transcoders.cxx

sloedgy open sip stack source code

/*
 * transcoders.cxx
 *
 * Abstractions for converting media from one format to another.
 *
 * Open H323 Library
 *
 * 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): ______________________________________.
 *
 * $Log: transcoders.cxx,v $
 * Revision 1.2  2007/03/08 03:36:47  joegenbaclor
 * Transferred declarration of allcodecs.h in transacoders.cxx to avoid multiple definition
 *
 * Revision 1.1  2006/06/26 03:03:24  joegenbaclor
 * I have decided to include the latest development realease  of OPAL tagged Deimos Devel 1 (June 8 2006) as inegrated classes to opensipstack to avoid future version conflicts due to the fast pace in OPAL development.   This move is also aimed to reduce the size of projects using OPAL componets such as the soon to be relased OpenSIPPhone.
 *
 * Revision 2.20  2006/04/09 12:12:54  rjongbloed
 * Changed the media format option merging to include the transcoder formats.
 *
 * Revision 2.19  2006/02/08 04:00:19  csoutheren
 * Fixed for G.726 codec
 * Thanks to Michael Tinglof
 *
 * Revision 2.18  2006/02/02 07:02:58  csoutheren
 * Added RTP payload map to transcoders and connections to allow remote SIP endpoints
 * to change the payload type used for outgoing RTP.
 *
 * Revision 2.17  2005/12/30 14:33:12  dsandras
 * Added support for Packet Loss Concealment frames for framed codecs supporting it similarly to what was done for OpenH323.
 *
 * Revision 2.16  2005/09/13 20:48:22  dominance
 * minor cleanups needed to support mingw compilation. Thanks goes to Julien Puydt.
 *
 * Revision 2.15  2005/09/06 12:44:49  rjongbloed
 * Many fixes to finalise the video processing: merging remote media
 *
 * Revision 2.14  2005/08/31 13:19:25  rjongbloed
 * Added mechanism for controlling media (especially codecs) including
 *   changing the OpalMediaFormat option list (eg bit rate) and a completely
 *   new OpalMediaCommand abstraction for things like video fast update.
 *
 * Revision 2.13  2005/08/28 07:59:17  rjongbloed
 * Converted OpalTranscoder to use factory, requiring sme changes in making sure
 *   OpalMediaFormat instances are initialised before use.
 *
 * Revision 2.12  2005/07/14 08:53:34  csoutheren
 * Change transcoding selection algorithm to prefer untranslated codec connections rather
 * than multi-stage transcoders
 *
 * Revision 2.11  2005/02/17 03:25:05  csoutheren
 * Added support for audio codecs that consume and produce variable size
 * frames, such as G.723.1
 *
 * Revision 2.10  2004/07/11 12:34:49  rjongbloed
 * Added function to get a list of all possible media formats that may be used given
 *   a list of media and taking into account all of the registered transcoders.
 *
 * Revision 2.9  2004/05/24 13:37:32  rjongbloed
 * Fixed propagating marker bit across transcoder which is important for
 *   silence suppression, thanks Ted Szoczei
 *
 * Revision 2.8  2004/03/22 11:32:42  rjongbloed
 * Added new codec type for 16 bit Linear PCM as must distinguish between the internal
 *   format used by such things as the sound card and the RTP payload format which
 *   is always big endian.
 *
 * Revision 2.7  2004/02/16 09:15:20  csoutheren
 * Fixed problems with codecs on Unix systems
 *
 * Revision 2.6  2004/01/18 15:35:21  rjongbloed
 * More work on video support
 *
 * Revision 2.5  2003/12/15 11:56:17  rjongbloed
 * Applied numerous bug fixes, thank you very much Ted Szoczei
 *
 * Revision 2.4  2003/06/02 02:59:24  rjongbloed
 * Changed transcoder search so uses destination list as preference order.
 *
 * Revision 2.3  2003/03/17 10:27:00  robertj
 * Added video support.
 *
 * Revision 2.2  2002/02/13 02:30:37  robertj
 * Added ability for media patch (and transcoders) to handle multiple RTP frames.
 *
 * Revision 2.1  2001/08/01 05:46:55  robertj
 * Made OpalMediaFormatList class global to help with documentation.
 * Added functions to aid in determining if a transcoder can be used to get
 *   to another media format.
 * Fixed problem with streamed transcoder used in G.711.
 *
 * Revision 2.0  2001/07/27 15:48:25  robertj
 * Conversion of OpenH323 to Open Phone Abstraction Library (OPAL)
 *
 */

#include <ptlib.h>

#ifdef __GNUC__
#pragma implementation "transcoders.h"
#endif

#define H323_STATIC_LIB
#include <codec/allcodecs.h>

#include <opal/transcoders.h>


#define new PNEW


/////////////////////////////////////////////////////////////////////////////

OpalMediaFormatPair::OpalMediaFormatPair(const OpalMediaFormat & inputFmt,
                                         const OpalMediaFormat & outputFmt)
  : inputMediaFormat(inputFmt),
    outputMediaFormat(outputFmt)
{
}


void OpalMediaFormatPair::PrintOn(ostream & strm) const
{
  strm << inputMediaFormat << "->" << outputMediaFormat;
}


PObject::Comparison OpalMediaFormatPair::Compare(const PObject & obj) const
{
  PAssert(PIsDescendant(&obj, OpalMediaFormatPair), PInvalidCast);
  const OpalMediaFormatPair & other = (const OpalMediaFormatPair &)obj;
  if (inputMediaFormat < other.inputMediaFormat)
    return LessThan;
  if (inputMediaFormat > other.inputMediaFormat)
    return GreaterThan;
  return outputMediaFormat.Compare(other.outputMediaFormat);
}


