FFmpeg: libavformat/rtp.c Source File

00001 /*
00002  * RTP input/output format
00003  * Copyright (c) 2002 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include <libavutil/opt.h>
00023 #include "avformat.h"
00024 
00025 #include "rtp.h"
00026 
00027 //#define DEBUG
00028 
00029 /* from http://www.iana.org/assignments/rtp-parameters last updated 05 January 2005 */
00030 /* payload types >= 96 are dynamic;
00031  * payload types between 72 and 76 are reserved for RTCP conflict avoidance;
00032  * all the other payload types not present in the table are unassigned or
00033  * reserved
00034  */
00035 static const struct
00036 {
00037     int pt;
00038     const char enc_name[6];
00039     enum AVMediaType codec_type;
00040     enum AVCodecID codec_id;
00041     int clock_rate;
00042     int audio_channels;
00043 } AVRtpPayloadTypes[]=
00044 {
00045   {0, "PCMU",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_PCM_MULAW, 8000, 1},
00046   {3, "GSM",         AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 8000, 1},
00047   {4, "G723",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_G723_1, 8000, 1},
00048   {5, "DVI4",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 8000, 1},
00049   {6, "DVI4",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 16000, 1},
00050   {7, "LPC",         AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 8000, 1},
00051   {8, "PCMA",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_PCM_ALAW, 8000, 1},
00052   {9, "G722",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_ADPCM_G722, 8000, 1},
00053   {10, "L16",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_PCM_S16BE, 44100, 2},
00054   {11, "L16",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_PCM_S16BE, 44100, 1},
00055   {12, "QCELP",      AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_QCELP, 8000, 1},
00056   {13, "CN",         AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 8000, 1},
00057   {14, "MPA",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_MP2, -1, -1},
00058   {14, "MPA",        AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_MP3, -1, -1},
00059   {15, "G728",       AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 8000, 1},
00060   {16, "DVI4",       AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 11025, 1},
00061   {17, "DVI4",       AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 22050, 1},
00062   {18, "G729",       AVMEDIA_TYPE_AUDIO,   AV_CODEC_ID_NONE, 8000, 1},
00063   {25, "CelB",       AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_NONE, 90000, -1},
00064   {26, "JPEG",       AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_MJPEG, 90000, -1},
00065   {28, "nv",         AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_NONE, 90000, -1},
00066   {31, "H261",       AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_H261, 90000, -1},
00067   {32, "MPV",        AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_MPEG1VIDEO, 90000, -1},
00068   {32, "MPV",        AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_MPEG2VIDEO, 90000, -1},
00069   {33, "MP2T",       AVMEDIA_TYPE_DATA,    AV_CODEC_ID_MPEG2TS, 90000, -1},
00070   {34, "H263",       AVMEDIA_TYPE_VIDEO,   AV_CODEC_ID_H263, 90000, -1},
00071   {-1, "",           AVMEDIA_TYPE_UNKNOWN, AV_CODEC_ID_NONE, -1, -1}
00072 };
00073 
00074 int ff_rtp_get_codec_info(AVCodecContext *codec, int payload_type)
00075 {
00076     int i = 0;
00077 
00078     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; i++)
00079         if (AVRtpPayloadTypes[i].pt == payload_type) {
00080             if (AVRtpPayloadTypes[i].codec_id != AV_CODEC_ID_NONE) {
00081                 codec->codec_type = AVRtpPayloadTypes[i].codec_type;
00082                 codec->codec_id = AVRtpPayloadTypes[i].codec_id;
00083                 if (AVRtpPayloadTypes[i].audio_channels > 0)
00084                     codec->channels = AVRtpPayloadTypes[i].audio_channels;
00085                 if (AVRtpPayloadTypes[i].clock_rate > 0)
00086                     codec->sample_rate = AVRtpPayloadTypes[i].clock_rate;
00087                 return 0;
00088             }
00089         }
00090     return -1;
00091 }
00092 
00093 int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecContext *codec)
00094 {
00095     int i;
00096     AVOutputFormat *ofmt = fmt ? fmt->oformat : NULL;
00097 
00098     /* Was the payload type already specified for the RTP muxer? */
00099     if (ofmt && ofmt->priv_class) {
00100         int64_t payload_type;
00101         if (av_opt_get_int(fmt->priv_data, "payload_type", 0, &payload_type) >= 0 &&
00102             payload_type >= 0)
00103             return (int)payload_type;
00104     }
00105 
00106     /* static payload type */
00107     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; ++i)
00108         if (AVRtpPayloadTypes[i].codec_id == codec->codec_id) {
00109             if (codec->codec_id == AV_CODEC_ID_H263 && (!fmt ||
00110                 !fmt->oformat->priv_class ||
00111                 !av_opt_flag_is_set(fmt->priv_data, "rtpflags", "rfc2190")))
00112                 continue;
00113             /* G722 has 8000 as nominal rate even if the sample rate is 16000,
00114              * see section 4.5.2 in RFC 3551. */
00115             if (codec->codec_id == AV_CODEC_ID_ADPCM_G722 &&
00116                 codec->sample_rate == 16000 && codec->channels == 1)
00117                 return AVRtpPayloadTypes[i].pt;
00118             if (codec->codec_type == AVMEDIA_TYPE_AUDIO &&
00119                 ((AVRtpPayloadTypes[i].clock_rate > 0 &&
00120                   codec->sample_rate != AVRtpPayloadTypes[i].clock_rate) ||
00121                  (AVRtpPayloadTypes[i].audio_channels > 0 &&
00122                   codec->channels != AVRtpPayloadTypes[i].audio_channels)))
00123                 continue;
00124             return AVRtpPayloadTypes[i].pt;
00125         }
00126 
00127     /* dynamic payload type */
00128     return RTP_PT_PRIVATE + (codec->codec_type == AVMEDIA_TYPE_AUDIO);
00129 }
00130 
00131 const char *ff_rtp_enc_name(int payload_type)
00132 {
00133     int i;
00134 
00135     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; i++)
00136         if (AVRtpPayloadTypes[i].pt == payload_type) {
00137             return AVRtpPayloadTypes[i].enc_name;
00138         }
00139 
00140     return "";
00141 }
00142 
00143 enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type)
00144 {
00145     int i;
00146 
00147     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; i++)
00148         if (!strcmp(buf, AVRtpPayloadTypes[i].enc_name) && (codec_type == AVRtpPayloadTypes[i].codec_type)){
00149             return AVRtpPayloadTypes[i].codec_id;
00150         }
00151 
00152     return AV_CODEC_ID_NONE;
00153 }