MP3ADUinterleaving.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) 1996-2021 Live Networks, Inc.  All rights reserved.
// Interleaving of MP3 ADUs
// C++ header
 
#ifndef _MP3_ADU_INTERLEAVING_HH
#define _MP3_ADU_INTERLEAVING_HH
 
#ifndef _FRAMED_FILTER_HH
#include "FramedFilter.hh"
#endif
 
// A data structure used to represent an interleaving
#define MAX_CYCLE_SIZE 256
class Interleaving {
public:
  Interleaving(unsigned cycleSize, unsigned char const* cycleArray);
  virtual ~Interleaving();
 
  unsigned cycleSize() const {return fCycleSize;}
  unsigned char lookupInverseCycle(unsigned char index) const {
    return fInverseCycle[index];
  }
 
private:
  unsigned fCycleSize;
  unsigned char fInverseCycle[MAX_CYCLE_SIZE];
};
 
// This class is used only as a base for the following two:
 
class MP3ADUinterleaverBase: public FramedFilter {
protected:
  MP3ADUinterleaverBase(UsageEnvironment& env,
                        FramedSource* inputSource);
      // abstract base class
  virtual ~MP3ADUinterleaverBase();
 
  static FramedSource* getInputSource(UsageEnvironment& env,
                                      char const* inputSourceName);
  static void afterGettingFrame(void* clientData,
                                unsigned numBytesRead,
                                unsigned numTruncatedBytes,
                                struct timeval presentationTime,
                                unsigned durationInMicroseconds);
  virtual void afterGettingFrame(unsigned numBytesRead,
                                 struct timeval presentationTime,
                                 unsigned durationInMicroseconds) = 0;
};
 
// This class is used to convert an ADU sequence from non-interleaved
// to interleaved form:
 
class MP3ADUinterleaver: public MP3ADUinterleaverBase {
public:
  static MP3ADUinterleaver* createNew(UsageEnvironment& env,
                                      Interleaving const& interleaving,
                                      FramedSource* inputSource);
 
protected:
  MP3ADUinterleaver(UsageEnvironment& env,
                    Interleaving const& interleaving,
                    FramedSource* inputSource);
      // called only by createNew()
  virtual ~MP3ADUinterleaver();
 
private:
  // redefined virtual functions:
  virtual void doGetNextFrame();
  virtual void afterGettingFrame(unsigned numBytesRead,
                                 struct timeval presentationTime,
                                 unsigned durationInMicroseconds);
 
private:
  void releaseOutgoingFrame();
 
private:
  Interleaving const fInterleaving;
  class InterleavingFrames* fFrames;
  unsigned char fPositionOfNextIncomingFrame;
  unsigned fII, fICC;
};
 
// This class is used to convert an ADU sequence from interleaved
// to non-interleaved form:
 
class MP3ADUdeinterleaver: public MP3ADUinterleaverBase {
public:
  static MP3ADUdeinterleaver* createNew(UsageEnvironment& env,
                                        FramedSource* inputSource);
 
protected:
  MP3ADUdeinterleaver(UsageEnvironment& env,
                      FramedSource* inputSource);
      // called only by createNew()
  virtual ~MP3ADUdeinterleaver();
 
private:
  // redefined virtual functions:
  virtual void doGetNextFrame();
  virtual void afterGettingFrame(unsigned numBytesRead,
                                 struct timeval presentationTime,
                                 unsigned durationInMicroseconds);
 
private:
  void releaseOutgoingFrame();
 
private:
  class DeinterleavingFrames* fFrames;
  unsigned fIIlastSeen, fICClastSeen;
};
 
#endif