1/**********
2This library is free software; you can redistribute it and/or modify it under
3the terms of the GNU Lesser General Public License as published by the
4Free Software Foundation; either version 3 of the License, or (at your
5option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
6
7This library is distributed in the hope that it will be useful, but WITHOUT
8ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
9FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
10more details.
11
12You should have received a copy of the GNU Lesser General Public License
13along with this library; if not, write to the Free Software Foundation, Inc.,
1451 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
15**********/
16// "liveMedia"
17// Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved.
18// Collects a stream of incoming MPEG Transport Stream packets into
19// a chunk sufficiently large to send in a single outgoing (RTP or UDP) packet.
20// Implementation
21
22#include "MPEG2TransportStreamAccumulator.hh"
23
24MPEG2TransportStreamAccumulator*
25MPEG2TransportStreamAccumulator::createNew(UsageEnvironment& env,
26 FramedSource* inputSource, unsigned maxPacketSize) {
27 return new MPEG2TransportStreamAccumulator(env, inputSource, maxPacketSize);
28}
29
30#ifndef TRANSPORT_PACKET_SIZE
31#define TRANSPORT_PACKET_SIZE 188
32#endif
33
34MPEG2TransportStreamAccumulator
35::MPEG2TransportStreamAccumulator(UsageEnvironment& env,
36 FramedSource* inputSource, unsigned maxPacketSize)
37 : FramedFilter(env, inputSource),
38 fDesiredPacketSize(maxPacketSize < TRANSPORT_PACKET_SIZE ? TRANSPORT_PACKET_SIZE : (maxPacketSize/TRANSPORT_PACKET_SIZE)),
39 fNumBytesGathered(0) {
40}
41
42MPEG2TransportStreamAccumulator::~MPEG2TransportStreamAccumulator() {
43}
44
45void MPEG2TransportStreamAccumulator::doGetNextFrame() {
46 if (fNumBytesGathered >= fDesiredPacketSize) {
47 // Complete the delivery to the client:
48 fFrameSize = fNumBytesGathered;
49 fNumBytesGathered = 0;
50 afterGetting(this);
51 } else {
52 // Ask for more data (delivered directly to the client's buffer);
53 fInputSource->getNextFrame(fTo, fMaxSize, afterGettingFrame, this,
54 FramedSource::handleClosure, this);
55 }
56}
57
58void MPEG2TransportStreamAccumulator
59::afterGettingFrame(void* clientData, unsigned frameSize,
60 unsigned numTruncatedBytes,
61 struct timeval presentationTime,
62 unsigned durationInMicroseconds) {
63 MPEG2TransportStreamAccumulator* accumulator
64 = (MPEG2TransportStreamAccumulator*)clientData;
65 accumulator->afterGettingFrame1(frameSize, numTruncatedBytes,
66 presentationTime, durationInMicroseconds);
67}
68
69void MPEG2TransportStreamAccumulator
70::afterGettingFrame1(unsigned frameSize,
71 unsigned numTruncatedBytes,
72 struct timeval presentationTime,
73 unsigned durationInMicroseconds) {
74 if (fNumBytesGathered == 0) { // this is the first frame of the new chunk
75 fPresentationTime = presentationTime;
76 fDurationInMicroseconds = 0;
77 }
78 fNumBytesGathered += frameSize;
79 fTo += frameSize;
80 fMaxSize -= frameSize;
81 fDurationInMicroseconds += durationInMicroseconds;
82
83 // Try again to complete delivery:
84 doGetNextFrame();
85}
86