liveMedia/QuickTimeFileSink.cpp

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/**********
This library 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. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library 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 library; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2008 Live Networks, Inc.  All rights reserved.
// A sink that generates a QuickTime file from a composite media session
// Implementation

#include "QuickTimeFileSink.hh"
#include "QuickTimeGenericRTPSource.hh"
#include "GroupsockHelper.hh"
#include "OutputFile.hh"
#include "H263plusVideoRTPSource.hh" // for the special header
#include "MPEG4GenericRTPSource.hh" //for "samplingFrequencyFromAudioSpecificConfig()"
#include "MPEG4LATMAudioRTPSource.hh" // for "parseGeneralConfigStr()"
#include "Base64.hh"

#include <ctype.h>

#define fourChar(x,y,z,w) ( ((x)<<24)|((y)<<16)|((z)<<8)|(w) )

// A structure used to represent the I/O state of each input 'subsession':

class ChunkDescriptor {
public:
  ChunkDescriptor(unsigned offsetInFile, unsigned size,
                  unsigned frameSize, unsigned frameDuration,
                  struct timeval presentationTime);
  virtual ~ChunkDescriptor();

  ChunkDescriptor* extendChunk(unsigned newOffsetInFile, unsigned newSize,
                               unsigned newFrameSize,
                               unsigned newFrameDuration,
                               struct timeval newPresentationTime);
      // this may end up allocating a new chunk instead
public:
  ChunkDescriptor* fNextChunk;
  unsigned fOffsetInFile;
  unsigned fNumFrames;
  unsigned fFrameSize;
  unsigned fFrameDuration;
  struct timeval fPresentationTime; // of the start of the data
};

class SubsessionBuffer {
public:
  SubsessionBuffer(unsigned bufferSize)
    : fBufferSize(bufferSize) {
    reset();
    fData = new unsigned char[bufferSize];
  }
  virtual ~SubsessionBuffer() { delete fData; }
  void reset() { fBytesInUse = 0; }
  void addBytes(unsigned numBytes) { fBytesInUse += numBytes; }

  unsigned char* dataStart() { return &fData[0]; }
  unsigned char* dataEnd() { return &fData[fBytesInUse]; }
  unsigned bytesInUse() const { return fBytesInUse; }
  unsigned bytesAvailable() const { return fBufferSize - fBytesInUse; }

  void setPresentationTime(struct timeval const& presentationTime) {
    fPresentationTime = presentationTime;
  }
  struct timeval const& presentationTime() const {return fPresentationTime;}

private:
  unsigned fBufferSize;
  struct timeval fPresentationTime;
  unsigned char* fData;
  unsigned fBytesInUse;
};

// A 64-bit counter, used below:

class Count64 {
public:
  Count64() { hi = lo = 0; }

  void operator+=(unsigned arg);

  unsigned hi, lo; // each 32 bits
};

class SubsessionIOState {
public:
  SubsessionIOState(QuickTimeFileSink& sink, MediaSubsession& subsession);
  virtual ~SubsessionIOState();

  Boolean setQTstate();
  void setFinalQTstate();

  void afterGettingFrame(unsigned packetDataSize,
                         struct timeval presentationTime);
  void onSourceClosure();

  Boolean syncOK(struct timeval presentationTime);
      // returns true iff data is usable despite a sync check

  static void setHintTrack(SubsessionIOState* hintedTrack,
                           SubsessionIOState* hintTrack);
  Boolean isHintTrack() const { return fTrackHintedByUs != NULL; }
  Boolean hasHintTrack() const { return fHintTrackForUs != NULL; }

  UsageEnvironment& envir() const { return fOurSink.envir(); }

public:
  static unsigned fCurrentTrackNumber;
  unsigned fTrackID;
  SubsessionIOState* fHintTrackForUs; SubsessionIOState* fTrackHintedByUs;

  SubsessionBuffer *fBuffer, *fPrevBuffer;
  QuickTimeFileSink& fOurSink;
  MediaSubsession& fOurSubsession;

  unsigned short fLastPacketRTPSeqNum;
  Boolean fOurSourceIsActive;

  Boolean fHaveBeenSynced; // used in synchronizing with other streams
  struct timeval fSyncTime;

