rtp: set the payload type as stream id
[libav.git] / libavformat / movenchint.c
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1/*
2 * MOV, 3GP, MP4 muxer RTP hinting
3 * Copyright (c) 2010 Martin Storsjo
4 *
2912e87a 5 * This file is part of Libav.
e977af6f 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 18 * License along with Libav; if not, write to the Free Software
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19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "movenc.h"
23#include "libavutil/intreadwrite.h"
648e41b3 24#include "internal.h"
5306bf41 25#include "rtpenc_chain.h"
403ee835 26#include "avio_internal.h"
df605018 27#include "rtp.h"
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28
29int ff_mov_init_hinting(AVFormatContext *s, int index, int src_index)
30{
31 MOVMuxContext *mov = s->priv_data;
32 MOVTrack *track = &mov->tracks[index];
33 MOVTrack *src_track = &mov->tracks[src_index];
34 AVStream *src_st = s->streams[src_index];
35 int ret = AVERROR(ENOMEM);
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36
37 track->tag = MKTAG('r','t','p',' ');
38 track->src_track = src_index;
39
71a861cf 40 track->enc = avcodec_alloc_context3(NULL);
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41 if (!track->enc)
42 goto fail;
43 track->enc->codec_type = AVMEDIA_TYPE_DATA;
44 track->enc->codec_tag = track->tag;
45
68c81308 46 ret = ff_rtp_chain_mux_open(&track->rtp_ctx, s, src_st, NULL,
8034130e 47 RTP_MAX_PACKET_SIZE, src_index);
68c81308 48 if (ret < 0)
e977af6f 49 goto fail;
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50
51 /* Copy the RTP AVStream timebase back to the hint AVStream */
52 track->timescale = track->rtp_ctx->streams[0]->time_base.den;
53
54 /* Mark the hinted track that packets written to it should be
55 * sent to this track for hinting. */
56 src_track->hint_track = index;
57 return 0;
58fail:
59 av_log(s, AV_LOG_WARNING,
60 "Unable to initialize hinting of stream %d\n", src_index);
e977af6f 61 av_freep(&track->enc);
610219a5 62 /* Set a default timescale, to avoid crashes in av_dump_format */
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63 track->timescale = 90000;
64 return ret;
65}
66
44bf251a
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67/**
68 * Remove the first sample from the sample queue.
69 */
70static void sample_queue_pop(HintSampleQueue *queue)
71{
72 if (queue->len <= 0)
73 return;
74 if (queue->samples[0].own_data)
75 av_free(queue->samples[0].data);
76 queue->len--;
77 memmove(queue->samples, queue->samples + 1, sizeof(HintSample)*queue->len);
78}
79
80/**
81 * Empty the sample queue, releasing all memory.
82 */
83static void sample_queue_free(HintSampleQueue *queue)
84{
85 int i;
86 for (i = 0; i < queue->len; i++)
87 if (queue->samples[i].own_data)
88 av_free(queue->samples[i].data);
89 av_freep(&queue->samples);
90 queue->len = 0;
91 queue->size = 0;
92}
93
94/**
95 * Add a reference to the sample data to the sample queue. The data is
96 * not copied. sample_queue_retain should be called before pkt->data
97 * is reused/freed.
98 */
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99static void sample_queue_push(HintSampleQueue *queue, uint8_t *data, int size,
100 int sample)
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101{
102 /* No need to keep track of smaller samples, since describing them
103 * with immediates is more efficient. */
e2484fb6 104 if (size <= 14)
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105 return;
106 if (!queue->samples || queue->len >= queue->size) {
107 HintSample* samples;
108 queue->size += 10;
109 samples = av_realloc(queue->samples, sizeof(HintSample)*queue->size);
110 if (!samples)
111 return;
112 queue->samples = samples;
113 }
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114 queue->samples[queue->len].data = data;
115 queue->samples[queue->len].size = size;
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116 queue->samples[queue->len].sample_number = sample;
117 queue->samples[queue->len].offset = 0;
118 queue->samples[queue->len].own_data = 0;
119 queue->len++;
120}
121
122/**
123 * Make local copies of all referenced sample data in the queue.
