FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/bsf/dts2pts.c
Date: 2024-02-29 09:57:37
Exec Total Coverage
Lines: 0 281 0.0%
Functions: 0 14 0.0%
Branches: 0 171 0.0%

Line Branch Exec Source
1 /*
2 * Copyright (c) 2022 James Almer
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * Derive PTS by reordering DTS from supported streams
24 */
25
26 #include "libavutil/avassert.h"
27 #include "libavutil/fifo.h"
28 #include "libavutil/tree.h"
29
30 #include "bsf.h"
31 #include "bsf_internal.h"
32 #include "cbs.h"
33 #include "cbs_h264.h"
34 #include "h264_parse.h"
35 #include "h264_ps.h"
36
37 typedef struct DTS2PTSNode {
38 int64_t dts;
39 int64_t duration;
40 int poc;
41 int gop;
42 } DTS2PTSNode;
43
44 typedef struct DTS2PTSFrame {
45 AVPacket *pkt;
46 int poc;
47 int poc_diff;
48 int gop;
49 } DTS2PTSFrame;
50
51 typedef struct DTS2PTSH264Context {
52 H264POCContext poc;
53 SPS sps;
54 int poc_diff;
55 int last_poc;
56 int highest_poc;
57 int picture_structure;
58 } DTS2PTSH264Context;
59
60 typedef struct DTS2PTSContext {
61 struct AVTreeNode *root;
62 AVFifo *fifo;
63
64 // Codec specific function pointers and constants
65 int (*init)(AVBSFContext *ctx);
66 int (*filter)(AVBSFContext *ctx);
67 void (*flush)(AVBSFContext *ctx);
68 size_t fifo_size;
69
70 CodedBitstreamContext *cbc;
71 CodedBitstreamFragment au;
72
73 union {
74 DTS2PTSH264Context h264;
75 } u;
76
77 int nb_frame;
78 int gop;
79 int eof;
80 } DTS2PTSContext;
81
82 // AVTreeNode callbacks
83 static int cmp_insert(const void *key, const void *node)
84 {
85 int ret = ((const DTS2PTSNode *)key)->poc - ((const DTS2PTSNode *)node)->poc;
86 if (!ret)
87 ret = ((const DTS2PTSNode *)key)->gop - ((const DTS2PTSNode *)node)->gop;
88 return ret;
89 }
90
91 static int cmp_find(const void *key, const void *node)
92 {
93 const DTS2PTSFrame * key1 = key;
94 const DTS2PTSNode *node1 = node;
95 int ret = FFDIFFSIGN(key1->poc, node1->poc);
96 if (!ret)
97 ret = key1->gop - node1->gop;
98 return ret;
99 }
100
101 static int dec_poc(void *opaque, void *elem)
102 {
103 DTS2PTSNode *node = elem;
104 int dec = *(int *)opaque;
105 node->poc -= dec;
106 return 0;
107 }
108
109 static int free_node(void *opaque, void *elem)
110 {
111 DTS2PTSNode *node = elem;
112 av_free(node);
113 return 0;
114 }
115
116 // Shared functions
117 static int alloc_and_insert_node(AVBSFContext *ctx, int64_t ts, int64_t duration,
118 int poc, int poc_diff, int gop)
119 {
120 DTS2PTSContext *s = ctx->priv_data;
121 for (int i = 0; i < poc_diff; i++) {
122 struct AVTreeNode *node = av_tree_node_alloc();
123 DTS2PTSNode *poc_node, *ret;
124 if (!node)
125 return AVERROR(ENOMEM);
126 poc_node = av_malloc(sizeof(*poc_node));
127 if (!poc_node) {
128 av_free(node);
129 return AVERROR(ENOMEM);
130 }
131 if (i && ts != AV_NOPTS_VALUE)
132 ts += duration / poc_diff;
133 *poc_node = (DTS2PTSNode) { ts, duration, poc++, gop };
134 ret = av_tree_insert(&s->root, poc_node, cmp_insert, &node);
135 if (ret && ret != poc_node) {
136 *ret = *poc_node;
137 av_free(poc_node);
