transcoders.h

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/*
 * transcoders.h
 *
 * Abstractions for converting media from one format to another.
 *
 * Open Phone Abstraction Library (OPAL)
 * Formally known as the Open H323 project.
 *
 * Copyright (c) 2001 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Open Phone Abstraction Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Contributor(s): ______________________________________.
 */

#ifndef OPAL_OPAL_TRANSCODERS_H
#define OPAL_OPAL_TRANSCODERS_H

#ifdef P_USE_PRAGMA
#pragma interface
#endif

#include <opal_config.h>

#include <opal/mediafmt.h>
#include <opal/mediacmd.h>
#include <opal/mediasession.h>

#include <rtp/rtp.h>

class RTP_DataFrame;
class OpalTranscoder;



class OpalMediaFormatPair : public PObject
{
    PCLASSINFO(OpalMediaFormatPair, PObject);
  public:
    OpalMediaFormatPair(
      const OpalMediaFormat & inputMediaFormat,  
      const OpalMediaFormat & outputMediaFormat  
    );

    void PrintOn(
      ostream & strm    
    ) const;

    virtual Comparison Compare(
      const PObject & obj   
    ) const;

    const OpalMediaFormat & GetInputFormat() const { return inputMediaFormat; }

    const OpalMediaFormat & GetOutputFormat() const { return outputMediaFormat; }

  protected:
    OpalMediaFormat inputMediaFormat;
    OpalMediaFormat outputMediaFormat;
};


typedef std::pair<PString, PString>                                      OpalTranscoderKey;
typedef PFactory<OpalTranscoder, OpalTranscoderKey>                      OpalTranscoderFactory;
typedef PFactory<OpalTranscoder, OpalTranscoderKey>::KeyList_T           OpalTranscoderList;
typedef PFactory<OpalTranscoder, OpalTranscoderKey>::KeyList_T::iterator OpalTranscoderIterator;

__inline OpalTranscoderKey MakeOpalTranscoderKey(const OpalMediaFormat & from, const OpalMediaFormat & to)
{
  return OpalTranscoderKey(from.GetName(), to.GetName());
}

__inline OpalTranscoderKey MakeOpalTranscoderKey(const char * from, const char * to)
{
  return OpalTranscoderKey(from, to);
}

#define OPAL_REGISTER_TRANSCODER(cls, input, output) \
  PFACTORY_CREATE(OpalTranscoderFactory, cls, MakeOpalTranscoderKey(input, output), false)


class OpalTranscoder : public OpalMediaFormatPair
{
    PCLASSINFO(OpalTranscoder, OpalMediaFormatPair);
  public:
    OpalTranscoder(
      const OpalMediaFormat & inputMediaFormat,  
      const OpalMediaFormat & outputMediaFormat  
    );

    virtual bool UpdateMediaFormats(
      const OpalMediaFormat & inputMediaFormat,  
      const OpalMediaFormat & outputMediaFormat  
    );

    virtual PBoolean ExecuteCommand(
      const OpalMediaCommand & command    
    );

    virtual PINDEX GetOptimalDataFrameSize(
      PBoolean input      
    ) const = 0;

    virtual PBoolean ConvertFrames(
      const RTP_DataFrame & input,  
      RTP_DataFrameList & output    
    );

    virtual PBoolean Convert(
      const RTP_DataFrame & input,  
      RTP_DataFrame & output        
    ) = 0;

    static OpalTranscoder * Create(
      const OpalMediaFormat & srcFormat,  
      const OpalMediaFormat & dstFormat,  
      const BYTE * instance = NULL,       
      unsigned instanceLen = 0            
    );

    static bool SelectFormats(
      const OpalMediaType & mediaType,        
      const OpalMediaFormatList & srcFormats, 
      const OpalMediaFormatList & dstFormats, 
      const OpalMediaFormatList & masterFormats, 
      OpalMediaFormat & srcFormat,            
      OpalMediaFormat & dstFormat             
    );

    static bool FindIntermediateFormat(
      const OpalMediaFormat & srcFormat,    
      const OpalMediaFormat & dstFormat,    
      OpalMediaFormat & intermediateFormat  
    );

    static OpalMediaFormatList GetDestinationFormats(
      const OpalMediaFormat & srcFormat    
    );

    static OpalMediaFormatList GetSourceFormats(
      const OpalMediaFormat & dstFormat    
    );

    static OpalMediaFormatList GetPossibleFormats(
      const OpalMediaFormatList & formats    
    );

    PINDEX GetMaxOutputSize() const { return maxOutputSize; }

    void SetMaxOutputSize(
      PINDEX size
    );

    void SetCommandNotifier(
      const PNotifier & notifier    
    ) { commandNotifier = notifier; }

    const PNotifier & GetCommandNotifier() const { return commandNotifier; }

    void NotifyCommand(
      const OpalMediaCommand & command
    ) const;

    unsigned GetSessionID() const { return m_sessionID; }

    void SetSessionID(unsigned id) { m_sessionID = id; }

    RTP_DataFrame::PayloadTypes GetPayloadType(
      PBoolean input      
    ) const;

    virtual bool AcceptComfortNoise() const  { return false; }
    virtual bool AcceptEmptyPayload() const  { return acceptEmptyPayload; }
    virtual bool AcceptOtherPayloads() const { return acceptOtherPayloads; }

