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libavformat/rtp.c

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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 "avformat.h"
00023 
00024 #include "rtp.h"
00025 
00026 //#define DEBUG
00027 
00028 /* from http://www.iana.org/assignments/rtp-parameters last updated 05 January 2005 */
00029 /* payload types >= 96 are dynamic;
00030  * payload types between 72 and 76 are reserved for RTCP conflict avoidance;
00031  * all the other payload types not present in the table are unassigned or
00032  * reserved
00033  */
00034 static const struct
00035 {
00036     int pt;
00037     const char enc_name[6];
00038     enum AVMediaType codec_type;
00039     enum CodecID codec_id;
00040     int clock_rate;
00041     int audio_channels;
00042 } AVRtpPayloadTypes[]=
00043 {
00044   {0, "PCMU",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_PCM_MULAW, 8000, 1},
00045   {3, "GSM",         AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00046   {4, "G723",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00047   {5, "DVI4",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00048   {6, "DVI4",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 16000, 1},
00049   {7, "LPC",         AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00050   {8, "PCMA",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_PCM_ALAW, 8000, 1},
00051   {9, "G722",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00052   {10, "L16",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_PCM_S16BE, 44100, 2},
00053   {11, "L16",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_PCM_S16BE, 44100, 1},
00054   {12, "QCELP",      AVMEDIA_TYPE_AUDIO,   CODEC_ID_QCELP, 8000, 1},
00055   {13, "CN",         AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00056   {14, "MPA",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_MP2, -1, -1},
00057   {14, "MPA",        AVMEDIA_TYPE_AUDIO,   CODEC_ID_MP3, -1, -1},
00058   {15, "G728",       AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00059   {16, "DVI4",       AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 11025, 1},
00060   {17, "DVI4",       AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 22050, 1},
00061   {18, "G729",       AVMEDIA_TYPE_AUDIO,   CODEC_ID_NONE, 8000, 1},
00062   {25, "CelB",       AVMEDIA_TYPE_VIDEO,   CODEC_ID_NONE, 90000, -1},
00063   {26, "JPEG",       AVMEDIA_TYPE_VIDEO,   CODEC_ID_MJPEG, 90000, -1},
00064   {28, "nv",         AVMEDIA_TYPE_VIDEO,   CODEC_ID_NONE, 90000, -1},
00065   {31, "H261",       AVMEDIA_TYPE_VIDEO,   CODEC_ID_H261, 90000, -1},
00066   {32, "MPV",        AVMEDIA_TYPE_VIDEO,   CODEC_ID_MPEG1VIDEO, 90000, -1},
00067   {32, "MPV",        AVMEDIA_TYPE_VIDEO,   CODEC_ID_MPEG2VIDEO, 90000, -1},
00068   {33, "MP2T",       AVMEDIA_TYPE_DATA,    CODEC_ID_MPEG2TS, 90000, -1},
00069   {34, "H263",       AVMEDIA_TYPE_VIDEO,   CODEC_ID_H263, 90000, -1},
00070   {-1, "",           AVMEDIA_TYPE_UNKNOWN, CODEC_ID_NONE, -1, -1}
00071 };
00072 
00073 int ff_rtp_get_codec_info(AVCodecContext *codec, int payload_type)
00074 {
00075     int i = 0;
00076 
00077     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; i++)
00078         if (AVRtpPayloadTypes[i].pt == payload_type) {
00079             if (AVRtpPayloadTypes[i].codec_id != CODEC_ID_NONE) {
00080                 codec->codec_type = AVRtpPayloadTypes[i].codec_type;
00081                 codec->codec_id = AVRtpPayloadTypes[i].codec_id;
00082                 if (AVRtpPayloadTypes[i].audio_channels > 0)
00083                     codec->channels = AVRtpPayloadTypes[i].audio_channels;
00084                 if (AVRtpPayloadTypes[i].clock_rate > 0)
00085                     codec->sample_rate = AVRtpPayloadTypes[i].clock_rate;
00086                 return 0;
00087             }
00088         }
00089     return -1;
00090 }
00091 
00092 int ff_rtp_get_payload_type(AVCodecContext *codec)
00093 {
00094     int i, payload_type;
00095 
00096     /* compute the payload type */
00097     for (payload_type = -1, i = 0; AVRtpPayloadTypes[i].pt >= 0; ++i)
00098         if (AVRtpPayloadTypes[i].codec_id == codec->codec_id) {
00099             if (codec->codec_id == CODEC_ID_H263)
00100                 continue;
00101             if (codec->codec_id == CODEC_ID_PCM_S16BE)
00102                 if (codec->channels != AVRtpPayloadTypes[i].audio_channels)
00103                     continue;
00104             payload_type = AVRtpPayloadTypes[i].pt;
00105         }
00106     return payload_type;
00107 }
00108 
00109 const char *ff_rtp_enc_name(int payload_type)
00110 {
00111     int i;
00112 
00113     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; i++)
00114         if (AVRtpPayloadTypes[i].pt == payload_type) {
00115             return AVRtpPayloadTypes[i].enc_name;
00116         }
00117 
00118     return "";
00119 }
00120 
00121 enum CodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type)
00122 {
00123     int i;
00124 
00125     for (i = 0; AVRtpPayloadTypes[i].pt >= 0; i++)
00126         if (!strcmp(buf, AVRtpPayloadTypes[i].enc_name) && (codec_type == AVRtpPayloadTypes[i].codec_type)){
00127             return AVRtpPayloadTypes[i].codec_id;
00128         }
00129 
00130     return CODEC_ID_NONE;
00131 }

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