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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.
// MPEG-1 or MPEG-2 Video RTP Sources
// Implementation
#include "MPEG1or2VideoRTPSource.hh"
MPEG1or2VideoRTPSource*
MPEG1or2VideoRTPSource::createNew(UsageEnvironment& env, Groupsock* RTPgs,
unsigned char rtpPayloadFormat,
unsigned rtpTimestampFrequency) {
return new MPEG1or2VideoRTPSource(env, RTPgs, rtpPayloadFormat,
rtpTimestampFrequency);
}
MPEG1or2VideoRTPSource::MPEG1or2VideoRTPSource(UsageEnvironment& env,
Groupsock* RTPgs,
unsigned char rtpPayloadFormat,
unsigned rtpTimestampFrequency)
: MultiFramedRTPSource(env, RTPgs,
rtpPayloadFormat, rtpTimestampFrequency){
}
MPEG1or2VideoRTPSource::~MPEG1or2VideoRTPSource() {
}
Boolean MPEG1or2VideoRTPSource
::processSpecialHeader(BufferedPacket* packet,
unsigned& resultSpecialHeaderSize) {
// There's a 4-byte video-specific header
if (packet->dataSize() < 4) return False;
u_int32_t header = ntohl(*(unsigned*)(packet->data()));
u_int32_t sBit = header&0x00002000; // sequence-header-present
u_int32_t bBit = header&0x00001000; // beginning-of-slice
u_int32_t eBit = header&0x00000800; // end-of-slice
fCurrentPacketBeginsFrame = (sBit|bBit) != 0;
fCurrentPacketCompletesFrame = ((sBit&~bBit)|eBit) != 0;
resultSpecialHeaderSize = 4;
return True;
}
Boolean MPEG1or2VideoRTPSource
::packetIsUsableInJitterCalculation(unsigned char* packet,
unsigned packetSize) {
// There's a 4-byte video-specific header
if (packetSize < 4) return False;
// Extract the "Picture-Type" field from this, to determine whether
// this packet can be used in jitter calculations:
unsigned header = ntohl(*(unsigned*)packet);
unsigned short pictureType = (header>>8)&0x7;
if (pictureType == 1) { // an I frame
return True;
} else { // a P, B, D, or other unknown frame type
return False;
}
}
char const* MPEG1or2VideoRTPSource::MIMEtype() const {
return "video/MPEG";
}
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