D:/Storage/CVS_Head/h323plus/include/codecs.h

/*
 * codecs.h
 *
 * H.323 protocol handler
 *
 * Open H323 Library
 *
 * Copyright (c) 1998-2000 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 H323 Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions of this code were written with the assisance of funding from
 * Vovida Networks, Inc. http://www.vovida.com.
 *
 * Contributor(s): ______________________________________.
 *
 * $Log: codecs.h,v $
 * Revision 1.2  2007/10/19 19:53:44  shorne
 * ported latest Video updates in OpenH323 committed after h323plus initial fork thanks
 *  Robert
 *
 * Revision 1.1  2007/08/06 20:50:48  shorne
 * First commit of h323plus
 *
 * Revision 1.81.2.5  2007/07/19 20:10:27  shorne
 * Changed HAS_AEC to H323_AEC
 *
 * Revision 1.81.2.4  2007/02/10 23:56:40  shorne
 * Added comment
 *
 * Revision 1.81.2.3  2007/02/05 05:17:00  shorne
 * Added ability to send general codec options to Video Plugins
 *
 * Revision 1.81.2.2  2007/01/30 14:39:55  shorne
 * Corrections and Improvements patch supplied by Guilhem Tardy
 *
 * Revision 1.81.2.1  2006/12/23 19:08:02  shorne
 * Plugin video codecs & sundry
 *
 * Revision 1.81  2006/08/01 06:17:48  csoutheren
 * Fix bit rate control units
 * Add access function on code for max bit rate
 * Thanks to Paolo Amadini
 *
 * Revision 1.80  2006/05/16 11:28:58  shorne
 * added AEC support and  more call hold support.
 *
 * Revision 1.79  2006/01/26 03:31:08  shorne
 * Add the ability to remove a local input device when placing a call on hold
 *
 * Revision 1.78  2005/11/30 13:05:01  csoutheren
 * Changed tags for Doxygen
 *
 * Revision 1.77  2005/06/07 07:09:13  csoutheren
 * Removed compiler warnings on Windows
 *
 * Revision 1.76  2005/06/07 03:22:22  csoutheren
 * Added patch 1198741 with support for plugin codecs with generic capabilities
 * Added patch 1198754 with support for setting quality level on audio codecs
 * Added patch 1198760 with GSM-AMR codec support
 * Many thanks to Richard van der Hoff for his work
 *
 * Revision 1.75  2005/01/03 06:25:52  csoutheren
 * Added extensive support for disabling code modules at compile time
 *
 * Revision 1.74  2004/07/03 06:48:26  rjongbloed
 * Split video temporal/spatial trade off H.245 packets to separate command and
 *   indication functions and added quality parameter, thanks Guilhem Tardy.
 *
 * Revision 1.73  2004/05/09 10:08:34  csoutheren
 * Changed new DecodeFrame to return bytes decoded rather than samples decoded
 * Added support for new DecodeFrame to plugin manager
 *
 * Revision 1.72  2004/05/02 04:52:23  rjongbloed
 * Fixed problems with G.711 caused by fixing problem with G.723.1-5k3 mode.
 *
 * Revision 1.71  2004/03/24 00:39:12  dereksmithies
 * Changes from Michael Smith for use in reporting frames/second. Many Thanks
 *
 * Revision 1.70  2003/12/14 10:42:29  rjongbloed
 * Changes for compilability without video support.
 *
 * Revision 1.69  2003/11/12 11:14:21  csoutheren
 * Added H323FramedAudioCodec::DecodeSilenceFrame thanks to Henry Harrison of AliceStreet
 *
 * Revision 1.68  2003/07/16 10:43:12  csoutheren
 * Added SwapChannel function to H323Codec to allow media hold channels
 * to work better. Thanks to Federico Pinna
 *
 * Revision 1.67  2003/05/27 09:39:15  dereksmithies
 * Add frames per sec variable to the videocodec class
 *
 * Revision 1.66  2002/12/16 09:11:15  robertj
 * Added new video bit rate control, thanks Walter H. Whitlock
 *
 * Revision 1.65  2002/09/16 01:14:15  robertj
 * Added #define so can select if #pragma interface/implementation is used on
 *   platform basis (eg MacOS) rather than compiler, thanks Robert Monaghan.
 *
 * Revision 1.64  2002/08/05 10:03:47  robertj
 * Cosmetic changes to normalise the usage of pragma interface/implementation.
 *
 * Revision 1.63  2002/01/23 06:13:52  robertj
 * Added filter function hooks to codec raw data channel.
 *
 * Revision 1.62  2002/01/23 01:58:25  robertj
