add documentation for the revno,h target

[gnash.git] / libmedia / FLVParser.cpp

// FLVParser.cpp:  Flash Video file parser, for Gnash.
//
//   Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
//


#include "FLVParser.h"
#include "log.h"
#include "utility.h"
#include "GnashException.h"
#include "IOChannel.h"
#include "SimpleBuffer.h"
#include "GnashAlgorithm.h"

#include <string>
#include <iosfwd>

// Define the following macro the have seek() operations printed
//#define GNASH_DEBUG_SEEK 1

namespace gnash {
namespace media {


const size_t FLVParser::paddingBytes;
const boost::uint16_t FLVParser::FLVAudioTag::flv_audio_rates [] = 
    { 5500, 11000, 22050, 44100 };

FLVParser::FLVParser(std::auto_ptr<IOChannel> lt)
        :
        MediaParser(lt),
        _lastParsedPosition(0),
        _nextPosToIndex(0),
        _nextAudioFrame(0),
        _nextVideoFrame(0),
        _audio(false),
        _video(false),
        _cuePoints(),
        _indexingCompleted(false)
{
        if (!parseHeader()) {
                throw MediaException("FLVParser couldn't parse header from input");
    }

        startParserThread();
}

FLVParser::~FLVParser()
{
        stopParserThread();
}


// would be called by main thread
bool
FLVParser::seek(boost::uint32_t& time)
{

        boost::mutex::scoped_lock streamLock(_streamMutex);
        // we might obtain this lock while the parser is pushing the last
        // encoded frame on the queue, or while it is waiting on the wakeup
        // condition

        // Setting _seekRequest to true will make the parser thread
        // take care of cleaning up the buffers before going on with
        // parsing, thus fixing the case in which streamLock was obtained
        // while the parser was pushing to queue
        _seekRequest = true;

        if ( _cuePoints.empty() )
        {
                log_debug("No known cue points yet, can't seek");
                return false;
        }

        CuePointsMap::iterator it = _cuePoints.lower_bound(time);
        if ( it == _cuePoints.end() )
        {
                log_debug("No cue points greater or equal requested time %d", time);
                return false;
        }

        long lowerBoundPosition = it->second;
        log_debug("Seek requested to time %d triggered seek to cue point at "
            "position %d and time %d", time, it->second, it->first);
        time = it->first;
        _lastParsedPosition=lowerBoundPosition; 
        _parsingComplete=false; // or NetStream will send the Play.Stop event...


        // Finally, clear the buffers.
        // The call will also wake the parse up if it was sleeping.
        // WARNING: a race condition might be pending here:
        // If we handled to do all the seek work in the *small*
        // time that the parser runs w/out mutex locked (ie:
        // after it unlocked the stream mutex and before it locked
        // the queue mutex), it will still push an old encoded frame
        // to the queue; if the pushed frame alone makes it block
        // again (bufferFull) we'll have a problem.
        // Note though, that a single frame can't reach a bufferFull
        // condition, as it takes at least two for anything != 0.
        //
        clearBuffers();

        return true;
}

// would be called by parser thread
bool
FLVParser::parseNextChunk()
{
        bool indexOnly = bufferFull(); // won't lock, but our caller locked...
        return parseNextTag(indexOnly);
}

// would be called by parser thread
void
FLVParser::indexAudioTag(const FLVTag& tag, boost::uint32_t thisTagPos)
{
        if ( _videoInfo.get()) {
                // if we have video we let that drive cue points
                return;
        }

        // we can theoretically seek anywhere, but
        // let's just keep 5 seconds of distance
        CuePointsMap::iterator it = _cuePoints.lower_bound(tag.timestamp);
        if ( it == _cuePoints.end() || it->first - tag.timestamp >= 5000)
        {
                //log_debug("Added cue point at timestamp %d and position %d "
        //"(audio frame)", tag.timestamp, thisTagPos);
                _cuePoints[tag.timestamp] = thisTagPos; 
        }
}

void
FLVParser::indexVideoTag(const FLVTag& tag, const FLVVideoTag& videotag, boost::uint32_t thisTagPos)
{
        if ( videotag.frametype != FLV_VIDEO_KEYFRAME ) {
                return;
        }

