/*
  * 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 "libavformat/avformat.h"

 #include "libavcodec/avcodec.h"

 #include "libavutil/mathematics.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 codec The context of the codec

  * @param idx   The stream index

  * @return The payload type (the 'PT' field in the RTP header).

  */

 int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecContext *codec,
                             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 codec The context of the codec

  * @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(AVCodecContext *codec, 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 */