libavformat/rtpdec.h

   1 /*
   2  * RTP demuxer definitions
   3  * Copyright (c) 2002 Fabrice Bellard
   4  * Copyright (c) 2006 Ryan Martell <rdm4@martellventures.com>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #ifndef AVFORMAT_RTPDEC_H
  24 #define AVFORMAT_RTPDEC_H
  25
  26 #include "libavcodec/avcodec.h"
  27 #include "avformat.h"
  28 #include "rtp.h"
  29 #include "url.h"
  30 #include "srtp.h"
  31
  32 typedef struct PayloadContext PayloadContext;
  33 typedef struct RTPDynamicProtocolHandler RTPDynamicProtocolHandler;
  34
  35 #define RTP_MIN_PACKET_LENGTH 12
  36 #define RTP_MAX_PACKET_LENGTH 1500
  37
  38 #define RTP_REORDER_QUEUE_DEFAULT_SIZE 10
  39
  40 #define RTP_NOTS_VALUE ((uint32_t)-1)
  41
  42 typedef struct RTPDemuxContext RTPDemuxContext;
  43 RTPDemuxContext *ff_rtp_parse_open(AVFormatContext *s1, AVStream *st,
  44                                    int payload_type, int queue_size);
  45 void ff_rtp_parse_set_dynamic_protocol(RTPDemuxContext *s, PayloadContext *ctx,
  46                                        RTPDynamicProtocolHandler *handler);
  47 void ff_rtp_parse_set_crypto(RTPDemuxContext *s, const char *suite,
  48                              const char *params);
  49 int ff_rtp_parse_packet(RTPDemuxContext *s, AVPacket *pkt,
  50                         uint8_t **buf, int len);
  51 void ff_rtp_parse_close(RTPDemuxContext *s);
  52 int64_t ff_rtp_queued_packet_time(RTPDemuxContext *s);
  53 void ff_rtp_reset_packet_queue(RTPDemuxContext *s);
  54 int ff_rtp_get_local_rtp_port(URLContext *h);
  55 int ff_rtp_get_local_rtcp_port(URLContext *h);
  56
  57 int ff_rtp_set_remote_url(URLContext *h, const char *uri);
  58
  59 /**
  60  * Send a dummy packet on both port pairs to set up the connection
  61  * state in potential NAT routers, so that we're able to receive
  62  * packets.
  63  *
  64  * Note, this only works if the NAT router doesn't remap ports. This
  65  * isn't a standardized procedure, but it works in many cases in practice.
  66  *
  67  * The same routine is used with RDT too, even if RDT doesn't use normal
  68  * RTP packets otherwise.
  69  */
  70 void ff_rtp_send_punch_packets(URLContext* rtp_handle);
  71
  72 /**
  73  * some rtp servers assume client is dead if they don't hear from them...
  74  * so we send a Receiver Report to the provided URLContext or AVIOContext
  75  * (we don't have access to the rtcp handle from here)
  76  */
  77 int ff_rtp_check_and_send_back_rr(RTPDemuxContext *s, URLContext *fd,
  78                                   AVIOContext *avio, int count);
  79 int ff_rtp_send_rtcp_feedback(RTPDemuxContext *s, URLContext *fd,
  80                               AVIOContext *avio);
  81
  82 // these statistics are used for rtcp receiver reports...
  83 typedef struct RTPStatistics {
  84     uint16_t max_seq;           ///< highest sequence number seen
  85     uint32_t cycles;            ///< shifted count of sequence number cycles
  86     uint32_t base_seq;          ///< base sequence number
  87     uint32_t bad_seq;           ///< last bad sequence number + 1
  88     int probation;              ///< sequence packets till source is valid
  89     uint32_t received;          ///< packets received
  90     uint32_t expected_prior;    ///< packets expected in last interval
  91     uint32_t received_prior;    ///< packets received in last interval
  92     uint32_t transit;           ///< relative transit time for previous packet
  93     uint32_t jitter;            ///< estimated jitter.
  94 } RTPStatistics;
  95
  96 #define RTP_FLAG_KEY    0x1 ///< RTP packet contains a keyframe
  97 #define RTP_FLAG_MARKER 0x2 ///< RTP marker bit was set for this packet
  98 /**
  99  * Packet parsing for "private" payloads in the RTP specs.
