FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
rtp.h
Go to the documentation of this file.
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 "libavformat/avformat.h"
25 #include "libavcodec/avcodec.h"
26 #include "libavutil/mathematics.h"
27 
28 /**
29  * Return the payload type for a given stream used in the given format context.
30  * Static payload types are derived from the codec.
31  * Dynamic payload type are derived from the id field in AVStream.
32  * The format context private option payload_type overrides both.
33  *
34  * @param fmt The context of the format
35  * @param par The codec parameters
36  * @param idx The stream index
37  * @return The payload type (the 'PT' field in the RTP header).
38  */
40  int idx);
41 
42 /**
43  * Initialize a codec context based on the payload type.
44  *
45  * Fill the codec_type and codec_id fields of a codec context with
46  * information depending on the payload type; for audio codecs, the
47  * channels and sample_rate fields are also filled.
48  *
49  * @param par The codec parameters
50  * @param payload_type The payload type (the 'PT' field in the RTP header)
51  * @return In case of unknown payload type or dynamic payload type, a
52  * negative value is returned; otherwise, 0 is returned
53  */
54 int ff_rtp_get_codec_info(AVCodecParameters *par, int payload_type);
55 
56 /**
57  * Return the encoding name (as defined in
58  * http://www.iana.org/assignments/rtp-parameters) for a given payload type.
59  *
60  * @param payload_type The payload type (the 'PT' field in the RTP header)
61  * @return In case of unknown payload type or dynamic payload type, a pointer
62  * to an empty string is returned; otherwise, a pointer to a string containing
63  * the encoding name is returned
64  */
65 const char *ff_rtp_enc_name(int payload_type);
66 
67 /**
68  * Return the codec id for the given encoding name and codec type.
69  *
70  * @param buf A pointer to the string containing the encoding name
71  * @param codec_type The codec type
72  * @return In case of unknown encoding name, AV_CODEC_ID_NONE is returned;
73  * otherwise, the codec id is returned
74  */
75 enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type);
76 
77 #define RTP_PT_PRIVATE 96
78 #define RTP_VERSION 2
79 #define RTP_MAX_SDES 256 /**< maximum text length for SDES */
80 
81 /* RTCP packets use 0.5% of the bandwidth */
82 #define RTCP_TX_RATIO_NUM 5
83 #define RTCP_TX_RATIO_DEN 1000
84 
85 /* An arbitrary id value for RTP Xiph streams - only relevant to indicate
86  * that the configuration has changed within a stream (by changing the
87  * ident value sent).
88  */
89 #define RTP_XIPH_IDENT 0xfecdba
90 
91 /* RTCP packet types */
92 enum RTCPType {
93  RTCP_FIR = 192,
94  RTCP_NACK, // 193
95  RTCP_SMPTETC,// 194
96  RTCP_IJ, // 195
97  RTCP_SR = 200,
98  RTCP_RR, // 201
99  RTCP_SDES, // 202
100  RTCP_BYE, // 203
101  RTCP_APP, // 204
102  RTCP_RTPFB,// 205
103  RTCP_PSFB, // 206
104  RTCP_XR, // 207
105  RTCP_AVB, // 208
106  RTCP_RSI, // 209
107  RTCP_TOKEN,// 210
108 };
109 
110 #define RTP_PT_IS_RTCP(x) (((x) >= RTCP_FIR && (x) <= RTCP_IJ) || \
111  ((x) >= RTCP_SR && (x) <= RTCP_TOKEN))
112 
113 #define NTP_TO_RTP_FORMAT(x) av_rescale((x), INT64_C(1) << 32, 1000000)
114 
115 #endif /* AVFORMAT_RTP_H */
Definition: rtp.h:105
const char * fmt
Definition: avisynth_c.h:632
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
enum AVMediaType codec_type
Definition: rtp.c:37
Definition: rtp.h:104
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3931
Format I/O context.
Definition: avformat.h:1325
int ff_rtp_get_codec_info(AVCodecParameters *par, int payload_type)
Initialize a codec context based on the payload type.
Definition: rtp.c:71
Definition: rtp.h:99
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:189
Definition: rtp.h:103
Definition: rtp.h:94
Definition: rtp.h:96
Definition: rtp.h:98
Definition: rtp.h:106
RTCPType
Definition: rtp.h:92
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
Definition: rtp.h:93
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
Libavcodec external API header.
Definition: rtp.h:100
void * buf
Definition: avisynth_c.h:553
AVMediaType
Definition: avutil.h:191
Definition: rtp.h:101
Main libavformat public API header.
Definition: rtp.h:97