FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/movenchint.c
Date: 2026-08-26 10:34:04
Exec Total Coverage
Lines: 195 249 78.3%
Functions: 13 13 100.0%
Branches: 70 114 61.4%
Line Branch Exec Source
1 /*
2 * MOV, 3GP, MP4 muxer RTP hinting
3 * Copyright (c) 2010 Martin Storsjo
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 #include "movenc.h"
23 #include "libavutil/intreadwrite.h"
24 #include "libavutil/mem.h"
25 #include "mux.h"
26 #include "rtpenc_chain.h"
27 #include "avio_internal.h"
28 #include "rtp.h"
29
30 2 int ff_mov_init_hinting(AVFormatContext *s, int index, int src_index)
31 {
32 2 MOVMuxContext *mov = s->priv_data;
33 2 MOVTrack *track = &mov->tracks[index];
34 2 MOVTrack *src_track = &mov->tracks[src_index];
35 2 AVStream *src_st = s->streams[src_index];
36 2 int ret = AVERROR(ENOMEM);
37
38 2 track->tag = MKTAG('r','t','p',' ');
39 2 track->src_track = av_malloc(sizeof(*track->src_track));
40
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 2 if (!track->src_track)
41 ✗ return AVERROR(ENOMEM);
42 2 *track->src_track = src_index;
43 2 track->nb_src_track = 1;
44
45 2 track->par = avcodec_parameters_alloc();
46
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 2 if (!track->par)
47 ✗ goto fail;
48 2 track->par->codec_type = AVMEDIA_TYPE_DATA;
49 2 track->par->codec_tag = track->tag;
50
51 2 ret = ff_rtp_chain_mux_open(&track->rtp_ctx, s, src_st, NULL,
52 RTP_MAX_PACKET_SIZE, src_index);
53
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 2 if (ret < 0)
54 ✗ goto fail;
55
56 /* Copy the RTP AVStream timebase back to the hint AVStream */
57 2 track->timescale = track->rtp_ctx->streams[0]->time_base.den;
58
59 /* Mark the hinted track that packets written to it should be
60 * sent to this track for hinting. */
61 2 src_track->hint_track = index;
62 2 return 0;
63 ✗ fail:
64 ✗ av_log(s, AV_LOG_WARNING,
65 "Unable to initialize hinting of stream %d\n", src_index);
66 ✗ avcodec_parameters_free(&track->par);
67 /* Set a default timescale, to avoid crashes in av_dump_format */
68 ✗ track->timescale = 90000;
69 ✗ return ret;
70 }
71
72 /**
73 * Remove the first sample from the sample queue.
74 */
75 36 static void sample_queue_pop(HintSampleQueue *queue)
76 {
77
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 36 if (queue->len <= 0)
78 ✗ return;
79
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 36 if (queue->samples[0].own_data)
80 ✗ av_freep(&queue->samples[0].data);
81 36 queue->len--;
82 36 memmove(queue->samples, queue->samples + 1, sizeof(HintSample)*queue->len);
83 }
84
85 /**
86 * Empty the sample queue, releasing all memory.
87 */
88 2 static void sample_queue_free(HintSampleQueue *queue)
89 {
90 int i;
91
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 2 for (i = 0; i < queue->len; i++)
92 ✗ if (queue->samples[i].own_data)
93 ✗ av_freep(&queue->samples[i].data);
94 2 av_freep(&queue->samples);
95 2 queue->len = 0;
96 2 queue->size = 0;
97 2 }
98
99 /**
100 * Add a reference to the sample data to the sample queue. The data is
101 * not copied. sample_queue_retain should be called before pkt->data
102 * is reused/freed.
103 */
104 36 static void sample_queue_push(HintSampleQueue *queue, const uint8_t *data, int size,
105 int sample)
106 {
107 /* No need to keep track of smaller samples, since describing them
108 * with immediates is more efficient. */
109
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 36 if (size <= 14)
110 ✗ return;
111
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 36 if (!queue->samples || queue->len >= queue->size) {
112 HintSample *samples;
113 2 samples = av_realloc_array(queue->samples, queue->size + 10, sizeof(HintSample));
114
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 2 if (!samples)
115 ✗ return;
116 2 queue->size += 10;
117 2 queue->samples = samples;
118 }
119 36 queue->samples[queue->len].data = data;
120 36 queue->samples[queue->len].size = size;
121 36 queue->samples[queue->len].sample_number = sample;
122 36 queue->samples[queue->len].offset = 0;
123 36 queue->samples[queue->len].own_data = 0;
124 36 queue->len++;
125 }
126
127 /**
128 * Make local copies of all referenced sample data in the queue.