 * Added function to determine if codecs raw data channel is native format.
 *
 * Revision 1.61  2002/01/22 16:17:19  rogerh
 * Back out the DTMF Decoder class. There will soon be a better way
 * to do this.
 *
 * Revision 1.60  2002/01/22 16:09:38  rogerh
 * Back out the DTMF detection from H323FramedAudioCodec::Write().
 * There will shortly be a better place for it.
 *
 * Revision 1.59  2002/01/22 15:21:47  rogerh
 * Add DTMF decoding to PCM audio streams. This has been tested with
 * NetMeeting sending Dial Pad codes, using the G.711 codec.
 * At this time, DTMF codes (fron NetMeeting) are just displayed on the
 * screen and are not passed up to the users application.
 *
 * Revision 1.58  2002/01/13 23:56:01  robertj
 * Added mutex so can change raw data channel while reading/writing from codec.
 *
 * Revision 1.57  2001/12/04 05:13:09  robertj
 * Added videa bandwidth limiting code for H.261, thanks Jose Luis Urien.
 *
 * Revision 1.56  2001/11/16 01:05:21  craigs
 * Changed to allow access to uLaw/ALaw to/from linear functions
 *
 * Revision 1.55  2001/10/23 02:18:06  dereks
 * Initial release of CU30 video codec.
 *
 * Revision 1.54  2001/09/25 03:14:47  dereks
 * Add constant bitrate control for the h261 video codec.
 * Thanks Tiziano Morganti for the code to set bit rate. Good work!
 *
 * Revision 1.53  2001/09/11 01:24:36  robertj
 * Added conditional compilation to remove video and/or audio codecs.
 *
 * Revision 1.52  2001/08/28 09:27:38  robertj
 * Updated documentation to reflect some relationships between functions.
 *
 * Revision 1.51  2001/03/29 23:44:35  robertj
 * Added ability to get current silence detect state and threshold.
 * Changed silence detection to use G.723.1 SID frames as indicator of
 *   silence instead of using the average energy and adaptive threshold.
 * Changed default signal on deadband time to be much shorter.
 *
 * Revision 1.50  2001/02/09 05:16:24  robertj
 * Added #pragma interface for GNU C++.
 *
 * Revision 1.49  2001/01/25 07:27:14  robertj
 * Major changes to add more flexible OpalMediaFormat class to normalise
 *   all information about media types, especially codecs.
 *
 * Revision 1.48  2000/12/19 22:33:44  dereks
 * Adjust so that the video channel is used for reading/writing raw video
 * data, which better modularizes the video codec.
 *
 * Revision 1.47  2000/10/13 01:47:26  dereks
 * Include command option for setting the number of transmitted video
 * frames per second.   use --videotxfps n
 *
 * Revision 1.46  2000/09/08 06:41:37  craigs
 * Added ability to set video device
 * Added ability to select test input frames
 *
 * Revision 1.45  2000/08/31 08:15:32  robertj
 * Added support for dynamic RTP payload types in H.245 OpenLogicalChannel negotiations.
 *
 * Revision 1.44  2000/08/21 04:45:06  dereks
 * Fix dangling pointer that caused segfaults for windows&unix users.
 * Improved the test image which is used when video grabber won't open.
 * Added code to handle setting of video Tx Quality.
 * Added code to set the number of background blocks sent with every frame.
 *
 * Revision 1.43  2000/05/16 02:04:16  craigs
 * Added access functions for silence compression mode
 *
 * Revision 1.42  2000/05/02 04:32:24  robertj
 * Fixed copyright notice comment.
 *
 * Revision 1.41  2000/04/14 20:11:16  robertj
 * Removed redundent member variable from H323FramedAudioCodec.
 *
 * Revision 1.40  2000/03/30 23:10:50  robertj
 * Fixed error in comments regarding GetFramerate() function.
 *
 * Revision 1.39  2000/03/21 03:06:47  robertj
 * Changes to make RTP TX of exact numbers of frames in some codecs.
 *
 * Revision 1.38  2000/02/28 13:00:22  robertj
 * Added some virtual keywords at the request of Yura Ershov
 *
 * Revision 1.37  2000/02/10 03:08:02  craigs
 * Added ability to specify NTSC or PAL video format
 *
 * Revision 1.36  2000/02/04 05:00:08  craigs
 * Changes for video transmission
 *
 * Revision 1.35  2000/01/13 04:03:45  robertj
