FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/movenchint.c
Date: 2026-04-20 11:33:30
Exec Total Coverage
Lines: 192 245 78.4%
Functions: 13 13 100.0%
Branches: 69 112 61.6%
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 = src_index;
40
41 2 track->par = avcodec_parameters_alloc();
42
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 2 if (!track->par)
43 ✗ goto fail;
44 2 track->par->codec_type = AVMEDIA_TYPE_DATA;
45 2 track->par->codec_tag = track->tag;
46
47 2 ret = ff_rtp_chain_mux_open(&track->rtp_ctx, s, src_st, NULL,
48 RTP_MAX_PACKET_SIZE, src_index);
49
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 2 if (ret < 0)
50 ✗ goto fail;
51
52 /* Copy the RTP AVStream timebase back to the hint AVStream */
53 2 track->timescale = track->rtp_ctx->streams[0]->time_base.den;
54
55 /* Mark the hinted track that packets written to it should be
56 * sent to this track for hinting. */
57 2 src_track->hint_track = index;
58 2 return 0;
59 ✗ fail:
60 ✗ av_log(s, AV_LOG_WARNING,
61 "Unable to initialize hinting of stream %d\n", src_index);
62 ✗ avcodec_parameters_free(&track->par);
63 /* Set a default timescale, to avoid crashes in av_dump_format */
64 ✗ track->timescale = 90000;
65 ✗ return ret;
66 }
67
68 /**
69 * Remove the first sample from the sample queue.
70 */
71 36 static void sample_queue_pop(HintSampleQueue *queue)
72 {
73
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 36 if (queue->len <= 0)
74 ✗ return;
75
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 36 if (queue->samples[0].own_data)
76 ✗ av_freep(&queue->samples[0].data);
77 36 queue->len--;
78 36 memmove(queue->samples, queue->samples + 1, sizeof(HintSample)*queue->len);
79 }
80
81 /**
82 * Empty the sample queue, releasing all memory.
83 */
84 2 static void sample_queue_free(HintSampleQueue *queue)
85 {
86 int i;
87
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 2 for (i = 0; i < queue->len; i++)
88 ✗ if (queue->samples[i].own_data)
89 ✗ av_freep(&queue->samples[i].data);
90 2 av_freep(&queue->samples);
91 2 queue->len = 0;
92 2 queue->size = 0;
93 2 }
94
95 /**
96 * Add a reference to the sample data to the sample queue. The data is
97 * not copied. sample_queue_retain should be called before pkt->data
98 * is reused/freed.
99 */
100 36 static void sample_queue_push(HintSampleQueue *queue, const uint8_t *data, int size,
101 int sample)
102 {
103 /* No need to keep track of smaller samples, since describing them
104 * with immediates is more efficient. */
105
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 36 if (size <= 14)
106 ✗ return;
107
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 36 if (!queue->samples || queue->len >= queue->size) {
108 HintSample *samples;
109 2 samples = av_realloc_array(queue->samples, queue->size + 10, sizeof(HintSample));
110
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 2 if (!samples)
111 ✗ return;
112 2 queue->size += 10;
113 2 queue->samples = samples;
114 }
115 36 queue->samples[queue->len].data = data;
116 36 queue->samples[queue->len].size = size;
117 36 queue->samples[queue->len].sample_number = sample;
118 36 queue->samples[queue->len].offset = 0;
119 36 queue->samples[queue->len].own_data = 0;
120 36 queue->len++;
121 }
122
123 /**
124 * Make local copies of all referenced sample data in the queue.
125 */
126 36 static void sample_queue_retain(HintSampleQueue *queue)
127 {
128 int i;
129
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 36 for (i = 0; i < queue->len; ) {
130 ✗ HintSample *sample = &queue->samples[i];
131 ✗ if (!sample->own_data) {
132 ✗ uint8_t *ptr = av_malloc(sample->size);
133 ✗ if (!ptr) {
134 /* Unable to allocate memory for this one, remove it */
135 ✗ memmove(queue->samples + i, queue->samples + i + 1,
136 ✗ sizeof(HintSample)*(queue->len - i - 1));
137 ✗ queue->len--;
138 ✗ continue;
139 }
140 ✗ memcpy(ptr, sample->data, sample->size);
141 ✗ sample->data = ptr;
142 ✗ sample->own_data = 1;
143 }
144 ✗ i++;
145 }
146 36 }
147
148 /**
149 * Find matches of needle[n_pos ->] within haystack. If a sufficiently
150 * large match is found, matching bytes before n_pos are included
151 * in the match, too (within the limits of the arrays).
