MP3StreamState.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
along with this library; if not, write to the Free Software Foundation, Inc.,
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**********/
// "liveMedia"
// Copyright (c) 1996-2024 Live Networks, Inc.  All rights reserved.
// A class encapsulating the state of a MP3 stream
// C++ header
 
#ifndef _MP3_STREAM_STATE_HH
#define _MP3_STREAM_STATE_HH
 
#ifndef _USAGE_ENVIRONMENT_HH
#include "UsageEnvironment.hh"
#endif
#ifndef _BOOLEAN_HH
#include "Boolean.hh"
#endif
#ifndef _MP3_INTERNALS_HH
#include "MP3Internals.hh"
#endif
#ifndef _NET_COMMON_H
#include "NetCommon.h"
#endif
 
#include <stdio.h>
 
#define XING_TOC_LENGTH 100
 
class MP3StreamState {
public:
  MP3StreamState();
  virtual ~MP3StreamState();
 
  void assignStream(FILE* fid, unsigned fileSize);
 
  unsigned findNextHeader(struct timeval& presentationTime);
  Boolean readFrame(unsigned char* outBuf, unsigned outBufSize,
                    unsigned& resultFrameSize,
                    unsigned& resultDurationInMicroseconds);
      // called after findNextHeader()
 
  void getAttributes(char* buffer, unsigned bufferSize) const;
 
  float filePlayTime() const; // in seconds
  unsigned fileSize() const { return fFileSize; }
  void setPresentationTimeScale(unsigned scale) { fPresentationTimeScale = scale; }
  unsigned getByteNumberFromPositionFraction(float fraction); // 0.0 <= fraction <= 1.0
  void seekWithinFile(unsigned seekByteNumber);
 
  void checkForXingHeader(); // hack for Xing VBR files
 
protected: // private->protected requested by Pierre l'Hussiez
  unsigned readFromStream(unsigned char* buf, unsigned numChars);
 
private:
  MP3FrameParams& fr() {return fCurrentFrame;}
  MP3FrameParams const& fr() const {return fCurrentFrame;}
 
  struct timeval currentFramePlayTime() const;
 
  Boolean findNextFrame();
 
private:
  FILE* fFid;
  Boolean fFidIsReallyASocket;
  unsigned fFileSize;
  unsigned fNumFramesInFile;
  unsigned fPresentationTimeScale;
    // used if we're streaming at other than the normal rate
  Boolean fIsVBR, fHasXingTOC;
  u_int8_t fXingTOC[XING_TOC_LENGTH]; // set iff "fHasXingTOC" is True
 
  MP3FrameParams fCurrentFrame;
  struct timeval fNextFramePresentationTime;
};
 
#endif