        //log_debug("Added cue point at timestamp %d and position %d "
    //"(key video frame)", tag.timestamp, thisTagPos);
        _cuePoints[tag.timestamp] = thisTagPos;
}


std::auto_ptr<EncodedAudioFrame>
FLVParser::parseAudioTag(const FLVTag& flvtag, const FLVAudioTag& audiotag, boost::uint32_t thisTagPos)
{
        std::auto_ptr<EncodedAudioFrame> frame;

        if ( ! _audio ) {
                log_error(_("Unexpected audio tag found at offset %d FLV stream "
                    "advertising no audio in header. We'll warn only once for "
                    "each FLV, expecting any further audio tag."), thisTagPos);
                _audio = true; // TOCHECK: is this safe ?
        }

        bool header = false;
        boost::uint32_t bodyLength = flvtag.body_size;

        if (audiotag.codec == AUDIO_CODEC_AAC) {
                boost::uint8_t packettype = _stream->read_byte();
                header = (packettype == 0);
                --bodyLength;
        }

        frame = readAudioFrame(bodyLength-1, flvtag.timestamp);
        if ( ! frame.get() ) {
                log_error("could not read audio frame?");
        }

        // If this is the first audioframe no info about the
        // audio format has been noted, so we do that now
        if (!_audioInfo.get()) {
                _audioInfo.reset(new AudioInfo(audiotag.codec, audiotag.samplerate,
                    audiotag.samplesize, audiotag.stereo, 0,
                    CODEC_TYPE_FLASH));

        if (header) {

            // The frame is 0-padded up to the end. It may be larger than
            // this if fewer bytes were read than requested, but it is
            // never smaller.
            const size_t bufSize = frame->dataSize + paddingBytes;

            boost::uint8_t* data = new boost::uint8_t[bufSize];

            std::copy(frame->data.get(), frame->data.get() + bufSize, data);

                        _audioInfo->extra.reset( 
                                new ExtraAudioInfoFlv(data, frame->dataSize)
                        );

                        // The FAAD decoder will reject us if we pass the header buffer.
                        // It will receive the header via the extra audio info anyway.
                        frame.reset();
                }
        }

        return frame;
}

std::auto_ptr<EncodedVideoFrame>
FLVParser::parseVideoTag(const FLVTag& flvtag, const FLVVideoTag& videotag, boost::uint32_t thisTagPos)
{
        if ( ! _video ) {
                log_error(_("Unexpected video tag found at offset %d of FLV stream "
                    "advertising no video in header. We'll warn only once per "
                    "FLV, expecting any further video tag."), thisTagPos);
                _video = true; // TOCHECK: is this safe ?
        }

        bool header = false;
        boost::uint32_t bodyLength = flvtag.body_size;

        switch(videotag.codec) {
                case VIDEO_CODEC_VP6:
                case VIDEO_CODEC_VP6A:
                {
                        _stream->read_byte();
                        --bodyLength;
                        break;
                }
                case VIDEO_CODEC_H264:
                {
                        boost::uint8_t packettype = _stream->read_byte();
                        IF_VERBOSE_PARSE( log_debug(_("AVC packet type: %d"),
                        (unsigned)packettype) );

                        header = (packettype == 0);

                        // 24-bits value for composition time offset ignored for now.
                        boost::uint8_t tmp[3];
                        _stream->read(tmp, 3);
        
                        bodyLength -= 4;
                        break;
                }
                default:
                        break;
        }

        std::auto_ptr<EncodedVideoFrame> frame = readVideoFrame(bodyLength-1,
            flvtag.timestamp);
        if ( ! frame.get() ) {
                log_error("could not read video frame?");
        }

        // If this is the first videoframe no info about the
        // video format has been noted, so we do that now
        if ( ! _videoInfo.get() ) {
                _videoInfo.reset(new VideoInfo(videotag.codec, 0, 0, 0, 0,
                    CODEC_TYPE_FLASH));

                if (header) {
            // The frame is 0-padded up to the end. It may be larger than
            // this if fewer bytes were read than requested, but it is
            // never smaller.
            const size_t bufSize = frame->dataSize() + paddingBytes;

            boost::uint8_t* data = new boost::uint8_t[bufSize];

            std::copy(frame->data(), frame->data() + bufSize, data);
                        _videoInfo->extra.reset( 
                                new ExtraVideoInfoFlv(data, frame->dataSize())
                        );

                        // Don't bother emitting the header buffer.
                        frame.reset();
                }
        }
        return frame;
}


