Quelle  HLSStreams.cpp   Sprache: C

/*
 * HLSStreams.cpp
 *****************************************************************************
 * Copyright (C) 2015 - VideoLAN and VLC authors
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "HLSStreams.hpp"
#include "../adaptive/tools/Conversions.hpp"
#include <vlc_demux.h>
#include <vlc_meta.h>

#include <limits>

#include "../mpeg/timestamps.h"

extern "C"
{
    #include "../../meta_engine/ID3Tag.h"
    #include "../../meta_engine/ID3Meta.h"
}

using namespace hls;

HLSStream::HLSStream(demux_t *demux)
    : AbstractStream(demux)
{
    p_meta = vlc_meta_New();
    b_meta_updated = false;
}

HLSStream::~HLSStream()
{
    if(p_meta)
        vlc_meta_Delete(p_meta);
}

void HLSStream::setMetadataTimeOffset(vlc_tick_t i_offset)
{
    if(i_offset >= 0)
        fakeEsOut()->setAssociatedTimestamp(i_offset);
    else
        fakeEsOut()->setAssociatedTimestamp(-1);
}

void HLSStream::setMetadataTimeMapping(vlc_tick_t mpegts, vlc_tick_t muxed)
{
    fakeEsOut()->setAssociatedTimestamp(mpegts, muxed);
}

void HLSStream::trackerEvent(const TrackerEvent &e)
{
    AbstractStream::trackerEvent(e);

    if(e.getType() == TrackerEvent::Type::FormatChange)
    {
        if(format == StreamFormat::Type::WebVTT)
        {
            contiguous = false;
        }
        else if(format == StreamFormat::Type::Unknown)
        {
            const Role r = segmentTracker->getStreamRole();
            contiguous = !(r == Role::Value::Caption || r == Role::Value::Subtitle);
        }
        else contiguous = true;
    }
}

int HLSStream::ParseID3PrivTag(const uint8_t *p_payload, size_t i_payload)
{
    if(i_payload == 53 &&
       !memcmp( p_payload, "com.apple.streaming.transportStreamTimestamp", 45))
    {
        setMetadataTimeOffset(FROM_SCALE_NZ(GetQWBE(&p_payload[45])));
    }
    return VLC_SUCCESS;
}

int HLSStream::ParseID3Tag(uint32_t i_tag, const uint8_t *p_payload, size_t i_payload)
{
    if(i_tag == VLC_FOURCC('P','R','I','V'))
        (void) ParseID3PrivTag(p_payload, i_payload);
    else
        (void) ID3HandleTag(p_payload, i_payload, i_tag, p_meta, &b_meta_updated);
    return VLC_SUCCESS;
}

int HLSStream::ID3TAG_Parse_Handler(uint32_t i_tag, const uint8_t *p_payload, size_t i_payload, void *p_priv)
{
    HLSStream *hlsstream = static_cast<HLSStream *>(p_priv);
    return hlsstream->ParseID3Tag(i_tag, p_payload, i_payload);
}

block_t * HLSStream::checkBlock(block_t *p_block, bool b_first)
{
    if(b_first && p_block)
    {
        while(ID3TAG_IsTag(p_block->p_buffer, p_block->i_buffer, false))
        {
            size_t i_size = ID3TAG_Parse( p_block->p_buffer, p_block->i_buffer,
                                          ID3TAG_Parse_Handler, static_cast<void *>(this) );
            if(i_size >= p_block->i_buffer || i_size == 0)
                break;
            /* Skip ID3 for demuxer */
            p_block->p_buffer += i_size;
            p_block->i_buffer -= i_size;
        }
    }

    if(b_first && p_block && format == StreamFormat::Type::WebVTT && p_block->i_buffer > 7)
    {
        /* "WEBVTT\n"
           "X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:2147483647\n" */
        const char *p = (const char *) p_block->p_buffer;
        const char *end = p + p_block->i_buffer;
        p = strnstr(p + 7, "X-TIMESTAMP-MAP=", p_block->i_buffer - 7);
        if(p)
        {
            const char *eol = (const char *) memchr(p, '\n', end - p);
            if(eol)
            {
                uint64_t mpegts = std::numeric_limits<uint64_t>::max();
                vlc_tick_t local = std::numeric_limits<vlc_tick_t>::max();
                std::string str(p + 16, eol - p - 16);

                std::string::size_type pos = str.find("LOCAL:");
                if(pos != std::string::npos && str.length() - pos >= 12+6)
                    local = UTCTime("T" + str.substr(pos + 6, 12));

                pos = str.find("MPEGTS:");
                if(pos != std::string::npos && str.size() - pos > 7)
                {
                    pos += 7;
                    std::string::size_type tail = str.find_last_not_of("0123456789", pos);
                    mpegts = Integer<uint64_t>(str.substr(pos, (tail != std::string::npos) ? tail - pos : tail));
                }

                if(mpegts != std::numeric_limits<uint64_t>::max() &&
                   local != std::numeric_limits<vlc_tick_t>::max())
                {
                    setMetadataTimeMapping(VLC_TICK_0 + mpegts * 100/9, VLC_TICK_0 + local);
                }
            }
        }
    }

    if( b_meta_updated )
    {
        b_meta_updated = false;
        AbstractCommand *command = fakeEsOut()->commandsFactory()->createEsOutMetaCommand( fakeesout, -1, p_meta );
        if( command )
            fakeEsOut()->commandsQueue()->Schedule( command );
    }

    return p_block;
}

AbstractDemuxer *HLSStream::newDemux(vlc_object_t *p_obj, const StreamFormat &format,
                                     es_out_t *out, AbstractSourceStream *source) const
{
    AbstractDemuxer *ret = nullptr;
    switch(format)
    {
        case StreamFormat::Type::PackedAAC:
            ret = new Demuxer(p_obj, "aac", out, source); /* "es" demuxer cannot probe AAC, need to force */
            break;
        case StreamFormat::Type::PackedMP3: /* MPGA / MP3, needs "es" to probe: do not force */
        case StreamFormat::Type::PackedAC3: /* AC3 / E-AC3, needs "es" to probe: do not force */
            ret = new Demuxer(p_obj, "es", out, source);
            break;

        case StreamFormat::Type::MPEG2TS:
            ret = new Demuxer(p_obj, "ts", out, source);
            if(ret)
                ret->setBitstreamSwitchCompatible(false); /* HLS and unique PAT/PMT versions */
            break;

        case StreamFormat::Type::MP4:
            ret = AbstractStream::newDemux(p_obj, format, out, source);
            break;

        case StreamFormat::Type::Ogg:
            ret = new Demuxer(p_obj, "ogg", out, source);
            break;

        case StreamFormat::Type::WebVTT:
            ret = new Demuxer(p_obj, "webvttstream", out, source);
            if(ret)
                ret->setRestartsOnEachSegment(true);
            break;

        default:
        case StreamFormat::Type::Unknown:
        case StreamFormat::Type::Unsupported:
            break;
    }
    return ret;
}

AbstractStream * HLSStreamFactory::create(demux_t *realdemux, const StreamFormat &format,
                               SegmentTracker *tracker) const
{
    HLSStream *stream = new (std::nothrow) HLSStream(realdemux);
    if(stream && !stream->init(format, tracker))
    {
        delete stream;
        return nullptr;
    }
    return stream;
}