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// A class for generating MPEG-2 Transport Stream from one or more input
19// Elementary Stream data sources
20// C++ header
21
22#ifndef _MPEG2_TRANSPORT_STREAM_MULTIPLEXOR_HH
23#define _MPEG2_TRANSPORT_STREAM_MULTIPLEXOR_HH
24
25#ifndef _FRAMED_SOURCE_HH
26#include "FramedSource.hh"
27#endif
28#ifndef _MPEG_1OR2_DEMUX_HH
29#include "MPEG1or2Demux.hh" // for SCR
30#endif
31
32#define PID_TABLE_SIZE 0x2000 // 2^13
33
34class MPEG2TransportStreamMultiplexor: public FramedSource {
35public:
36 typedef void (onEndOfSegmentFunc)(void* clientData, double segmentDuration);
37 void setTimedSegmentation(unsigned segmentationDuration,
38 onEndOfSegmentFunc* onEndOfSegmentFunc = NULL,
39 void* onEndOfSegmentClientData = NULL);
40 // Specifies that PAT and PMT packets should be output every "segmentationDuration" seconds.
41 // (If "segmentationDuration" is 0 (the default value), then PAT and PMT packets are output
42 // at a preset frequency.)
43 // The optional function "onEndOfSegmentFunc" is called after each segment is output.
44 double currentSegmentDuration() const { return fCurrentSegmentDuration; }
45 // Valid only if "setTimedSegmentation()" was previously called with "segmentationDuration" > 0
46
47 Boolean canDeliverNewFrameImmediately() const { return fInputBufferBytesUsed < fInputBufferSize; }
48 // Can be used by a downstream reader to test whether the next call to "doGetNextFrame()"
49 // will deliver data immediately).
50
51protected:
52 MPEG2TransportStreamMultiplexor(UsageEnvironment& env);
53 virtual ~MPEG2TransportStreamMultiplexor();
54
55 virtual void awaitNewBuffer(unsigned char* oldBuffer) = 0;
56 // implemented by subclasses
57
58 void handleNewBuffer(unsigned char* buffer, unsigned bufferSize,
59 int mpegVersion, MPEG1or2Demux::SCR scr, int16_t PID = -1);
60 // called by "awaitNewBuffer()"
61 // Note: For MPEG-4 video, set "mpegVersion" to 4; for H.264 video, set "mpegVersion" to 5;
62 // for H.265 video, set "mpegVersion" to 6.
63 // For Opus audio, set "mpegVersion" to 3.
64 // The buffer is assumed to be a PES packet, with a proper PES header.
65 // If "PID" is not -1, then it (currently, only the low 8 bits) is used as the stream's PID,
66 // otherwise the "stream_id" in the PES header is reused to be the stream's PID.
67
68private:
69 // Redefined virtual functions:
70 virtual Boolean isMPEG2TransportStreamMultiplexor() const;
71 virtual void doGetNextFrame();
72
73private:
74 void deliverDataToClient(u_int16_t pid, unsigned char* buffer, unsigned bufferSize,
75 unsigned& startPositionInBuffer);
76
77 void deliverPATPacket();
78 void deliverPMTPacket(Boolean hasChanged);
79
80 void setProgramStreamMap(unsigned frameSize);
81
82protected:
83 Boolean fHaveVideoStreams;
84
85private:
86 unsigned fOutgoingPacketCounter;
87 unsigned fProgramMapVersion;
88 u_int8_t fPreviousInputProgramMapVersion, fCurrentInputProgramMapVersion;
89 // These two fields are used if we see "program_stream_map"s in the input.
90 struct {
91 unsigned counter;
92 u_int8_t streamType; // for use in Program Maps
93 } fPIDState[PID_TABLE_SIZE];
94 u_int16_t fPCR_PID, fCurrentPID; // only the low 13 bits are used
95 MPEG1or2Demux::SCR fPCR;
96 unsigned char* fInputBuffer;
97 unsigned fInputBufferSize, fInputBufferBytesUsed;
98 Boolean fIsFirstAdaptationField;
99 unsigned fSegmentationDuration;
100 // if nonzero, this is the number of seconds between successive 'segments'. Each 'segment'
101 // begins with a PAT, followed by a PMT.
102 // if zero (the default value), then the frequency of PATs and PMTs depends on the constants
103 // PAT_PERIOD_IF_UNTIMED and PMT_PERIOD_IF_UNTIMED, defined in the .cpp file.
104 Boolean segmentationIsTimed() const { return fSegmentationDuration > 0; }
105 u_int8_t fSegmentationIndication;
106 // used only if fSegmentationDuration > 0:
107 // 1 if a segment has just ended and the next packet is to be a PAT
108 // 2 if a segment has just ended and the following PAT has been sent; a PMT is next
109 // 0 otherwise
110 double fCurrentSegmentDuration, fPreviousPTS; // used only if fSegmentationDuration > 0
111 onEndOfSegmentFunc* fOnEndOfSegmentFunc; // used only if fSegmentationDuration > 0
112 void* fOnEndOfSegmentClientData; // ditto
113};
114
115
116// The CRC calculation function that Transport Streams use. We make this function public
117// here in case it's useful elsewhere:
118u_int32_t calculateCRC(u_int8_t const* data, unsigned dataLength, u_int32_t initialValue = 0xFFFFFFFF);
119
120#endif
121