 * Added video transmission
 *
 * Revision 1.34  1999/12/31 00:05:36  robertj
 * Added Microsoft ACM G.723.1 codec capability.
 *
 * Revision 1.33  1999/12/29 01:19:16  craigs
 * Fixed problem with RTP payload type variable
 *
 * Revision 1.32  1999/12/23 23:02:34  robertj
 * File reorganision for separating RTP from H.323 and creation of LID for VPB support.
 *
 * Revision 1.31  1999/11/29 09:01:46  craigs
 * Added new code for new video code interface
 *
 * Revision 1.30  1999/11/29 04:50:11  robertj
 * Added adaptive threshold calculation to silence detection.
 *
 * Revision 1.29  1999/11/20 00:53:46  robertj
 * Fixed ability to have variable sized frames in single RTP packet under G.723.1
 *
 * Revision 1.28  1999/11/13 14:10:32  robertj
 * Changes to make silence detection selectable.
 *
 * Revision 1.27  1999/11/11 23:28:52  robertj
 * Added first cut silence detection algorithm.
 *
 * Revision 1.26  1999/11/04 00:43:42  robertj
 * Added extra constructors for nonStandard codecs.
 *
 * Revision 1.25  1999/10/14 12:03:08  robertj
 * Fixed comment.
 *
 * Revision 1.24  1999/10/08 09:59:01  robertj
 * Rewrite of capability for sending multiple audio frames
 *
 * Revision 1.23  1999/10/08 04:58:37  robertj
 * Added capability for sending multiple audio frames in single RTP packet
 *
 * Revision 1.22  1999/09/23 07:25:12  robertj
 * Added open audio and video function to connection and started multi-frame codec send functionality.
 *
 * Revision 1.21  1999/09/21 14:51:33  robertj
 * Fixed NonStandardCapabilityInfo class virtual destructor (and name).
 *
 * Revision 1.20  1999/09/21 14:04:41  robertj
 * Added non-standard codec capability classes
 *
 * Revision 1.19  1999/09/21 08:12:49  craigs
 * Added support for video codecs and H261
 *
 * Revision 1.18  1999/09/18 13:27:24  craigs
 * Added ability disable jitter buffer for codecs
 * Added ability to access entire RTP frame from codec Write
 *
 * Revision 1.17  1999/09/08 04:05:48  robertj
 * Added support for video capabilities & codec, still needs the actual codec itself!
 *
 * Revision 1.16  1999/08/31 12:34:18  robertj
 * Added gatekeeper support.
 *
 * Revision 1.15  1999/08/25 03:08:23  robertj
 * Added UserInput capability.
 * Allowed the attachment of a channel on a codec to optionally delete the channel object,
 *
 * Revision 1.14  1999/07/22 14:32:48  robertj
 * Fixed erroneous comments
 *
 * Revision 1.13  1999/07/16 16:05:48  robertj
 * Added "human readable" codec type name display.
 *
 * Revision 1.12  1999/07/15 14:45:35  robertj
 * Added propagation of codec open error to shut down logical channel.
 * Fixed control channel start up bug introduced with tunnelling.
 *
 * Revision 1.11  1999/07/13 09:53:24  robertj
 * Fixed some problems with jitter buffer and added more debugging.
 *
 * Revision 1.10  1999/07/09 06:09:49  robertj
 * Major implementation. An ENORMOUS amount of stuff added everywhere.
 *
 * Revision 1.9  1999/06/24 13:32:45  robertj
 * Fixed ability to change sound device on codec and fixed NM3 G.711 compatibility
 *
 * Revision 1.8  1999/06/22 13:49:40  robertj
 * Added GSM support and further RTP protocol enhancements.
 *
 * Revision 1.7  1999/06/14 15:08:40  robertj
 * Added GSM codec class frame work (still no actual codec).
 *
 * Revision 1.6  1999/06/14 06:39:08  robertj
 * Fixed problem with getting transmit flag to channel from PDU negotiator
 *
 * Revision 1.5  1999/06/14 05:15:55  robertj
 * Changes for using RTP sessions correctly in H323 Logical Channel context
 *
 * Revision 1.4  1999/06/13 12:41:14  robertj
 * Implement logical channel transmitter.
 * Fixed H245 connect on receiving call.
 *
 * Revision 1.3  1999/06/09 05:26:19  robertj
 * Major restructuring of classes.
 *
 * Revision 1.2  1999/06/06 06:06:36  robertj
 * Changes for new ASN compiler and v2 protocol ASN files.
 *
 * Revision 1.1  1999/01/16 01:31:01  robertj
 * Initial revision
 *
 */

