Remove angular brackets from Doxygen comments; Doxygen confuses them for HTML.
[libav.git] / libavformat / rdt.c
1 /*
2 * Realmedia RTSP protocol (RDT) support.
3 * Copyright (c) 2007 Ronald S. Bultje
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * @brief Realmedia RTSP protocol (RDT) support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
26 */
27
28 #include "avformat.h"
29 #include "libavutil/avstring.h"
30 #include "rtpdec.h"
31 #include "rdt.h"
32 #include "libavutil/base64.h"
33 #include "libavutil/md5.h"
34 #include "rm.h"
35 #include "internal.h"
36 #include "libavcodec/get_bits.h"
37
38 struct RDTDemuxContext {
39 AVFormatContext *ic; /**< the containing (RTSP) demux context */
40 /** Each RDT stream-set (represented by one RTSPStream) can contain
41 * multiple streams (of the same content, but with possibly different
42 * codecs/bitrates). Each such stream is represented by one AVStream
43 * in the AVFormatContext, and this variable points to the offset in
44 * that array such that the first is the first stream of this set. */
45 AVStream **streams;
46 int n_streams; /**< streams with identifical content in this set */
47 void *dynamic_protocol_context;
48 DynamicPayloadPacketHandlerProc parse_packet;
49 uint32_t prev_timestamp;
50 int prev_set_id, prev_stream_id;
51 };
52
53 RDTDemuxContext *
54 ff_rdt_parse_open(AVFormatContext *ic, int first_stream_of_set_idx,
55 void *priv_data, RTPDynamicProtocolHandler *handler)
56 {
57 RDTDemuxContext *s = av_mallocz(sizeof(RDTDemuxContext));
58 if (!s)
59 return NULL;
60
61 s->ic = ic;
62 s->streams = &ic->streams[first_stream_of_set_idx];
63 do {
64 s->n_streams++;
65 } while (first_stream_of_set_idx + s->n_streams < ic->nb_streams &&
66 s->streams[s->n_streams]->priv_data == s->streams[0]->priv_data);
67 s->prev_set_id = -1;
68 s->prev_stream_id = -1;
69 s->prev_timestamp = -1;
70 s->parse_packet = handler ? handler->parse_packet : NULL;
71 s->dynamic_protocol_context = priv_data;
72
73 return s;
74 }
75
76 void
77 ff_rdt_parse_close(RDTDemuxContext *s)
78 {
79 int i;
80
81 for (i = 1; i < s->n_streams; i++)
82 s->streams[i]->priv_data = NULL;
83
84 av_free(s);
85 }
86
87 struct PayloadContext {
88 AVFormatContext *rmctx;
89 RMStream *rmst[MAX_STREAMS];
90 uint8_t *mlti_data;
91 unsigned int mlti_data_size;
92 char buffer[RTP_MAX_PACKET_LENGTH + FF_INPUT_BUFFER_PADDING_SIZE];
93 int audio_pkt_cnt; /**< remaining audio packets in rmdec */
94 };
95
96 void
97 ff_rdt_calc_response_and_checksum(char response[41], char chksum[9],
98 const char *challenge)
99 {
100 int ch_len = strlen (challenge), i;
101 unsigned char zres[16],
102 buf[64] = { 0xa1, 0xe9, 0x14, 0x9d, 0x0e, 0x6b, 0x3b, 0x59 };
103 #define XOR_TABLE_SIZE 37
104 const unsigned char xor_table[XOR_TABLE_SIZE] = {
105 0x05, 0x18, 0x74, 0xd0, 0x0d, 0x09, 0x02, 0x53,
106 0xc0, 0x01, 0x05, 0x05, 0x67, 0x03, 0x19, 0x70,
107 0x08, 0x27, 0x66, 0x10, 0x10, 0x72, 0x08, 0x09,
108 0x63, 0x11, 0x03, 0x71, 0x08, 0x08, 0x70, 0x02,
109 0x10, 0x57, 0x05, 0x18, 0x54 };
110
111 /* some (length) checks */
112 if (ch_len == 40) /* what a hack... */
113 ch_len = 32;
114 else if (ch_len > 56)
115 ch_len = 56;
116 memcpy(buf + 8, challenge, ch_len);
117
118 /* xor challenge bytewise with xor_table */
119 for (i = 0; i < XOR_TABLE_SIZE; i++)
120 buf[8 + i] ^= xor_table[i];
121
122 av_md5_sum(zres, buf, 64);
123 ff_data_to_hex(response, zres, 16, 1);
124
125 /* add tail */
126 strcpy (response + 32, "01d0a8e3");
127
128 /* calculate checksum */
129 for (i = 0; i < 8; i++)
130 chksum[i] = response[i * 4];
131 chksum[8] = 0;
132 }
133
134 static int
135 rdt_load_mdpr (PayloadContext *rdt, AVStream *st, int rule_nr)
136 {
137 ByteIOContext pb;
138 int size;
139 uint32_t tag;
140
141 /**
142 * Layout of the MLTI chunk:
143 * 4: MLTI
144 * 2: number of streams
145 * Then for each stream ([number_of_streams] times):
146 * 2: mdpr index
147 * 2: number of mdpr chunks
148 * Then for each mdpr chunk ([number_of_mdpr_chunks] times):
149 * 4: size
150 * [size]: data
151 * we skip MDPR chunks until we reach the one of the stream
152 * we're interested in, and forward that ([size]+[data]) to
153 * the RM demuxer to parse the stream-specific header data.
