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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);
54 
55 /**
56  * Send a dummy packet on both port pairs to set up the connection
57  * state in potential NAT routers, so that we're able to receive
58  * packets.
59  *
60  * Note, this only works if the NAT router doesn't remap ports. This
61  * isn't a standardized procedure, but it works in many cases in practice.
62  *
63  * The same routine is used with RDT too, even if RDT doesn't use normal
64  * RTP packets otherwise.
65  */
66 void ff_rtp_send_punch_packets(URLContext* rtp_handle);
67 
68 /**
69  * some rtp servers assume client is dead if they don't hear from them...
70  * so we send a Receiver Report to the provided URLContext or AVIOContext
71  * (we don't have access to the rtcp handle from here)
72  */
74  AVIOContext *avio, int count);
76  AVIOContext *avio);
77 
78 // these statistics are used for rtcp receiver reports...
79 typedef struct RTPStatistics {
80  uint16_t max_seq; ///< highest sequence number seen
81  uint32_t cycles; ///< shifted count of sequence number cycles
82  uint32_t base_seq; ///< base sequence number
83  uint32_t bad_seq; ///< last bad sequence number + 1
84  int probation; ///< sequence packets till source is valid
85  uint32_t received; ///< packets received
86  uint32_t expected_prior; ///< packets expected in last interval
87  uint32_t received_prior; ///< packets received in last interval
88  uint32_t transit; ///< relative transit time for previous packet
89  uint32_t jitter; ///< estimated jitter.
91 
92 #define RTP_FLAG_KEY 0x1 ///< RTP packet contains a keyframe
93 #define RTP_FLAG_MARKER 0x2 ///< RTP marker bit was set for this packet
94 /**
95  * Packet parsing for "private" payloads in the RTP specs.
96  *
97  * @param ctx RTSP demuxer context
98  * @param s stream context
99  * @param st stream that this packet belongs to
100  * @param pkt packet in which to write the parsed data
101  * @param timestamp pointer to the RTP timestamp of the input data, can be
102  * updated by the function if returning older, buffered data
103  * @param buf pointer to raw RTP packet data
104  * @param len length of buf
105  * @param seq RTP sequence number of the packet
106  * @param flags flags from the RTP packet header (RTP_FLAG_*)
107  */
109  PayloadContext *s,
110  AVStream *st, AVPacket *pkt,
111  uint32_t *timestamp,
112  const uint8_t * buf,
113  int len, uint16_t seq, int flags);
114 
116  const char enc_name[50];
119  int static_payload_id; /* 0 means no payload id is set. 0 is a valid
120  * payload ID (PCMU), too, but that format doesn't
121  * require any custom depacketization code. */
122 
123  /** Initialize dynamic protocol handler, called after the full rtpmap line is parsed, may be null */
124  int (*init)(AVFormatContext *s, int st_index, PayloadContext *priv_data);
125  /** Parse the a= line from the sdp field */
126  int (*parse_sdp_a_line)(AVFormatContext *s, int st_index,
127  PayloadContext *priv_data, const char *line);
128  /** Allocate any data needed by the rtp parsing for this dynamic data. */
129  PayloadContext *(*alloc)(void);
130  /** Free any data needed by the rtp parsing for this dynamic data. */
131  void (*free)(PayloadContext *protocol_data);
132  /** Parse handler for this dynamic packet */
134  int (*need_keyframe)(PayloadContext *context);
135 
137 };
138 
139 typedef struct RTPPacket {
140  uint16_t seq;
142  int len;
143  int64_t recvtime;
144  struct RTPPacket *next;
145 } RTPPacket;
146 
151  uint32_t ssrc;
152  uint16_t seq;
153  uint32_t timestamp;
154  uint32_t base_timestamp;
155  uint32_t cur_timestamp;
159  /* used to send back RTCP RR */
160  char hostname[256];
161 
164 
165  /** Statistics for this stream (used by RTCP receiver reports) */
167 
168  /** Fields for packet reordering @{ */
169  int prev_ret; ///< The return value of the actual parsing of the previous packet
170  RTPPacket* queue; ///< A sorted queue of buffered packets not yet returned
171  int queue_len; ///< The number of packets in queue
172  int queue_size; ///< The size of queue, or 0 if reordering is disabled
173  /*@}*/
174 
175  /* rtcp sender statistics receive */
180  int64_t rtcp_ts_offset;
181 
182  /* rtcp sender statistics */
183  unsigned int packet_count;
184  unsigned int octet_count;
185  unsigned int last_octet_count;
187 
188  /* dynamic payload stuff */
191 };
192 
195  enum AVMediaType codec_type);
197  enum AVMediaType codec_type);
198 
199 /* from rtsp.c, but used by rtp dynamic protocol handlers. */
200 int ff_rtsp_next_attr_and_value(const char **p, char *attr, int attr_size,
201  char *value, int value_size);
202 
203 int ff_parse_fmtp(AVStream *stream, PayloadContext *data, const char *p,
204  int (*parse_fmtp)(AVStream *stream,
205  PayloadContext *data,
206  char *attr, char *value));
207 
209 
210 /**
211  * Close the dynamic buffer and make a packet from it.
212  */
213 int ff_rtp_finalize_packet(AVPacket *pkt, AVIOContext **dyn_buf, int stream_idx);
214 
215 #endif /* AVFORMAT_RTPDEC_H */