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Imported Debian version 2.5.0~trusty1.1
[deb_ffmpeg.git] / ffmpeg / libavformat / ffmdec.c
CommitLineData
2ba45a60
DM		 1/*
2 * FFM (ffserver live feed) demuxer
3 * Copyright (c) 2001 Fabrice Bellard
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 <stdint.h>
23
24#include "libavutil/intreadwrite.h"
25#include "libavutil/intfloat.h"
f6fa7814
DM		 26#include "libavutil/opt.h"
27#include "libavutil/avassert.h"
28#include "libavutil/avstring.h"
2ba45a60
DM		 29#include "avformat.h"
30#include "internal.h"
31#include "ffm.h"
32#include "avio_internal.h"
33
34static int ffm_is_avail_data(AVFormatContext *s, int size)
35{
36 FFMContext *ffm = s->priv_data;
37 int64_t pos, avail_size;
38 int len;
39
40 len = ffm->packet_end - ffm->packet_ptr;
41 if (size <= len)
42 return 1;
43 pos = avio_tell(s->pb);
44 if (!ffm->write_index) {
45 if (pos == ffm->file_size)
46 return AVERROR_EOF;
47 avail_size = ffm->file_size - pos;
48 } else {
49 if (pos == ffm->write_index) {
50 /* exactly at the end of stream */
51 return AVERROR(EAGAIN);
52 } else if (pos < ffm->write_index) {
53 avail_size = ffm->write_index - pos;
54 } else {
55 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
56 }
57 }
58 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
59 if (size <= avail_size)
60 return 1;
61 else
62 return AVERROR(EAGAIN);
63}
64
65static int ffm_resync(AVFormatContext *s, int state)
66{
67 av_log(s, AV_LOG_ERROR, "resyncing\n");
68 while (state != PACKET_ID) {
69 if (avio_feof(s->pb)) {
70 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
71 return -1;
72 }
73 state = (state << 8) | avio_r8(s->pb);
74 }
75 return 0;
76}
77
78/* first is true if we read the frame header */
79static int ffm_read_data(AVFormatContext *s,
80 uint8_t *buf, int size, int header)
81{
82 FFMContext *ffm = s->priv_data;
83 AVIOContext *pb = s->pb;
84 int len, fill_size, size1, frame_offset, id;
85
86 size1 = size;
87 while (size > 0) {
88 redo:
89 len = ffm->packet_end - ffm->packet_ptr;
90 if (len < 0)
91 return -1;
92 if (len > size)
93 len = size;
94 if (len == 0) {
95 if (avio_tell(pb) == ffm->file_size)
96 avio_seek(pb, ffm->packet_size, SEEK_SET);
97 retry_read:
98 if (pb->buffer_size != ffm->packet_size) {
99 int64_t tell = avio_tell(pb);
100 ffio_set_buf_size(pb, ffm->packet_size);
101 avio_seek(pb, tell, SEEK_SET);
102 }
103 id = avio_rb16(pb); /* PACKET_ID */
104 if (id != PACKET_ID)
105 if (ffm_resync(s, id) < 0)
106 return -1;
107 fill_size = avio_rb16(pb);
108 ffm->dts = avio_rb64(pb);
109 frame_offset = avio_rb16(pb);
110 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
111 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
112 if (ffm->packet_end < ffm->packet || frame_offset < 0)
113 return -1;
114 /* if first packet or resynchronization packet, we must
115 handle it specifically */
116 if (ffm->first_packet || (frame_offset & 0x8000)) {
117 if (!frame_offset) {
118 /* This packet has no frame headers in it */
119 if (avio_tell(pb) >= ffm->packet_size * 3LL) {
120 avio_seek(pb, -ffm->packet_size * 2LL, SEEK_CUR);
121 goto retry_read;
122 }
123 /* This is bad, we cannot find a valid frame header */
124 return 0;
125 }
126 ffm->first_packet = 0;
127 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
128 return -1;
129 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
130 if (!header)
131 break;
132 } else {
133 ffm->packet_ptr = ffm->packet;
134 }
135 goto redo;
136 }
137 memcpy(buf, ffm->packet_ptr, len);
138 buf += len;
139 ffm->packet_ptr += len;
140 size -= len;
141 header = 0;
142 }
143 return size1 - size;
144}
145
146/* ensure that acutal seeking happens between FFM_PACKET_SIZE