138 av_free(node);
139 }
140 }
141 return 0;
142 }
143
144 // H.264
145 static const CodedBitstreamUnitType h264_decompose_unit_types[] = {
146 H264_NAL_SPS,
147 H264_NAL_PPS,
148 H264_NAL_IDR_SLICE,
149 H264_NAL_SLICE,
150 };
151
152 static int h264_init(AVBSFContext *ctx)
153 {
154 DTS2PTSContext *s = ctx->priv_data;
155 DTS2PTSH264Context *h264 = &s->u.h264;
156
157 s->cbc->decompose_unit_types = h264_decompose_unit_types;
158 s->cbc->nb_decompose_unit_types = FF_ARRAY_ELEMS(h264_decompose_unit_types);
159
160 s->nb_frame = -(ctx->par_in->video_delay << 1);
161 h264->last_poc = h264->highest_poc = INT_MIN;
162
163 return 0;
164 }
165
166 static int get_mmco_reset(const H264RawSliceHeader *header)
167 {
168 if (header->nal_unit_header.nal_ref_idc == 0 ||
169 !header->adaptive_ref_pic_marking_mode_flag)
170 return 0;
171
172 for (int i = 0; i < H264_MAX_MMCO_COUNT; i++) {
173 if (header->mmco[i].memory_management_control_operation == 0)
174 return 0;
175 else if (header->mmco[i].memory_management_control_operation == 5)
176 return 1;
177 }
178
179 return 0;
180 }
181
182 static int h264_queue_frame(AVBSFContext *ctx, AVPacket *pkt, int poc, int *queued)
183 {
184 DTS2PTSContext *s = ctx->priv_data;
185 DTS2PTSH264Context *h264 = &s->u.h264;
186 DTS2PTSFrame frame;
187 int poc_diff, ret;
188
189 poc_diff = (h264->picture_structure == 3) + 1;
190 if (h264->sps.frame_mbs_only_flag && h264->poc_diff)
191 poc_diff = FFMIN(poc_diff, h264->poc_diff);
192 if (poc < 0) {
193 av_tree_enumerate(s->root, &poc_diff, NULL, dec_poc);
194 s->nb_frame -= poc_diff;
195 }
196 // Check if there was a POC reset (Like an IDR slice)
197 if (s->nb_frame > h264->highest_poc) {
198 s->nb_frame = 0;
199 s->gop = (s->gop + 1) % s->fifo_size;
200 h264->highest_poc = h264->last_poc;
201 }
202
203 ret = alloc_and_insert_node(ctx, pkt->dts, pkt->duration, s->nb_frame, poc_diff, s->gop);
204 if (ret < 0)
205 return ret;
206 av_log(ctx, AV_LOG_DEBUG, "Queueing frame with POC %d, GOP %d, dts %"PRId64"\n",
207 poc, s->gop, pkt->dts);
208 s->nb_frame += poc_diff;
209
210 // Add frame to output FIFO only once
211 if (*queued)
212 return 0;
213
214 frame = (DTS2PTSFrame) { pkt, poc, poc_diff, s->gop };
215 ret = av_fifo_write(s->fifo, &frame, 1);
216 av_assert2(ret >= 0);
217 *queued = 1;
218
219 return 0;
220 }
221
222 static int h264_filter(AVBSFContext *ctx)
223 {
224 DTS2PTSContext *s = ctx->priv_data;
225 DTS2PTSH264Context *h264 = &s->u.h264;
226 CodedBitstreamFragment *au = &s->au;
227 AVPacket *in;
228 int output_picture_number = INT_MIN;
229 int field_poc[2];
230 int queued = 0, ret;
231
232 ret = ff_bsf_get_packet(ctx, &in);
233 if (ret < 0)
234 return ret;
235
236 ret = ff_cbs_read_packet(s->cbc, au, in);
237 if (ret < 0) {
238 av_log(ctx, AV_LOG_WARNING, "Failed to parse access unit.\n");
239 goto fail;
240 }
241
242 for (int i = 0; i < au->nb_units; i++) {
243 CodedBitstreamUnit *unit = &au->units[i];
244
245 switch (unit->type) {
246 case H264_NAL_IDR_SLICE:
247 h264->poc.prev_frame_num = 0;
248 h264->poc.prev_frame_num_offset = 0;