152 *
153 * @param haystack buffer that may contain parts of needle
154 * @param h_len length of the haystack buffer
155 * @param needle buffer containing source data that have been used to
156 * construct haystack
157 * @param n_pos start position in needle used for looking for matches
158 * @param n_len length of the needle buffer
159 * @param match_h_offset_ptr offset of the first matching byte within haystack
160 * @param match_n_offset_ptr offset of the first matching byte within needle
161 * @param match_len_ptr length of the matched segment
162 * @return 0 if a match was found, < 0 if no match was found
163 */
164 263 static int match_segments(const uint8_t *haystack, int h_len,
165 const uint8_t *needle, int n_pos, int n_len,
166 int *match_h_offset_ptr, int *match_n_offset_ptr,
167 int *match_len_ptr)
168 {
169 int h_pos;
170
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 1578 for (h_pos = 0; h_pos < h_len; h_pos++) {
171 1578 int match_len = 0;
172 int match_h_pos, match_n_pos;
173
174 /* Check how many bytes match at needle[n_pos] and haystack[h_pos] */
175
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 355483 while (h_pos + match_len < h_len && n_pos + match_len < n_len &&
176
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 355220 needle[n_pos + match_len] == haystack[h_pos + match_len])
177 353905 match_len++;
178
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 1578 if (match_len <= 8)
179 1315 continue;
180
181 /* If a sufficiently large match was found, try to expand
182 * the matched segment backwards. */
183 263 match_h_pos = h_pos;
184 263 match_n_pos = n_pos;
185
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 1578 while (match_n_pos > 0 && match_h_pos > 0 &&
186
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 1315 needle[match_n_pos - 1] == haystack[match_h_pos - 1]) {
187 1315 match_n_pos--;
188 1315 match_h_pos--;
189 1315 match_len++;
190 }
191
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 263 if (match_len <= 14)
192 ✗ continue;
193 263 *match_h_offset_ptr = match_h_pos;
194 263 *match_n_offset_ptr = match_n_pos;
195 263 *match_len_ptr = match_len;
196 263 return 0;
197 }
198 ✗ return -1;
199 }
200
201 /**
202 * Look for segments in samples in the sample queue matching the data
203 * in ptr. Samples not matching are removed from the queue. If a match
204 * is found, the next time it will look for matches starting from the
205 * end of the previous matched segment.
206 *
207 * @param data data to find matches for in the sample queue
208 * @param len length of the data buffer
209 * @param queue samples used for looking for matching segments
210 * @param pos the offset in data of the matched segment
211 * @param match_sample the number of the sample that contained the match
212 * @param match_offset the offset of the matched segment within the sample
213 * @param match_len the length of the matched segment
214 * @return 0 if a match was found, < 0 if no match was found
215 */
216 263 static int find_sample_match(const uint8_t *data, int len,
217 HintSampleQueue *queue, int *pos,
218 int *match_sample, int *match_offset,
219 int *match_len)
220 {
221
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 263 while (queue->len > 0) {
222 263 HintSample *sample = &queue->samples[0];
223 /* If looking for matches in a new sample, skip the first 5 bytes,
224 * since they often may be modified/removed in the output packet. */
225
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 263 if (sample->offset == 0 && sample->size > 5)
226 36 sample->offset = 5;
227
228
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 263 if (match_segments(data, len, sample->data, sample->offset,
229 sample->size, pos, match_offset, match_len) == 0) {
230 263 *match_sample = sample->sample_number;
231 /* Next time, look for matches at this offset, with a little
232 * margin to this match. */
233 263 sample->offset = *match_offset + *match_len + 5;
234
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 263 if (sample->offset + 10 >= sample->size)
235 36 sample_queue_pop(queue); /* Not enough useful data left */