147 and file_size - FFM_PACKET_SIZE */
148static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
149{
150 FFMContext *ffm = s->priv_data;
151 AVIOContext *pb = s->pb;
152 int64_t pos;
153
154 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
155 pos = FFMAX(pos, FFM_PACKET_SIZE);
156 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
157 return avio_seek(pb, pos, SEEK_SET);
158}
159
160static int64_t get_dts(AVFormatContext *s, int64_t pos)
161{
162 AVIOContext *pb = s->pb;
163 int64_t dts;
164
165 ffm_seek1(s, pos);
166 avio_skip(pb, 4);
167 dts = avio_rb64(pb);
168 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
169 return dts;
170}
171
172static void adjust_write_index(AVFormatContext *s)
173{
174 FFMContext *ffm = s->priv_data;
175 AVIOContext *pb = s->pb;
176 int64_t pts;
177 //int64_t orig_write_index = ffm->write_index;
178 int64_t pos_min, pos_max;
179 int64_t pts_start;
180 int64_t ptr = avio_tell(pb);
181
182
183 pos_min = 0;
184 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
185
186 pts_start = get_dts(s, pos_min);
187
188 pts = get_dts(s, pos_max);
189
190 if (pts - 100000 > pts_start)
191 goto end;
192
193 ffm->write_index = FFM_PACKET_SIZE;
194
195 pts_start = get_dts(s, pos_min);
196
197 pts = get_dts(s, pos_max);
198
199 if (pts - 100000 <= pts_start) {
200 while (1) {
201 int64_t newpos;
202 int64_t newpts;
203
204 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
205
206 if (newpos == pos_min)
207 break;
208
209 newpts = get_dts(s, newpos);
210
211 if (newpts - 100000 <= pts) {
212 pos_max = newpos;
213 pts = newpts;
214 } else {
215 pos_min = newpos;
216 }
217 }
218 ffm->write_index += pos_max;
219 }
220
221 end:
222 avio_seek(pb, ptr, SEEK_SET);
223}
224
225
226static int ffm_close(AVFormatContext *s)
227{
228 int i;
229
230 for (i = 0; i < s->nb_streams; i++)
231 av_freep(&s->streams[i]->codec->rc_eq);
232
233 return 0;
234}
235
f6fa7814
DM		 236static int ffm_append_recommended_configuration(AVStream *st, char **conf)
237{
238 int ret;
239 size_t newsize;
240 av_assert0(conf && st);
241 if (!*conf)
242 return 0;
243 if (!st->recommended_encoder_configuration) {
244 st->recommended_encoder_configuration = *conf;
245 *conf = 0;
246 return 0;
247 }
248 newsize = strlen(*conf) + strlen(st->recommended_encoder_configuration) + 2;
249 if ((ret = av_reallocp(&st->recommended_encoder_configuration, newsize)) < 0)
250 return ret;
251 av_strlcat(st->recommended_encoder_configuration, ",", newsize);
252 av_strlcat(st->recommended_encoder_configuration, *conf, newsize);
253 av_freep(conf);
254 return 0;
255}
256
2ba45a60
DM		 257static int ffm2_read_header(AVFormatContext *s)
258{
259 FFMContext *ffm = s->priv_data;
260 AVStream *st;
261 AVIOContext *pb = s->pb;
262 AVCodecContext *codec;
263 int ret;
f6fa7814
DM		 264 int f_main = 0, f_cprv, f_stvi, f_stau;
265 AVCodec *enc;
266 char *buffer;
2ba45a60
DM		 267
268 ffm->packet_size = avio_rb32(pb);
269 if (ffm->packet_size != FFM_PACKET_SIZE) {
270 av_log(s, AV_LOG_ERROR, "Invalid packet size %d, expected size was %d\n",
271 ffm->packet_size, FFM_PACKET_SIZE);
272 ret = AVERROR_INVALIDDATA;
273 goto fail;
274 }
275
276 ffm->write_index = avio_rb64(pb);
277 /* get also filesize */
278 if (pb->seekable) {
279 ffm->file_size = avio_size(pb);
280 if (ffm->write_index && 0)
281 adjust_write_index(s);
282 } else {
283 ffm->file_size = (UINT64_C(1) << 63) - 1;
284 }
285
286 while(!avio_feof(pb)) {
287 unsigned id = avio_rb32(pb);
288 unsigned size = avio_rb32(pb);
289 int64_t next = avio_tell(pb) + size;
290 char rc_eq_buf[128];
291
292 if(!id)
293 break;
294
295 switch(id) {
296 case MKBETAG('M', 'A', 'I', 'N'):
f6fa7814
