FFmpeg coverage

Line	Branch	Exec	Source
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 "libavutil/mem.h"
31			#include "demux.h"
32			#include "rtpdec.h"
33			#include "rdt.h"
34			#include "libavutil/base64.h"
35			#include "libavutil/md5.h"
36			#include "rm.h"
37			#include "internal.h"
38			#include "avio_internal.h"
39			#include "libavcodec/get_bits.h"
40
41			struct RDTDemuxContext {
42			AVFormatContext *ic; /**< the containing (RTSP) demux context */
43			/** Each RDT stream-set (represented by one RTSPStream) can contain
44			* multiple streams (of the same content, but with possibly different
45			* codecs/bitrates). Each such stream is represented by one AVStream
46			* in the AVFormatContext, and this variable points to the offset in
47			* that array such that the first is the first stream of this set. */
48			AVStream **streams;
49			int n_streams; /**< streams with identical content in this set */
50			void *dynamic_protocol_context;
51			DynamicPayloadPacketHandlerProc parse_packet;
52			uint32_t prev_timestamp;
53			int prev_set_id, prev_stream_id;
54			};
55
56			RDTDemuxContext *
57		✗	ff_rdt_parse_open(AVFormatContext *ic, int first_stream_of_set_idx,
58			void *priv_data, const RTPDynamicProtocolHandler *handler)
59			{
60		✗	RDTDemuxContext *s = av_mallocz(sizeof(RDTDemuxContext));
61		✗	if (!s)
62		✗	return NULL;
63
64		✗	s->ic = ic;
65		✗	s->streams = &ic->streams[first_stream_of_set_idx];
66			do {
67		✗	s->n_streams++;
68		✗	} while (first_stream_of_set_idx + s->n_streams < ic->nb_streams &&
69		✗	s->streams[s->n_streams]->id == s->streams[0]->id);
70		✗	s->prev_set_id = -1;
71		✗	s->prev_stream_id = -1;
72		✗	s->prev_timestamp = -1;
73		✗	s->parse_packet = handler ? handler->parse_packet : NULL;
74		✗	s->dynamic_protocol_context = priv_data;
75
76		✗	return s;
77			}
78
79			void
80		✗	ff_rdt_parse_close(RDTDemuxContext *s)
81			{
82		✗	av_free(s);
83		✗	}
84
85			struct PayloadContext {
86			AVFormatContext *rmctx;
87			int nb_rmst;
88			RMStream **rmst;
89			uint8_t *mlti_data;
90			unsigned int mlti_data_size;
91			char buffer[RTP_MAX_PACKET_LENGTH + AV_INPUT_BUFFER_PADDING_SIZE];
92			int audio_pkt_cnt; /**< remaining audio packets in rmdec */
93			};
94
95			void
96		✗	ff_rdt_calc_response_and_checksum(char response[41], char chksum[9],
97			const char *challenge)
98			{
99		✗	int ch_len = strlen (challenge), i;
100			unsigned char zres[16],
101		✗	buf[64] = { 0xa1, 0xe9, 0x14, 0x9d, 0x0e, 0x6b, 0x3b, 0x59 };
102			#define XOR_TABLE_SIZE 37
103			static const unsigned char xor_table[XOR_TABLE_SIZE] = {
104			0x05, 0x18, 0x74, 0xd0, 0x0d, 0x09, 0x02, 0x53,
105			0xc0, 0x01, 0x05, 0x05, 0x67, 0x03, 0x19, 0x70,
106			0x08, 0x27, 0x66, 0x10, 0x10, 0x72, 0x08, 0x09,
107			0x63, 0x11, 0x03, 0x71, 0x08, 0x08, 0x70, 0x02,
108			0x10, 0x57, 0x05, 0x18, 0x54 };
109
110			/* some (length) checks */
111		✗	if (ch_len == 40) /* what a hack... */
112		✗	ch_len = 32;
113		✗	else if (ch_len > 56)
114		✗	ch_len = 56;
115		✗	memcpy(buf + 8, challenge, ch_len);
116
117			/* xor challenge bytewise with xor_table */
118		✗	for (i = 0; i < XOR_TABLE_SIZE; i++)
119		✗	buf[8 + i] ^= xor_table[i];
120
121		✗	av_md5_sum(zres, buf, 64);
122		✗	ff_data_to_hex(response, zres, 16, 1);
123
124			/* add tail */
125		✗	strcpy (response + 32, "01d0a8e3");
126
127			/* calculate checksum */
128		✗	for (i = 0; i < 8; i++)
129		✗	chksum[i] = response[i * 4];
130		✗	chksum[8] = 0;
131		✗	}