#ifndef __CODECS_H
#define __CODECS_H

#ifdef P_USE_PRAGMA
#pragma interface
#endif


#include <mediafmt.h>
#include <rtp.h>
#include <channels.h>
#include "openh323buildopts.h"


/* The following classes have forward references to avoid including the VERY
   large header files for H225 and H245. If an application requires access
   to the protocol classes they can include them, but for simple usage their
   inclusion can be avoided.
 */
class H245_MiscellaneousCommand_type;
class H245_MiscellaneousIndication_type;
class H323Connection;




class PAec;
class H323Codec : public PObject
{
  PCLASSINFO(H323Codec, PObject);

  public:
    enum Direction {
      Encoder,
      Decoder
    };

    H323Codec(
      const OpalMediaFormat & mediaFormat, 
      Direction direction       
    );


    virtual BOOL Open(
      H323Connection & connection 
    );

    virtual void Close() = 0;

    virtual BOOL Read(
      BYTE * buffer,            
      unsigned & length,        
      RTP_DataFrame & rtpFrame  
    ) = 0;

    virtual BOOL Write(
      const BYTE * buffer,          
      unsigned length,              
      const RTP_DataFrame & frame,  
      unsigned & written            
    ) = 0;

    virtual unsigned GetFrameRate() const;

    virtual void OnFlowControl(
      long bitRateRestriction   
    );

    virtual void OnMiscellaneousCommand(
      const H245_MiscellaneousCommand_type & type  
    );

    virtual void OnMiscellaneousIndication(
      const H245_MiscellaneousIndication_type & type  
    );

