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rtpdec.h
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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 FFmpeg.
7  *
8  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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;
34 
35 #define RTP_MIN_PACKET_LENGTH 12
36 #define RTP_MAX_PACKET_LENGTH 8192
37 
38 #define RTP_REORDER_QUEUE_DEFAULT_SIZE 10
39 
40 #define RTP_NOTS_VALUE ((uint32_t)-1)
41 
42 typedef struct RTPDemuxContext RTPDemuxContext;
44  int payload_type, int queue_size);
47 void ff_rtp_parse_set_crypto(RTPDemuxContext *s, const char *suite,
48  const char *params);
50  uint8_t **buf, int len);
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  */
78  AVIOContext *avio, int count);
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.
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  */
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 
120  const char enc_name[50];
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 */
138  int (*need_keyframe)(PayloadContext *context);
139 
141 };
142 
143 typedef struct RTPPacket {
144  uint16_t seq;
146  int len;
147  int64_t recvtime;
148  struct RTPPacket *next;
149 } RTPPacket;
150 
155  uint32_t ssrc;
156  uint16_t seq;
157  uint32_t timestamp;
158  uint32_t base_timestamp;
159  uint32_t cur_timestamp;
163  /* used to send back RTCP RR */
164  char hostname[256];
165 
168 
169  /** Statistics for this stream (used by RTCP receiver reports) */
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 */
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;
191 
192  /* dynamic payload stuff */
195 };
196 
199  enum AVMediaType codec_type);
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 
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 */