132
133			static int
134		✗	rdt_load_mdpr (PayloadContext *rdt, AVStream *st, int rule_nr)
135			{
136			FFIOContext pb0;
137		✗	AVIOContext *const pb = &pb0.pub;
138			unsigned 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		✗	ffio_init_read_context(&pb0, rdt->mlti_data, rdt->mlti_data_size);
158		✗	tag = avio_rl32(pb);
159		✗	if (tag == MKTAG('M', 'L', 'T', 'I')) {
160			int num, chunk_nr;
161
162			/* read index of MDPR chunk numbers */
163		✗	num = avio_rb16(pb);
164		✗	if (rule_nr < 0 || rule_nr >= num)
165		✗	return -1;
166		✗	avio_skip(pb, rule_nr * 2);
167		✗	chunk_nr = avio_rb16(pb);
168		✗	avio_skip(pb, (num - 1 - rule_nr) * 2);
169
170			/* read MDPR chunks */
171		✗	num = avio_rb16(pb);
172		✗	if (chunk_nr >= num)
173		✗	return -1;
174		✗	while (chunk_nr--)
175		✗	avio_skip(pb, avio_rb32(pb));
176		✗	size = avio_rb32(pb);
177			} else {
178		✗	size = rdt->mlti_data_size;
179		✗	avio_seek(pb, 0, SEEK_SET);
180			}
181		✗	if (ff_rm_read_mdpr_codecdata(rdt->rmctx, pb, st, rdt->rmst[st->index], size, NULL) < 0)
182		✗	return -1;
183
184		✗	return 0;
185			}
186
187			/**
188			* Actual data handling.
189			*/
190
191			int
192		✗	ff_rdt_parse_header(const uint8_t *buf, int len,
193			int *pset_id, int *pseq_no, int *pstream_id,
194			int *pis_keyframe, uint32_t *ptimestamp)
195			{
196			GetBitContext gb;
197		✗	int consumed = 0, set_id, seq_no, stream_id, is_keyframe,
198			len_included, need_reliable;
199			uint32_t timestamp;
200
201			/* skip status packets */
202		✗	while (len >= 5 && buf[1] == 0xFF /* status packet */) {
203			int pkt_len;
204
205		✗	if (!(buf[0] & 0x80))
206		✗	return -1; /* not followed by a data packet */
207
208		✗	pkt_len = AV_RB16(buf+3);
209		✗	if (pkt_len > len)
210		✗	return AVERROR_INVALIDDATA;
211		✗	buf += pkt_len;
212		✗	len -= pkt_len;
213		✗	consumed += pkt_len;
214			}
215		✗	if (len < 16)
216		✗	return -1;
217			/**
218			* Layout of the header (in bits):
219			* 1: len_included
220			* Flag indicating whether this header includes a length field;
221			* this can be used to concatenate multiple RDT packets in a
222			* single UDP/TCP data frame and is used to precede RDT data
223			* by stream status packets
224			* 1: need_reliable
225			* Flag indicating whether this header includes a "reliable
226			* sequence number"; these are apparently sequence numbers of
227			* data packets alone. For data packets, this flag is always
228			* set, according to the Real documentation [1]
229			* 5: set_id
230			* ID of a set of streams of identical content, possibly with
231			* different codecs or bitrates
232			* 1: is_reliable
233			* Flag set for certain streams deemed less tolerable for packet
234			* loss
235			* 16: seq_no
236			* Packet sequence number; if >=0xFF00, this is a non-data packet
237			* containing stream status info, the second byte indicates the
238			* type of status packet (see wireshark docs / source code [2])
239			* if (len_included) {
240			* 16: packet_len
241			* } else {
242			* packet_len = remainder of UDP/TCP frame
243			* }
244			* 1: is_back_to_back
245			* Back-to-Back flag; used for timing, set for one in every 10
246			* packets, according to the Real documentation [1]
247			* 1: is_slow_data
248			* Slow-data flag; currently unused, according to Real docs [1]
249			* 5: stream_id
250			* ID of the stream within this particular set of streams
251			* 1: is_no_keyframe
252			* Non-keyframe flag (unset if packet belongs to a keyframe)