154 */
155 if (!rdt->mlti_data)
156 return -1;
157 init_put_byte(&pb, rdt->mlti_data, rdt->mlti_data_size, 0,
158 NULL, NULL, NULL, NULL);
159 tag = get_le32(&pb);
160 if (tag == MKTAG('M', 'L', 'T', 'I')) {
161 int num, chunk_nr;
162
163 /* read index of MDPR chunk numbers */
164 num = get_be16(&pb);
165 if (rule_nr < 0 || rule_nr >= num)
166 return -1;
167 url_fskip(&pb, rule_nr * 2);
168 chunk_nr = get_be16(&pb);
169 url_fskip(&pb, (num - 1 - rule_nr) * 2);
170
171 /* read MDPR chunks */
172 num = get_be16(&pb);
173 if (chunk_nr >= num)
174 return -1;
175 while (chunk_nr--)
176 url_fskip(&pb, get_be32(&pb));
177 size = get_be32(&pb);
178 } else {
179 size = rdt->mlti_data_size;
180 url_fseek(&pb, 0, SEEK_SET);
181 }
182 if (ff_rm_read_mdpr_codecdata(rdt->rmctx, &pb, st, rdt->rmst[st->index], size) < 0)
183 return -1;
184
185 return 0;
186 }
187
188 /**
189 * Actual data handling.
190 */
191
192 int
193 ff_rdt_parse_header(const uint8_t *buf, int len,
194 int *pset_id, int *pseq_no, int *pstream_id,
195 int *pis_keyframe, uint32_t *ptimestamp)
196 {
197 GetBitContext gb;
198 int consumed = 0, set_id, seq_no, stream_id, is_keyframe,
199 len_included, need_reliable;
200 uint32_t timestamp;
201
202 /* skip status packets */
203 while (len >= 5 && buf[1] == 0xFF /* status packet */) {
204 int pkt_len;
205
206 if (!(buf[0] & 0x80))
207 return -1; /* not followed by a data packet */
208
209 pkt_len = AV_RB16(buf+3);
210 buf += pkt_len;
211 len -= pkt_len;
212 consumed += pkt_len;
213 }
214 if (len < 16)
215 return -1;
216 /**
217 * Layout of the header (in bits):
218 * 1: len_included
219 * Flag indicating whether this header includes a length field;
220 * this can be used to concatenate multiple RDT packets in a
221 * single UDP/TCP data frame and is used to precede RDT data
222 * by stream status packets
223 * 1: need_reliable
224 * Flag indicating whether this header includes a "reliable
225 * sequence number"; these are apparently sequence numbers of
226 * data packets alone. For data packets, this flag is always
227 * set, according to the Real documentation [1]
228 * 5: set_id
229 * ID of a set of streams of identical content, possibly with
230 * different codecs or bitrates
231 * 1: is_reliable
232 * Flag set for certain streams deemed less tolerable for packet
233 * loss
234 * 16: seq_no
235 * Packet sequence number; if >=0xFF00, this is a non-data packet
236 * containing stream status info, the second byte indicates the
237 * type of status packet (see wireshark docs / source code [2])
238 * if (len_included) {
239 * 16: packet_len
240 * } else {
241 * packet_len = remainder of UDP/TCP frame
242 * }
243 * 1: is_back_to_back
244 * Back-to-Back flag; used for timing, set for one in every 10
245 * packets, according to the Real documentation [1]
246 * 1: is_slow_data
247 * Slow-data flag; currently unused, according to Real docs [1]
248 * 5: stream_id
249 * ID of the stream within this particular set of streams
250 * 1: is_no_keyframe
251 * Non-keyframe flag (unset if packet belongs to a keyframe)
252 * 32: timestamp (PTS)
