/*
  * RTP demuxer definitions
  * Copyright (c) 2002 Fabrice Bellard
  * Copyright (c) 2006 Ryan Martell <rdm4@martellventures.com>
  *
  * 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_RTPDEC_H
 #define AVFORMAT_RTPDEC_H
 
 #include "libavcodec/avcodec.h"
 #include "avformat.h"
 #include "rtp.h"

 #include "url.h"

 #include "srtp.h"

 
 typedef struct PayloadContext PayloadContext;

 typedef struct RTPDynamicProtocolHandler RTPDynamicProtocolHandler;

 
 #define RTP_MIN_PACKET_LENGTH 12

 #define RTP_MAX_PACKET_LENGTH 8192

 #define RTP_REORDER_QUEUE_DEFAULT_SIZE 10
 

 #define RTP_NOTS_VALUE ((uint32_t)-1)
 

 typedef struct RTPDemuxContext RTPDemuxContext;

 RTPDemuxContext *ff_rtp_parse_open(AVFormatContext *s1, AVStream *st,

                                    int payload_type, int queue_size);

 void ff_rtp_parse_set_dynamic_protocol(RTPDemuxContext *s, PayloadContext *ctx,
                                        RTPDynamicProtocolHandler *handler);

 void ff_rtp_parse_set_crypto(RTPDemuxContext *s, const char *suite,
                              const char *params);

 int ff_rtp_parse_packet(RTPDemuxContext *s, AVPacket *pkt,
                         uint8_t **buf, int len);
 void ff_rtp_parse_close(RTPDemuxContext *s);

 int64_t ff_rtp_queued_packet_time(RTPDemuxContext *s);
 void ff_rtp_reset_packet_queue(RTPDemuxContext *s);

 
 /**

  * Send a dummy packet on both port pairs to set up the connection
  * state in potential NAT routers, so that we're able to receive
  * packets.
  *
  * Note, this only works if the NAT router doesn't remap ports. This
  * isn't a standardized procedure, but it works in many cases in practice.
  *
  * The same routine is used with RDT too, even if RDT doesn't use normal
  * RTP packets otherwise.
  */

 void ff_rtp_send_punch_packets(URLContext* rtp_handle);

 
 /**

  * some rtp servers assume client is dead if they don't hear from them...

  * so we send a Receiver Report to the provided URLContext or AVIOContext

  * (we don't have access to the rtcp handle from here)
  */

 int ff_rtp_check_and_send_back_rr(RTPDemuxContext *s, URLContext *fd,
                                   AVIOContext *avio, int count);

 int ff_rtp_send_rtcp_feedback(RTPDemuxContext *s, URLContext *fd,
                               AVIOContext *avio);

 
 // these statistics are used for rtcp receiver reports...

 typedef struct RTPStatistics {

     uint16_t max_seq;           ///< highest sequence number seen
     uint32_t cycles;            ///< shifted count of sequence number cycles
     uint32_t base_seq;          ///< base sequence number
     uint32_t bad_seq;           ///< last bad sequence number + 1
     int probation;              ///< sequence packets till source is valid

     uint32_t received;          ///< packets received
     uint32_t expected_prior;    ///< packets expected in last interval
     uint32_t received_prior;    ///< packets received in last interval

     uint32_t transit;           ///< relative transit time for previous packet
     uint32_t jitter;            ///< estimated jitter.
 } RTPStatistics;
 

 #define RTP_FLAG_KEY    0x1 ///< RTP packet contains a keyframe

 #define RTP_FLAG_MARKER 0x2 ///< RTP marker bit was set for this packet

 /**
  * Packet parsing for "private" payloads in the RTP specs.
  *
  * @param ctx RTSP demuxer context
  * @param s stream context
  * @param st stream that this packet belongs to
  * @param pkt packet in which to write the parsed data

  * @param timestamp pointer to the RTP timestamp of the input data, can be
  *                  updated by the function if returning older, buffered data

  * @param buf pointer to raw RTP packet data
  * @param len length of buf

  * @param seq RTP sequence number of the packet

  * @param flags flags from the RTP packet header (RTP_FLAG_*)

