quicktimefilesink.cpp

流媒体传输协议的实现代码,非常有用.可以支持rtsp mms等流媒体传输协议

    if (ioState == NULL) continue;

    haveActiveSubsessions = True;
    unsigned char* toPtr = ioState->fBuffer->dataEnd();
    unsigned toSize = ioState->fBuffer->bytesAvailable();
    subsessionSource->getNextFrame(toPtr, toSize,
				   afterGettingFrame, ioState,
				   onSourceClosure, ioState);
  }
  if (!haveActiveSubsessions) {
    envir().setResultMsg("No subsessions are currently active");
    return False;
  }

  return True;
}

void QuickTimeFileSink
::afterGettingFrame(void* clientData, unsigned packetDataSize,
		    unsigned /*numTruncatedBytes*/,
		    struct timeval presentationTime,
		    unsigned /*durationInMicroseconds*/) {
  SubsessionIOState* ioState = (SubsessionIOState*)clientData;
  if (!ioState->syncOK(presentationTime)) {
    // Ignore this data:
    ioState->fOurSink.continuePlaying();
    return;
  }
  ioState->afterGettingFrame(packetDataSize, presentationTime);
}

void QuickTimeFileSink::onSourceClosure(void* clientData) {
  SubsessionIOState* ioState = (SubsessionIOState*)clientData;
  ioState->onSourceClosure();
}

void QuickTimeFileSink::onSourceClosure1() {
  // Check whether *all* of the subsession sources have closed.
  // If not, do nothing for now:
  MediaSubsessionIterator iter(fInputSession);
  MediaSubsession* subsession;
  while ((subsession = iter.next()) != NULL) {
    SubsessionIOState* ioState
      = (SubsessionIOState*)(subsession->miscPtr); 
    if (ioState == NULL) continue;

    if (ioState->fOurSourceIsActive) return; // this source hasn't closed
  }

  completeOutputFile();

  // Call our specified 'after' function:
  if (fAfterFunc != NULL) {
    (*fAfterFunc)(fAfterClientData);
  }
}

void QuickTimeFileSink::onRTCPBye(void* clientData) {
  SubsessionIOState* ioState = (SubsessionIOState*)clientData;

  struct timeval timeNow;
  gettimeofday(&timeNow, NULL);
  unsigned secsDiff
    = timeNow.tv_sec - ioState->fOurSink.fStartTime.tv_sec;

  MediaSubsession& subsession = ioState->fOurSubsession;
  ioState->envir() << "Received RTCP \"BYE\" on \""
		   << subsession.mediumName()
		   << "/" << subsession.codecName()
		   << "\" subsession (after "
		   << secsDiff << " seconds)\n";

  // Handle the reception of a RTCP "BYE" as if the source had closed:
  ioState->onSourceClosure();
}

static Boolean timevalGE(struct timeval const& tv1,
			 struct timeval const& tv2) {
  return (unsigned)tv1.tv_sec > (unsigned)tv2.tv_sec
    || (tv1.tv_sec == tv2.tv_sec
	&& (unsigned)tv1.tv_usec >= (unsigned)tv2.tv_usec);
}

void QuickTimeFileSink::completeOutputFile() {
  if (fHaveCompletedOutputFile || fOutFid == NULL) return;

  // Begin by filling in the initial "mdat" atom with the current
  // file size:
  unsigned curFileSize = ftell(fOutFid);
  setWord(fMDATposition, curFileSize);

  // Then, note the time of the first received data:
  MediaSubsessionIterator iter(fInputSession);
  MediaSubsession* subsession;
  while ((subsession = iter.next()) != NULL) {
    SubsessionIOState* ioState
      = (SubsessionIOState*)(subsession->miscPtr); 
    if (ioState == NULL) continue;

    ChunkDescriptor* const headChunk = ioState->fHeadChunk;
    if (headChunk != NULL
	&& timevalGE(fFirstDataTime, headChunk->fPresentationTime)) {
      fFirstDataTime = headChunk->fPresentationTime;
    }
  }