253			* 32: timestamp (PTS)
254			* if (set_id == 0x1F) {
255			* 16: set_id (extended set-of-streams ID; see set_id)
256			* }
257			* if (need_reliable) {
258			* 16: reliable_seq_no
259			* Reliable sequence number (see need_reliable)
260			* }
261			* if (stream_id == 0x3F) {
262			* 16: stream_id (extended stream ID; see stream_id)
263			* }
264			* [1] https://protocol.helixcommunity.org/files/2005/devdocs/RDT_Feature_Level_20.txt
265			* [2] http://www.wireshark.org/docs/dfref/r/rdt.html and
266			* http://anonsvn.wireshark.org/viewvc/trunk/epan/dissectors/packet-rdt.c
267			*/
268		✗	init_get_bits(&gb, buf, len << 3);
269		✗	len_included = get_bits1(&gb);
270		✗	need_reliable = get_bits1(&gb);
271		✗	set_id = get_bits(&gb, 5);
272		✗	skip_bits(&gb, 1);
273		✗	seq_no = get_bits(&gb, 16);
274		✗	if (len_included)
275		✗	skip_bits(&gb, 16);
276		✗	skip_bits(&gb, 2);
277		✗	stream_id = get_bits(&gb, 5);
278		✗	is_keyframe = !get_bits1(&gb);
279		✗	timestamp = get_bits_long(&gb, 32);
280		✗	if (set_id == 0x1f)
281		✗	set_id = get_bits(&gb, 16);
282		✗	if (need_reliable)
283		✗	skip_bits(&gb, 16);
284		✗	if (stream_id == 0x1f)
285		✗	stream_id = get_bits(&gb, 16);
286
287		✗	if (pset_id) *pset_id = set_id;
288		✗	if (pseq_no) *pseq_no = seq_no;
289		✗	if (pstream_id) *pstream_id = stream_id;
290		✗	if (pis_keyframe) *pis_keyframe = is_keyframe;
291		✗	if (ptimestamp) *ptimestamp = timestamp;
292
293		✗	return consumed + (get_bits_count(&gb) >> 3);
294			}
295
296			/** return 0 on packet, no more left, 1 on packet, 1 on partial packet... */
297			static int
298		✗	rdt_parse_packet (AVFormatContext *ctx, PayloadContext *rdt, AVStream *st,
299			AVPacket *pkt, uint32_t *timestamp,
300			const uint8_t *buf, int len, uint16_t rtp_seq, int flags)
301			{
302		✗	int seq = 1, res;
303
304		✗	if (rdt->audio_pkt_cnt == 0) {
305			FFIOContext pb;
306			int pos, rmflags;
307
308		✗	ffio_init_read_context(&pb, buf, len);
309		✗	rmflags = (flags & RTP_FLAG_KEY) ? 2 : 0;
310		✗	res = ff_rm_parse_packet(rdt->rmctx, &pb.pub, st, rdt->rmst[st->index],
311		✗	len, pkt, &seq, rmflags, *timestamp);
312		✗	pos = avio_tell(&pb.pub);
313		✗	if (res < 0)
314		✗	return res;
315		✗	if (res > 0) {
316		✗	if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
317		✗	memcpy (rdt->buffer, buf + pos, len - pos);
318		✗	rdt->rmctx->pb = avio_alloc_context (rdt->buffer, len - pos, 0,
319			NULL, NULL, NULL, NULL);
320			}
321		✗	goto get_cache;
322			}
323			} else {
324		✗	get_cache:
325		✗	rdt->audio_pkt_cnt =
326		✗	ff_rm_retrieve_cache (rdt->rmctx, rdt->rmctx->pb,
327		✗	st, rdt->rmst[st->index], pkt);
328		✗	if (rdt->audio_pkt_cnt == 0 &&
329		✗	st->codecpar->codec_id == AV_CODEC_ID_AAC)
330		✗	avio_context_free(&rdt->rmctx->pb);
331			}
332		✗	pkt->stream_index = st->index;
333		✗	pkt->pts = *timestamp;
334
335		✗	return rdt->audio_pkt_cnt > 0;
336			}
337
338			int
339		✗	ff_rdt_parse_packet(RDTDemuxContext *s, AVPacket *pkt,
340			uint8_t **bufptr, int len)
341			{
342		✗	uint8_t *buf = bufptr ? *bufptr : NULL;
343		✗	int seq_no, flags = 0, stream_id, set_id, is_keyframe;
344			uint32_t timestamp;
345		✗	int rv= 0;
346
347		✗	if (!s->parse_packet)
348		✗	return -1;
349
350		✗	if (!buf && s->prev_stream_id != -1) {
351			/* return the next packets, if any */
352		✗	timestamp= 0; ///< Should not be used if buf is NULL, but should be set to the timestamp of the packet returned....