  */

 typedef int (*DynamicPayloadPacketHandlerProc)(AVFormatContext *ctx,
                                                PayloadContext *s,
                                                AVStream *st, AVPacket *pkt,
                                                uint32_t *timestamp,
                                                const uint8_t * buf,

                                                int len, uint16_t seq, int flags);

 struct RTPDynamicProtocolHandler {

     const char enc_name[50];

     enum AVMediaType codec_type;

     enum AVCodecID codec_id;

     int static_payload_id; /* 0 means no payload id is set. 0 is a valid
                             * payload ID (PCMU), too, but that format doesn't
                             * require any custom depacketization code. */

     /** Initialize dynamic protocol handler, called after the full rtpmap line is parsed, may be null */
     int (*init)(AVFormatContext *s, int st_index, PayloadContext *priv_data);
     /** Parse the a= line from the sdp field */
     int (*parse_sdp_a_line)(AVFormatContext *s, int st_index,
                             PayloadContext *priv_data, const char *line);
     /** Allocate any data needed by the rtp parsing for this dynamic data. */
     PayloadContext *(*alloc)(void);
     /** Free any data needed by the rtp parsing for this dynamic data. */
     void (*free)(PayloadContext *protocol_data);
     /** Parse handler for this dynamic packet */
     DynamicPayloadPacketHandlerProc parse_packet;

     int (*need_keyframe)(PayloadContext *context);

     struct RTPDynamicProtocolHandler *next;

 };
 

 typedef struct RTPPacket {
     uint16_t seq;
     uint8_t *buf;
     int len;
     int64_t recvtime;
     struct RTPPacket *next;
 } RTPPacket;
 

 struct RTPDemuxContext {
     AVFormatContext *ic;
     AVStream *st;
     int payload_type;
     uint32_t ssrc;
     uint16_t seq;
     uint32_t timestamp;
     uint32_t base_timestamp;
     uint32_t cur_timestamp;

     int64_t  unwrapped_timestamp;

     int64_t  range_start_offset;

     int max_payload_size;
     /* used to send back RTCP RR */
     char hostname[256];
 

     int srtp_enabled;
     struct SRTPContext srtp;
 

     /** Statistics for this stream (used by RTCP receiver reports) */
     RTPStatistics statistics;

     /** Fields for packet reordering @{ */
     int prev_ret;     ///< The return value of the actual parsing of the previous packet
     RTPPacket* queue; ///< A sorted queue of buffered packets not yet returned
     int queue_len;    ///< The number of packets in queue
     int queue_size;   ///< The size of queue, or 0 if reordering is disabled
     /*@}*/
 

     /* rtcp sender statistics receive */

     int64_t last_rtcp_ntp_time;

     int64_t last_rtcp_reception_time;

     int64_t first_rtcp_ntp_time;
     uint32_t last_rtcp_timestamp;

     int64_t rtcp_ts_offset;

 
     /* rtcp sender statistics */

     unsigned int packet_count;
     unsigned int octet_count;
     unsigned int last_octet_count;

     int64_t last_feedback_time;
 

     /* dynamic payload stuff */

     const RTPDynamicProtocolHandler *handler;

     PayloadContext *dynamic_protocol_context;

 };
 
 void ff_register_dynamic_payload_handler(RTPDynamicProtocolHandler *handler);

 RTPDynamicProtocolHandler *ff_rtp_handler_find_by_name(const char *name,
                                                   enum AVMediaType codec_type);
 RTPDynamicProtocolHandler *ff_rtp_handler_find_by_id(int id,
                                                 enum AVMediaType codec_type);

 /* from rtsp.c, but used by rtp dynamic protocol handlers. */
 int ff_rtsp_next_attr_and_value(const char **p, char *attr, int attr_size,
                                 char *value, int value_size);

 int ff_parse_fmtp(AVStream *stream, PayloadContext *data, const char *p,
                   int (*parse_fmtp)(AVStream *stream,
                                     PayloadContext *data,
                                     char *attr, char *value));
 

 void ff_register_rtp_dynamic_payload_handlers(void);

 /**
  * Close the dynamic buffer and make a packet from it.
  */
 int ff_rtp_finalize_packet(AVPacket *pkt, AVIOContext **dyn_buf, int stream_idx);
 

 #endif /* AVFORMAT_RTPDEC_H */