253 * if (set_id == 0x1F) {
254 * 16: set_id (extended set-of-streams ID; see set_id)
255 * }
256 * if (need_reliable) {
257 * 16: reliable_seq_no
258 * Reliable sequence number (see need_reliable)
259 * }
260 * if (stream_id == 0x3F) {
261 * 16: stream_id (extended stream ID; see stream_id)
262 * }
263 * [1] https://protocol.helixcommunity.org/files/2005/devdocs/RDT_Feature_Level_20.txt
264 * [2] http://www.wireshark.org/docs/dfref/r/rdt.html and
265 * http://anonsvn.wireshark.org/viewvc/trunk/epan/dissectors/packet-rdt.c
266 */
267 init_get_bits(&gb, buf, len << 3);
268 len_included = get_bits1(&gb);
269 need_reliable = get_bits1(&gb);
270 set_id = get_bits(&gb, 5);
271 skip_bits(&gb, 1);
272 seq_no = get_bits(&gb, 16);
273 if (len_included)
274 skip_bits(&gb, 16);
275 skip_bits(&gb, 2);
276 stream_id = get_bits(&gb, 5);
277 is_keyframe = !get_bits1(&gb);
278 timestamp = get_bits_long(&gb, 32);
279 if (set_id == 0x1f)
280 set_id = get_bits(&gb, 16);
281 if (need_reliable)
282 skip_bits(&gb, 16);
283 if (stream_id == 0x1f)
284 stream_id = get_bits(&gb, 16);
285
286 if (pset_id) *pset_id = set_id;
287 if (pseq_no) *pseq_no = seq_no;
288 if (pstream_id) *pstream_id = stream_id;
289 if (pis_keyframe) *pis_keyframe = is_keyframe;
290 if (ptimestamp) *ptimestamp = timestamp;
291
292 return consumed + (get_bits_count(&gb) >> 3);
293 }
294
295 /**< return 0 on packet, no more left, 1 on packet, 1 on partial packet... */
296 static int
297 rdt_parse_packet (AVFormatContext *ctx, PayloadContext *rdt, AVStream *st,
298 AVPacket *pkt, uint32_t *timestamp,
299 const uint8_t *buf, int len, int flags)
300 {
301 int seq = 1, res;
302 ByteIOContext pb;
303
304 if (rdt->audio_pkt_cnt == 0) {
305 int pos;
306
307 init_put_byte(&pb, buf, len, 0, NULL, NULL, NULL, NULL);
308 flags = (flags & RTP_FLAG_KEY) ? 2 : 0;
309 res = ff_rm_parse_packet (rdt->rmctx, &pb, st, rdt->rmst[st->index], len, pkt,
310 &seq, flags, *timestamp);
311 pos = url_ftell(&pb);
312 if (res < 0)
313 return res;
314 if (res > 0) {
315 if (st->codec->codec_id == CODEC_ID_AAC) {
316 memcpy (rdt->buffer, buf + pos, len - pos);
317 rdt->rmctx->pb = av_alloc_put_byte (rdt->buffer, len - pos, 0,
318 NULL, NULL, NULL, NULL);
319 }
320 goto get_cache;
321 }
322 } else {
323 get_cache:
324 rdt->audio_pkt_cnt =
325 ff_rm_retrieve_cache (rdt->rmctx, rdt->rmctx->pb,
326 st, rdt->rmst[st->index], pkt);
327 if (rdt->audio_pkt_cnt == 0 &&
328 st->codec->codec_id == CODEC_ID_AAC)
329 av_freep(&rdt->rmctx->pb);
330 }
331 pkt->stream_index = st->index;
332 pkt->pts = *timestamp;
333
334 return rdt->audio_pkt_cnt > 0;
335 }
336
337 int
338 ff_rdt_parse_packet(RDTDemuxContext *s, AVPacket *pkt,
339 const uint8_t *buf, int len)
340 {
341 int seq_no, flags = 0, stream_id, set_id, is_keyframe;
342 uint32_t timestamp;
343 int rv= 0;
344
345 if (!s->parse_packet)
346 return -1;
347
348 if (!buf && s->prev_stream_id != -1) {
349 /* return the next packets, if any */
350 timestamp= 0; ///< Should not be used if buf is NULL, but should be set to the timestamp of the packet returned....
