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