/////////////////////////////////////////////////////////////////////////////

OpalTranscoder::OpalTranscoder(const OpalMediaFormat & inputMediaFormat,
                               const OpalMediaFormat & outputMediaFormat)
  : OpalMediaFormatPair(inputMediaFormat, outputMediaFormat)
{
  maxOutputSize = RTP_DataFrame::MaxEthernetPayloadSize;
}


BOOL OpalTranscoder::UpdateOutputMediaFormat(const OpalMediaFormat & mediaFormat)
{
  PWaitAndSignal mutex(updateMutex);

  if (outputMediaFormat != mediaFormat)
    return FALSE;

  outputMediaFormat = mediaFormat;
  outputMediaFormatUpdated = true;
  return TRUE;
}


BOOL OpalTranscoder::ExecuteCommand(const OpalMediaCommand & /*command*/)
{
  return FALSE;
}


BOOL OpalTranscoder::ConvertFrames(const RTP_DataFrame & input,
                                   RTP_DataFrameList & output)
{
  if (output.IsEmpty())
    output.Append(new RTP_DataFrame);
  else {
    while (output.GetSize() > 1)
      output.RemoveAt(1);
  }

  if (payloadTypeMap.size() == 0)
    output[0].SetPayloadType(outputMediaFormat.GetPayloadType());
  else {
    RTP_DataFrame::PayloadMapType::iterator r = payloadTypeMap.find(outputMediaFormat.GetPayloadType());
    if (r != payloadTypeMap.end())
      output[0].SetPayloadType(r->second);
    else
      output[0].SetPayloadType(outputMediaFormat.GetPayloadType());
  }
  output[0].SetTimestamp(input.GetTimestamp());
  output[0].SetMarker(input.GetMarker());
  return Convert(input, output[0]);
}


OpalTranscoder * OpalTranscoder::Create(const OpalMediaFormat & srcFormat,
                                        const OpalMediaFormat & destFormat)
{
  OpalTranscoder * transcoder = OpalTranscoderFactory::CreateInstance(OpalMediaFormatPair(srcFormat, destFormat));
  if (transcoder != NULL)
    transcoder->UpdateOutputMediaFormat(destFormat);
  return transcoder;
}


BOOL OpalTranscoder::SelectFormats(unsigned sessionID,
                                   const OpalMediaFormatList & srcFormats,
                                   const OpalMediaFormatList & dstFormats,
                                   OpalMediaFormat & srcFormat,
                                   OpalMediaFormat & dstFormat)
{
  PINDEX s, d;

  // Search through the supported formats to see if can pass data
  // directly from the given format to a possible one with no transcoders.
  for (d = 0; d < dstFormats.GetSize(); d++) {
    dstFormat = dstFormats[d];
    if (dstFormat.GetDefaultSessionID() == sessionID) {
      for (s = 0; s < srcFormats.GetSize(); s++) {
        srcFormat = srcFormats[s];
        if (srcFormat == dstFormat)
          return srcFormat.Merge(dstFormat) && dstFormat.Merge(srcFormat);
      }
    }
  }

  // Search for a single transcoder to get from a to b
  for (d = 0; d < dstFormats.GetSize(); d++) {
    dstFormat = dstFormats[d];
    for (s = 0; s < srcFormats.GetSize(); s++) {
      srcFormat = srcFormats[s];
      OpalMediaFormatPair search(srcFormat, dstFormat);
      OpalTranscoderList availableTranscoders = OpalTranscoderFactory::GetKeyList();
      for (OpalTranscoderIterator i = availableTranscoders.begin(); i != availableTranscoders.end(); ++i) {
        if (search == *i)
          return srcFormat.Merge(i->GetInputFormat()) &&
                 dstFormat.Merge(i->GetOutputFormat()) &&
                 srcFormat.Merge(dstFormat);
      }
    }
  }

  // Last gasp search for a double transcoder to get from a to b
  for (d = 0; d < dstFormats.GetSize(); d++) {
    dstFormat = dstFormats[d];
    for (s = 0; s < srcFormats.GetSize(); s++) {
      srcFormat = srcFormats[s];
      OpalMediaFormat intermediateFormat;
      if (FindIntermediateFormat(srcFormat, dstFormat, intermediateFormat))
        return TRUE;
    }
  }

  return FALSE;
}


BOOL OpalTranscoder::FindIntermediateFormat(OpalMediaFormat & srcFormat,
                                            OpalMediaFormat & dstFormat,
                                            OpalMediaFormat & intermediateFormat)
{
  intermediateFormat = OpalMediaFormat();

  OpalTranscoderList availableTranscoders = OpalTranscoderFactory::GetKeyList();
  for (OpalTranscoderIterator find1 = availableTranscoders.begin(); find1 != availableTranscoders.end(); ++find1) {
    if (find1->GetInputFormat() == srcFormat) {
      for (OpalTranscoderIterator find2 = availableTranscoders.begin(); find2 != availableTranscoders.end(); ++find2) {
        if (find2->GetInputFormat() == find1->GetOutputFormat() && find2->GetOutputFormat() == dstFormat) {
          intermediateFormat = find1->GetOutputFormat();
          intermediateFormat.Merge(find2->GetInputFormat());
          return srcFormat.Merge(find1->GetInputFormat()) &&
                 dstFormat.Merge(find2->GetOutputFormat()) &&
                 srcFormat.Merge(dstFormat);
        }
      }
    }