124 */
125static void sample_queue_retain(HintSampleQueue *queue)
126{
127 int i;
128 for (i = 0; i < queue->len; ) {
129 HintSample *sample = &queue->samples[i];
130 if (!sample->own_data) {
131 uint8_t* ptr = av_malloc(sample->size);
132 if (!ptr) {
133 /* Unable to allocate memory for this one, remove it */
134 memmove(queue->samples + i, queue->samples + i + 1,
135 sizeof(HintSample)*(queue->len - i - 1));
136 queue->len--;
137 continue;
138 }
139 memcpy(ptr, sample->data, sample->size);
140 sample->data = ptr;
141 sample->own_data = 1;
142 }
143 i++;
144 }
145}
146
147/**
148 * Find matches of needle[n_pos ->] within haystack. If a sufficiently
149 * large match is found, matching bytes before n_pos are included
150 * in the match, too (within the limits of the arrays).
151 *
152 * @param haystack buffer that may contain parts of needle
153 * @param h_len length of the haystack buffer
154 * @param needle buffer containing source data that have been used to
155 * construct haystack
156 * @param n_pos start position in needle used for looking for matches
157 * @param n_len length of the needle buffer
158 * @param match_h_offset_ptr offset of the first matching byte within haystack
159 * @param match_n_offset_ptr offset of the first matching byte within needle
160 * @param match_len_ptr length of the matched segment
161 * @return 0 if a match was found, < 0 if no match was found
162 */
163static int match_segments(const uint8_t *haystack, int h_len,
164 const uint8_t *needle, int n_pos, int n_len,
165 int *match_h_offset_ptr, int *match_n_offset_ptr,
166 int *match_len_ptr)
167{
168 int h_pos;
169 for (h_pos = 0; h_pos < h_len; h_pos++) {
170 int match_len = 0;
171 int match_h_pos, match_n_pos;
172
173 /* Check how many bytes match at needle[n_pos] and haystack[h_pos] */
174 while (h_pos + match_len < h_len && n_pos + match_len < n_len &&
175 needle[n_pos + match_len] == haystack[h_pos + match_len])
176 match_len++;
177 if (match_len <= 8)
178 continue;
179
180 /* If a sufficiently large match was found, try to expand
181 * the matched segment backwards. */
182 match_h_pos = h_pos;
183 match_n_pos = n_pos;
184 while (match_n_pos > 0 && match_h_pos > 0 &&
185 needle[match_n_pos - 1] == haystack[match_h_pos - 1]) {
186 match_n_pos--;
187 match_h_pos--;
188 match_len++;
189 }
190 if (match_len <= 14)
191 continue;
192 *match_h_offset_ptr = match_h_pos;
193 *match_n_offset_ptr = match_n_pos;
194 *match_len_ptr = match_len;
195 return 0;
196 }
197 return -1;
198}
199
200/**
201 * Look for segments in samples in the sample queue matching the data
202 * in ptr. Samples not matching are removed from the queue. If a match
203 * is found, the next time it will look for matches starting from the
204 * end of the previous matched segment.
205 *
206 * @param data data to find matches for in the sample queue
207 * @param len length of the data buffer
208 * @param queue samples used for looking for matching segments
209 * @param pos the offset in data of the matched segment
210 * @param match_sample the number of the sample that contained the match
211 * @param match_offset the offset of the matched segment within the sample
212 * @param match_len the length of the matched segment
213 * @return 0 if a match was found, < 0 if no match was found
214 */
215static int find_sample_match(const uint8_t *data, int len,
216 HintSampleQueue *queue, int *pos,
217 int *match_sample, int *match_offset,
218 int *match_len)
219{
220 while (queue->len > 0) {
221 HintSample *sample = &queue->samples[0];
222 /* If looking for matches in a new sample, skip the first 5 bytes,
223 * since they often may be modified/removed in the output packet. */
224 if (sample->offset == 0 && sample->size > 5)
225 sample->offset = 5;
226
227 if (match_segments(data, len, sample->data, sample->offset,
228 sample->size, pos, match_offset, match_len) == 0) {
229 *match_sample = sample->sample_number;
230 /* Next time, look for matches at this offset, with a little
231 * margin to this match. */
232 sample->offset = *match_offset + *match_len + 5;
233 if (sample->offset + 10 >= sample->size)