129 */
130 36 static void sample_queue_retain(HintSampleQueue *queue)
131 {
132 int i;
133
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 36 for (i = 0; i < queue->len; ) {
134 ✗ HintSample *sample = &queue->samples[i];
135 ✗ if (!sample->own_data) {
136 ✗ uint8_t *ptr = av_malloc(sample->size);
137 ✗ if (!ptr) {
138 /* Unable to allocate memory for this one, remove it */
139 ✗ memmove(queue->samples + i, queue->samples + i + 1,
140 ✗ sizeof(HintSample)*(queue->len - i - 1));
141 ✗ queue->len--;
142 ✗ continue;
143 }
144 ✗ memcpy(ptr, sample->data, sample->size);
145 ✗ sample->data = ptr;
146 ✗ sample->own_data = 1;
147 }
148 ✗ i++;
149 }
150 36 }
151
152 /**
153 * Find matches of needle[n_pos ->] within haystack. If a sufficiently
154 * large match is found, matching bytes before n_pos are included
155 * in the match, too (within the limits of the arrays).
156 *
157 * @param haystack buffer that may contain parts of needle
158 * @param h_len length of the haystack buffer
159 * @param needle buffer containing source data that have been used to
160 * construct haystack
161 * @param n_pos start position in needle used for looking for matches
162 * @param n_len length of the needle buffer
163 * @param match_h_offset_ptr offset of the first matching byte within haystack
164 * @param match_n_offset_ptr offset of the first matching byte within needle
165 * @param match_len_ptr length of the matched segment
166 * @return 0 if a match was found, < 0 if no match was found
167 */
168 263 static int match_segments(const uint8_t *haystack, int h_len,
169 const uint8_t *needle, int n_pos, int n_len,
170 int *match_h_offset_ptr, int *match_n_offset_ptr,
171 int *match_len_ptr)
172 {
173 int h_pos;
174
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 1578 for (h_pos = 0; h_pos < h_len; h_pos++) {
175 1578 int match_len = 0;
176 int match_h_pos, match_n_pos;
177
178 /* Check how many bytes match at needle[n_pos] and haystack[h_pos] */
179
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 355483 while (h_pos + match_len < h_len && n_pos + match_len < n_len &&
180
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 355220 needle[n_pos + match_len] == haystack[h_pos + match_len])
181 353905 match_len++;
182
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 1578 if (match_len <= 8)
183 1315 continue;
184
185 /* If a sufficiently large match was found, try to expand
186 * the matched segment backwards. */
187 263 match_h_pos = h_pos;
188 263 match_n_pos = n_pos;
189
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 1578 while (match_n_pos > 0 && match_h_pos > 0 &&
190
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 1315 needle[match_n_pos - 1] == haystack[match_h_pos - 1]) {
191 1315 match_n_pos--;
192 1315 match_h_pos--;
193 1315 match_len++;
194 }
195
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 263 if (match_len <= 14)
196 ✗ continue;
197 263 *match_h_offset_ptr = match_h_pos;
198 263 *match_n_offset_ptr = match_n_pos;
199 263 *match_len_ptr = match_len;
200 263 return 0;
201 }
202 ✗ return -1;
203 }
204
205 /**
206 * Look for segments in samples in the sample queue matching the data
207 * in ptr. Samples not matching are removed from the queue. If a match
208 * is found, the next time it will look for matches starting from the
209 * end of the previous matched segment.
210 *
211 * @param data data to find matches for in the sample queue
212 * @param len length of the data buffer
213 * @param queue samples used for looking for matching segments
214 * @param pos the offset in data of the matched segment
215 * @param match_sample the number of the sample that contained the match
216 * @param match_offset the offset of the matched segment within the sample
217 * @param match_len the length of the matched segment
218 * @return 0 if a match was found, < 0 if no match was found
219 */
220 263 static int find_sample_match(const uint8_t *data, int len,
221 HintSampleQueue *queue, int *pos,
222 int *match_sample, int *match_offset,
223 int *match_len)
224 {
225
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 263 while (queue->len > 0) {
226 263 HintSample *sample = &queue->samples[0];
227 /* If looking for matches in a new sample, skip the first 5 bytes,
228 * since they often may be modified/removed in the output packet. */
229
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 263 if (sample->offset == 0 && sample->size > 5)
230 36 sample->offset = 5;
231
232
