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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.
// Transcoder for ADUized MP3 frames
// Implementation
#include "MP3ADUTranscoder.hh"
#include "MP3Internals.hh"
#include <string.h>
MP3ADUTranscoder::MP3ADUTranscoder(UsageEnvironment& env,
unsigned outBitrate /* in kbps */,
FramedSource* inputSource)
: FramedFilter(env, inputSource),
fOutBitrate(outBitrate),
fAvailableBytesForBackpointer(0),
fOrigADU(new unsigned char[MAX_MP3_FRAME_SIZE]) {
}
MP3ADUTranscoder::~MP3ADUTranscoder() {
delete[] fOrigADU;
}
MP3ADUTranscoder* MP3ADUTranscoder::createNew(UsageEnvironment& env,
unsigned outBitrate /* in kbps */,
FramedSource* inputSource) {
// The source must be an MP3 ADU source:
if (strcmp(inputSource->MIMEtype(), "audio/MPA-ROBUST") != 0) {
env.setResultMsg(inputSource->name(), " is not an MP3 ADU source");
return NULL;
}
return new MP3ADUTranscoder(env, outBitrate, inputSource);
}
void MP3ADUTranscoder::getAttributes() const {
// Begin by getting the attributes from our input source:
fInputSource->getAttributes();
// Then modify them by appending the corrected bandwidth
char buffer[30];
sprintf(buffer, " bandwidth %d", outBitrate());
envir().appendToResultMsg(buffer);
}
void MP3ADUTranscoder::doGetNextFrame() {
fInputSource->getNextFrame(fOrigADU, MAX_MP3_FRAME_SIZE,
afterGettingFrame, this, handleClosure, this);
}
void MP3ADUTranscoder::afterGettingFrame(void* clientData,
unsigned numBytesRead,
unsigned numTruncatedBytes,
struct timeval presentationTime,
unsigned durationInMicroseconds) {
MP3ADUTranscoder* transcoder = (MP3ADUTranscoder*)clientData;
transcoder->afterGettingFrame1(numBytesRead, numTruncatedBytes,
presentationTime, durationInMicroseconds);
}
void MP3ADUTranscoder::afterGettingFrame1(unsigned numBytesRead,
unsigned numTruncatedBytes,
struct timeval presentationTime,
unsigned durationInMicroseconds) {
fNumTruncatedBytes = numTruncatedBytes; // but can we handle this being >0? #####
fPresentationTime = presentationTime;
fDurationInMicroseconds = durationInMicroseconds;
fFrameSize = TranscodeMP3ADU(fOrigADU, numBytesRead, fOutBitrate,
fTo, fMaxSize, fAvailableBytesForBackpointer);
if (fFrameSize == 0) { // internal error - bad ADU data?
handleClosure(this);
return;
}
// Call our own 'after getting' function. Because we're not a 'leaf'
// source, we can call this directly, without risking infinite recursion.
afterGetting(this);
}
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