| /********** |
| 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 H.263+ video (RFC 4629) |
| // Implementation |
| |
| #include "H263plusVideoRTPSink.hh" |
| |
| H263plusVideoRTPSink |
| ::H263plusVideoRTPSink(UsageEnvironment& env, Groupsock* RTPgs, |
| unsigned char rtpPayloadFormat, |
| u_int32_t rtpTimestampFrequency) |
| : VideoRTPSink(env, RTPgs, rtpPayloadFormat, rtpTimestampFrequency, "H263-1998") { |
| } |
| |
| H263plusVideoRTPSink::~H263plusVideoRTPSink() { |
| } |
| |
| H263plusVideoRTPSink* |
| H263plusVideoRTPSink::createNew(UsageEnvironment& env, Groupsock* RTPgs, |
| unsigned char rtpPayloadFormat, |
| u_int32_t rtpTimestampFrequency) { |
| return new H263plusVideoRTPSink(env, RTPgs, rtpPayloadFormat, rtpTimestampFrequency); |
| } |
| |
| Boolean H263plusVideoRTPSink |
| ::frameCanAppearAfterPacketStart(unsigned char const* /*frameStart*/, |
| unsigned /*numBytesInFrame*/) const { |
| // A packet can contain only one frame |
| return False; |
| } |
| |
| void H263plusVideoRTPSink |
| ::doSpecialFrameHandling(unsigned fragmentationOffset, |
| unsigned char* frameStart, |
| unsigned numBytesInFrame, |
| struct timeval framePresentationTime, |
| unsigned numRemainingBytes) { |
| if (fragmentationOffset == 0) { |
| // This packet contains the first (or only) fragment of the frame. |
| // Set the 'P' bit in the special header: |
| unsigned short specialHeader = 0x0400; |
| |
| // Also, reuse the first two bytes of the payload for this special |
| // header. (They should both have been zero.) |
| if (numBytesInFrame < 2) { |
| envir() << "H263plusVideoRTPSink::doSpecialFrameHandling(): bad frame size " |
| << numBytesInFrame << "\n"; |
| return; |
| } |
| if (frameStart[0] != 0 || frameStart[1] != 0) { |
| envir() << "H263plusVideoRTPSink::doSpecialFrameHandling(): unexpected non-zero first two bytes!\n"; |
| } |
| frameStart[0] = specialHeader>>8; |
| frameStart[1] = (unsigned char)specialHeader; |
| } else { |
| unsigned short specialHeader = 0; |
| setSpecialHeaderBytes((unsigned char*)&specialHeader, 2); |
| } |
| |
| if (numRemainingBytes == 0) { |
| // This packet contains the last (or only) fragment of the frame. |
| // Set the RTP 'M' ('marker') bit: |
| setMarkerBit(); |
| } |
| |
| // Also set the RTP timestamp: |
| setTimestamp(framePresentationTime); |
| } |
| |
| |
| unsigned H263plusVideoRTPSink::specialHeaderSize() const { |
| // There's a 2-byte special video header. However, if we're the first |
| // (or only) fragment of a frame, then we reuse the first 2 bytes of |
| // the payload instead. |
| return (curFragmentationOffset() == 0) ? 0 : 2; |
| } |