    Direction GetDirection()   const { return direction; }

    virtual const OpalMediaFormat & GetMediaFormat() const { return mediaFormat; }
    OpalMediaFormat & GetWritableMediaFormat() { return mediaFormat; }

    virtual BOOL SetFrameSize(int /*frameWidth*/, int /*frameHeight*/) { return FALSE; };

    virtual BOOL AttachChannel(
      PChannel * channel,     
      BOOL autoDelete = TRUE  
    );

    virtual PChannel * SwapChannel(
      PChannel * newChannel,  
      BOOL autoDelete = TRUE  
    );

    virtual BOOL CloseRawDataChannel();

    PChannel *GetRawDataChannel()
      { return rawDataChannel; }

    virtual BOOL IsRawDataChannelNative() const;

    BOOL ReadRaw(
      void * data,
      PINDEX size,
      PINDEX & length
    );

    BOOL WriteRaw(
      void * data,
      PINDEX length
    );

    BOOL AttachLogicalChannel(H323Channel *channel);

    class FilterInfo : public PObject {
        PCLASSINFO(FilterInfo, PObject);
      public:
        FilterInfo(H323Codec & c, void * b, PINDEX s, PINDEX l)
          : codec(c), buffer(b), bufferSize(s), bufferLength(l) { }

        H323Codec & codec;
        void      * buffer;
        PINDEX      bufferSize;
        PINDEX      bufferLength;
    };

    void AddFilter(
      const PNotifier & notifier
    );

    virtual BOOL SetRawDataHeld(BOOL hold );

  protected:
    Direction direction;
    OpalMediaFormat mediaFormat;
    
    H323Channel * logicalChannel; // sends messages from receive codec to tx codec.

    PChannel * rawDataChannel;  // connection to the hardware for reading/writing data.
    BOOL       deleteChannel;
    PMutex     rawChannelMutex;

    PINDEX     lastSequenceNumber;  // Detects lost RTP packets in the video codec.

    PLIST(FilterList, PNotifier);
    FilterList filters;
};

#ifndef NO_H323_AUDIO_CODECS


class PAec;
class H323AudioCodec : public H323Codec
{
  PCLASSINFO(H323AudioCodec, H323Codec);

  public:
    H323AudioCodec(
      const OpalMediaFormat & mediaFormat, 
      Direction direction       
    );

    ~H323AudioCodec();

    virtual BOOL Open(
      H323Connection & connection 
    );

    virtual void Close();

    virtual unsigned GetFrameRate() const;

    enum SilenceDetectionMode {
      NoSilenceDetection,
      FixedSilenceDetection,
      AdaptiveSilenceDetection
    };

    void SetSilenceDetectionMode(
      SilenceDetectionMode mode,   
      unsigned threshold = 0,      
      unsigned signalDeadband = 80,    
      unsigned silenceDeadband = 3200, 
      unsigned adaptivePeriod = 4800   
    );

    SilenceDetectionMode GetSilenceDetectionMode(
      BOOL * isInTalkBurst = NULL,        
      unsigned * currentThreshold = NULL  
    ) const;

    
    virtual void SetTxQualityLevel(int /*qlevel*/) {}

    virtual int GetTxQualityLevel(int /*qlevel*/) { return 1; }
    
    virtual BOOL DetectSilence();

    virtual unsigned GetAverageSignalLevel();

    virtual BOOL SetRawDataHeld(BOOL hold);

#ifdef H323_AEC 

        virtual void AttachAEC(
       PAec * /*_ARC*/   
    ) {};
#endif

  protected:
    unsigned samplesPerFrame;

    SilenceDetectionMode silenceDetectMode;

    unsigned signalDeadbandFrames;  // Frames of signal before talk burst starts
    unsigned silenceDeadbandFrames; // Frames of silence before talk burst ends
    unsigned adaptiveThresholdFrames; // Frames to min/max over for adaptive threshold