234 sample_queue_pop(queue); /* Not enough useful data left */
235 return 0;
236 }
237
238 if (sample->offset < 10 && sample->size > 20) {
239 /* No match found from the start of the sample,
240 * try from the middle of the sample instead. */
241 sample->offset = sample->size/2;
242 } else {
243 /* No match for this sample, remove it */
244 sample_queue_pop(queue);
245 }
246 }
247 return -1;
248}
249
e977af6f 250static void output_immediate(const uint8_t *data, int size,
ae628ec1 251 AVIOContext *out, int *entries)
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252{
253 while (size > 0) {
254 int len = size;
255 if (len > 14)
256 len = 14;
77eb5504
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257 avio_w8(out, 1); /* immediate constructor */
258 avio_w8(out, len); /* amount of valid data */
259 avio_write(out, data, len);
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260 data += len;
261 size -= len;
262
263 for (; len < 14; len++)
77eb5504 264 avio_w8(out, 0);
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265
266 (*entries)++;
267 }
268}
269
ae628ec1 270static void output_match(AVIOContext *out, int match_sample,
44bf251a
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271 int match_offset, int match_len, int *entries)
272{
77eb5504
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273 avio_w8(out, 2); /* sample constructor */
274 avio_w8(out, 0); /* track reference */
275 avio_wb16(out, match_len);
276 avio_wb32(out, match_sample);
277 avio_wb32(out, match_offset);
278 avio_wb16(out, 1); /* bytes per block */
279 avio_wb16(out, 1); /* samples per block */
44bf251a
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280 (*entries)++;
281}
282
e977af6f 283static void describe_payload(const uint8_t *data, int size,
ae628ec1 284 AVIOContext *out, int *entries,
44bf251a 285 HintSampleQueue *queue)
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286{
287 /* Describe the payload using different constructors */
44bf251a
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288 while (size > 0) {
289 int match_sample, match_offset, match_len, pos;
290 if (find_sample_match(data, size, queue, &pos, &match_sample,
291 &match_offset, &match_len) < 0)
292 break;
293 output_immediate(data, pos, out, entries);
294 data += pos;
295 size -= pos;
296 output_match(out, match_sample, match_offset, match_len, entries);
297 data += match_len;
298 size -= match_len;
299 }
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300 output_immediate(data, size, out, entries);
301}
302
303/**
304 * Write an RTP hint (that may contain one or more RTP packets)
305 * for the packets in data. data contains one or more packets with a
306 * BE32 size header.
307 *
308 * @param out buffer where the hints are written
309 * @param data buffer containing RTP packets
310 * @param size the size of the data buffer
311 * @param trk the MOVTrack for the hint track
312 * @param pts pointer where the timestamp for the written RTP hint is stored
313 * @return the number of RTP packets in the written hint
314 */
ae628ec1 315static int write_hint_packets(AVIOContext *out, const uint8_t *data,
e977af6f
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316 int size, MOVTrack *trk, int64_t *pts)
317{
318 int64_t curpos;
319 int64_t count_pos, entries_pos;
320 int count = 0, entries;
321
a2704c97 322 count_pos = avio_tell(out);
e977af6f 323 /* RTPsample header */
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324 avio_wb16(out, 0); /* packet count */
325 avio_wb16(out, 0); /* reserved */
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326
327 while (size > 4) {
328 uint32_t packet_len = AV_RB32(data);
329 uint16_t seq;
330 uint32_t ts;
331
332 data += 4;
333 size -= 4;
334 if (packet_len > size || packet_len <= 12)
335 break;
298a587f 336 if (RTP_PT_IS_RTCP(data[1])) {
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337 /* RTCP packet, just skip */
338 data += packet_len;
339 size -= packet_len;
340 continue;
341 }
342
343 if (packet_len > trk->max_packet_size)
344 trk->max_packet_size = packet_len;
345
346 seq = AV_RB16(&data[2]);
347 ts = AV_RB32(&data[4]);
348
