avifilesink.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

/**********
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.,
59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2004 Live Networks, Inc.  All rights reserved.
// A sink that generates an AVI file from a composite media session
// Implementation

#include "AVIFileSink.hh"
#include "OutputFile.hh"
#include "GroupsockHelper.hh"

#define fourChar(x,y,z,w) ( ((w)<<24)|((z)<<16)|((y)<<8)|(x) )/*little-endian*/

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

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;
};

class AVISubsessionIOState {
public:
  AVISubsessionIOState(AVIFileSink& sink, MediaSubsession& subsession);
  virtual ~AVISubsessionIOState();

  void setAVIstate(unsigned subsessionIndex);
  void setFinalAVIstate();

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

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

public:
  SubsessionBuffer *fBuffer, *fPrevBuffer;
  AVIFileSink& fOurSink;
  MediaSubsession& fOurSubsession;

  unsigned short fLastPacketRTPSeqNum;
  Boolean fOurSourceIsActive;
  struct timeval fPrevPresentationTime;
  unsigned fMaxBytesPerSecond;
  Boolean fIsVideo, fIsAudio, fIsByteSwappedAudio;
  unsigned fAVISubsessionTag;
  unsigned fAVICodecHandlerType;
  unsigned fAVISamplingFrequency; // for audio
  u_int16_t fWAVCodecTag; // for audio
  unsigned fAVIScale;
  unsigned fAVIRate;
  unsigned fAVISize;
  unsigned fNumFrames;
  unsigned fSTRHFrameCountPosition;

private:
  void useFrame(SubsessionBuffer& buffer);
};


////////// AVIFileSink implementation //////////

AVIFileSink::AVIFileSink(UsageEnvironment& env,
			 MediaSession& inputSession,
			 FILE* outFid,
			 unsigned bufferSize,
			 unsigned short movieWidth, unsigned short movieHeight,
			 unsigned movieFPS, Boolean packetLossCompensate)
  : Medium(env), fInputSession(inputSession), fOutFid(outFid),
    fBufferSize(bufferSize), fPacketLossCompensate(packetLossCompensate),
    fAreCurrentlyBeingPlayed(False), fNumSubsessions(0), fNumBytesWritten(0),
    fHaveCompletedOutputFile(False),
    fMovieWidth(movieWidth), fMovieHeight(movieHeight), fMovieFPS(movieFPS) {
  // 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.
    if (subsession->videoWidth() != 0) {
      fMovieWidth = subsession->videoWidth();
    }
    if (subsession->videoHeight() != 0) {
      fMovieHeight = subsession->videoHeight();
    }
    if (subsession->videoFPS() != 0) {
      fMovieFPS = subsession->videoFPS();
    }

    AVISubsessionIOState* ioState
      = new AVISubsessionIOState(*this, *subsession);
    subsession->miscPtr = (void*)ioState;

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

    ++fNumSubsessions;
  }

  // Begin by writing an AVI header:
  addFileHeader_AVI();
}

AVIFileSink::~AVIFileSink() {
  completeOutputFile();

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

    delete ioState;
  }
}

AVIFileSink* AVIFileSink
::createNew(UsageEnvironment& env, MediaSession& inputSession,
	    char const* outputFileName,
	    unsigned bufferSize,
	    unsigned short movieWidth, unsigned short movieHeight,
	    unsigned movieFPS, Boolean packetLossCompensate) {
  AVIFileSink* newSink = NULL;

  do {
    FILE* fid = OpenOutputFile(env, outputFileName);
    if (fid == NULL) break;

    return new AVIFileSink(env, inputSession, fid, bufferSize,
			   movieWidth, movieHeight, movieFPS,
			   packetLossCompensate);
  } while (0);

  delete newSink;
  return NULL;
}

Boolean AVIFileSink::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 AVIFileSink::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;