353		✗	rv= s->parse_packet(s->ic, s->dynamic_protocol_context,
354		✗	s->streams[s->prev_stream_id],
355			pkt, &timestamp, NULL, 0, 0, flags);
356		✗	return rv;
357			}
358
359		✗	if (len < 12)
360		✗	return -1;
361		✗	rv = ff_rdt_parse_header(buf, len, &set_id, &seq_no, &stream_id, &is_keyframe, &timestamp);
362		✗	if (rv < 0)
363		✗	return rv;
364		✗	if (is_keyframe &&
365		✗	(set_id != s->prev_set_id || timestamp != s->prev_timestamp ||
366		✗	stream_id != s->prev_stream_id)) {
367		✗	flags |= RTP_FLAG_KEY;
368		✗	s->prev_set_id = set_id;
369		✗	s->prev_timestamp = timestamp;
370			}
371		✗	s->prev_stream_id = stream_id;
372		✗	buf += rv;
373		✗	len -= rv;
374
375		✗	if (s->prev_stream_id >= s->n_streams) {
376		✗	s->prev_stream_id = -1;
377		✗	return -1;
378			}
379
380		✗	rv = s->parse_packet(s->ic, s->dynamic_protocol_context,
381		✗	s->streams[s->prev_stream_id],
382			pkt, &timestamp, buf, len, 0, flags);
383
384		✗	return rv;
385			}
386
387			void
388		✗	ff_rdt_subscribe_rule (char *cmd, int size,
389			int stream_nr, int rule_nr)
390			{
391		✗	av_strlcatf(cmd, size, "stream=%d;rule=%d,stream=%d;rule=%d",
392		✗	stream_nr, rule_nr * 2, stream_nr, rule_nr * 2 + 1);
393		✗	}
394
395			static unsigned char *
396		✗	rdt_parse_b64buf (unsigned int *target_len, const char *p)
397			{
398			unsigned char *target;
399		✗	int len = strlen(p);
400		✗	if (*p == '\"') {
401		✗	p++;
402		✗	len -= 2; /* skip embracing " at start/end */
403			}
404		✗	*target_len = len * 3 / 4;
405		✗	target = av_mallocz(*target_len + AV_INPUT_BUFFER_PADDING_SIZE);
406		✗	if (!target)
407		✗	return NULL;
408		✗	av_base64_decode(target, p, *target_len);
409		✗	return target;
410			}
411
412			static int
413		✗	rdt_parse_sdp_line (AVFormatContext *s, int st_index,
414			PayloadContext *rdt, const char *line)
415			{
416		✗	AVStream *stream = s->streams[st_index];
417		✗	const char *p = line;
418
419		✗	if (av_strstart(p, "OpaqueData:buffer;", &p)) {
420		✗	rdt->mlti_data = rdt_parse_b64buf(&rdt->mlti_data_size, p);
421		✗	} else if (av_strstart(p, "StartTime:integer;", &p))
422		✗	ffstream(stream)->first_dts = atoi(p);
423		✗	else if (av_strstart(p, "ASMRuleBook:string;", &p)) {
424		✗	int n, first = -1;
425
426		✗	for (n = 0; n < s->nb_streams; n++)
427		✗	if (s->streams[n]->id == stream->id) {
428		✗	int count = s->streams[n]->index + 1, err;
429		✗	if (first == -1) first = n;
430		✗	if (rdt->nb_rmst < count) {
431		✗	if ((err = av_reallocp(&rdt->rmst,
432			count * sizeof(*rdt->rmst))) < 0) {
433		✗	rdt->nb_rmst = 0;
434		✗	return err;
435			}
436		✗	memset(rdt->rmst + rdt->nb_rmst, 0,
437		✗	(count - rdt->nb_rmst) * sizeof(*rdt->rmst));
438		✗	rdt->nb_rmst = count;
439			}
440		✗	rdt->rmst[s->streams[n]->index] = ff_rm_alloc_rmstream();
441		✗	if (!rdt->rmst[s->streams[n]->index])
442		✗	return AVERROR(ENOMEM);
443		✗	rdt_load_mdpr(rdt, s->streams[n], (n - first) * 2);
444			}
445			}
446
447		✗	return 0;
448			}
449
450			static void
451		✗	real_parse_asm_rule(AVStream *st, const char *p, const char *end)
452			{
453			do {
454			/* can be either averagebandwidth= or AverageBandwidth= */
455		✗	if (sscanf(p, " %*1[Aa]verage%*1[Bb]andwidth=%"SCNd64, &st->codecpar->bit_rate) == 1)
456		✗	break;
457		✗	if (!(p = strchr(p, ',')) || p > end)
458		✗	p = end;
459		✗	p++;
460		✗	} while (p < end);
461		✗	}
462
463			static AVStream *
464		✗	add_dstream(AVFormatContext *s, AVStream *orig_st)
465			{
466			AVStream *st;
467
468		✗	if (!(st = avformat_new_stream(s, NULL)))
469		✗	return NULL;
470		✗	st->id = orig_st->id;
471		✗	st->codecpar->codec_type = orig_st->codecpar->codec_type;
472		✗	ffstream(st)->first_dts = ffstream(orig_st)->first_dts;
473
474		✗	return st;
475			}
476
477			static void
478		✗	real_parse_asm_rulebook(AVFormatContext *s, AVStream *orig_st,
479			const char *p)
480			{
481			const char *end;
482		✗	int n_rules = 0, odd = 0;
483			AVStream *st;
484
485			/**
486			* The ASMRuleBook contains a list of comma-separated strings per rule,
487			* and each rule is separated by a ;. The last one also has a ; at the
488			* end so we can use it as delimiter.