  // Then, update the QuickTime-specific state for each active track:
  iter.reset();
  while ((subsession = iter.next()) != NULL) {
    SubsessionIOState* ioState
      = (SubsessionIOState*)(subsession->miscPtr); 
    if (ioState == NULL) continue;

    ioState->setFinalQTstate();
    // Do the same for a hint track (if any):
    if (ioState->hasHintTrack()) {
      ioState->fHintTrackForUs->setFinalQTstate();
    }
  }

  if (fGenerateMP4Format) {
    // Begin with a "ftyp" atom:
    addAtom_ftyp();
  }

  // Then, add a "moov" atom for the file metadata:
  addAtom_moov();

  // We're done:
  fHaveCompletedOutputFile = True;
}


////////// SubsessionIOState, ChunkDescriptor implementation ///////////

unsigned SubsessionIOState::fCurrentTrackNumber = 0;

SubsessionIOState::SubsessionIOState(QuickTimeFileSink& sink,
				     MediaSubsession& subsession)
  : fHintTrackForUs(NULL), fTrackHintedByUs(NULL),
    fOurSink(sink), fOurSubsession(subsession),
    fLastPacketRTPSeqNum(0), fHaveBeenSynced(False), fQTTotNumSamples(0),
    fHeadChunk(NULL), fTailChunk(NULL), fNumChunks(0) {
  fTrackID = ++fCurrentTrackNumber;

  fBuffer = new SubsessionBuffer(fOurSink.fBufferSize);
  fPrevBuffer = sink.fPacketLossCompensate
    ? new SubsessionBuffer(fOurSink.fBufferSize) : NULL;

  FramedSource* subsessionSource = subsession.readSource();
  fOurSourceIsActive = subsessionSource != NULL;

  fPrevFrameState.presentationTime.tv_sec = 0;
  fPrevFrameState.presentationTime.tv_usec = 0;
  fPrevFrameState.seqNum = 0;
}

SubsessionIOState::~SubsessionIOState() {
  delete fBuffer; delete fPrevBuffer;
  delete fHeadChunk;
}

Boolean SubsessionIOState::setQTstate() {
  char const* noCodecWarning1 = "Warning: We don't implement a QuickTime ";
  char const* noCodecWarning2 = " Media Data Type for the \"";
  char const* noCodecWarning3 = "\" track, so we'll insert a dummy \"????\" Media Data Atom instead.  A separate, codec-specific editing pass will be needed before this track can be played.\n";
  Boolean supportPartiallyOnly = False;

  do {
    fQTEnableTrack = True; // enable this track in the movie by default
    fQTTimeScale = fOurSubsession.rtpTimestampFrequency(); // by default
    fQTTimeUnitsPerSample = 1; // by default
    fQTBytesPerFrame = 0;
        // by default - indicates that the whole packet data is a frame
    fQTSamplesPerFrame = 1; // by default

    // Make sure our subsession's medium is one that we know how to
    // represent in a QuickTime file:
    if (isHintTrack()) {
      // Hint tracks are treated specially
      fQTEnableTrack = False; // hint tracks are marked as inactive
      fQTcomponentSubtype = fourChar('h','i','n','t');
      fQTcomponentName = "hint media handler";
      fQTMediaInformationAtomCreator = &QuickTimeFileSink::addAtom_gmhd;
      fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_rtp;
    } else if (strcmp(fOurSubsession.mediumName(), "audio") == 0) {
      fQTcomponentSubtype = fourChar('s','o','u','n');
      fQTcomponentName = "Apple Sound Media Handler";
      fQTMediaInformationAtomCreator = &QuickTimeFileSink::addAtom_smhd;
      fQTMediaDataAtomCreator
	= &QuickTimeFileSink::addAtom_soundMediaGeneral; // by default
      fQTSoundSampleVersion = 0; // by default

