ffmpeg/libavformat/rtp.h

118 lines
3.9 KiB
C

/*
* RTP definitions
* Copyright (c) 2002 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVFORMAT_RTP_H
#define AVFORMAT_RTP_H
#include <stdint.h>
#include "libavutil/avutil.h"
#include "libavcodec/codec_id.h"
#include "libavcodec/codec_par.h"
#include "libavformat/avformat.h"
/**
* Return the payload type for a given stream used in the given format context.
* Static payload types are derived from the codec.
* Dynamic payload type are derived from the id field in AVStream.
* The format context private option payload_type overrides both.
*
* @param fmt The context of the format
* @param par The codec parameters
* @param idx The stream index
* @return The payload type (the 'PT' field in the RTP header).
*/
int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecParameters *par,
int idx);
/**
* Initialize a codec context based on the payload type.
*
* Fill the codec_type and codec_id fields of a codec context with
* information depending on the payload type; for audio codecs, the
* channels and sample_rate fields are also filled.
*
* @param par The codec parameters
* @param payload_type The payload type (the 'PT' field in the RTP header)
* @return In case of unknown payload type or dynamic payload type, a
* negative value is returned; otherwise, 0 is returned
*/
int ff_rtp_get_codec_info(AVCodecParameters *par, int payload_type);
/**
* Return the encoding name (as defined in
* http://www.iana.org/assignments/rtp-parameters) for a given payload type.
*
* @param payload_type The payload type (the 'PT' field in the RTP header)
* @return In case of unknown payload type or dynamic payload type, a pointer
* to an empty string is returned; otherwise, a pointer to a string containing
* the encoding name is returned
*/
const char *ff_rtp_enc_name(int payload_type);
/**
* Return the codec id for the given encoding name and codec type.
*
* @param buf A pointer to the string containing the encoding name
* @param codec_type The codec type
* @return In case of unknown encoding name, AV_CODEC_ID_NONE is returned;
* otherwise, the codec id is returned
*/
enum AVCodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type);
#define RTP_PT_PRIVATE 96
#define RTP_VERSION 2
#define RTP_MAX_SDES 256 /**< maximum text length for SDES */
/* RTCP packets use 0.5% of the bandwidth */
#define RTCP_TX_RATIO_NUM 5
#define RTCP_TX_RATIO_DEN 1000
/* An arbitrary id value for RTP Xiph streams - only relevant to indicate
* that the configuration has changed within a stream (by changing the
* ident value sent).
*/
#define RTP_XIPH_IDENT 0xfecdba
/* RTCP packet types */
enum RTCPType {
RTCP_FIR = 192,
RTCP_NACK, // 193
RTCP_SMPTETC,// 194
RTCP_IJ, // 195
RTCP_SR = 200,
RTCP_RR, // 201
RTCP_SDES, // 202
RTCP_BYE, // 203
RTCP_APP, // 204
RTCP_RTPFB,// 205
RTCP_PSFB, // 206
RTCP_XR, // 207
RTCP_AVB, // 208
RTCP_RSI, // 209
RTCP_TOKEN,// 210
};
#define RTP_PT_IS_RTCP(x) (((x) >= RTCP_FIR && (x) <= RTCP_IJ) || \
((x) >= RTCP_SR && (x) <= RTCP_TOKEN))
#define NTP_TO_RTP_FORMAT(x) av_rescale((x), INT64_C(1) << 32, 1000000)
#endif /* AVFORMAT_RTP_H */