351 rv= s->parse_packet(s->ic, s->dynamic_protocol_context,
352 s->streams[s->prev_stream_id],
353 pkt, &timestamp, NULL, 0, flags);
354 return rv;
355 }
356
357 if (len < 12)
358 return -1;
359 rv = ff_rdt_parse_header(buf, len, &set_id, &seq_no, &stream_id, &is_keyframe, &timestamp);
360 if (rv < 0)
361 return rv;
362 if (is_keyframe &&
363 (set_id != s->prev_set_id || timestamp != s->prev_timestamp ||
364 stream_id != s->prev_stream_id)) {
365 flags |= RTP_FLAG_KEY;
366 s->prev_set_id = set_id;
367 s->prev_timestamp = timestamp;
368 }
369 s->prev_stream_id = stream_id;
370 buf += rv;
371 len -= rv;
372
373 if (s->prev_stream_id >= s->n_streams) {
374 s->prev_stream_id = -1;
375 return -1;
376 }
377
378 rv = s->parse_packet(s->ic, s->dynamic_protocol_context,
379 s->streams[s->prev_stream_id],
380 pkt, &timestamp, buf, len, flags);
381
382 return rv;
383 }
384
385 void
386 ff_rdt_subscribe_rule (char *cmd, int size,
387 int stream_nr, int rule_nr)
388 {
389 av_strlcatf(cmd, size, "stream=%d;rule=%d,stream=%d;rule=%d",
390 stream_nr, rule_nr * 2, stream_nr, rule_nr * 2 + 1);
391 }
392
393 static unsigned char *
394 rdt_parse_b64buf (unsigned int *target_len, const char *p)
395 {
396 unsigned char *target;
397 int len = strlen(p);
398 if (*p == '\"') {
399 p++;
400 len -= 2; /* skip embracing " at start/end */
401 }
402 *target_len = len * 3 / 4;
403 target = av_mallocz(*target_len + FF_INPUT_BUFFER_PADDING_SIZE);
404 av_base64_decode(target, p, *target_len);
405 return target;
406 }
407
408 static int
409 rdt_parse_sdp_line (AVFormatContext *s, int st_index,
410 PayloadContext *rdt, const char *line)
411 {
412 AVStream *stream = s->streams[st_index];
413 const char *p = line;
414
415 if (av_strstart(p, "OpaqueData:buffer;", &p)) {
416 rdt->mlti_data = rdt_parse_b64buf(&rdt->mlti_data_size, p);
417 } else if (av_strstart(p, "StartTime:integer;", &p))
418 stream->first_dts = atoi(p);
419 else if (av_strstart(p, "ASMRuleBook:string;", &p)) {
420 int n, first = -1;
421
422 for (n = 0; n < s->nb_streams; n++)
423 if (s->streams[n]->priv_data == stream->priv_data) {
424 if (first == -1) first = n;
425 rdt->rmst[s->streams[n]->index] = ff_rm_alloc_rmstream();
426 rdt_load_mdpr(rdt, s->streams[n], (n - first) * 2);
427
428 if (s->streams[n]->codec->codec_id == CODEC_ID_AAC)
429 s->streams[n]->codec->frame_size = 1; // FIXME
430 }
431 }
432
433 return 0;
434 }
435
436 static void
437 real_parse_asm_rule(AVStream *st, const char *p, const char *end)
438 {
439 do {
440 /* can be either averagebandwidth= or AverageBandwidth= */
441 if (sscanf(p, " %*1[Aa]verage%*1[Bb]andwidth=%d", &st->codec->bit_rate) == 1)
442 break;
443 if (!(p = strchr(p, ',')) || p > end)
444 p = end;
445 p++;
446 } while (p < end);
447 }
448
449 static AVStream *
450 add_dstream(AVFormatContext *s, AVStream *orig_st)
451 {
452 AVStream *st;
453
454 if (!(st = av_new_stream(s, 0)))
455 return NULL;
456 st->codec->codec_type = orig_st->codec->codec_type;
457 st->priv_data = orig_st->priv_data;
458 st->first_dts = orig_st->first_dts;
459
460 return st;
461 }
462
463 static void
464 real_parse_asm_rulebook(AVFormatContext *s, AVStream *orig_st,
465 const char *p)
466 {
467 const char *end;
468 int n_rules, odd = 0;
469 AVStream *st;
470
471 /**
472 * The ASMRuleBook contains a list of comma-separated strings per rule,
473 * and each rule is separated by a ;. The last one also has a ; at the
474 * end so we can use it as delimiter.