    BOOL     inTalkBurst;           // Currently sending RTP data
    unsigned framesReceived;        // Signal/Silence frames received so far.
    unsigned levelThreshold;        // Threshold level for silence/signal
    unsigned signalMinimum;         // Minimum of frames above threshold
    unsigned silenceMaximum;        // Maximum of frames below threshold
    unsigned signalFramesReceived;  // Frames of signal received
    unsigned silenceFramesReceived; // Frames of silence received
    BOOL         IsRawDataHeld;
};


class PAec;
class H323FramedAudioCodec : public H323AudioCodec
{
  PCLASSINFO(H323FramedAudioCodec, H323AudioCodec);

  public:
    H323FramedAudioCodec(
      const OpalMediaFormat & mediaFormat, 
      Direction direction       
    );

    virtual BOOL Read(
      BYTE * buffer,            
      unsigned & length,        
      RTP_DataFrame & rtpFrame  
    );

    virtual BOOL Write(
      const BYTE * buffer,            
      unsigned length,                
      const RTP_DataFrame & rtpFrame, 
      unsigned & written              
    );


    virtual unsigned GetAverageSignalLevel();


    virtual BOOL EncodeFrame(
      BYTE * buffer,    
      unsigned & length 
    ) = 0;

    virtual BOOL DecodeFrame(
      const BYTE * buffer,   
      unsigned length,       
      unsigned & written,    
      unsigned & bytesOutput 
    );
    virtual BOOL DecodeFrame(
      const BYTE * buffer,  
      unsigned length,      
      unsigned & written    
    );

    virtual void DecodeSilenceFrame(
      void * buffer,  
      unsigned length       
    )
    { memset(buffer, 0, length); }

#ifdef H323_AEC 

        virtual void AttachAEC(
       PAec * _ARC   
    );
#endif

  protected:
        PAec * aec;     // Acoustic Echo Canceller
    PShortArray sampleBuffer;
    unsigned    bytesPerFrame;
};


class H323StreamedAudioCodec : public H323FramedAudioCodec
{
  PCLASSINFO(H323StreamedAudioCodec, H323FramedAudioCodec);

  public:
    H323StreamedAudioCodec(
      const OpalMediaFormat & mediaFormat, 
      Direction direction,      
      unsigned samplesPerFrame, 
      unsigned bits             
    );

    virtual BOOL EncodeFrame(
      BYTE * buffer,    
      unsigned & length 
    );

    virtual BOOL DecodeFrame(
      const BYTE * buffer,  
      unsigned length,      
      unsigned & written,   
      unsigned & samples    
    );

    virtual int Encode(short sample) const = 0;

    virtual short Decode(int sample) const = 0;

  protected:
    unsigned bitsPerSample;
};

#endif // NO_H323_AUDIO_CODECS


#ifndef NO_H323_VIDEO

class H323VideoCodec : public H323Codec
{
  PCLASSINFO(H323VideoCodec, H323Codec);

  public:
    H323VideoCodec(
      const OpalMediaFormat & mediaFormat, 
      Direction direction      
    );

    ~H323VideoCodec();

    virtual BOOL Open(
      H323Connection & connection 
    );

    virtual void Close();


    virtual void OnMiscellaneousCommand(
      const H245_MiscellaneousCommand_type & type  
    );

    virtual void OnMiscellaneousIndication(
      const H245_MiscellaneousIndication_type & type  
    );

    //    /**Attach the raw data device for use by codec.
    //   Note the device provided will be deleted on destruction of the codec.
    //   */
    // virtual BOOL AttachDevice(
    //  H323VideoDevice * device, ///< Device to read/write data
    //  BOOL autoDelete = TRUE    ///< Device is to be automatically deleted
    // );

    virtual void OnFreezePicture();

    virtual void OnFastUpdatePicture();

    virtual void OnFastUpdateGOB(unsigned firstGOB, unsigned numberOfGOBs);

    virtual void OnFastUpdateMB(int firstGOB, int firstMB, unsigned numberOfMBs);

    virtual void OnVideoIndicateReadyToActivate();

    virtual void OnVideoTemporalSpatialTradeOffCommand(int newQuality);