  Boolean fQTEnableTrack;
  unsigned fQTcomponentSubtype;
  char const* fQTcomponentName;
  typedef unsigned (QuickTimeFileSink::*atomCreationFunc)();
  atomCreationFunc fQTMediaInformationAtomCreator;
  atomCreationFunc fQTMediaDataAtomCreator;
  char const* fQTAudioDataType;
  unsigned short fQTSoundSampleVersion;
  unsigned fQTTimeScale;
  unsigned fQTTimeUnitsPerSample;
  unsigned fQTBytesPerFrame;
  unsigned fQTSamplesPerFrame;
  // These next fields are derived from the ones above,
  // plus the information from each chunk:
  unsigned fQTTotNumSamples;
  unsigned fQTDurationM; // in media time units
  unsigned fQTDurationT; // in track time units
  unsigned fTKHD_durationPosn;
      // position of the duration in the output 'tkhd' atom
  unsigned fQTInitialOffsetDuration;
      // if there's a pause at the beginning

  ChunkDescriptor *fHeadChunk, *fTailChunk;
  unsigned fNumChunks;

  // Counters to be used in the hint track's 'udta'/'hinf' atom;
  struct hinf {
    Count64 trpy;
    Count64 nump;
    Count64 tpyl;
    // Is 'maxr' needed? Computing this would be a PITA. #####
    Count64 dmed;
    Count64 dimm;
    // 'drep' is always 0
    // 'tmin' and 'tmax' are always 0
    unsigned pmax;
    unsigned dmax;
  } fHINF;

private:
  void useFrame(SubsessionBuffer& buffer);
  void useFrameForHinting(unsigned frameSize,
                          struct timeval presentationTime,
                          unsigned startSampleNumber);

  // used by the above two routines:
  unsigned useFrame1(unsigned sourceDataSize,
                     struct timeval presentationTime,
                     unsigned frameDuration, unsigned destFileOffset);
      // returns the number of samples in this data

private:
  // A structure used for temporarily storing frame state:
  struct {
    unsigned frameSize;
    struct timeval presentationTime;
    unsigned destFileOffset; // used for non-hint tracks only

    // The remaining fields are used for hint tracks only:
    unsigned startSampleNumber;
    unsigned short seqNum;
    unsigned rtpHeader;
    unsigned char numSpecialHeaders; // used when our RTP source has special headers
    unsigned specialHeaderBytesLength; // ditto
    unsigned char specialHeaderBytes[SPECIAL_HEADER_BUFFER_SIZE]; // ditto
    unsigned packetSizes[256];
  } fPrevFrameState;
};



QuickTimeFileSink::QuickTimeFileSink(UsageEnvironment& env,
                                     MediaSession& inputSession,
                                     char const* outputFileName,
                                     unsigned bufferSize,
                                     unsigned short movieWidth,
                                     unsigned short movieHeight,
                                     unsigned movieFPS,
                                     Boolean packetLossCompensate,
                                     Boolean syncStreams,
                                     Boolean generateHintTracks,
                                     Boolean generateMP4Format)
  : Medium(env), fInputSession(inputSession),
    fBufferSize(bufferSize), fPacketLossCompensate(packetLossCompensate),
    fSyncStreams(syncStreams), fGenerateMP4Format(generateMP4Format),
    fAreCurrentlyBeingPlayed(False),
    fLargestRTPtimestampFrequency(0),
    fNumSubsessions(0), fNumSyncedSubsessions(0),
    fHaveCompletedOutputFile(False),
    fMovieWidth(movieWidth), fMovieHeight(movieHeight),
    fMovieFPS(movieFPS), fMaxTrackDurationM(0) {
  fOutFid = OpenOutputFile(env, outputFileName);
  if (fOutFid == NULL) return;

  fNewestSyncTime.tv_sec = fNewestSyncTime.tv_usec = 0;
  fFirstDataTime.tv_sec = fFirstDataTime.tv_usec = (unsigned)(~0);

  // Set up I/O state for each input subsession:
  MediaSubsessionIterator iter(fInputSession);
  MediaSubsession* subsession;
  while ((subsession = iter.next()) != NULL) {
    // Ignore subsessions without a data source:
    FramedSource* subsessionSource = subsession->readSource();
    if (subsessionSource == NULL) continue;

    // If "subsession's" SDP description specified screen dimension
    // or frame rate parameters, then use these.  (Note that this must
    // be done before the call to "setQTState()" below.)
    if (subsession->videoWidth() != 0) {
      fMovieWidth = subsession->videoWidth();
    }
    if (subsession->videoHeight() != 0) {
      fMovieHeight = subsession->videoHeight();
    }
    if (subsession->videoFPS() != 0) {
      fMovieFPS = subsession->videoFPS();
    }