249 h264->poc.prev_poc_msb =
250 h264->poc.prev_poc_lsb = 0;
251 // fall-through
252 case H264_NAL_SLICE: {
253 const H264RawSlice *slice = unit->content;
254 const H264RawSliceHeader *header = &slice->header;
255 const CodedBitstreamH264Context *cbs_h264 = s->cbc->priv_data;
256 const H264RawSPS *sps = cbs_h264->active_sps;
257 int got_reset;
258
259 if (!sps) {
260 av_log(ctx, AV_LOG_ERROR, "No active SPS for a slice\n");
261 goto fail;
262 }
263 // Initialize the SPS struct with the fields ff_h264_init_poc() cares about
264 h264->sps.frame_mbs_only_flag = sps->frame_mbs_only_flag;
265 h264->sps.log2_max_frame_num = sps->log2_max_frame_num_minus4 + 4;
266 h264->sps.poc_type = sps->pic_order_cnt_type;
267 h264->sps.log2_max_poc_lsb = sps->log2_max_pic_order_cnt_lsb_minus4 + 4;
268 h264->sps.offset_for_non_ref_pic = sps->offset_for_non_ref_pic;
269 h264->sps.offset_for_top_to_bottom_field = sps->offset_for_top_to_bottom_field;
270 h264->sps.poc_cycle_length = sps->num_ref_frames_in_pic_order_cnt_cycle;
271 for (int i = 0; i < h264->sps.poc_cycle_length; i++)
272 h264->sps.offset_for_ref_frame[i] = sps->offset_for_ref_frame[i];
273
274 h264->picture_structure = sps->frame_mbs_only_flag ? 3 :
275 (header->field_pic_flag ?
276 header->field_pic_flag + header->bottom_field_flag : 3);
277
278 h264->poc.frame_num = header->frame_num;
279 h264->poc.poc_lsb = header->pic_order_cnt_lsb;
280 h264->poc.delta_poc_bottom = header->delta_pic_order_cnt_bottom;
281 h264->poc.delta_poc[0] = header->delta_pic_order_cnt[0];
282 h264->poc.delta_poc[1] = header->delta_pic_order_cnt[1];
283
284 field_poc[0] = field_poc[1] = INT_MAX;
285 ret = ff_h264_init_poc(field_poc, &output_picture_number, &h264->sps,
286 &h264->poc, h264->picture_structure,
287 header->nal_unit_header.nal_ref_idc);
288 if (ret < 0) {
289 av_log(ctx, AV_LOG_ERROR, "ff_h264_init_poc() failure\n");
290 goto fail;
291 }
292
293 got_reset = get_mmco_reset(header);
294 h264->poc.prev_frame_num = got_reset ? 0 : h264->poc.frame_num;
295 h264->poc.prev_frame_num_offset = got_reset ? 0 : h264->poc.frame_num_offset;
296 if (header->nal_unit_header.nal_ref_idc != 0) {
297 h264->poc.prev_poc_msb = got_reset ? 0 : h264->poc.poc_msb;
298 if (got_reset)
299 h264->poc.prev_poc_lsb = h264->picture_structure == 2 ? 0 : field_poc[0];
300 else
301 h264->poc.prev_poc_lsb = h264->poc.poc_lsb;
302 }
303
304 if (output_picture_number != h264->last_poc) {
305 if (h264->last_poc != INT_MIN) {
306 int64_t diff = FFABS(h264->last_poc - (int64_t)output_picture_number);
307
308 if ((output_picture_number < 0) && !h264->last_poc)
309 h264->poc_diff = 0;
310 else if (FFABS((int64_t)output_picture_number) < h264->poc_diff) {
311 diff = FFABS(output_picture_number);
312 h264->poc_diff = 0;
313 }
314 if ((!h264->poc_diff || (h264->poc_diff > diff)) && diff <= INT_MAX) {
315 h264->poc_diff = diff;
316 if (h264->poc_diff == 1 && h264->sps.frame_mbs_only_flag) {
317 av_tree_enumerate(s->root, &h264->poc_diff, NULL, dec_poc);
318 s->nb_frame -= 2;
319 }
320 }
321 }
