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 (st->index >= rdt->nb_rmst || !rdt->rmst[st->index])
305		✗	return AVERROR_INVALIDDATA;
306
307		✗	if (rdt->audio_pkt_cnt == 0) {
308			FFIOContext pb;
309			int pos, rmflags;
310
311		✗	ffio_init_read_context(&pb, buf, len);
312		✗	rmflags = (flags & RTP_FLAG_KEY) ? 2 : 0;
313		✗	res = ff_rm_parse_packet(rdt->rmctx, &pb.pub, st, rdt->rmst[st->index],
314		✗	len, pkt, &seq, rmflags, *timestamp);
315		✗	pos = avio_tell(&pb.pub);
316		✗	if (res < 0)
317		✗	return res;
318		✗	if (res > 0) {
319		✗	if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
320		✗	if (len - pos > sizeof(rdt->buffer))
321		✗	return AVERROR_INVALIDDATA;
322		✗	memcpy (rdt->buffer, buf + pos, len - pos);
323		✗	rdt->rmctx->pb = avio_alloc_context (rdt->buffer, len - pos, 0,
324			NULL, NULL, NULL, NULL);
325			}
326		✗	goto get_cache;
327			}
328			} else {
329		✗	get_cache:
330		✗	rdt->audio_pkt_cnt =
331		✗	ff_rm_retrieve_cache (rdt->rmctx, rdt->rmctx->pb,
332		✗	st, rdt->rmst[st->index], pkt);
333		✗	if (rdt->audio_pkt_cnt == 0 &&
334		✗	st->codecpar->codec_id == AV_CODEC_ID_AAC)
335		✗	avio_context_free(&rdt->rmctx->pb);
336			}
337		✗	pkt->stream_index = st->index;
338		✗	pkt->pts = *timestamp;
339
340		✗	return rdt->audio_pkt_cnt > 0;
341			}
342
343			int
344		✗	ff_rdt_parse_packet(RDTDemuxContext *s, AVPacket *pkt,
345			uint8_t **bufptr, int len)
346			{
347		✗	uint8_t *buf = bufptr ? *bufptr : NULL;
348		✗	int seq_no, flags = 0, stream_id, set_id, is_keyframe;
349			uint32_t timestamp;
350		✗	int rv= 0;
351
352		✗	if (!s->parse_packet)
353		✗	return -1;
354
355		✗	if (!buf && s->prev_stream_id != -1) {
356			/* return the next packets, if any */
357		✗	timestamp= 0; ///< Should not be used if buf is NULL, but should be set to the timestamp of the packet returned....
358		✗	rv= s->parse_packet(s->ic, s->dynamic_protocol_context,
359		✗	s->streams[s->prev_stream_id],
360			pkt, &timestamp, NULL, 0, 0, flags);
361		✗	return rv;
362			}
363
364		✗	if (len < 12)
365		✗	return -1;
366		✗	rv = ff_rdt_parse_header(buf, len, &set_id, &seq_no, &stream_id, &is_keyframe, &timestamp);
367		✗	if (rv < 0)
368		✗	return rv;
369		✗	if (is_keyframe &&
370		✗	(set_id != s->prev_set_id || timestamp != s->prev_timestamp ||
371		✗	stream_id != s->prev_stream_id)) {
372		✗	flags |= RTP_FLAG_KEY;
373		✗	s->prev_set_id = set_id;
374		✗	s->prev_timestamp = timestamp;
375			}
376		✗	s->prev_stream_id = stream_id;
377		✗	buf += rv;
378		✗	len -= rv;
379
380		✗	if (s->prev_stream_id >= s->n_streams) {
381		✗	s->prev_stream_id = -1;
382		✗	return -1;
383			}
384
385		✗	rv = s->parse_packet(s->ic, s->dynamic_protocol_context,
386		✗	s->streams[s->prev_stream_id],
387			pkt, &timestamp, buf, len, 0, flags);
388
389		✗	return rv;
390			}
391
392			void
393		✗	ff_rdt_subscribe_rule (char *cmd, int size,
394			int stream_nr, int rule_nr)
395			{
396		✗	av_strlcatf(cmd, size, "stream=%d;rule=%d,stream=%d;rule=%d",
397		✗	stream_nr, rule_nr * 2, stream_nr, rule_nr * 2 + 1);
