const int im_height =
(((h - 1) * y_step_q4 + y0_q4) >> SUBPEL_BITS) + SUBPEL_TAPS;
const ptrdiff_t im_stride = 64;
assert(w <= 64);
assert(h <= 64);
assert(y_step_q4 <= 32 || (y_step_q4 <= 64 && h <= 32));
assert(x_step_q4 <= 64);
// Account for needing SUBPEL_TAPS / 2 - 1 lines prior and SUBPEL_TAPS / 2
// lines post both horizontally and vertically.
const ptrdiff_t horiz_offset = SUBPEL_TAPS / 2 - 1;
const ptrdiff_t vert_offset = (SUBPEL_TAPS / 2 - 1) * src_stride;
scaled_convolve_horiz_neon(src - horiz_offset - vert_offset, src_stride,
im_block, im_stride, filter, x0_q4, x_step_q4, w,
im_height);
scaled_convolve_vert_neon(im_block, im_stride, dst, dst_stride, filter, y0_q4,
y_step_q4, w, h);
}
