FFmpeg
rtp.h
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1 /*
2  * RTP definitions
3  * Copyright (c) 2002 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 #ifndef AVFORMAT_RTP_H
22 #define AVFORMAT_RTP_H
23 
24 #include <stdint.h>
25 #include "libavutil/avutil.h"
26 #include "libavcodec/codec_id.h"
27 #include "libavcodec/codec_par.h"
28 #include "libavformat/avformat.h"
29 
30 /**
31  * Return the payload type for a given stream used in the given format context.
32  * Static payload types are derived from the codec.
33  * Dynamic payload type are derived from the id field in AVStream.
34  * The format context private option payload_type overrides both.
35  *
36  * @param fmt The context of the format
37  * @param par The codec parameters
38  * @param idx The stream index
39  * @return The payload type (the 'PT' field in the RTP header).
40  */
42  int idx);
43 
44 /**
45  * Initialize a codec context based on the payload type.
46  *
47  * Fill the codec_type and codec_id fields of a codec context with
48  * information depending on the payload type; for audio codecs, the
49  * channels and sample_rate fields are also filled.
50  *
51  * @param par The codec parameters
52  * @param payload_type The payload type (the 'PT' field in the RTP header)
53  * @return In case of unknown payload type or dynamic payload type, a
54  * negative value is returned; otherwise, 0 is returned
55  */
56 int ff_rtp_get_codec_info(AVCodecParameters *par, int payload_type);
57 
58 /**
59  * Return the encoding name (as defined in
60  * http://www.iana.org/assignments/rtp-parameters) for a given payload type.
61  *
62  * @param payload_type The payload type (the 'PT' field in the RTP header)
63  * @return In case of unknown payload type or dynamic payload type, a pointer
64  * to an empty string is returned; otherwise, a pointer to a string containing
65  * the encoding name is returned
66  */
67 const char *ff_rtp_enc_name(int payload_type);
68 
69 /**
70  * Return the codec id for the given encoding name and codec type.
71  *
72  * @param buf A pointer to the string containing the encoding name
73  * @param codec_type The codec type
74  * @return In case of unknown encoding name, AV_CODEC_ID_NONE is returned;
75  * otherwise, the codec id is returned
76  */
77 enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type);
78 
79 #define RTP_PT_PRIVATE 96
80 #define RTP_VERSION 2
81 #define RTP_MAX_SDES 256 /**< maximum text length for SDES */
82 
83 /* RTCP packets use 0.5% of the bandwidth */
84 #define RTCP_TX_RATIO_NUM 5
85 #define RTCP_TX_RATIO_DEN 1000
86 
87 /* An arbitrary id value for RTP Xiph streams - only relevant to indicate
88  * that the configuration has changed within a stream (by changing the
89  * ident value sent).
90  */
91 #define RTP_XIPH_IDENT 0xfecdba
92 
93 /* RTCP packet types */
94 enum RTCPType {
95  RTCP_FIR = 192,
96  RTCP_NACK, // 193
97  RTCP_SMPTETC,// 194
98  RTCP_IJ, // 195
99  RTCP_SR = 200,
100  RTCP_RR, // 201
101  RTCP_SDES, // 202
102  RTCP_BYE, // 203
103  RTCP_APP, // 204
104  RTCP_RTPFB,// 205
105  RTCP_PSFB, // 206
106  RTCP_XR, // 207
107  RTCP_AVB, // 208
108  RTCP_RSI, // 209
109  RTCP_TOKEN,// 210
110 };
111 
112 #define RTP_PT_IS_RTCP(x) (((x) >= RTCP_FIR && (x) <= RTCP_IJ) || \
113  ((x) >= RTCP_SR && (x) <= RTCP_TOKEN))
114 
115 #define NTP_TO_RTP_FORMAT(x) av_rescale((x), INT64_C(1) << 32, 1000000)
116 
117 #endif /* AVFORMAT_RTP_H */
RTCP_AVB
@ RTCP_AVB
Definition: rtp.h:107
ff_rtp_codec_id
enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type)
Return the codec id for the given encoding name and codec type.
Definition: rtp.c:143
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
ff_rtp_enc_name
const char * ff_rtp_enc_name(int payload_type)
Return the encoding name (as defined in http://www.iana.org/assignments/rtp-parameters) for a given p...
Definition: rtp.c:132
ff_rtp_get_payload_type
int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecParameters *par, int idx)
Return the payload type for a given stream used in the given format context.
Definition: rtp.c:90
RTCP_SMPTETC
@ RTCP_SMPTETC
Definition: rtp.h:97
RTCP_IJ
@ RTCP_IJ
Definition: rtp.h:98
RTCP_XR
@ RTCP_XR
Definition: rtp.h:106
codec_type
enum AVMediaType codec_type
Definition: rtp.c:37
RTCP_NACK
@ RTCP_NACK
Definition: rtp.h:96
codec_id.h
RTCP_TOKEN
@ RTCP_TOKEN
Definition: rtp.h:109
AVFormatContext
Format I/O context.
Definition: avformat.h:1107
RTCP_SDES
@ RTCP_SDES
Definition: rtp.h:101
RTCP_PSFB
@ RTCP_PSFB
Definition: rtp.h:105
RTCP_RR
@ RTCP_RR
Definition: rtp.h:100
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
RTCP_APP
@ RTCP_APP
Definition: rtp.h:103
AVMediaType
AVMediaType
Definition: avutil.h:199
RTCP_RSI
@ RTCP_RSI
Definition: rtp.h:108
ff_rtp_get_codec_info
int ff_rtp_get_codec_info(AVCodecParameters *par, int payload_type)
Initialize a codec context based on the payload type.
Definition: rtp.c:71
RTCP_BYE
@ RTCP_BYE
Definition: rtp.h:102
RTCP_FIR
@ RTCP_FIR
Definition: rtp.h:95
avformat.h
RTCP_RTPFB
@ RTCP_RTPFB
Definition: rtp.h:104
RTCP_SR
@ RTCP_SR
Definition: rtp.h:99
avutil.h
RTCPType
RTCPType
Definition: rtp.h:94
codec_par.h