    SubsessionIOState* ioState
      = new SubsessionIOState(*this, *subsession);
    if (ioState == NULL || !ioState->setQTstate()) {
      // We're not able to output a QuickTime track for this subsession
      delete ioState; ioState = NULL;
      continue;
    }
    subsession->miscPtr = (void*)ioState;

    if (generateHintTracks) {
      // Also create a hint track for this track:
      SubsessionIOState* hintTrack
        = new SubsessionIOState(*this, *subsession);
      SubsessionIOState::setHintTrack(ioState, hintTrack);
      if (!hintTrack->setQTstate()) {
        delete hintTrack;
        SubsessionIOState::setHintTrack(ioState, NULL);
      }
    }

    // Also set a 'BYE' handler for this subsession's RTCP instance:
    if (subsession->rtcpInstance() != NULL) {
      subsession->rtcpInstance()->setByeHandler(onRTCPBye, ioState);
    }

    unsigned rtpTimestampFrequency = subsession->rtpTimestampFrequency();
    if (rtpTimestampFrequency > fLargestRTPtimestampFrequency) {
      fLargestRTPtimestampFrequency = rtpTimestampFrequency;
    }

    ++fNumSubsessions;
  }

  // Use the current time as the file's creation and modification
  // time.  Use Apple's time format: seconds since January 1, 1904

  gettimeofday(&fStartTime, NULL);
  fAppleCreationTime = fStartTime.tv_sec - 0x83dac000;

  // Begin by writing a "mdat" atom at the start of the file.
  // (Later, when we've finished copying data to the file, we'll come
  // back and fill in its size.)
  fMDATposition = ftell(fOutFid);
  addAtomHeader("mdat");
}

QuickTimeFileSink::~QuickTimeFileSink() {
  completeOutputFile();

  // Then, delete each active "SubsessionIOState":
  MediaSubsessionIterator iter(fInputSession);
  MediaSubsession* subsession;
  while ((subsession = iter.next()) != NULL) {
    SubsessionIOState* ioState
      = (SubsessionIOState*)(subsession->miscPtr);
    if (ioState == NULL) continue;

    delete ioState->fHintTrackForUs; // if any
    delete ioState;
  }

  // Finally, close our output file:
  CloseOutputFile(fOutFid);
}

QuickTimeFileSink*
QuickTimeFileSink::createNew(UsageEnvironment& env,
                             MediaSession& inputSession,
                             char const* outputFileName,
                             unsigned bufferSize,
                             unsigned short movieWidth,
                             unsigned short movieHeight,
                             unsigned movieFPS,
                             Boolean packetLossCompensate,
                             Boolean syncStreams,
                             Boolean generateHintTracks,
                             Boolean generateMP4Format) {
  QuickTimeFileSink* newSink = 
    new QuickTimeFileSink(env, inputSession, outputFileName, bufferSize, movieWidth, movieHeight, movieFPS,
                          packetLossCompensate, syncStreams, generateHintTracks, generateMP4Format);
  if (newSink == NULL || newSink->fOutFid == NULL) {
    Medium::close(newSink);
    return NULL;
  }

  return newSink;
}

Boolean QuickTimeFileSink::startPlaying(afterPlayingFunc* afterFunc,
                                        void* afterClientData) {
  // Make sure we're not already being played:
  if (fAreCurrentlyBeingPlayed) {
    envir().setResultMsg("This sink has already been played");
    return False;
  }

  fAreCurrentlyBeingPlayed = True;
  fAfterFunc = afterFunc;
  fAfterClientData = afterClientData;

  return continuePlaying();
}

Boolean QuickTimeFileSink::continuePlaying() {
  // Run through each of our input session's 'subsessions',
  // asking for a frame from each one:
  Boolean haveActiveSubsessions = False;
  MediaSubsessionIterator iter(fInputSession);
  MediaSubsession* subsession;
  while ((subsession = iter.next()) != NULL) {
    FramedSource* subsessionSource = subsession->readSource();
    if (subsessionSource == NULL) continue;

    if (subsessionSource->isCurrentlyAwaitingData()) continue;

    SubsessionIOState* ioState
      = (SubsessionIOState*)(subsession->miscPtr);
    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;
}



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";

  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(), "H264") == 0) {
        fQTMediaDataAtomCreator = &QuickTimeFileSink::addAtom_avc1;
        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;
    }

#ifdef QT_SUPPORT_PARTIALLY_ONLY
    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
#endif

    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:
    SubsessionBuffer* tmp = fPrevBuffer; // assert: != NULL
    fPrevBuffer = fBuffer;
    fBuffer = tmp;
  }
  fBuffer->