398		✗	}
399
400			static unsigned char *
401		✗	rdt_parse_b64buf (unsigned int *target_len, const char *p)
402			{
403			unsigned char *target;
404		✗	int len = strlen(p);
405		✗	if (*p == '\"') {
406		✗	p++;
407		✗	len -= 2; /* skip embracing " at start/end */
408			}
409		✗	*target_len = len * 3 / 4;
410		✗	target = av_mallocz(*target_len + AV_INPUT_BUFFER_PADDING_SIZE);
411		✗	if (!target)
412		✗	return NULL;
413		✗	av_base64_decode(target, p, *target_len);
414		✗	return target;
415			}
416
417			static int
418		✗	rdt_parse_sdp_line (AVFormatContext *s, int st_index,
419			PayloadContext *rdt, const char *line)
420			{
421		✗	AVStream *stream = s->streams[st_index];
422		✗	const char *p = line;
423
424		✗	if (av_strstart(p, "OpaqueData:buffer;", &p)) {
425		✗	rdt->mlti_data = rdt_parse_b64buf(&rdt->mlti_data_size, p);
426		✗	} else if (av_strstart(p, "StartTime:integer;", &p))
427		✗	ffstream(stream)->first_dts = atoi(p);
428		✗	else if (av_strstart(p, "ASMRuleBook:string;", &p)) {
429		✗	int n, first = -1;
430
431		✗	for (n = 0; n < s->nb_streams; n++)
432		✗	if (s->streams[n]->id == stream->id) {
433		✗	int count = s->streams[n]->index + 1, err;
434		✗	if (first == -1) first = n;
435		✗	if (rdt->nb_rmst < count) {
436		✗	if ((err = av_reallocp(&rdt->rmst,
437			count * sizeof(*rdt->rmst))) < 0) {
438		✗	rdt->nb_rmst = 0;
439		✗	return err;
440			}
441		✗	memset(rdt->rmst + rdt->nb_rmst, 0,
442		✗	(count - rdt->nb_rmst) * sizeof(*rdt->rmst));
443		✗	rdt->nb_rmst = count;
444			}
445		✗	if (rdt->rmst[s->streams[n]->index])
446		✗	continue;
447		✗	rdt->rmst[s->streams[n]->index] = ff_rm_alloc_rmstream();
448		✗	if (!rdt->rmst[s->streams[n]->index])
449		✗	return AVERROR(ENOMEM);
450		✗	rdt_load_mdpr(rdt, s->streams[n], (n - first) * 2);
451			}
452			}
453
454		✗	return 0;
455			}
456
457			static void
458		✗	real_parse_asm_rule(AVStream *st, const char *p, const char *end)
459			{
460			do {
461			/* can be either averagebandwidth= or AverageBandwidth= */
462		✗	if (sscanf(p, " %*1[Aa]verage%*1[Bb]andwidth=%"SCNd64, &st->codecpar->bit_rate) == 1)
463		✗	break;
464		✗	if (!(p = strchr(p, ',')) || p > end)
465		✗	p = end;
466		✗	p++;
467		✗	} while (p < end);
468		✗	}
469
470			static AVStream *
471		✗	add_dstream(AVFormatContext *s, AVStream *orig_st)
472			{
473			AVStream *st;
474
475		✗	if (!(st = avformat_new_stream(s, NULL)))
476		✗	return NULL;
477		✗	st->id = orig_st->id;
478		✗	st->codecpar->codec_type = orig_st->codecpar->codec_type;
479		✗	ffstream(st)->first_dts = ffstream(orig_st)->first_dts;
480
481		✗	return st;
482			}
483
484			static void
485		✗	real_parse_asm_rulebook(AVFormatContext *s, AVStream *orig_st,
486			const char *p)
487			{
488			const char *end;
489		✗	int n_rules = 0, odd = 0;
490			AVStream *st;
491
492			/**
493			* The ASMRuleBook contains a list of comma-separated strings per rule,
494			* and each rule is separated by a ;. The last one also has a ; at the
495			* end so we can use it as delimiter.
