AC3AudioStreamFramer.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.
// A filter that breaks up an AC3 audio elementary stream into frames
// C++ header
 
#ifndef _AC3_AUDIO_STREAM_FRAMER_HH
#define _AC3_AUDIO_STREAM_FRAMER_HH
 
#ifndef _FRAMED_FILTER_HH
#include "FramedFilter.hh"
#endif
 
class AC3AudioStreamFramer: public FramedFilter {
public:
  static AC3AudioStreamFramer*
  createNew(UsageEnvironment& env, FramedSource* inputSource,
            unsigned char streamCode = 0);
  // If "streamCode" != 0, then we assume that there's a 1-byte code at the beginning of each chunk of data that we read from
  // our source.  If that code is not the value we want, we discard the chunk of data.
  // However, if "streamCode" == 0 (the default), then we don't expect this 1-byte code.
 
  unsigned samplingRate();
 
  void flushInput(); // called if there is a discontinuity (seeking) in the input
 
private:
  AC3AudioStreamFramer(UsageEnvironment& env, FramedSource* inputSource,
                       unsigned char streamCode);
      // called only by createNew()
  virtual ~AC3AudioStreamFramer();
 
  static void handleNewData(void* clientData,
                            unsigned char* ptr, unsigned size,
                            struct timeval presentationTime);
  void handleNewData(unsigned char* ptr, unsigned size);
 
  void parseNextFrame();
 
private:
  // redefined virtual functions:
  virtual void doGetNextFrame();
 
private:
  struct timeval currentFramePlayTime() const;
 
private:
  struct timeval fNextFramePresentationTime;
 
private: // parsing state
  class AC3AudioStreamParser* fParser;
  unsigned char fOurStreamCode;
  friend class AC3AudioStreamParser; // hack
};
 
#endif