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