// would be called by parser thread
bool
FLVParser::parseNextTag(bool index_only)
{
        // lock the stream while reading from it, so actionscript
        // won't mess with the parser on seek  or on getBytesLoaded
        boost::mutex::scoped_lock streamLock(_streamMutex);

        if ( index_only && _indexingCompleted ) return false; 
        if ( _parsingComplete ) return false;

        if ( _seekRequest )
        {
                clearBuffers();
                _seekRequest = false;
        }

        boost::uint64_t& position = index_only ? _nextPosToIndex : _lastParsedPosition;
        bool& completed = index_only ? _indexingCompleted : _parsingComplete;

        //log_debug("parseNextTag: _lastParsedPosition:%d, _nextPosToIndex:%d, index_only:%d", _lastParsedPosition, _nextPosToIndex, index_only);

        unsigned long thisTagPos = position;

        // Seek to next frame and skip the tag size 
        //log_debug("FLVParser::parseNextTag seeking to %d", thisTagPos+4);
        if (!_stream->seek(thisTagPos+4))
        {
                log_error("FLVParser::parseNextTag: can't seek to %d", thisTagPos+4);

                completed = true;
                return false;
        }
        //log_debug("FLVParser::parseNextTag seeked to %d", thisTagPos+4);

        // Read the tag info
        boost::uint8_t chunk[12];
        int actuallyRead = _stream->read(chunk, 12);
        if ( actuallyRead < 12 )
        {
                if ( actuallyRead )
                        log_error("FLVParser::parseNextTag: can't read tag info "
                    "(needed 12 bytes, only got %d)", actuallyRead);
                // else { assert(_stream->eof(); } ?

                completed = true;

        // update bytes loaded
        boost::mutex::scoped_lock lock(_bytesLoadedMutex);
                _bytesLoaded = _stream->tell(); 
                return false;
        }

        FLVTag flvtag(chunk);

    // May be _lastParsedPosition OR _nextPosToIndex
    position += 15 + flvtag.body_size; 

        bool doIndex = (_lastParsedPosition+4 > _nextPosToIndex) || index_only;
        if ( _lastParsedPosition > _nextPosToIndex )
        {
                //log_debug("::parseNextTag setting _nextPosToIndex=%d", _lastParsedPosition+4);
                _nextPosToIndex = _lastParsedPosition;
        }

        if ( position > _bytesLoaded ) {
                boost::mutex::scoped_lock lock(_bytesLoadedMutex);
                _bytesLoaded = position;
        }

        // check for empty tag
        if (flvtag.body_size == 0) return true;

        if (flvtag.type == FLV_AUDIO_TAG)
        {
                FLVAudioTag audiotag(chunk[11]);

                if (doIndex) {
                        indexAudioTag(flvtag, thisTagPos);
                        if (index_only) {
                                return true;
                        }
                }


                std::auto_ptr<EncodedAudioFrame> frame = 
            parseAudioTag(flvtag, audiotag, thisTagPos);
                if (!frame.get()) {
                        return false;
                }
                // Release the stream lock 
                // *before* pushing the frame as that 
                // might block us waiting for buffers flush
                // the _qMutex...
                // We've done using the stream for this tag parsing anyway
                streamLock.unlock();
                pushEncodedAudioFrame(frame);
        }
        else if (flvtag.type == FLV_VIDEO_TAG)
        {
                FLVVideoTag videotag(chunk[11]);

                if (doIndex) {
                        indexVideoTag(flvtag, videotag, thisTagPos);
                        if (index_only) {
                                return true;
                        }
                }

                std::auto_ptr<EncodedVideoFrame> frame = 
            parseVideoTag(flvtag, videotag, thisTagPos);
                if (!frame.get()) {
                        return false;
                }

                // Release the stream lock 
                // *before* pushing the frame as that 
                // might block us waiting for buffers flush
                // the _qMutex...
                streamLock.unlock();
                pushEncodedVideoFrame(frame);

        }
        else if (flvtag.type == FLV_META_TAG)
        {
                if ( chunk[11] != 2 )
                {
                        // ::processTags relies on the first AMF0 value being a string...
                        log_unimpl(_("First byte of FLV_META_TAG is %d, expected "
                        "0x02 (STRING AMF0 type)"),
                    static_cast<int>(chunk[11]));
                }
                // Extract information from the meta tag
                std::auto_ptr<SimpleBuffer> metaTag(new SimpleBuffer(
                    flvtag.body_size-1));
                size_t actuallyRead = _stream->read(metaTag->data(),
                flvtag.body_size - 1);

        if ( actuallyRead < flvtag.body_size-1 )
                {
                        log_error("FLVParser::parseNextTag: can't read metaTag (%d) "
                    "body (needed %d bytes, only got %d)",
                                FLV_META_TAG, flvtag.body_size, actuallyRead);
                        return false;
                }
                metaTag->resize(actuallyRead);

                boost::uint32_t terminus = getUInt24(metaTag->data() +
                actuallyRead - 3);

        if (terminus != 9) {
                        log_error(_("Corrupt FLV: Meta tag unterminated!"));
                }

                boost::mutex::scoped_lock lock(_metaTagsMutex);
                _metaTags.insert(std::make_pair(flvtag.timestamp, metaTag.release()));
        }
        else
        {
                log_error(_("FLVParser::parseNextTag: unknown FLV tag type %d"),
                (int)chunk[0]);
                return false;
        }

