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