322 h264->last_poc = output_picture_number;
323 h264->highest_poc = FFMAX(h264->highest_poc, output_picture_number);
324
325 ret = h264_queue_frame(ctx, in, output_picture_number, &queued);
326 if (ret < 0)
327 goto fail;
328 }
329 break;
330 }
331 default:
332 break;
333 }
334 }
335
336 if (output_picture_number == INT_MIN) {
337 av_log(ctx, AV_LOG_ERROR, "No slices in access unit\n");
338 ret = AVERROR_INVALIDDATA;
339 goto fail;
340 }
341
342 ret = 0;
343 fail:
344 ff_cbs_fragment_reset(au);
345 if (!queued)
346 av_packet_free(&in);
347
348 return ret;
349 }
350
351 static void h264_flush(AVBSFContext *ctx)
352 {
353 DTS2PTSContext *s = ctx->priv_data;
354 DTS2PTSH264Context *h264 = &s->u.h264;
355
356 memset(&h264->sps, 0, sizeof(h264->sps));
357 memset(&h264->poc, 0, sizeof(h264->poc));
358 s->nb_frame = -(ctx->par_in->video_delay << 1);
359 h264->last_poc = h264->highest_poc = INT_MIN;
360 }
361
362 // Core functions
363 static const struct {
364 enum AVCodecID id;
365 int (*init)(AVBSFContext *ctx);
366 int (*filter)(AVBSFContext *ctx);
367 void (*flush)(AVBSFContext *ctx);
368 size_t fifo_size;
369 } func_tab[] = {
370 { AV_CODEC_ID_H264, h264_init, h264_filter, h264_flush, H264_MAX_DPB_FRAMES * 2 * 2 },
371 };
372
373 static int dts2pts_init(AVBSFContext *ctx)
374 {
375 DTS2PTSContext *s = ctx->priv_data;
376 CodedBitstreamFragment *au = &s->au;
377 int i, ret;
378
379 for (i = 0; i < FF_ARRAY_ELEMS(func_tab); i++) {
380 if (func_tab[i].id == ctx->par_in->codec_id) {
381 s->init = func_tab[i].init;
382 s->filter = func_tab[i].filter;
383 s->flush = func_tab[i].flush;
384 s->fifo_size = func_tab[i].fifo_size;
385 break;
386 }
387 }
388 if (i == FF_ARRAY_ELEMS(func_tab))
389 return AVERROR_BUG;
390 av_assert0(s->filter && s->fifo_size);
391
392 s->fifo = av_fifo_alloc2(s->fifo_size, sizeof(DTS2PTSFrame), 0);
393 if (!s->fifo)
394 return AVERROR(ENOMEM);
395
396 ret = ff_cbs_init(&s->cbc, ctx->par_in->codec_id, ctx);
397 if (ret < 0)
398 return ret;
399
400 if (s->init) {
401 ret = s->init(ctx);
402 if (ret < 0)
403 return ret;
404 }
405
406 if (!ctx->par_in->extradata_size)
407 return 0;
408
409 ret = ff_cbs_read_extradata(s->cbc, au, ctx->par_in);
410 if (ret < 0)
411 av_log(ctx, AV_LOG_WARNING, "Failed to parse extradata.\n");
412
413 ff_cbs_fragment_reset(au);
414
415 return 0;
416 }
417
418 static int dts2pts_filter(AVBSFContext *ctx, AVPacket *out)
419 {
420 DTS2PTSContext *s = ctx->priv_data;
421 DTS2PTSNode *poc_node = NULL, *next[2] = { NULL, NULL };
422 DTS2PTSFrame frame;
423 int ret;
424
425 // Fill up the FIFO and POC tree
426 while (!s->eof && av_fifo_can_write(s->fifo)) {
427 ret = s->filter(ctx);
428 if (ret < 0) {
429 if (ret != AVERROR_EOF)
430 return ret;
431 s->eof = 1;
432 }
433 }
434
435 if (!av_fifo_can_read(s->fifo))
436 return AVERROR_EOF;
437
438 // Fetch a packet from the FIFO
439 ret = av_fifo_read(s->fifo, &frame, 1);
440 av_assert2(ret >= 0);
441 av_packet_move_ref(out, frame.pkt);
442 av_packet_free(&frame.pkt);
443
444 // Search the timestamp for the requested POC and set PTS