      // Make sure that our subsession's codec is one that we can handle:
      if (strcmp(fOurSubsession.codecName(), "X-QT") == 0 ||
	  strcmp(fOurSubsession.codecName(), "X-QUICKTIME") == 0) {
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_genericMedia;
      } else if (strcmp(fOurSubsession.codecName(), "PCMU") == 0) {
	fQTAudioDataType = "ulaw";
	fQTBytesPerFrame = 1;
      } else if (strcmp(fOurSubsession.codecName(), "GSM") == 0) {
	fQTAudioDataType = "agsm";
	fQTBytesPerFrame = 33;
	fQTSamplesPerFrame = 160;
      } else if (strcmp(fOurSubsession.codecName(), "PCMA") == 0) {
	fQTAudioDataType = "alaw";
	fQTBytesPerFrame = 1;
      } else if (strcmp(fOurSubsession.codecName(), "QCELP") == 0) {
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_Qclp;
	fQTSamplesPerFrame = 160;
      } else if (strcmp(fOurSubsession.codecName(), "MPEG4-GENERIC") == 0 ||
		 strcmp(fOurSubsession.codecName(), "MP4A-LATM") == 0) {
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_mp4a;
	fQTTimeUnitsPerSample = 1024; // QT considers each frame to be a 'sample'
	// The time scale (frequency) comes from the 'config' information.
	// It might be different from the RTP timestamp frequency (e.g., aacPlus).
	unsigned frequencyFromConfig
	  = samplingFrequencyFromAudioSpecificConfig(fOurSubsession.fmtp_config());
	if (frequencyFromConfig != 0) fQTTimeScale = frequencyFromConfig;
      } else {
	envir() << noCodecWarning1 << "Audio" << noCodecWarning2
		<< fOurSubsession.codecName() << noCodecWarning3;
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_dummy;
	fQTEnableTrack = False; // disable this track in the movie
      }
    } else if (strcmp(fOurSubsession.mediumName(), "video") == 0) {
      fQTcomponentSubtype = fourChar('v','i','d','e');
      fQTcomponentName = "Apple Video Media Handler";
      fQTMediaInformationAtomCreator = &QuickTimeFileSink::addAtom_vmhd;

      // Make sure that our subsession's codec is one that we can handle:
      if (strcmp(fOurSubsession.codecName(), "X-QT") == 0 ||
	  strcmp(fOurSubsession.codecName(), "X-QUICKTIME") == 0) {
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_genericMedia;
      } else if (strcmp(fOurSubsession.codecName(), "H263-1998") == 0 ||
		 strcmp(fOurSubsession.codecName(), "H263-2000") == 0) {
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_h263;
	fQTTimeScale = 600;
	fQTTimeUnitsPerSample = fQTTimeScale/fOurSink.fMovieFPS;
      } else if (strcmp(fOurSubsession.codecName(), "MP4V-ES") == 0) {
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_mp4v;
	fQTTimeScale = 600;
	fQTTimeUnitsPerSample = fQTTimeScale/fOurSink.fMovieFPS;
      } else {
	envir() << noCodecWarning1 << "Video" << noCodecWarning2
		<< fOurSubsession.codecName() << noCodecWarning3;
	fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_dummy;
	fQTEnableTrack = False; // disable this track in the movie
      }
    } else {
      envir() << "Warning: We don't implement a QuickTime Media Handler for media type \""
	      << fOurSubsession.mediumName() << "\"";
      break;
    }

    if (supportPartiallyOnly) {
      envir() << "Warning: We don't have sufficient codec-specific information (e.g., sample sizes) to fully generate the \""
	      << fOurSubsession.mediumName() << "/"
	      << fOurSubsession.codecName()
	      << "\" track, so we'll disable this track in the movie.  A separate, codec-specific editing pass will be needed before this track can be played\n";
      fQTEnableTrack = False; // disable this track in the movie
    }

    return True;
  } while (0);

  envir() << ", so a track for the \"" << fOurSubsession.mediumName()
	  << "/" << fOurSubsession.codecName()
	  << "\" subsession will not be included in the output QuickTime file\n";
  return False; 
}

void SubsessionIOState::setFinalQTstate() {
  // Compute derived parameters, by running through the list of chunks:
  fQTDurationT = 0;