496			* Every rule occurs twice, once for when the RTSP packet header marker
497			* is set and once for if it isn't. We only read the first because we
498			* don't care much (that's what the "odd" variable is for).
499			* Each rule contains a set of one or more statements, optionally
500			* preceded by a single condition. If there's a condition, the rule
501			* starts with a '#'. Multiple conditions are merged between brackets,
502			* so there are never multiple conditions spread out over separate
503			* statements. Generally, these conditions are bitrate limits (min/max)
504			* for multi-bitrate streams.
505			*/
506		✗	if (*p == '\"') p++;
507			while (1) {
508		✗	if (!(end = strchr(p, ';')))
509		✗	break;
510		✗	if (!odd && end != p) {
511		✗	if (n_rules > 0)
512		✗	st = add_dstream(s, orig_st);
513			else
514		✗	st = orig_st;
515		✗	if (!st)
516		✗	break;
517		✗	real_parse_asm_rule(st, p, end);
518		✗	n_rules++;
519			}
520		✗	p = end + 1;
521		✗	odd ^= 1;
522			}
523		✗	}
524
525			void
526		✗	ff_real_parse_sdp_a_line (AVFormatContext *s, int stream_index,
527			const char *line)
528			{
529		✗	const char *p = line;
530
531		✗	if (av_strstart(p, "ASMRuleBook:string;", &p))
532		✗	real_parse_asm_rulebook(s, s->streams[stream_index], p);
533		✗	}
534
535
536
537		✗	static av_cold int rdt_init(AVFormatContext *s, int st_index, PayloadContext *rdt)
538			{
539			int ret;
540
541		✗	rdt->rmctx = avformat_alloc_context();
542		✗	if (!rdt->rmctx)
543		✗	return AVERROR(ENOMEM);
544
545		✗	if ((ret = ff_copy_whiteblacklists(rdt->rmctx, s)) < 0)
546		✗	return ret;
547
548		✗	return avformat_open_input(&rdt->rmctx, "", &ff_rdt_demuxer.p, NULL);
549			}
550
551			static void
552		✗	rdt_close_context (PayloadContext *rdt)
553			{
554			int i;
555
556		✗	for (i = 0; i < rdt->nb_rmst; i++)
557		✗	if (rdt->rmst[i]) {
558		✗	ff_rm_free_rmstream(rdt->rmst[i]);
559		✗	av_freep(&rdt->rmst[i]);
560			}
561		✗	if (rdt->rmctx)
562		✗	avformat_close_input(&rdt->rmctx);
563		✗	av_freep(&rdt->mlti_data);
564		✗	av_freep(&rdt->rmst);
565		✗	}
566
567			#define RDT_HANDLER(n, s, t) \
568			const RTPDynamicProtocolHandler ff_rdt_ ## n ## _handler = { \
569			.enc_name = s, \
570			.codec_type = t, \
571			.codec_id = AV_CODEC_ID_NONE, \
572			.priv_data_size = sizeof(PayloadContext), \
573			.init = rdt_init, \
574			.parse_sdp_a_line = rdt_parse_sdp_line, \
575			.close = rdt_close_context, \
576			.parse_packet = rdt_parse_packet \
577			}
578
579			RDT_HANDLER(live_video, "x-pn-multirate-realvideo-live", AVMEDIA_TYPE_VIDEO);
580			RDT_HANDLER(live_audio, "x-pn-multirate-realaudio-live", AVMEDIA_TYPE_AUDIO);
581			RDT_HANDLER(video, "x-pn-realvideo", AVMEDIA_TYPE_VIDEO);
582			RDT_HANDLER(audio, "x-pn-realaudio", AVMEDIA_TYPE_AUDIO);
583