 100  *
 101  * @param ctx RTSP demuxer context
 102  * @param s stream context
 103  * @param st stream that this packet belongs to
 104  * @param pkt packet in which to write the parsed data
 105  * @param timestamp pointer to the RTP timestamp of the input data, can be
 106  *                  updated by the function if returning older, buffered data
 107  * @param buf pointer to raw RTP packet data
 108  * @param len length of buf
 109  * @param seq RTP sequence number of the packet
 110  * @param flags flags from the RTP packet header (RTP_FLAG_*)
 111  */
 112 typedef int (*DynamicPayloadPacketHandlerProc)(AVFormatContext *ctx,
 113                                                PayloadContext *s,
 114                                                AVStream *st, AVPacket *pkt,
 115                                                uint32_t *timestamp,
 116                                                const uint8_t * buf,
 117                                                int len, uint16_t seq, int flags);
 118
 119 struct RTPDynamicProtocolHandler {
 120     const char enc_name[50];
 121     enum AVMediaType codec_type;
 122     enum AVCodecID codec_id;
 123     int static_payload_id; /* 0 means no payload id is set. 0 is a valid
 124                             * payload ID (PCMU), too, but that format doesn't
 125                             * require any custom depacketization code. */
 126
 127     /** Initialize dynamic protocol handler, called after the full rtpmap line is parsed, may be null */
 128     int (*init)(AVFormatContext *s, int st_index, PayloadContext *priv_data);
 129     /** Parse the a= line from the sdp field */
 130     int (*parse_sdp_a_line)(AVFormatContext *s, int st_index,
 131                             PayloadContext *priv_data, const char *line);
 132     /** Allocate any data needed by the rtp parsing for this dynamic data. */
 133     PayloadContext *(*alloc)(void);
 134     /** Free any data needed by the rtp parsing for this dynamic data. */
 135     void (*free)(PayloadContext *protocol_data);
 136     /** Parse handler for this dynamic packet */
 137     DynamicPayloadPacketHandlerProc parse_packet;
 138     int (*need_keyframe)(PayloadContext *context);
 139
 140     struct RTPDynamicProtocolHandler *next;
 141 };
 142
 143 typedef struct RTPPacket {
 144     uint16_t seq;
 145     uint8_t *buf;
 146     int len;
 147     int64_t recvtime;
 148     struct RTPPacket *next;
 149 } RTPPacket;
 150
 151 struct RTPDemuxContext {
 152     AVFormatContext *ic;
 153     AVStream *st;
 154     int payload_type;
 155     uint32_t ssrc;
 156     uint16_t seq;
 157     uint32_t timestamp;
 158     uint32_t base_timestamp;
 159     uint32_t cur_timestamp;
 160     int64_t  unwrapped_timestamp;
 161     int64_t  range_start_offset;
 162     int max_payload_size;
 163     /* used to send back RTCP RR */
 164     char hostname[256];
 165
 166     int srtp_enabled;
 167     struct SRTPContext srtp;
 168
 169     /** Statistics for this stream (used by RTCP receiver reports) */
 170     RTPStatistics statistics;
 171
 172     /** Fields for packet reordering @{ */
 173     int prev_ret;     ///< The return value of the actual parsing of the previous packet
 174     RTPPacket* queue; ///< A sorted queue of buffered packets not yet returned
 175     int queue_len;    ///< The number of packets in queue
 176     int queue_size;   ///< The size of queue, or 0 if reordering is disabled
 177     /*@}*/
 178
 179     /* rtcp sender statistics receive */
 180     int64_t last_rtcp_ntp_time;
 181     int64_t last_rtcp_reception_time;
 182     int64_t first_rtcp_ntp_time;
 183     uint32_t last_rtcp_timestamp;
 184     int64_t rtcp_ts_offset;
 185
 186     /* rtcp sender statistics */
 187     unsigned int packet_count;
 188     unsigned int octet_count;
 189     unsigned int last_octet_count;
 190     int64_t last_feedback_time;
 191
 192     /* dynamic payload stuff */
 193     const RTPDynamicProtocolHandler *handler;
 194     PayloadContext *dynamic_protocol_context;
 195 };
 196
 197 void ff_register_dynamic_payload_handler(RTPDynamicProtocolHandler *handler);
 198 RTPDynamicProtocolHandler *ff_rtp_handler_find_by_name(const char *name,
 199                                                   enum AVMediaType codec_type);
 200 RTPDynamicProtocolHandler *ff_rtp_handler_find_by_id(int id,
 201                                                 enum AVMediaType codec_type);
 202
 203 /* from rtsp.c, but used by rtp dynamic protocol handlers. */
 204 int ff_rtsp_next_attr_and_value(const char **p, char *attr, int attr_size,
 205                                 char *value, int value_size);
 206
 207 int ff_parse_fmtp(AVStream *stream, PayloadContext *data, const char *p,
 208                   int (*parse_fmtp)(AVStream *stream,
 209                                     PayloadContext *data,
 210                                     char *attr, char *value));
 211
 212 void av_register_rtp_dynamic_payload_handlers(void);
 213
 214 /**
 215  * Close the dynamic buffer and make a packet from it.
 216  */
 217 int ff_rtp_finalize_packet(AVPacket *pkt, AVIOContext **dyn_buf, int stream_idx);
 218
 219 #endif /* AVFORMAT_RTPDEC_H */