489			* Every rule occurs twice, once for when the RTSP packet header marker
490			* is set and once for if it isn't. We only read the first because we
491			* don't care much (that's what the "odd" variable is for).
492			* Each rule contains a set of one or more statements, optionally
493			* preceded by a single condition. If there's a condition, the rule
494			* starts with a '#'. Multiple conditions are merged between brackets,
495			* so there are never multiple conditions spread out over separate
496			* statements. Generally, these conditions are bitrate limits (min/max)
497			* for multi-bitrate streams.
498			*/
499		✗	if (*p == '\"') p++;
500			while (1) {
501		✗	if (!(end = strchr(p, ';')))
502		✗	break;
503		✗	if (!odd && end != p) {
504		✗	if (n_rules > 0)
505		✗	st = add_dstream(s, orig_st);
506			else
507		✗	st = orig_st;
508		✗	if (!st)
509		✗	break;
510		✗	real_parse_asm_rule(st, p, end);
511		✗	n_rules++;
512			}
513		✗	p = end + 1;
514		✗	odd ^= 1;
515			}
516		✗	}
517
518			void
519		✗	ff_real_parse_sdp_a_line (AVFormatContext *s, int stream_index,
520			const char *line)
521			{
522		✗	const char *p = line;
523
524		✗	if (av_strstart(p, "ASMRuleBook:string;", &p))
525		✗	real_parse_asm_rulebook(s, s->streams[stream_index], p);
526		✗	}
527
528
529
530		✗	static av_cold int rdt_init(AVFormatContext *s, int st_index, PayloadContext *rdt)
531			{
532			int ret;
533
534		✗	rdt->rmctx = avformat_alloc_context();
535		✗	if (!rdt->rmctx)
536		✗	return AVERROR(ENOMEM);
537
538		✗	if ((ret = ff_copy_whiteblacklists(rdt->rmctx, s)) < 0)
539		✗	return ret;
540
541		✗	return avformat_open_input(&rdt->rmctx, "", &ff_rdt_demuxer.p, NULL);
542			}
543
544			static void
545		✗	rdt_close_context (PayloadContext *rdt)
546			{
547			int i;
548
549		✗	for (i = 0; i < rdt->nb_rmst; i++)
550		✗	if (rdt->rmst[i]) {
551		✗	ff_rm_free_rmstream(rdt->rmst[i]);
552		✗	av_freep(&rdt->rmst[i]);
553			}
554		✗	if (rdt->rmctx)
555		✗	avformat_close_input(&rdt->rmctx);
556		✗	av_freep(&rdt->mlti_data);
557		✗	av_freep(&rdt->rmst);
558		✗	}
559
560			#define RDT_HANDLER(n, s, t) \
561			const RTPDynamicProtocolHandler ff_rdt_ ## n ## _handler = { \
562			.enc_name = s, \
563			.codec_type = t, \
564			.codec_id = AV_CODEC_ID_NONE, \
565			.priv_data_size = sizeof(PayloadContext), \
566			.init = rdt_init, \
567			.parse_sdp_a_line = rdt_parse_sdp_line, \
568			.close = rdt_close_context, \
569			.parse_packet = rdt_parse_packet \
570			}
571
572			RDT_HANDLER(live_video, "x-pn-multirate-realvideo-live", AVMEDIA_TYPE_VIDEO);
573			RDT_HANDLER(live_audio, "x-pn-multirate-realaudio-live", AVMEDIA_TYPE_AUDIO);
574			RDT_HANDLER(video, "x-pn-realvideo", AVMEDIA_TYPE_VIDEO);
575			RDT_HANDLER(audio, "x-pn-realaudio", AVMEDIA_TYPE_AUDIO);
576