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 263 if (match_segments(data, len, sample->data, sample->offset,
233 sample->size, pos, match_offset, match_len) == 0) {
234 263 *match_sample = sample->sample_number;
235 /* Next time, look for matches at this offset, with a little
236 * margin to this match. */
237 263 sample->offset = *match_offset + *match_len + 5;
238
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 263 if (sample->offset + 10 >= sample->size)
239 36 sample_queue_pop(queue); /* Not enough useful data left */
240 263 return 0;
241 }
242
243 ✗ if (sample->offset < 10 && sample->size > 20) {
244 /* No match found from the start of the sample,
245 * try from the middle of the sample instead. */
246 ✗ sample->offset = sample->size/2;
247 } else {
248 /* No match for this sample, remove it */
249 ✗ sample_queue_pop(queue);
250 }
251 }
252 ✗ return -1;
253 }
254
255 526 static void output_immediate(const uint8_t *data, int size,
256 AVIOContext *out, int *entries)
257 {
258
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 526 while (size > 0) {
259 ✗ int len = size;
260 ✗ if (len > 14)
261 ✗ len = 14;
262 ✗ avio_w8(out, 1); /* immediate constructor */
263 ✗ avio_w8(out, len); /* amount of valid data */
264 ✗ avio_write(out, data, len);
265 ✗ data += len;
266 ✗ size -= len;
267
268 ✗ ffio_fill(out, 0, 14 - len);
269
270 ✗ (*entries)++;
271 }
272 526 }
273
274 263 static void output_match(AVIOContext *out, int match_sample,
275 int match_offset, int match_len, int *entries)
276 {
277 263 avio_w8(out, 2); /* sample constructor */
278 263 avio_w8(out, 0); /* track reference */
279 263 avio_wb16(out, match_len);
280 263 avio_wb32(out, match_sample);
281 263 avio_wb32(out, match_offset);
282 263 avio_wb16(out, 1); /* bytes per block */
283 263 avio_wb16(out, 1); /* samples per block */
284 263 (*entries)++;
285 263 }
286
287 263 static void describe_payload(const uint8_t *data, int size,
288 AVIOContext *out, int *entries,
289 HintSampleQueue *queue)
290 {
291 /* Describe the payload using different constructors */
292
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 526 while (size > 0) {
293 int match_sample, match_offset, match_len, pos;
294
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 263 if (find_sample_match(data, size, queue, &pos, &match_sample,
295 &match_offset, &match_len) < 0)
296 ✗ break;
297 263 output_immediate(data, pos, out, entries);
298 263 data += pos;
299 263 size -= pos;
300 263 output_match(out, match_sample, match_offset, match_len, entries);
301 263 data += match_len;
302 263 size -= match_len;
303 }
304 263 output_immediate(data, size, out, entries);
305 263 }
306
307 /**
308 * Write an RTP hint (that may contain one or more RTP packets)
309 * for the packets in data. data contains one or more packets with a
310 * BE32 size header.
311 *
312 * @param out buffer where the hints are written
313 * @param data buffer containing RTP packets
314 * @param size the size of the data buffer
315 * @param trk the MOVTrack for the hint track
316 * @param dts pointer where the timestamp for the written RTP hint is stored
317 * @return the number of RTP packets in the written hint
318 */
319 36 static int write_hint_packets(AVIOContext *out, const uint8_t *data,
320 int size, MOVTrack *trk, int64_t *dts)
321 {
322 int64_t curpos;
323 int64_t count_pos, entries_pos;
324 36 int count = 0, entries;
325
326 36 count_pos = avio_tell(out);
327 /* RTPsample header */
328 36 avio_wb16(out, 0); /* packet count */
329 36 avio_wb16(out, 0); /* reserved */
330
331
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 301 while (size > 4) {
332 265 uint32_t packet_len = AV_RB32(data);
333 uint16_t seq;
334 uint32_t ts;
335 int32_t ts_diff;
336
337 265 data += 4;
338 265 size -= 4;
339
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 265 if (packet_len > size || packet_len <= 12)
340 break;
341
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 265 if (RTP_PT_IS_RTCP(data[1])) {
342 /* RTCP packet, just skip */
343 2 data += packet_len;
344 2 size -= packet_len;
345 2 continue;
346 }
347
348
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 263 if (packet_len > trk->max_packet_size)
349 2 trk->max_packet_size = packet_len;
350
351 263 seq = AV_RB16(&data[2]);
352 263 ts = AV_RB32(&data[4]);
353
354
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 263 if (trk->prev_rtp_ts == 0)
355 2 trk->prev_rtp_ts = ts;
356 /* Unwrap the 32-bit RTP timestamp that wraps around often
357 * into a not (as often) wrapping 64-bit timestamp. */