236 263 return 0;
237 }
238
239 ✗ if (sample->offset < 10 && sample->size > 20) {
240 /* No match found from the start of the sample,
241 * try from the middle of the sample instead. */
242 ✗ sample->offset = sample->size/2;
243 } else {
244 /* No match for this sample, remove it */
245 ✗ sample_queue_pop(queue);
246 }
247 }
248 ✗ return -1;
249 }
250
251 526 static void output_immediate(const uint8_t *data, int size,
252 AVIOContext *out, int *entries)
253 {
254
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 526 while (size > 0) {
255 ✗ int len = size;
256 ✗ if (len > 14)
257 ✗ len = 14;
258 ✗ avio_w8(out, 1); /* immediate constructor */
259 ✗ avio_w8(out, len); /* amount of valid data */
260 ✗ avio_write(out, data, len);
261 ✗ data += len;
262 ✗ size -= len;
263
264 ✗ ffio_fill(out, 0, 14 - len);
265
266 ✗ (*entries)++;
267 }
268 526 }
269
270 263 static void output_match(AVIOContext *out, int match_sample,
271 int match_offset, int match_len, int *entries)
272 {
273 263 avio_w8(out, 2); /* sample constructor */
274 263 avio_w8(out, 0); /* track reference */
275 263 avio_wb16(out, match_len);
276 263 avio_wb32(out, match_sample);
277 263 avio_wb32(out, match_offset);
278 263 avio_wb16(out, 1); /* bytes per block */
279 263 avio_wb16(out, 1); /* samples per block */
280 263 (*entries)++;
281 263 }
282
283 263 static void describe_payload(const uint8_t *data, int size,
284 AVIOContext *out, int *entries,
285 HintSampleQueue *queue)
286 {
287 /* Describe the payload using different constructors */
288
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 526 while (size > 0) {
289 int match_sample, match_offset, match_len, pos;
290
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 263 if (find_sample_match(data, size, queue, &pos, &match_sample,
291 &match_offset, &match_len) < 0)
292 ✗ break;
293 263 output_immediate(data, pos, out, entries);
294 263 data += pos;
295 263 size -= pos;
296 263 output_match(out, match_sample, match_offset, match_len, entries);
297 263 data += match_len;
298 263 size -= match_len;
299 }
300 263 output_immediate(data, size, out, entries);
301 263 }
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 dts pointer where the timestamp for the written RTP hint is stored
313 * @return the number of RTP packets in the written hint
314 */
315 36 static int write_hint_packets(AVIOContext *out, const uint8_t *data,
316 int size, MOVTrack *trk, int64_t *dts)
317 {
318 int64_t curpos;
319 int64_t count_pos, entries_pos;
320 36 int count = 0, entries;
321
322 36 count_pos = avio_tell(out);
323 /* RTPsample header */
324 36 avio_wb16(out, 0); /* packet count */
325 36 avio_wb16(out, 0); /* reserved */
326
327
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 301 while (size > 4) {
328 265 uint32_t packet_len = AV_RB32(data);
329 uint16_t seq;
330 uint32_t ts;
331 int32_t ts_diff;
332
333 265 data += 4;
334 265 size -= 4;
335
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 265 if (packet_len > size || packet_len <= 12)
336 break;
337
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 265 if (RTP_PT_IS_RTCP(data[1])) {
338 /* RTCP packet, just skip */
339 2 data += packet_len;
340 2 size -= packet_len;
341 2 continue;
342 }
343
344
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 263 if (packet_len > trk->max_packet_size)
345 2 trk->max_packet_size = packet_len;
346
347 263 seq = AV_RB16(&data[2]);
348 263 ts = AV_RB32(&data[4]);
349
350
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 263 if (trk->prev_rtp_ts == 0)
351 2 trk->prev_rtp_ts = ts;
352 /* Unwrap the 32-bit RTP timestamp that wraps around often
353 * into a not (as often) wrapping 64-bit timestamp. */
354 263 ts_diff = ts - trk->prev_rtp_ts;
355
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 263 if (ts_diff > 0) {
356 56 trk->cur_rtp_ts_unwrapped += ts_diff;
357 56 trk->prev_rtp_ts = ts;
358 56 ts_diff = 0;
359 }
360
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 263 if (*dts == AV_NOPTS_VALUE)
361 36 *dts = trk->cur_rtp_ts_unwrapped;
362
363 263 count++;
364 /* RTPpacket header */
