liveMedia/OggFileServerDemux.cpp

/**********
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
Free Software Foundation; either version 3 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2020 Live Networks, Inc.  All rights reserved.
// A server demultiplexor for a Ogg file
// Implementation

#include "OggFileServerDemux.hh"
#include "OggFileServerMediaSubsession.hh"

void OggFileServerDemux
::createNew(UsageEnvironment& env, char const* fileName,
	    onCreationFunc* onCreation, void* onCreationClientData) {
  (void)new OggFileServerDemux(env, fileName,
			       onCreation, onCreationClientData);
}

ServerMediaSubsession* OggFileServerDemux::newServerMediaSubsession() {
  u_int32_t dummyResultTrackNumber;
  return newServerMediaSubsession(dummyResultTrackNumber);
}

ServerMediaSubsession* OggFileServerDemux
::newServerMediaSubsession(u_int32_t& resultTrackNumber) {
  resultTrackNumber = 0;

  OggTrack* nextTrack = fIter->next();
  if (nextTrack == NULL) return NULL;

  return newServerMediaSubsessionByTrackNumber(nextTrack->trackNumber);
}

ServerMediaSubsession* OggFileServerDemux
::newServerMediaSubsessionByTrackNumber(u_int32_t trackNumber) {
  OggTrack* track = fOurOggFile->lookup(trackNumber);
  if (track == NULL) return NULL;

  ServerMediaSubsession* result = OggFileServerMediaSubsession::createNew(*this, track);
  if (result != NULL) {
#ifdef DEBUG
    fprintf(stderr, "Created 'ServerMediaSubsession' object for track #%d: (%s)\n", track->trackNumber, track->mimeType);
#endif
  }

  return result;
}

FramedSource* OggFileServerDemux::newDemuxedTrack(unsigned clientSessionId, u_int32_t trackNumber) {
  OggDemux* demuxToUse = NULL;

  if (clientSessionId != 0 && clientSessionId == fLastClientSessionId) {
    demuxToUse = fLastCreatedDemux; // use the same demultiplexor as before
      // Note: This code relies upon the fact that the creation of streams for different
      // client sessions do not overlap - so all demuxed tracks are created for one "OggDemux" at a time.
      // Also, the "clientSessionId != 0" test is a hack, because 'session 0' is special; its audio and video streams
      // are created and destroyed one-at-a-time, rather than both streams being
      // created, and then (later) both streams being destroyed (as is the case
      // for other ('real') session ids).  Because of this, a separate demultiplexor is used for each 'session 0' track.
  }

  if (demuxToUse == NULL) demuxToUse = fOurOggFile->newDemux();

  fLastClientSessionId = clientSessionId;
  fLastCreatedDemux = demuxToUse;

  return demuxToUse->newDemuxedTrackByTrackNumber(trackNumber);
}

OggFileServerDemux
::OggFileServerDemux(UsageEnvironment& env, char const* fileName,
		     onCreationFunc* onCreation, void* onCreationClientData)
  : Medium(env),
    fFileName(fileName), fOnCreation(onCreation), fOnCreationClientData(onCreationClientData),
    fIter(NULL/*until the OggFile is created*/),
    fLastClientSessionId(0), fLastCreatedDemux(NULL) {
  OggFile::createNew(env, fileName, onOggFileCreation, this);
}

OggFileServerDemux::~OggFileServerDemux() {
  Medium::close(fOurOggFile);

  delete fIter;
}

void OggFileServerDemux::onOggFileCreation(OggFile* newFile, void* clientData) {
  ((OggFileServerDemux*)clientData)->onOggFileCreation(newFile);
}

void OggFileServerDemux::onOggFileCreation(OggFile* newFile) {
  fOurOggFile = newFile;

  fIter = new OggTrackTableIterator(fOurOggFile->trackTable());

  // Now, call our own creation notification function:
  if (fOnCreation != NULL) (*fOnCreation)(this, fOnCreationClientData);
}