1 /**********
2 This library is free software; you can redistribute it and/or modify it under
3 the terms of the GNU Lesser General Public License as published by the
4 Free Software Foundation; either version 3 of the License, or (at your
5 option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
6
7 This library is distributed in the hope that it will be useful, but WITHOUT
8 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
9 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
10 more details.
11
12 You should have received a copy of the GNU Lesser General Public License
13 along with this library; if not, write to the Free Software Foundation, Inc.,
14 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
15 **********/
16 // "liveMedia"
17 // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved.
18 // RTP source for 'ADUized' MP3 frames ("mpa-robust")
19 // Implementation
20
21 #include "MP3ADURTPSource.hh"
22 #include "MP3ADUdescriptor.hh"
23
24 ////////// ADUBufferedPacket and ADUBufferedPacketFactory //////////
25
26 class ADUBufferedPacket: public BufferedPacket {
27 private: // redefined virtual functions
28 virtual unsigned nextEnclosedFrameSize(unsigned char*& framePtr,
29 unsigned dataSize);
30 };
31
32 class ADUBufferedPacketFactory: public BufferedPacketFactory {
33 private: // redefined virtual functions
34 virtual BufferedPacket* createNewPacket(MultiFramedRTPSource* ourSource);
35 };
36
37 ///////// MP3ADURTPSource implementation ////////
38
39 MP3ADURTPSource*
createNew(UsageEnvironment & env,Groupsock * RTPgs,unsigned char rtpPayloadFormat,unsigned rtpTimestampFrequency)40 MP3ADURTPSource::createNew(UsageEnvironment& env, Groupsock* RTPgs,
41 unsigned char rtpPayloadFormat,
42 unsigned rtpTimestampFrequency) {
43 return new MP3ADURTPSource(env, RTPgs, rtpPayloadFormat,
44 rtpTimestampFrequency);
45 }
46
MP3ADURTPSource(UsageEnvironment & env,Groupsock * RTPgs,unsigned char rtpPayloadFormat,unsigned rtpTimestampFrequency)47 MP3ADURTPSource::MP3ADURTPSource(UsageEnvironment& env, Groupsock* RTPgs,
48 unsigned char rtpPayloadFormat,
49 unsigned rtpTimestampFrequency)
50 : MultiFramedRTPSource(env, RTPgs,
51 rtpPayloadFormat, rtpTimestampFrequency,
52 new ADUBufferedPacketFactory) {
53 }
54
~MP3ADURTPSource()55 MP3ADURTPSource::~MP3ADURTPSource() {
56 }
57
MIMEtype() const58 char const* MP3ADURTPSource::MIMEtype() const {
59 return "audio/MPA-ROBUST";
60 }
61
62 ////////// ADUBufferedPacket and ADUBufferredPacketFactory implementation
63
64 unsigned ADUBufferedPacket
nextEnclosedFrameSize(unsigned char * & framePtr,unsigned dataSize)65 ::nextEnclosedFrameSize(unsigned char*& framePtr, unsigned dataSize) {
66 // Return the size of the next MP3 'ADU', on the assumption that
67 // the input data is ADU-encoded MP3 frames.
68 unsigned char* frameDataPtr = framePtr;
69 unsigned remainingFrameSize
70 = ADUdescriptor::getRemainingFrameSize(frameDataPtr);
71 unsigned descriptorSize = (unsigned)(frameDataPtr - framePtr);
72 unsigned fullADUSize = descriptorSize + remainingFrameSize;
73
74 return (fullADUSize <= dataSize) ? fullADUSize : dataSize;
75 }
76
77 BufferedPacket* ADUBufferedPacketFactory
createNewPacket(MultiFramedRTPSource *)78 ::createNewPacket(MultiFramedRTPSource* /*ourSource*/) {
79 return new ADUBufferedPacket;
80 }
81