365 263 avio_wb32(out, 0); /* relative_time */
366 263 avio_write(out, data, 2); /* RTP header */
367 263 avio_wb16(out, seq); /* RTPsequenceseed */
368
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 263 avio_wb16(out, ts_diff ? 4 : 0); /* reserved + flags (extra_flag) */
369 263 entries_pos = avio_tell(out);
370 263 avio_wb16(out, 0); /* entry count */
371
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 263 if (ts_diff) { /* if extra_flag is set */
372 ✗ avio_wb32(out, 16); /* extra_information_length */
373 ✗ avio_wb32(out, 12); /* rtpoffsetTLV box */
374 ✗ avio_write(out, "rtpo", 4);
375 ✗ avio_wb32(out, ts_diff);
376 }
377
378 263 data += 12;
379 263 size -= 12;
380 263 packet_len -= 12;
381
382 263 entries = 0;
383 /* Write one or more constructors describing the payload data */
384 263 describe_payload(data, packet_len, out, &entries, &trk->sample_queue);
385 263 data += packet_len;
386 263 size -= packet_len;
387
388 263 curpos = avio_tell(out);
389 263 avio_seek(out, entries_pos, SEEK_SET);
390 263 avio_wb16(out, entries);
391 263 avio_seek(out, curpos, SEEK_SET);
392 }
393
394 36 curpos = avio_tell(out);
395 36 avio_seek(out, count_pos, SEEK_SET);
396 36 avio_wb16(out, count);
397 36 avio_seek(out, curpos, SEEK_SET);
398 36 return count;
399 }
400
401 82 int ff_mov_add_hinted_packet(AVFormatContext *s, AVPacket *pkt,
402 int track_index, int sample,
403 uint8_t *sample_data, int sample_size)
404 {
405 82 MOVMuxContext *mov = s->priv_data;
406 82 MOVTrack *trk = &mov->tracks[track_index];
407 82 AVFormatContext *rtp_ctx = trk->rtp_ctx;
408 82 uint8_t *buf = NULL;
409 int size;
410 82 AVIOContext *hintbuf = NULL;
411 82 AVPacket *hint_pkt = mov->pkt;
412 82 int ret = 0, count;
413
414
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 82 if (!rtp_ctx)
415 46 return AVERROR(ENOENT);
416
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 36 if (!rtp_ctx->pb)
417 ✗ return AVERROR(ENOMEM);
418
419
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 36 if (sample_data)
420 ✗ sample_queue_push(&trk->sample_queue, sample_data, sample_size, sample);
421 else
422 36 sample_queue_push(&trk->sample_queue, pkt->data, pkt->size, sample);
423
424 /* Feed the packet to the RTP muxer */
425 36 ff_write_chained(rtp_ctx, 0, pkt, s, 0);
426
427 /* Fetch the output from the RTP muxer, open a new output buffer
428 * for next time. */
429 36 size = avio_close_dyn_buf(rtp_ctx->pb, &buf);
430
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 36 if ((ret = ffio_open_dyn_packet_buf(&rtp_ctx->pb,
431 RTP_MAX_PACKET_SIZE)) < 0)
432 ✗ goto done;
433
434
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 36 if (size <= 0)
435 ✗ goto done;
436
437 /* Open a buffer for writing the hint */
438
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 36 if ((ret = avio_open_dyn_buf(&hintbuf)) < 0)
439 ✗ goto done;
440 36 av_packet_unref(hint_pkt);
441 36 count = write_hint_packets(hintbuf, buf, size, trk, &hint_pkt->dts);
442 36 av_freep(&buf);
443
444 /* Write the hint data into the hint track */
445 36 hint_pkt->size = size = avio_close_dyn_buf(hintbuf, &buf);
446 36 hint_pkt->data = buf;
447 36 hint_pkt->pts = hint_pkt->dts;
448 36 hint_pkt->stream_index = track_index;
449
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 36 if (pkt->flags & AV_PKT_FLAG_KEY)
450 14 hint_pkt->flags |= AV_PKT_FLAG_KEY;
451
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 36 if (count > 0)
452 36 ff_mov_write_packet(s, hint_pkt);
453 ✗ done:
454 36 av_free(buf);
455 36 av_packet_unref(hint_pkt);
456 36 sample_queue_retain(&trk->sample_queue);
457 36 return ret;
458 }
459
460 2 void ff_mov_close_hinting(MOVTrack *track)
461 {
462 2 AVFormatContext *rtp_ctx = track->rtp_ctx;
463
464 2 avcodec_parameters_free(&track->par);
465 2 sample_queue_free(&track->sample_queue);
466
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 2 if (!rtp_ctx)
467 ✗ return;
468
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 2 if (rtp_ctx->pb) {
469 2 av_write_trailer(rtp_ctx);
470 2 ffio_free_dyn_buf(&rtp_ctx->pb);
471 }
472 2 avformat_free_context(rtp_ctx);
473 }
474