| /********** |
| 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 3 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., |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| **********/ |
| // "liveMedia" |
| // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved. |
| // RTP sink for MPEG audio (RFC 2250) |
| // Implementation |
| |
| #include "MPEG1or2AudioRTPSink.hh" |
| |
| MPEG1or2AudioRTPSink::MPEG1or2AudioRTPSink(UsageEnvironment& env, Groupsock* RTPgs) |
| : AudioRTPSink(env, RTPgs, 14, 90000, "MPA") { |
| } |
| |
| MPEG1or2AudioRTPSink::~MPEG1or2AudioRTPSink() { |
| } |
| |
| MPEG1or2AudioRTPSink* |
| MPEG1or2AudioRTPSink::createNew(UsageEnvironment& env, Groupsock* RTPgs) { |
| return new MPEG1or2AudioRTPSink(env, RTPgs); |
| } |
| |
| void MPEG1or2AudioRTPSink::doSpecialFrameHandling(unsigned fragmentationOffset, |
| unsigned char* frameStart, |
| unsigned numBytesInFrame, |
| struct timeval framePresentationTime, |
| unsigned numRemainingBytes) { |
| // If this is the 1st frame in the 1st packet, set the RTP 'M' (marker) |
| // bit (because this is considered the start of a talk spurt): |
| if (isFirstPacket() && isFirstFrameInPacket()) { |
| setMarkerBit(); |
| } |
| |
| // If this is the first frame in the packet, set the lower half of the |
| // audio-specific header (to the "fragmentationOffset"): |
| if (isFirstFrameInPacket()) { |
| setSpecialHeaderWord(fragmentationOffset&0xFFFF); |
| } |
| |
| // Important: Also call our base class's doSpecialFrameHandling(), |
| // to set the packet's timestamp: |
| MultiFramedRTPSink::doSpecialFrameHandling(fragmentationOffset, |
| frameStart, numBytesInFrame, |
| framePresentationTime, |
| numRemainingBytes); |
| } |
| |
| unsigned MPEG1or2AudioRTPSink::specialHeaderSize() const { |
| // There's a 4 byte special audio header: |
| return 4; |
| } |