66 lines
2.1 KiB
C++
Executable File
66 lines
2.1 KiB
C++
Executable File
/**********
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This library is free software; you can redistribute it and/or modify it under
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the terms of the GNU Lesser General Public License as published by the
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Free Software Foundation; either version 2.1 of the License, or (at your
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option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
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This library is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
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more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this library; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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**********/
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// "liveMedia"
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// Copyright (c) 1996-2016 Live Networks, Inc. All rights reserved.
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// Descriptor preceding frames of 'ADU' MP3 streams (for improved loss-tolerance)
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// Implementation
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#include "MP3ADUdescriptor.hh"
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////////// ADUdescriptor //////////
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//##### NOTE: For now, ignore fragmentation. Fix this later! #####
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#define TWO_BYTE_DESCR_FLAG 0x40
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unsigned ADUdescriptor::generateDescriptor(unsigned char*& toPtr,
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unsigned remainingFrameSize) {
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unsigned descriptorSize = ADUdescriptor::computeSize(remainingFrameSize);
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switch (descriptorSize) {
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case 1: {
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*toPtr++ = (unsigned char)remainingFrameSize;
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break;
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}
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case 2: {
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generateTwoByteDescriptor(toPtr, remainingFrameSize);
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break;
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}
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}
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return descriptorSize;
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}
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void ADUdescriptor::generateTwoByteDescriptor(unsigned char*& toPtr,
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unsigned remainingFrameSize) {
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*toPtr++ = (TWO_BYTE_DESCR_FLAG|(unsigned char)(remainingFrameSize>>8));
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*toPtr++ = (unsigned char)(remainingFrameSize&0xFF);
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}
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unsigned ADUdescriptor::getRemainingFrameSize(unsigned char*& fromPtr) {
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unsigned char firstByte = *fromPtr++;
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if (firstByte&TWO_BYTE_DESCR_FLAG) {
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// This is a 2-byte descriptor
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unsigned char secondByte = *fromPtr++;
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return ((firstByte&0x3F)<<8) | secondByte;
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} else {
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// This is a 1-byte descriptor
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return (firstByte&0x3F);
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}
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}
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