liveMedia/MPEG1or2DemuxedElementaryStream.cpp

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This library is distributed in the hope that it will be useful, but WITHOUT
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FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
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**********/
// "liveMedia"
// Copyright (c) 1996-2013 Live Networks, Inc.  All rights reserved.
// A MPEG 1 or 2 Elementary Stream, demultiplexed from a Program Stream
// Implementation

#include "MPEG1or2DemuxedElementaryStream.hh"


MPEG1or2DemuxedElementaryStream::
MPEG1or2DemuxedElementaryStream(UsageEnvironment& env, u_int8_t streamIdTag,
                            MPEG1or2Demux& sourceDemux)
  : FramedSource(env),
    fOurStreamIdTag(streamIdTag), fOurSourceDemux(sourceDemux), fMPEGversion(0) {
  // Set our MIME type string for known media types:
  if ((streamIdTag&0xE0) == 0xC0) {
    fMIMEtype = "audio/MPEG";
  } else if ((streamIdTag&0xF0) == 0xE0) {
    fMIMEtype = "video/MPEG";
  } else {
    fMIMEtype = MediaSource::MIMEtype();
  }
}

MPEG1or2DemuxedElementaryStream::~MPEG1or2DemuxedElementaryStream() {
  fOurSourceDemux.noteElementaryStreamDeletion(this);
}

void MPEG1or2DemuxedElementaryStream::doGetNextFrame() {
  fOurSourceDemux.getNextFrame(fOurStreamIdTag, fTo, fMaxSize,
                               afterGettingFrame, this,
                               handleClosure, this);
}

void MPEG1or2DemuxedElementaryStream::doStopGettingFrames() {
  fOurSourceDemux.stopGettingFrames(fOurStreamIdTag);
}

char const* MPEG1or2DemuxedElementaryStream::MIMEtype() const {
  return fMIMEtype;
}

unsigned MPEG1or2DemuxedElementaryStream::maxFrameSize() const {
  return 6+65535;
      // because the MPEG spec allows for PES packets as large as
      // (6 + 65535) bytes (header + data)
}

void MPEG1or2DemuxedElementaryStream
::afterGettingFrame(void* clientData,
                    unsigned frameSize, unsigned numTruncatedBytes,
                    struct timeval presentationTime,
                    unsigned durationInMicroseconds) {
  MPEG1or2DemuxedElementaryStream* stream
    = (MPEG1or2DemuxedElementaryStream*)clientData;
  stream->afterGettingFrame1(frameSize, numTruncatedBytes,
                             presentationTime, durationInMicroseconds);
}

void MPEG1or2DemuxedElementaryStream
::afterGettingFrame1(unsigned frameSize, unsigned numTruncatedBytes,
                     struct timeval presentationTime,
                     unsigned durationInMicroseconds) {
  fFrameSize = frameSize;
  fNumTruncatedBytes = numTruncatedBytes;
  fPresentationTime = presentationTime;
  fDurationInMicroseconds = durationInMicroseconds;

  fLastSeenSCR = fOurSourceDemux.lastSeenSCR();
  fMPEGversion = fOurSourceDemux.mpegVersion();

  FramedSource::afterGetting(this);
}

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