358 263 ts_diff = ts - trk->prev_rtp_ts;
359
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 263 if (ts_diff > 0) {
360 56 trk->cur_rtp_ts_unwrapped += ts_diff;
361 56 trk->prev_rtp_ts = ts;
362 56 ts_diff = 0;
363 }
364
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 263 if (*dts == AV_NOPTS_VALUE)
365 36 *dts = trk->cur_rtp_ts_unwrapped;
366
367 263 count++;
368 /* RTPpacket header */
369 263 avio_wb32(out, 0); /* relative_time */
370 263 avio_write(out, data, 2); /* RTP header */
371 263 avio_wb16(out, seq); /* RTPsequenceseed */
372
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 263 avio_wb16(out, ts_diff ? 4 : 0); /* reserved + flags (extra_flag) */
373 263 entries_pos = avio_tell(out);
374 263 avio_wb16(out, 0); /* entry count */
375
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 263 if (ts_diff) { /* if extra_flag is set */
376 ✗ avio_wb32(out, 16); /* extra_information_length */
377 ✗ avio_wb32(out, 12); /* rtpoffsetTLV box */
378 ✗ avio_write(out, "rtpo", 4);
379 ✗ avio_wb32(out, ts_diff);
380 }
381
382 263 data += 12;
383 263 size -= 12;
384 263 packet_len -= 12;
385
386 263 entries = 0;
387 /* Write one or more constructors describing the payload data */
388 263 describe_payload(data, packet_len, out, &entries, &trk->sample_queue);
389 263 data += packet_len;
390 263 size -= packet_len;
391
392 263 curpos = avio_tell(out);
393 263 avio_seek(out, entries_pos, SEEK_SET);
394 263 avio_wb16(out, entries);
395 263 avio_seek(out, curpos, SEEK_SET);
396 }
397
398 36 curpos = avio_tell(out);
399 36 avio_seek(out, count_pos, SEEK_SET);
400 36 avio_wb16(out, count);
401 36 avio_seek(out, curpos, SEEK_SET);
402 36 return count;
403 }
404
405 82 int ff_mov_add_hinted_packet(AVFormatContext *s, AVPacket *pkt,
406 int track_index, int sample,
407 uint8_t *sample_data, int sample_size)
408 {
409 82 MOVMuxContext *mov = s->priv_data;
410 82 MOVTrack *trk = &mov->tracks[track_index];
411 82 AVFormatContext *rtp_ctx = trk->rtp_ctx;
412 82 uint8_t *buf = NULL;
413 int size;
414 82 AVIOContext *hintbuf = NULL;
415 82 AVPacket *hint_pkt = mov->pkt;
416 82 int ret = 0, count;
417
418
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 82 if (!rtp_ctx)
419 46 return AVERROR(ENOENT);
420
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 36 if (!rtp_ctx->pb)
421 ✗ return AVERROR(ENOMEM);
422
423
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 36 if (sample_data)
424 ✗ sample_queue_push(&trk->sample_queue, sample_data, sample_size, sample);
425 else
426 36 sample_queue_push(&trk->sample_queue, pkt->data, pkt->size, sample);
427
428 /* Feed the packet to the RTP muxer */
429 36 ff_write_chained(rtp_ctx, 0, pkt, s, 0);
430
431 /* Fetch the output from the RTP muxer, open a new output buffer
432 * for next time. */
433 36 size = avio_close_dyn_buf(rtp_ctx->pb, &buf);
434
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 36 if ((ret = ffio_open_dyn_packet_buf(&rtp_ctx->pb,
435 RTP_MAX_PACKET_SIZE)) < 0)
436 ✗ goto done;
437
438
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 36 if (size <= 0)
439 ✗ goto done;
440
441 /* Open a buffer for writing the hint */
442
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 36 if ((ret = avio_open_dyn_buf(&hintbuf)) < 0)
443 ✗ goto done;
444 36 av_packet_unref(hint_pkt);
445 36 count = write_hint_packets(hintbuf, buf, size, trk, &hint_pkt->dts);
446 36 av_freep(&buf);
447
448 /* Write the hint data into the hint track */
449 36 hint_pkt->size = size = avio_close_dyn_buf(hintbuf, &buf);
450 36 hint_pkt->data = buf;
451 36 hint_pkt->pts = hint_pkt->dts;
452 36 hint_pkt->stream_index = track_index;
453
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 36 if (pkt->flags & AV_PKT_FLAG_KEY)
454 14 hint_pkt->flags |= AV_PKT_FLAG_KEY;
455
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 36 if (count > 0)
456 36 ff_mov_write_packet(s, hint_pkt);
457 ✗ done:
458 36 av_free(buf);
459 36 av_packet_unref(hint_pkt);
460 36 sample_queue_retain(&trk->sample_queue);
461 36 return ret;
462 }
463
464 2 void ff_mov_close_hinting(MOVTrack *track)
465 {
466 2 AVFormatContext *rtp_ctx = track->rtp_ctx;
467
468 2 avcodec_parameters_free(&track->par);
469 2 sample_queue_free(&track->sample_queue);
470
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 2 if (!rtp_ctx)
471 ✗ return;
472
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 2 if (rtp_ctx->pb) {
473 2 av_write_trailer(rtp_ctx);
474 2 ffio_free_dyn_buf(&rtp_ctx->pb);
475 }
476 2 avformat_free_context(rtp_ctx);
477 }
478