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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
Free Software Foundation; either version 2.1 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.,
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
**********/
// "liveMedia"
// Copyright (c) 1996-2005 Live Networks, Inc. All rights reserved.
// A 'ServerMediaSubsession' object that creates new, unicast, "RTPSink"s
// on demand, from a MPEG-1 or 2 demuxer.
// Implementation
#include "MPEG1or2DemuxedServerMediaSubsession.hh"
#include "MPEG1or2AudioStreamFramer.hh"
#include "MPEG1or2AudioRTPSink.hh"
#include "MPEG1or2VideoStreamFramer.hh"
#include "MPEG1or2VideoRTPSink.hh"
#include "AC3AudioStreamFramer.hh"
#include "AC3AudioRTPSink.hh"
#include "ByteStreamFileSource.hh"
MPEG1or2DemuxedServerMediaSubsession* MPEG1or2DemuxedServerMediaSubsession
::createNew(MPEG1or2FileServerDemux& demux, u_int8_t streamIdTag,
Boolean reuseFirstSource, Boolean iFramesOnly, double vshPeriod) {
return new MPEG1or2DemuxedServerMediaSubsession(demux, streamIdTag,
reuseFirstSource,
iFramesOnly, vshPeriod);
}
MPEG1or2DemuxedServerMediaSubsession
::MPEG1or2DemuxedServerMediaSubsession(MPEG1or2FileServerDemux& demux,
u_int8_t streamIdTag, Boolean reuseFirstSource,
Boolean iFramesOnly, double vshPeriod)
: OnDemandServerMediaSubsession(demux.envir(), reuseFirstSource),
fOurDemux(demux), fStreamIdTag(streamIdTag),
fIFramesOnly(iFramesOnly), fVSHPeriod(vshPeriod) {
}
MPEG1or2DemuxedServerMediaSubsession::~MPEG1or2DemuxedServerMediaSubsession() {
}
FramedSource* MPEG1or2DemuxedServerMediaSubsession
::createNewStreamSource(unsigned clientSessionId, unsigned& estBitrate) {
FramedSource* es = NULL;
do {
es = fOurDemux.newElementaryStream(clientSessionId, fStreamIdTag);
if (es == NULL) break;
if ((fStreamIdTag&0xF0) == 0xC0 /*MPEG audio*/) {
estBitrate = 128; // kbps, estimate
return MPEG1or2AudioStreamFramer::createNew(envir(), es);
} else if ((fStreamIdTag&0xF0) == 0xE0 /*video*/) {
estBitrate = 500; // kbps, estimate
return MPEG1or2VideoStreamFramer::createNew(envir(), es,
fIFramesOnly, fVSHPeriod);
} else if (fStreamIdTag == 0xBD /*AC-3 audio*/) {
estBitrate = 192; // kbps, estimate
return AC3AudioStreamFramer::createNew(envir(), es);
} else { // unknown stream type
break;
}
} while (0);
// An error occurred:
Medium::close(es);
return NULL;
}
RTPSink* MPEG1or2DemuxedServerMediaSubsession
::createNewRTPSink(Groupsock* rtpGroupsock, unsigned char rtpPayloadTypeIfDynamic,
FramedSource* inputSource) {
if ((fStreamIdTag&0xF0) == 0xC0 /*MPEG audio*/) {
return MPEG1or2AudioRTPSink::createNew(envir(), rtpGroupsock);
} else if ((fStreamIdTag&0xF0) == 0xE0 /*video*/) {
return MPEG1or2VideoRTPSink::createNew(envir(), rtpGroupsock);
} else if (fStreamIdTag == 0xBD /*AC-3 audio*/) {
// Get the sampling frequency from the audio source; use it for the RTP frequency:
AC3AudioStreamFramer* audioSource
= (AC3AudioStreamFramer*)inputSource;
return AC3AudioRTPSink::createNew(envir(), rtpGroupsock, rtpPayloadTypeIfDynamic,
audioSource->samplingRate());
} else {
return NULL;
}
}
void MPEG1or2DemuxedServerMediaSubsession
::seekStreamSource(FramedSource* inputSource, float seekNPT) {
float const dur = duration();
unsigned const size = fOurDemux.fileSize();
unsigned absBytePosition = dur == 0.0 ? 0 : (unsigned)((seekNPT/dur)*size);
// "inputSource" is a 'framer'
// Flush its data, to account for the seek that we're about to do:
if ((fStreamIdTag&0xF0) == 0xC0 /*MPEG audio*/) {
MPEG1or2AudioStreamFramer* framer = (MPEG1or2AudioStreamFramer*)inputSource;
framer->flushInput();
} else if ((fStreamIdTag&0xF0) == 0xE0 /*video*/) {
MPEG1or2VideoStreamFramer* framer = (MPEG1or2VideoStreamFramer*)inputSource;
framer->flushInput();
}
// "inputSource" is a filter; its input source is the original elem stream source:
MPEG1or2DemuxedElementaryStream* elemStreamSource
= (MPEG1or2DemuxedElementaryStream*)(((FramedFilter*)inputSource)->inputSource());
// Next, get the original source demux:
MPEG1or2Demux& sourceDemux = elemStreamSource->sourceDemux();
// and flush its input buffers:
sourceDemux.flushInput();
// Then, get the original input file stream from the source demux:
ByteStreamFileSource* inputFileSource
= (ByteStreamFileSource*)(sourceDemux.inputSource());
// Note: We can make that cast, because we know that the demux was originally
// created from a "ByteStreamFileSource".
// Do the appropriate seek within the input file stream:
inputFileSource->seekToByteAbsolute(absBytePosition);
}
float MPEG1or2DemuxedServerMediaSubsession::duration() const {
return fOurDemux.fileDuration();
}
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