OggFileSink.hh

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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
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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
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// "liveMedia"
// Copyright (c) 1996-2024 Live Networks, Inc.  All rights reserved.
// 'Ogg' File Sink (recording a single media track only)
// C++ header
 
#ifndef _OGG_FILE_SINK_HH
#define _OGG_FILE_SINK_HH
 
#ifndef _FILE_SINK_HH
#include "FileSink.hh"
#endif
 
class OggFileSink: public FileSink {
public:
  static OggFileSink* createNew(UsageEnvironment& env, char const* fileName,
                                unsigned samplingFrequency = 0, // used for granule_position
                                char const* configStr = NULL,
      // "configStr" is an optional 'SDP format' string (Base64-encoded)
      // representing 'packed configuration headers' ("identification", "comment", "setup")
      // to prepend to the output.  (For 'Vorbis" audio and 'Theora' video.)
                                unsigned bufferSize = 100000,
                                Boolean oneFilePerFrame = False);
      // See "FileSink.hh" for a description of these parameters.
 
protected:
  OggFileSink(UsageEnvironment& env, FILE* fid, unsigned samplingFrequency, char const* configStr,
              unsigned bufferSize, char const* perFrameFileNamePrefix);
      // called only by createNew()
  virtual ~OggFileSink();
 
protected: // redefined virtual functions:
  virtual Boolean continuePlaying();
  virtual void addData(unsigned char const* data, unsigned dataSize,
                       struct timeval presentationTime);
  virtual void afterGettingFrame(unsigned frameSize, unsigned numTruncatedBytes,
                                 struct timeval presentationTime);
 
private:
  static void ourOnSourceClosure(void* clientData);
  void ourOnSourceClosure();
 
private:
  unsigned fSamplingFrequency;
  char const* fConfigStr;
  Boolean fHaveWrittenFirstFrame, fHaveSeenEOF;
  struct timeval fFirstPresentationTime;
  int64_t fGranulePosition;
  int64_t fGranulePositionAdjustment; // used to ensure that "fGranulePosition" stays monotonic
  u_int32_t fPageSequenceNumber;
  u_int8_t fPageHeaderBytes[27];
      // the header of each Ogg page, through the "number_page_segments" byte
 
  // Special fields used for Theora video:
  Boolean fIsTheora;
  u_int64_t fGranuleIncrementPerFrame; // == 1 << KFGSHIFT
 
  // Because the last Ogg page before EOF needs to have a special 'eos' bit set in the header,
  // we need to defer the writing of each incoming frame.  To do this, we maintain a 2nd buffer:
  unsigned char* fAltBuffer;
  unsigned fAltFrameSize, fAltNumTruncatedBytes;
  struct timeval fAltPresentationTime;
};
 
#endif