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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 MP3 audio file.
// (Actually, any MPEG-1 or MPEG-2 audio file should work.)
// Implementation
#include "MP3AudioFileServerMediaSubsession.hh"
#include "MPEG1or2AudioRTPSink.hh"
#include "MP3ADURTPSink.hh"
#include "MP3FileSource.hh"
#include "MP3ADU.hh"
MP3AudioFileServerMediaSubsession* MP3AudioFileServerMediaSubsession
::createNew(UsageEnvironment& env, char const* fileName, Boolean reuseFirstSource,
Boolean generateADUs, Interleaving* interleaving) {
return new MP3AudioFileServerMediaSubsession(env, fileName, reuseFirstSource,
generateADUs, interleaving);
}
MP3AudioFileServerMediaSubsession
::MP3AudioFileServerMediaSubsession(UsageEnvironment& env,
char const* fileName, Boolean reuseFirstSource,
Boolean generateADUs,
Interleaving* interleaving)
: FileServerMediaSubsession(env, fileName, reuseFirstSource),
fGenerateADUs(generateADUs), fInterleaving(interleaving), fFileDuration(0.0) {
}
MP3AudioFileServerMediaSubsession
::~MP3AudioFileServerMediaSubsession() {
delete fInterleaving;
}
void MP3AudioFileServerMediaSubsession
::seekStreamSource(FramedSource* inputSource, float seekNPT) {
MP3FileSource* mp3Source;
if (fGenerateADUs) {
// "inputSource" is a filter; use its input source instead.
ADUFromMP3Source* filter;
if (fInterleaving != NULL) {
// There's another filter as well.
filter = (ADUFromMP3Source*)(((FramedFilter*)inputSource)->inputSource());
} else {
filter = (ADUFromMP3Source*)inputSource;
}
filter->resetInput(); // because we're about to seek within its source
mp3Source = (MP3FileSource*)(filter->inputSource());
} else if (fFileDuration > 0.0) {
// There are a pair of filters - MP3->ADU and ADU->MP3 - in front of the
// original MP3 source:
MP3FromADUSource* filter2 = (MP3FromADUSource*)inputSource;
ADUFromMP3Source* filter1 = (ADUFromMP3Source*)(filter2->inputSource());
filter1->resetInput(); // because we're about to seek within its source
mp3Source = (MP3FileSource*)(filter1->inputSource());
} else {
// "inputSource" is the original MP3 source:
mp3Source = (MP3FileSource*)inputSource;
}
mp3Source->seekWithinFile(seekNPT);
}
void MP3AudioFileServerMediaSubsession
::setStreamSourceScale(FramedSource* inputSource, float scale) {
int iScale = (int)scale;
MP3FileSource* mp3Source;
ADUFromMP3Source* aduSource = NULL;
if (fGenerateADUs) {
if (fInterleaving != NULL) {
// There's an interleaving filter in front.
aduSource = (ADUFromMP3Source*)(((FramedFilter*)inputSource)->inputSource());
} else {
aduSource = (ADUFromMP3Source*)inputSource;
}
mp3Source = (MP3FileSource*)(aduSource->inputSource());
} else if (fFileDuration > 0.0) {
// There are a pair of filters - MP3->ADU and ADU->MP3 - in front of the
// original MP3 source. So, go back one, to reach the ADU source:
aduSource = (ADUFromMP3Source*)(((FramedFilter*)inputSource)->inputSource());
// Then, go back one more, to reach the MP3 source:
mp3Source = (MP3FileSource*)(aduSource->inputSource());
} else return; // the stream is not scalable
aduSource->setScaleFactor(iScale);
mp3Source->setPresentationTimeScale(iScale);
}
FramedSource* MP3AudioFileServerMediaSubsession
::createNewStreamSource(unsigned /*clientSessionId*/, unsigned& estBitrate) {
estBitrate = 128; // kbps, estimate
FramedSource* streamSource;
do {
MP3FileSource* mp3Source;
streamSource = mp3Source = MP3FileSource::createNew(envir(), fFileName);
if (streamSource == NULL) break;
fFileDuration = mp3Source->filePlayTime();
if (fGenerateADUs) {
// Add a filter that converts the source MP3s to ADUs:
streamSource = ADUFromMP3Source::createNew(envir(), streamSource);
if (streamSource == NULL) break;
if (fInterleaving != NULL) {
// Add another filter that interleaves the ADUs before packetizing:
streamSource = MP3ADUinterleaver::createNew(envir(), *fInterleaving,
streamSource);
if (streamSource == NULL) break;
}
} else if (fFileDuration > 0.0) {
// Because this is a seekable file, insert a pair of filters: one that
// converts the input MP3 stream to ADUs; another that converts these
// ADUs back to MP3. This allows us to seek within the input stream without
// tripping over the MP3 'bit reservoir':
streamSource = ADUFromMP3Source::createNew(envir(), streamSource);
if (streamSource == NULL) break;
streamSource = MP3FromADUSource::createNew(envir(), streamSource);
if (streamSource == NULL) break;
}
} while (0);
return streamSource;
}
RTPSink* MP3AudioFileServerMediaSubsession
::createNewRTPSink(Groupsock* rtpGroupsock,
unsigned char rtpPayloadTypeIfDynamic,
FramedSource* /*inputSource*/) {
if (fGenerateADUs) {
return MP3ADURTPSink::createNew(envir(), rtpGroupsock,
rtpPayloadTypeIfDynamic);
} else {
return MPEG1or2AudioRTPSink::createNew(envir(), rtpGroupsock);
}
}
void MP3AudioFileServerMediaSubsession::testScaleFactor(float& scale) {
if (fFileDuration <= 0.0) {
// The file is non-seekable, so is probably a live input source.
// We don't support scale factors other than 1
scale = 1;
} else {
// We support any integral scale >= 1
int iScale = (int)(scale + 0.5); // round
if (iScale < 1) iScale = 1;
scale = (float)iScale;
}
}
float MP3AudioFileServerMediaSubsession::duration() const {
return fFileDuration;
}
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