  ChunkDescriptor* chunk = fHeadChunk;
  while (chunk != NULL) {
    unsigned const numFrames = chunk->fNumFrames;
    unsigned const dur = numFrames*chunk->fFrameDuration;
    fQTDurationT += dur;

    chunk = chunk->fNextChunk;
  }

  // Convert this duration from track to movie time scale:
  double scaleFactor = fOurSink.movieTimeScale()/(double)fQTTimeScale;
  fQTDurationM = (unsigned)(fQTDurationT*scaleFactor);

  if (fQTDurationM > fOurSink.fMaxTrackDurationM) {
    fOurSink.fMaxTrackDurationM = fQTDurationM;
  }
}

void SubsessionIOState::afterGettingFrame(unsigned packetDataSize,
					  struct timeval presentationTime) {
  // Begin by checking whether there was a gap in the RTP stream.
  // If so, try to compensate for this (if desired):
  unsigned short rtpSeqNum
    = fOurSubsession.rtpSource()->curPacketRTPSeqNum();
  if (fOurSink.fPacketLossCompensate && fPrevBuffer->bytesInUse() > 0) {
    short seqNumGap = rtpSeqNum - fLastPacketRTPSeqNum;
    for (short i = 1; i < seqNumGap; ++i) {
      // Insert a copy of the previous frame, to compensate for the loss:
      useFrame(*fPrevBuffer);
    }
  }
  fLastPacketRTPSeqNum = rtpSeqNum;

  // Now, continue working with the frame that we just got
  if (fBuffer->bytesInUse() == 0) {
    fBuffer->setPresentationTime(presentationTime);
  }
  fBuffer->addBytes(packetDataSize);

  // If our RTP source is a "QuickTimeGenericRTPSource", then
  // use its 'qtState' to set some parameters that we need:
  if (fQTMediaDataAtomCreator == &QuickTimeFileSink::addAtom_genericMedia){
    QuickTimeGenericRTPSource* rtpSource
      = (QuickTimeGenericRTPSource*)fOurSubsession.rtpSource();
    QuickTimeGenericRTPSource::QTState& qtState = rtpSource->qtState;
    fQTTimeScale = qtState.timescale;
    if (qtState.width != 0) {
      fOurSink.fMovieWidth = qtState.width;
    }
    if (qtState.height != 0) {
      fOurSink.fMovieHeight = qtState.height;
    }

    // Also, if the media type in the "sdAtom" is one that we recognize
    // to have a special parameters, then fix this here:
    if (qtState.sdAtomSize >= 8) {
      char const* atom = qtState.sdAtom;
      unsigned mediaType = fourChar(atom[4],atom[5],atom[6],atom[7]);
      switch (mediaType) {
      case fourChar('a','g','s','m'): {
	fQTBytesPerFrame = 33;
	fQTSamplesPerFrame = 160;
	break;
      }
      case fourChar('Q','c','l','p'): {
	fQTBytesPerFrame = 35;
	fQTSamplesPerFrame = 160;
	break;
      }
      case fourChar('H','c','l','p'): {
	fQTBytesPerFrame = 17;
	fQTSamplesPerFrame = 160;
	break;
      }
      case fourChar('h','2','6','3'): {
	fQTTimeUnitsPerSample = fQTTimeScale/fOurSink.fMovieFPS;
	break;
      }
      }
    }
  } else if (fQTMediaDataAtomCreator == &QuickTimeFileSink::addAtom_Qclp) {
    // For QCELP data, make a note of the frame size (even though it's the
    // same as the packet data size), because it varies depending on the
    // 'rate' of the stream, and this size gets used later when setting up
    // the 'Qclp' QuickTime atom:
    fQTBytesPerFrame = packetDataSize;
  }

  useFrame(*fBuffer);
  if (fOurSink.fPacketLossCompensate) {
    // Save this frame, in case we need it for recovery: