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rtp.c
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1 /*
2  * RTP input/output format
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 
22 #include "libavutil/avstring.h"
23 #include "libavutil/opt.h"
24 #include "avformat.h"
25 
26 #include "rtp.h"
27 
28 /* from http://www.iana.org/assignments/rtp-parameters last updated 05 January 2005 */
29 /* payload types >= 96 are dynamic;
30  * payload types between 72 and 76 are reserved for RTCP conflict avoidance;
31  * all the other payload types not present in the table are unassigned or
32  * reserved
33  */
34 static const struct {
35  int pt;
36  const char enc_name[6];
37  enum AVMediaType codec_type;
38  enum AVCodecID codec_id;
39  int clock_rate;
40  int audio_channels;
41 } rtp_payload_types[] = {
42  {0, "PCMU", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_PCM_MULAW, 8000, 1},
43  {3, "GSM", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 8000, 1},
44  {4, "G723", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_G723_1, 8000, 1},
45  {5, "DVI4", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 8000, 1},
46  {6, "DVI4", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 16000, 1},
47  {7, "LPC", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 8000, 1},
48  {8, "PCMA", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_PCM_ALAW, 8000, 1},
49  {9, "G722", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_ADPCM_G722, 8000, 1},
50  {10, "L16", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_PCM_S16BE, 44100, 2},
51  {11, "L16", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_PCM_S16BE, 44100, 1},
52  {12, "QCELP", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_QCELP, 8000, 1},
53  {13, "CN", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 8000, 1},
54  {14, "MPA", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP2, -1, -1},
55  {14, "MPA", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP3, -1, -1},
56  {15, "G728", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 8000, 1},
57  {16, "DVI4", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 11025, 1},
58  {17, "DVI4", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 22050, 1},
59  {18, "G729", AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_NONE, 8000, 1},
60  {25, "CelB", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_NONE, 90000, -1},
61  {26, "JPEG", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MJPEG, 90000, -1},
62  {28, "nv", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_NONE, 90000, -1},
63  {31, "H261", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_H261, 90000, -1},
64  {32, "MPV", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG1VIDEO, 90000, -1},
65  {32, "MPV", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG2VIDEO, 90000, -1},
66  {33, "MP2T", AVMEDIA_TYPE_DATA, AV_CODEC_ID_MPEG2TS, 90000, -1},
67  {34, "H263", AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_H263, 90000, -1},
68  {-1, "", AVMEDIA_TYPE_UNKNOWN, AV_CODEC_ID_NONE, -1, -1}
69 };
70 
71 int ff_rtp_get_codec_info(AVCodecContext *codec, int payload_type)
72 {
73  int i = 0;
74 
75  for (i = 0; rtp_payload_types[i].pt >= 0; i++)
76  if (rtp_payload_types[i].pt == payload_type) {
77  if (rtp_payload_types[i].codec_id != AV_CODEC_ID_NONE) {
78  codec->codec_type = rtp_payload_types[i].codec_type;
79  codec->codec_id = rtp_payload_types[i].codec_id;
80  if (rtp_payload_types[i].audio_channels > 0)
81  codec->channels = rtp_payload_types[i].audio_channels;
82  if (rtp_payload_types[i].clock_rate > 0)
83  codec->sample_rate = rtp_payload_types[i].clock_rate;
84  return 0;
85  }
86  }
87  return -1;
88 }
89 
90 int ff_rtp_get_payload_type(AVFormatContext *fmt,
91  AVCodecContext *codec, int idx)
92 {
93  int i;
94  AVOutputFormat *ofmt = fmt ? fmt->oformat : NULL;
95 
96  /* Was the payload type already specified for the RTP muxer? */
97  if (ofmt && ofmt->priv_class && fmt->priv_data) {
98  int64_t payload_type;
99  if (av_opt_get_int(fmt->priv_data, "payload_type", 0, &payload_type) >= 0 &&
100  payload_type >= 0)
101  return (int)payload_type;
102  }
103 
104  /* static payload type */
105  for (i = 0; rtp_payload_types[i].pt >= 0; ++i)
106  if (rtp_payload_types[i].codec_id == codec->codec_id) {
107  if (codec->codec_id == AV_CODEC_ID_H263 && (!fmt || !fmt->oformat ||
108  !fmt->oformat->priv_class || !fmt->priv_data ||
109  !av_opt_flag_is_set(fmt->priv_data, "rtpflags", "rfc2190")))
110  continue;
111  /* G722 has 8000 as nominal rate even if the sample rate is 16000,
112  * see section 4.5.2 in RFC 3551. */
113  if (codec->codec_id == AV_CODEC_ID_ADPCM_G722 &&
114  codec->sample_rate == 16000 && codec->channels == 1)
115  return rtp_payload_types[i].pt;
116  if (codec->codec_type == AVMEDIA_TYPE_AUDIO &&
117  ((rtp_payload_types[i].clock_rate > 0 &&
118  codec->sample_rate != rtp_payload_types[i].clock_rate) ||
119  (rtp_payload_types[i].audio_channels > 0 &&
120  codec->channels != rtp_payload_types[i].audio_channels)))
121  continue;
122  return rtp_payload_types[i].pt;
123  }
124 
125  if (idx < 0)
126  idx = codec->codec_type == AVMEDIA_TYPE_AUDIO;
127 
128  /* dynamic payload type */
129  return RTP_PT_PRIVATE + idx;
130 }
131 
132 const char *ff_rtp_enc_name(int payload_type)
133 {
134  int i;
135 
136  for (i = 0; rtp_payload_types[i].pt >= 0; i++)
137  if (rtp_payload_types[i].pt == payload_type)
138  return rtp_payload_types[i].enc_name;
139 
140  return "";
141 }
142 
143 enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type)
144 {
145  int i;
146 
147  for (i = 0; rtp_payload_types[i].pt >= 0; i++)
148  if (!av_strcasecmp(buf, rtp_payload_types[i].enc_name) && (codec_type == rtp_payload_types[i].codec_type))
149  return rtp_payload_types[i].codec_id;
150 
151  return AV_CODEC_ID_NONE;
152 }
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