475 * Every rule occurs twice, once for when the RTSP packet header marker
476 * is set and once for if it isn't. We only read the first because we
477 * don't care much (that's what the "odd" variable is for).
478 * Each rule contains a set of one or more statements, optionally
479 * preceeded by a single condition. If there's a condition, the rule
480 * starts with a '#'. Multiple conditions are merged between brackets,
481 * so there are never multiple conditions spread out over separate
482 * statements. Generally, these conditions are bitrate limits (min/max)
483 * for multi-bitrate streams.
484 */
485 if (*p == '\"') p++;
486 for (n_rules = 0; s->nb_streams < MAX_STREAMS;) {
487 if (!(end = strchr(p, ';')))
488 break;
489 if (!odd && end != p) {
490 if (n_rules > 0)
491 st = add_dstream(s, orig_st);
492 else
493 st = orig_st;
494 real_parse_asm_rule(st, p, end);
495 n_rules++;
496 }
497 p = end + 1;
498 odd ^= 1;
499 }
500 }
501
502 void
503 ff_real_parse_sdp_a_line (AVFormatContext *s, int stream_index,
504 const char *line)
505 {
506 const char *p = line;
507
508 if (av_strstart(p, "ASMRuleBook:string;", &p))
509 real_parse_asm_rulebook(s, s->streams[stream_index], p);
510 }
511
512 static PayloadContext *
513 rdt_new_context (void)
514 {
515 PayloadContext *rdt = av_mallocz(sizeof(PayloadContext));
516
517 av_open_input_stream(&rdt->rmctx, NULL, "", &rdt_demuxer, NULL);
518
519 return rdt;
520 }
521
522 static void
523 rdt_free_context (PayloadContext *rdt)
524 {
525 int i;
526
527 for (i = 0; i < MAX_STREAMS; i++)
528 if (rdt->rmst[i]) {
529 ff_rm_free_rmstream(rdt->rmst[i]);
530 av_freep(&rdt->rmst[i]);
531 }
532 if (rdt->rmctx)
533 av_close_input_stream(rdt->rmctx);
534 av_freep(&rdt->mlti_data);
535 av_free(rdt);
536 }
537
538 #define RDT_HANDLER(n, s, t) \
539 static RTPDynamicProtocolHandler ff_rdt_ ## n ## _handler = { \
540 .enc_name = s, \
541 .codec_type = t, \
542 .codec_id = CODEC_ID_NONE, \
543 .parse_sdp_a_line = rdt_parse_sdp_line, \
544 .open = rdt_new_context, \
545 .close = rdt_free_context, \
546 .parse_packet = rdt_parse_packet \
547 };
548
549 RDT_HANDLER(live_video, "x-pn-multirate-realvideo-live", AVMEDIA_TYPE_VIDEO);
550 RDT_HANDLER(live_audio, "x-pn-multirate-realaudio-live", AVMEDIA_TYPE_AUDIO);
551 RDT_HANDLER(video, "x-pn-realvideo", AVMEDIA_TYPE_VIDEO);
552 RDT_HANDLER(audio, "x-pn-realaudio", AVMEDIA_TYPE_AUDIO);
553
554 void av_register_rdt_dynamic_payload_handlers(void)
555 {
556 ff_register_dynamic_payload_handler(&ff_rdt_video_handler);
557 ff_register_dynamic_payload_handler(&ff_rdt_audio_handler);
558 ff_register_dynamic_payload_handler(&ff_rdt_live_video_handler);
559 ff_register_dynamic_payload_handler(&ff_rdt_live_audio_handler);
560 }