349 if (trk->prev_rtp_ts == 0)
350 trk->prev_rtp_ts = ts;
351 /* Unwrap the 32-bit RTP timestamp that wraps around often
352 * into a not (as often) wrapping 64-bit timestamp. */
353 trk->cur_rtp_ts_unwrapped += (int32_t) (ts - trk->prev_rtp_ts);
354 trk->prev_rtp_ts = ts;
355 if (*pts == AV_NOPTS_VALUE)
356 *pts = trk->cur_rtp_ts_unwrapped;
357
358 count++;
359 /* RTPpacket header */
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360 avio_wb32(out, 0); /* relative_time */
361 avio_write(out, data, 2); /* RTP header */
362 avio_wb16(out, seq); /* RTPsequenceseed */
363 avio_wb16(out, 0); /* reserved + flags */
a2704c97 364 entries_pos = avio_tell(out);
77eb5504 365 avio_wb16(out, 0); /* entry count */
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366
367 data += 12;
368 size -= 12;
369 packet_len -= 12;
370
371 entries = 0;
372 /* Write one or more constructors describing the payload data */
44bf251a 373 describe_payload(data, packet_len, out, &entries, &trk->sample_queue);
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374 data += packet_len;
375 size -= packet_len;
376
a2704c97 377 curpos = avio_tell(out);
6b4aa5da 378 avio_seek(out, entries_pos, SEEK_SET);
77eb5504 379 avio_wb16(out, entries);
6b4aa5da 380 avio_seek(out, curpos, SEEK_SET);
e977af6f
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381 }
382
a2704c97 383 curpos = avio_tell(out);
6b4aa5da 384 avio_seek(out, count_pos, SEEK_SET);
77eb5504 385 avio_wb16(out, count);
6b4aa5da 386 avio_seek(out, curpos, SEEK_SET);
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387 return count;
388}
389
390int ff_mov_add_hinted_packet(AVFormatContext *s, AVPacket *pkt,
e2484fb6
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391 int track_index, int sample,
392 uint8_t *sample_data, int sample_size)
e977af6f
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393{
394 MOVMuxContext *mov = s->priv_data;
395 MOVTrack *trk = &mov->tracks[track_index];
396 AVFormatContext *rtp_ctx = trk->rtp_ctx;
397 uint8_t *buf = NULL;
398 int size;
ae628ec1 399 AVIOContext *hintbuf = NULL;
e977af6f 400 AVPacket hint_pkt;
e977af6f
MS
401 int ret = 0, count;
402
403 if (!rtp_ctx)
404 return AVERROR(ENOENT);
405 if (!rtp_ctx->pb)
406 return AVERROR(ENOMEM);
407
e2484fb6
MS
408 if (sample_data)
409 sample_queue_push(&trk->sample_queue, sample_data, sample_size, sample);
410 else
411 sample_queue_push(&trk->sample_queue, pkt->data, pkt->size, sample);
44bf251a 412
e977af6f 413 /* Feed the packet to the RTP muxer */
648e41b3 414 ff_write_chained(rtp_ctx, 0, pkt, s);
e977af6f
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415
416 /* Fetch the output from the RTP muxer, open a new output buffer
417 * for next time. */
6dc7d80d 418 size = avio_close_dyn_buf(rtp_ctx->pb, &buf);
403ee835 419 if ((ret = ffio_open_dyn_packet_buf(&rtp_ctx->pb,
e977af6f
MS
420 RTP_MAX_PACKET_SIZE)) < 0)
421 goto done;
422
423 if (size <= 0)
424 goto done;
425
426 /* Open a buffer for writing the hint */
b92c5452 427 if ((ret = avio_open_dyn_buf(&hintbuf)) < 0)
e977af6f
MS
428 goto done;
429 av_init_packet(&hint_pkt);
430 count = write_hint_packets(hintbuf, buf, size, trk, &hint_pkt.dts);
431 av_freep(&buf);
432
433 /* Write the hint data into the hint track */
6dc7d80d 434 hint_pkt.size = size = avio_close_dyn_buf(hintbuf, &buf);
e977af6f
MS
435 hint_pkt.data = buf;
436 hint_pkt.pts = hint_pkt.dts;
437 hint_pkt.stream_index = track_index;
438 if (pkt->flags & AV_PKT_FLAG_KEY)
439 hint_pkt.flags |= AV_PKT_FLAG_KEY;
440 if (count > 0)
441 ff_mov_write_packet(s, &hint_pkt);
442done:
443 av_free(buf);
44bf251a 444 sample_queue_retain(&trk->sample_queue);
e977af6f
MS
445 return ret;
446}
447
448void ff_mov_close_hinting(MOVTrack *track) {
449 AVFormatContext* rtp_ctx = track->rtp_ctx;
450 uint8_t *ptr;
451
452 av_freep(&track->enc);
44bf251a 453 sample_queue_free(&track->sample_queue);
e977af6f
MS
454 if (!rtp_ctx)
455 return;
456 if (rtp_ctx->pb) {
457 av_write_trailer(rtp_ctx);
6dc7d80d 458 avio_close_dyn_buf(rtp_ctx->pb, &ptr);
e977af6f
MS
459 av_free(ptr);
460 }
b22dbb29 461 avformat_free_context(rtp_ctx);
e977af6f 462}