445 poc_node = av_tree_find(s->root, &frame, cmp_find, (void **)next);
446 if (!poc_node) {
447 poc_node = next[1];
448 if (!poc_node || poc_node->poc != frame.poc)
449 poc_node = next[0];
450 }
451 if (poc_node && poc_node->poc == frame.poc) {
452 out->pts = poc_node->dts;
453 if (!s->eof) {
454 // Remove the found entry from the tree
455 DTS2PTSFrame dup = (DTS2PTSFrame) { NULL, frame.poc + 1, frame.poc_diff, frame.gop };
456 for (; dup.poc_diff > 0; dup.poc++, dup.poc_diff--) {
457 struct AVTreeNode *node = NULL;
458 if (!poc_node || poc_node->dts != out->pts)
459 continue;
460 av_tree_insert(&s->root, poc_node, cmp_insert, &node);
461 av_free(poc_node);
462 av_free(node);
463 poc_node = av_tree_find(s->root, &dup, cmp_find, NULL);
464 }
465 }
466 } else if (s->eof && frame.poc > INT_MIN) {
467 DTS2PTSFrame dup = (DTS2PTSFrame) { NULL, frame.poc - 1, frame.poc_diff, frame.gop };
468 poc_node = av_tree_find(s->root, &dup, cmp_find, NULL);
469 if (poc_node && poc_node->poc == dup.poc) {
470 out->pts = poc_node->dts;
471 if (out->pts != AV_NOPTS_VALUE)
472 out->pts += poc_node->duration;
473 ret = alloc_and_insert_node(ctx, out->pts, out->duration,
474 frame.poc, frame.poc_diff, frame.gop);
475 if (ret < 0) {
476 av_packet_unref(out);
477 return ret;
478 }
479 if (!ret)
480 av_log(ctx, AV_LOG_DEBUG, "Queueing frame for POC %d, GOP %d, dts %"PRId64", "
481 "generated from POC %d, GOP %d, dts %"PRId64", duration %"PRId64"\n",
482 frame.poc, frame.gop, out->pts,
483 poc_node->poc, poc_node->gop, poc_node->dts, poc_node->duration);
484 } else
485 av_log(ctx, AV_LOG_WARNING, "No timestamp for POC %d in tree\n", frame.poc);
486 } else
487 av_log(ctx, AV_LOG_WARNING, "No timestamp for POC %d in tree\n", frame.poc);
488 av_log(ctx, AV_LOG_DEBUG, "Returning frame for POC %d, GOP %d, dts %"PRId64", pts %"PRId64"\n",
489 frame.poc, frame.gop, out->dts, out->pts);
490
491 return 0;
492 }
493
494 static void dts2pts_flush(AVBSFContext *ctx)
495 {
496 DTS2PTSContext *s = ctx->priv_data;
497 DTS2PTSFrame frame;
498
499 if (s->flush)
500 s->flush(ctx);
501 s->eof = 0;
502 s->gop = 0;
503
504 while (s->fifo && av_fifo_read(s->fifo, &frame, 1) >= 0)
505 av_packet_free(&frame.pkt);
506
507 av_tree_enumerate(s->root, NULL, NULL, free_node);
508 av_tree_destroy(s->root);
509 s->root = NULL;
510
511 ff_cbs_fragment_reset(&s->au);
512 if (s->cbc)
513 ff_cbs_flush(s->cbc);
514 }
515
516 static void dts2pts_close(AVBSFContext *ctx)
517 {
518 DTS2PTSContext *s = ctx->priv_data;
519
520 dts2pts_flush(ctx);
521
522 av_fifo_freep2(&s->fifo);
523 ff_cbs_fragment_free(&s->au);
524 ff_cbs_close(&s->cbc);
525 }
526
527 static const enum AVCodecID dts2pts_codec_ids[] = {
528 AV_CODEC_ID_H264,
529 AV_CODEC_ID_NONE,
530 };
531
532 const FFBitStreamFilter ff_dts2pts_bsf = {
533 .p.name = "dts2pts",
534 .p.codec_ids = dts2pts_codec_ids,
535 .priv_data_size = sizeof(DTS2PTSContext),
536 .init = dts2pts_init,
537 .flush = dts2pts_flush,
538 .close = dts2pts_close,
539 .filter = dts2pts_filter,
540 };
541