    virtual void OnVideoTemporalSpatialTradeOffIndication(int newQuality);

    virtual void OnVideoNotDecodedMBs(
      unsigned firstMB,
      unsigned numberOfMBs,
      unsigned temporalReference
    );

    virtual void OnLostPartialPicture();

    virtual void OnLostPicture();

    virtual unsigned GetWidth() const { return frameWidth; }

    virtual unsigned GetHeight() const { return frameHeight; }

    virtual void SetTxQualityLevel(int qlevel) {videoQuality = qlevel; }

    virtual void SetTxMinQuality(int qlevel) {videoQMin = qlevel; }

    virtual void SetTxMaxQuality(int qlevel) {videoQMax = qlevel; }

    virtual void SetBackgroundFill(int idle) {fillLevel= idle; }
 
    enum BitRateModeBits {
      None                = 0x00,
      DynamicVideoQuality = 0x01,
      AdaptivePacketDelay = 0x02
    };

    virtual unsigned GetVideoMode(void) {return videoBitRateControlModes;}

    virtual void SetVideoMode(int mode) {videoBitRateControlModes = mode;}

    virtual BOOL SetMaxBitRate(
      unsigned bitRate 
    );

    virtual unsigned GetMaxBitRate() const { return bitRateHighLimit; }

    virtual BOOL SetTargetFrameTimeMs(
      unsigned ms 
    );

    virtual void SetGeneralCodecOption(
                const char * opt,    
                int val              
        );

    void SendMiscCommand(unsigned command);
 
   virtual int GetFrameNum() { return frameNum; }


  protected:

    int frameWidth;
    int frameHeight;
    int fillLevel;

    // used in h261codec.cxx
    unsigned videoBitRateControlModes;
    // variables used for video bit rate control
    int bitRateHighLimit; // maximum instantaneous bit rate allowed
    unsigned oldLength;
    PTimeInterval oldTime;
    PTimeInterval newTime;
    // variables used for dynamic video quality control
    int targetFrameTimeMs; //targetFrameTimeMs = 1000 / videoSendFPS
    int frameBytes; // accumulate count of bytes per frame
    int sumFrameTimeMs, sumAdjFrameTimeMs, sumFrameBytes; // accumulate running average
    int videoQMax, videoQMin; // dynamic video quality min/max limits
    int videoQuality; // current video encode quality setting, 1..31
    PTimeInterval frameStartTime;
    PTimeInterval grabInterval;
    
    int frameNum, packetNum, oldPacketNum;
    int framesPerSec;

    PMutex  videoHandlerActive;    
};

#endif // NO_H323_VIDEO

#ifndef NO_H323_AUDIO_CODECS

// The simplest codec is the G.711 PCM codec.

class H323_ALawCodec : public H323StreamedAudioCodec
{
  PCLASSINFO(H323_ALawCodec, H323StreamedAudioCodec)

  public:
    H323_ALawCodec(
      Direction direction,  
      BOOL at56kbps,        
      unsigned frameSize    
    );

    virtual int   Encode(short sample) const { return EncodeSample(sample); }
    virtual short Decode(int   sample) const { return DecodeSample(sample); }

    static int   EncodeSample(short sample);
    static short DecodeSample(int   sample);

  protected:
    BOOL sevenBit;
};


class H323_muLawCodec : public H323StreamedAudioCodec
{
  PCLASSINFO(H323_muLawCodec, H323StreamedAudioCodec)

  public:
    H323_muLawCodec(
      Direction direction,  
      BOOL at56kbps,        
      unsigned frameSize    
    );

    virtual int   Encode(short sample) const { return EncodeSample(sample); }
    virtual short Decode(int   sample) const { return DecodeSample(sample); }

    static int   EncodeSample(short sample);
    static short DecodeSample(int   sample);

  protected:
    BOOL sevenBit;
};

#endif // NO_H323_AUDIO_CODECS


#endif // __CODECS_H

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