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 <stdint.h> 25 #include "libavutil/avutil.h" 26 #include "libavcodec/codec_id.h" 27 #include "libavcodec/codec_par.h" 28 #include "libavformat/avformat.h" 29 30 /** 31 * Return the payload type for a given stream used in the given format context. 32 * Static payload types are derived from the codec. 33 * Dynamic payload type are derived from the id field in AVStream. 34 * The format context private option payload_type overrides both. 35 * 36 * @param fmt The context of the format 37 * @param par The codec parameters 38 * @param idx The stream index 39 * @return The payload type (the 'PT' field in the RTP header). 40 */ 41 int ff_rtp_get_payload_type(const AVFormatContext *fmt, 42 const AVCodecParameters *par, int idx); 43 44 /** 45 * Initialize a codec context based on the payload type. 46 * 47 * Fill the codec_type and codec_id fields of a codec context with 48 * information depending on the payload type; for audio codecs, the 49 * channels and sample_rate fields are also filled. 50 * 51 * @param par The codec parameters 52 * @param payload_type The payload type (the 'PT' field in the RTP header) 53 * @return In case of unknown payload type or dynamic payload type, a 54 * negative value is returned; otherwise, 0 is returned 55 */ 56 int ff_rtp_get_codec_info(AVCodecParameters *par, int payload_type); 57 58 /** 59 * Return the encoding name (as defined in 60 * http://www.iana.org/assignments/rtp-parameters) for a given payload type. 61 * 62 * @param payload_type The payload type (the 'PT' field in the RTP header) 63 * @return In case of unknown payload type or dynamic payload type, a pointer 64 * to an empty string is returned; otherwise, a pointer to a string containing 65 * the encoding name is returned 66 */ 67 const char *ff_rtp_enc_name(int payload_type); 68 69 /** 70 * Return the codec id for the given encoding name and codec type. 71 * 72 * @param buf A pointer to the string containing the encoding name 73 * @param codec_type The codec type 74 * @return In case of unknown encoding name, AV_CODEC_ID_NONE is returned; 75 * otherwise, the codec id is returned 76 */ 77 enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type); 78 79 #define RTP_PT_PRIVATE 96 80 #define RTP_VERSION 2 81 #define RTP_MAX_SDES 256 /**< maximum text length for SDES */ 82 83 /* RTCP packets use 0.5% of the bandwidth */ 84 #define RTCP_TX_RATIO_NUM 5 85 #define RTCP_TX_RATIO_DEN 1000 86 87 /* An arbitrary id value for RTP Xiph streams - only relevant to indicate 88 * that the configuration has changed within a stream (by changing the 89 * ident value sent). 90 */ 91 #define RTP_XIPH_IDENT 0xfecdba 92 93 /* RTCP packet types */ 94 enum RTCPType { 95 RTCP_FIR = 192, 96 RTCP_NACK, // 193 97 RTCP_SMPTETC,// 194 98 RTCP_IJ, // 195 99 RTCP_SR = 200, 100 RTCP_RR, // 201 101 RTCP_SDES, // 202 102 RTCP_BYE, // 203 103 RTCP_APP, // 204 104 RTCP_RTPFB,// 205 105 RTCP_PSFB, // 206 106 RTCP_XR, // 207 107 RTCP_AVB, // 208 108 RTCP_RSI, // 209 109 RTCP_TOKEN,// 210 110 }; 111 112 #define RTP_PT_IS_RTCP(x) (((x) >= RTCP_FIR && (x) <= RTCP_IJ) || \ 113 ((x) >= RTCP_SR && (x) <= RTCP_TOKEN)) 114 115 #define NTP_TO_RTP_FORMAT(x) av_rescale((x), INT64_C(1) << 32, 1000000) 116 117 #endif /* AVFORMAT_RTP_H */ 118