    AVISubsessionIOState* ioState
      = (AVISubsessionIOState*)(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 AVIFileSink
::afterGettingFrame(void* clientData, unsigned packetDataSize,
		    unsigned /*numTruncatedBytes*/,
		    struct timeval presentationTime,
		    unsigned /*durationInMicroseconds*/) {
  AVISubsessionIOState* ioState = (AVISubsessionIOState*)clientData;
  ioState->afterGettingFrame(packetDataSize, presentationTime);
}

void AVIFileSink::onSourceClosure(void* clientData) {
  AVISubsessionIOState* ioState = (AVISubsessionIOState*)clientData;
  ioState->onSourceClosure();
}

void AVIFileSink::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) {
    AVISubsessionIOState* ioState
      = (AVISubsessionIOState*)(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 AVIFileSink::onRTCPBye(void* clientData) {
  AVISubsessionIOState* ioState = (AVISubsessionIOState*)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();
}

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

  // Update various AVI 'size' fields to take account of the codec data that
  // we've now written to the file:
  unsigned maxBytesPerSecond = 0;
  unsigned numVideoFrames = 0;
  unsigned numAudioFrames = 0;

  //// Subsession-specific fields:
  MediaSubsessionIterator iter(fInputSession);
  MediaSubsession* subsession;
  while ((subsession = iter.next()) != NULL) {
    AVISubsessionIOState* ioState
      = (AVISubsessionIOState*)(subsession->miscPtr); 
    if (ioState == NULL) continue;

    maxBytesPerSecond += ioState->fMaxBytesPerSecond;

    setWord(ioState->fSTRHFrameCountPosition, ioState->fNumFrames);
    if (ioState->fIsVideo) numVideoFrames = ioState->fNumFrames;
    else if (ioState->fIsAudio) numAudioFrames = ioState->fNumFrames;
  }

  //// Global fields:
  fRIFFSizeValue += fNumBytesWritten;
  setWord(fRIFFSizePosition, fRIFFSizeValue);

  setWord(fAVIHMaxBytesPerSecondPosition, maxBytesPerSecond);
  setWord(fAVIHFrameCountPosition,
	  numVideoFrames > 0 ? numVideoFrames : numAudioFrames);

  fMoviSizeValue += fNumBytesWritten;
  setWord(fMoviSizePosition, fMoviSizeValue);

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


////////// AVISubsessionIOState implementation ///////////

AVISubsessionIOState::AVISubsessionIOState(AVIFileSink& sink,
				     MediaSubsession& subsession)
  : fOurSink(sink), fOurSubsession(subsession),
    fMaxBytesPerSecond(0), fNumFrames(0) {
  fBuffer = new SubsessionBuffer(fOurSink.fBufferSize);
  fPrevBuffer = sink.fPacketLossCompensate
    ? new SubsessionBuffer(fOurSink.fBufferSize) : NULL;

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

  fPrevPresentationTime.tv_sec = 0;
  fPrevPresentationTime.tv_usec = 0;
}

AVISubsessionIOState::~AVISubsessionIOState() {
  delete fBuffer; delete fPrevBuffer;
}

void AVISubsessionIOState::setAVIstate(unsigned subsessionIndex) {
  fIsVideo = strcmp(fOurSubsession.mediumName(), "video") == 0;
  fIsAudio = strcmp(fOurSubsession.mediumName(), "audio") == 0;

  if (fIsVideo) {
    fAVISubsessionTag
      = fourChar('0'+subsessionIndex/10,'0'+subsessionIndex%10,'d','c');
    if (strcmp(fOurSubsession.codecName(), "JPEG") == 0) {
      fAVICodecHandlerType = fourChar('m','j','p','g');
    } else if (strcmp(fOurSubsession.codecName(), "MP4V-ES") == 0) {
      fAVICodecHandlerType = fourChar('D','I','V','X');
    } else if (strcmp(fOurSubsession.codecName(), "MPV") == 0) {
      fAVICodecHandlerType = fourChar('m','p','g','1'); // what about MPEG-2?