        _stream->read(chunk, 4);
        boost::uint32_t prevtagsize = chunk[0] << 24 | chunk[1] << 16 |
        chunk[2] << 8 | chunk[3];
        if (prevtagsize != flvtag.body_size + 11) {
                log_error(_("Corrupt FLV: previous tag size record (%1%) unexpected "
                    "(actual size: %2%)"), prevtagsize, flvtag.body_size + 11);
        }

        return true;
}

// would be called by MAIN thread
bool
FLVParser::parseHeader()
{
        assert(_stream->tell() == static_cast<std::streampos>(0));

        // We only use 5 bytes of the header, because the last 4 bytes represent
    // an integer which is always 1.
        boost::uint8_t header[9];
        if ( _stream->read(header, 9) != 9 )
        {
                log_error("FLVParser::parseHeader: couldn't read 9 bytes of header");
                return false;
        }

        _lastParsedPosition = _bytesLoaded = _nextPosToIndex = 9;

        if (!std::equal(header, header + 3, "FLV")) {
                return false;
        }

        const boost::uint8_t version = header[3];

        // Parse the audio+video bitmask
        _audio = header[4]&(1<<2);
        _video = header[4]&(1<<0);

        log_debug("Parsing FLV version %d, audio:%d, video:%d",
                        (int)version, _audio, _video);

        return true;
}

inline boost::uint32_t
FLVParser::getUInt24(boost::uint8_t* in)
{
        // The bits are in big endian order
        return (in[0] << 16) | (in[1] << 8) | in[2];
}

boost::uint64_t
FLVParser::getBytesLoaded() const
{
        boost::mutex::scoped_lock lock(_bytesLoadedMutex);
        return _bytesLoaded;
}

// would be called by parser thread
/*private*/
std::auto_ptr<EncodedAudioFrame>
FLVParser::readAudioFrame(boost::uint32_t dataSize, boost::uint32_t timestamp)
{

        std::auto_ptr<EncodedAudioFrame> frame(new EncodedAudioFrame);
    
    const size_t bufSize = dataSize + paddingBytes;

    boost::uint8_t* data = new boost::uint8_t[bufSize];
        const size_t bytesRead = _stream->read(data, dataSize);

    std::fill(data + bytesRead, data + bufSize, 0);

        if (bytesRead < dataSize) {
                log_error("FLVParser::readAudioFrame: could only read %d/%d bytes",
                bytesRead, dataSize);
        }

        frame->dataSize = bytesRead;
        frame->timestamp = timestamp;
        frame->data.reset(data);

        return frame;
}

// would be called by parser thread
/*private*/
std::auto_ptr<EncodedVideoFrame>
FLVParser::readVideoFrame(boost::uint32_t dataSize, boost::uint32_t timestamp)
{
        std::auto_ptr<EncodedVideoFrame> frame;

    const size_t bufSize = dataSize + paddingBytes;

        boost::uint8_t* data = new boost::uint8_t[bufSize];
        const size_t bytesRead = _stream->read(data, dataSize);

    std::fill(data + bytesRead, data + bufSize, 0);

        // We won't need frameNum, so will set to zero...
        // TODO: fix this ?
        // NOTE: ownership of 'data' is transferred here

        frame.reset(new EncodedVideoFrame(data, bytesRead, 0, timestamp));
        return frame;
}


void
FLVParser::fetchMetaTags(OrderedMetaTags& tags, boost::uint64_t ts)
{
        boost::mutex::scoped_lock lock(_metaTagsMutex);
        if (!_metaTags.empty())
        {
        MetaTags::iterator it = _metaTags.upper_bound(ts);
        std::transform(_metaTags.begin(), it, std::back_inserter(tags),
                SecondElement<MetaTags::value_type>());
        _metaTags.erase(_metaTags.begin(), it);
       
        }
}

} // end of gnash::media namespace
} // end of gnash namespace