#if OPAL_STATISTICS
    virtual void GetStatistics(OpalMediaStatistics & statistics) const;
#endif

    void CopyTimestamp(RTP_DataFrame & dst, const RTP_DataFrame & src, bool inToOut) const;

  protected:
    virtual bool OnCreated(
      const OpalMediaFormat & srcFormat,  
      const OpalMediaFormat & destFormat, 
      const BYTE * instance,              
      unsigned instanceLen                
    );

    PINDEX    maxOutputSize;
    PNotifier commandNotifier;
    PDECLARE_MUTEX(updateMutex);

    unsigned m_sessionID;
    bool     outputIsRTP, inputIsRTP;
    bool     acceptEmptyPayload;
    bool     acceptOtherPayloads;
    unsigned m_inClockRate;
    unsigned m_outClockRate;

    RTP_DataFrame::PayloadTypes m_lastPayloadType;
    unsigned                    m_consecutivePayloadTypeMismatches;
};


class OpalFramedTranscoder : public OpalTranscoder
{
    PCLASSINFO(OpalFramedTranscoder, OpalTranscoder);
  public:
    OpalFramedTranscoder(
      const OpalMediaFormat & inputMediaFormat,  
      const OpalMediaFormat & outputMediaFormat  
    );

    virtual bool UpdateMediaFormats(
      const OpalMediaFormat & inputMediaFormat,  
      const OpalMediaFormat & outputMediaFormat  
    );

    virtual PINDEX GetOptimalDataFrameSize(
      PBoolean input      
    ) const;

    virtual PBoolean Convert(
      const RTP_DataFrame & input,  
      RTP_DataFrame & output        
    );

    virtual PBoolean ConvertFrame(
      const BYTE * input,   
      BYTE * output         
    );
    virtual PBoolean ConvertFrame(
      const BYTE * input,   
      PINDEX & consumed,    
      BYTE * output,        
      PINDEX & created      
    );
    virtual PBoolean ConvertSilentFrame(
      BYTE * output,        
      PINDEX & created      
    );

  protected:
    void CalculateSizes();

    PINDEX inputBytesPerFrame;
    PINDEX outputBytesPerFrame;
    PINDEX maxOutputDataSize;
    enum
    {
      AwaitingFirstNonEmptyPayload,
      AwaitingEmptyPayload,
      DelayedDecodeEmptyPayload
    } m_emptyPayloadState;
    RTP_Timestamp m_lastEmptyPayloadTimestamp;
};


class OpalStreamedTranscoder : public OpalTranscoder
{
    PCLASSINFO(OpalStreamedTranscoder, OpalTranscoder);
  public:
    OpalStreamedTranscoder(
      const OpalMediaFormat & inputMediaFormat,  
      const OpalMediaFormat & outputMediaFormat, 
      unsigned inputBits,           
      unsigned outputBits           
    );

    virtual PINDEX GetOptimalDataFrameSize(
      PBoolean input      
    ) const;

    virtual PBoolean Convert(
      const RTP_DataFrame & input,  
      RTP_DataFrame & output        
    );

    virtual int ConvertOne(int sample) const = 0;

  protected:
    unsigned inputBitsPerSample;
    unsigned outputBitsPerSample;
};



class Opal_Linear16Mono_PCM : public OpalStreamedTranscoder {
  public:
    Opal_Linear16Mono_PCM();
    virtual int ConvertOne(int sample) const;
};



class Opal_PCM_Linear16Mono : public OpalStreamedTranscoder {
  public:
    Opal_PCM_Linear16Mono();
    virtual int ConvertOne(int sample) const;
};



#define OPAL_REGISTER_L16_MONO() \
  OPAL_REGISTER_TRANSCODER(Opal_Linear16Mono_PCM, OpalL16_MONO_8KHZ, OpalPCM16); \
  OPAL_REGISTER_TRANSCODER(Opal_PCM_Linear16Mono, OpalPCM16,         OpalL16_MONO_8KHZ)


class OpalEmptyFramedAudioTranscoder : public OpalFramedTranscoder
{
  PCLASSINFO(OpalEmptyFramedAudioTranscoder, OpalFramedTranscoder);
  public:
    OpalEmptyFramedAudioTranscoder(const char * inFormat, const char * outFormat)
      : OpalFramedTranscoder(inFormat, outFormat)
    {  }

    PBoolean ConvertFrame(const BYTE *, PINDEX &, BYTE *, PINDEX &)
    { return false; }
};

#define OPAL_DECLARE_EMPTY_TRANSCODER(fmt) \
class Opal_Empty_##fmt##_Encoder : public OpalEmptyFramedAudioTranscoder \
{ \
  public: \
    Opal_Empty_##fmt##_Encoder() \
      : OpalEmptyFramedAudioTranscoder(OpalPCM16, fmt) \
    { } \
}; \
class Opal_Empty_##fmt##_Decoder : public OpalEmptyFramedAudioTranscoder \
{ \
  public: \
    Opal_Empty_##fmt##_Decoder() \
      : OpalEmptyFramedAudioTranscoder(fmt, OpalPCM16) \
    { } \
}; \

#define OPAL_DEFINE_EMPTY_TRANSCODER(fmt) \
OPAL_REGISTER_TRANSCODER(Opal_Empty_##fmt##_Encoder, OpalPCM16, fmt); \
OPAL_REGISTER_TRANSCODER(Opal_Empty_##fmt##_Decoder, fmt,       OpalPCM16); \

#endif // OPAL_OPAL_TRANSCODERS_H


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