DM		 297 if (f_main++) {
298 ret = AVERROR(EINVAL);
299 goto fail;
300 }
2ba45a60
DM		 301 avio_rb32(pb); /* nb_streams */
302 avio_rb32(pb); /* total bitrate */
303 break;
304 case MKBETAG('C', 'O', 'M', 'M'):
f6fa7814 305 f_cprv = f_stvi = f_stau = 0;
2ba45a60
DM		 306 st = avformat_new_stream(s, NULL);
307 if (!st) {
308 ret = AVERROR(ENOMEM);
309 goto fail;
310 }
311
312 avpriv_set_pts_info(st, 64, 1, 1000000);
313
314 codec = st->codec;
315 /* generic info */
316 codec->codec_id = avio_rb32(pb);
317 codec->codec_type = avio_r8(pb);
318 codec->bit_rate = avio_rb32(pb);
319 codec->flags = avio_rb32(pb);
320 codec->flags2 = avio_rb32(pb);
321 codec->debug = avio_rb32(pb);
322 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
323 if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)
324 return AVERROR(ENOMEM);
325 }
f6fa7814
DM		 326 break;
327 case MKBETAG('S', 'T', 'V', 'I'):
328 if (f_stvi++) {
329 ret = AVERROR(EINVAL);
330 goto fail;
331 }
332 codec->time_base.num = avio_rb32(pb);
333 codec->time_base.den = avio_rb32(pb);
334 codec->width = avio_rb16(pb);
335 codec->height = avio_rb16(pb);
336 codec->gop_size = avio_rb16(pb);
337 codec->pix_fmt = avio_rb32(pb);
338 codec->qmin = avio_r8(pb);
339 codec->qmax = avio_r8(pb);
340 codec->max_qdiff = avio_r8(pb);
341 codec->qcompress = avio_rb16(pb) / 10000.0;
342 codec->qblur = avio_rb16(pb) / 10000.0;
343 codec->bit_rate_tolerance = avio_rb32(pb);
344 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
345 codec->rc_eq = av_strdup(rc_eq_buf);
346 codec->rc_max_rate = avio_rb32(pb);
347 codec->rc_min_rate = avio_rb32(pb);
348 codec->rc_buffer_size = avio_rb32(pb);
349 codec->i_quant_factor = av_int2double(avio_rb64(pb));
350 codec->b_quant_factor = av_int2double(avio_rb64(pb));
351 codec->i_quant_offset = av_int2double(avio_rb64(pb));
352 codec->b_quant_offset = av_int2double(avio_rb64(pb));
353 codec->dct_algo = avio_rb32(pb);
354 codec->strict_std_compliance = avio_rb32(pb);
355 codec->max_b_frames = avio_rb32(pb);
356 codec->mpeg_quant = avio_rb32(pb);
357 codec->intra_dc_precision = avio_rb32(pb);
358 codec->me_method = avio_rb32(pb);
359 codec->mb_decision = avio_rb32(pb);
360 codec->nsse_weight = avio_rb32(pb);
361 codec->frame_skip_cmp = avio_rb32(pb);
362 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
363 codec->codec_tag = avio_rb32(pb);
364 codec->thread_count = avio_r8(pb);
365 codec->coder_type = avio_rb32(pb);
366 codec->me_cmp = avio_rb32(pb);
367 codec->me_subpel_quality = avio_rb32(pb);
368 codec->me_range = avio_rb32(pb);
369 codec->keyint_min = avio_rb32(pb);
370 codec->scenechange_threshold = avio_rb32(pb);
371 codec->b_frame_strategy = avio_rb32(pb);
372 codec->qcompress = av_int2double(avio_rb64(pb));
373 codec->qblur = av_int2double(avio_rb64(pb));
374 codec->max_qdiff = avio_rb32(pb);
375 codec->refs = avio_rb32(pb);
376 break;
377 case MKBETAG('S', 'T', 'A', 'U'):
378 if (f_stau++) {
379 ret = AVERROR(EINVAL);
380 goto fail;
381 }
382 codec->sample_rate = avio_rb32(pb);
383 codec->channels = avio_rl16(pb);
384 codec->frame_size = avio_rl16(pb);
385 break;
386 case MKBETAG('C', 'P', 'R', 'V'):
387 if (f_cprv++) {
388 ret = AVERROR(EINVAL);
389 goto fail;
390 }
391 enc = avcodec_find_encoder(codec->codec_id);
392 if (enc && enc->priv_data_size && enc->priv_class) {
393 buffer = av_malloc(size + 1);
394 if (!buffer) {
395 ret = AVERROR(ENOMEM);
396 goto fail;
397 }
398 avio_get_str(pb, size, buffer, size + 1);
399 if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
400 goto fail;
401 }
402 break;
403 case MKBETAG('S', '2', 'V', 'I'):
404 if (f_stvi++) {
405 ret = AVERROR(EINVAL);
406 goto fail;
407 }
408 buffer = av_malloc(size);
409 if (!buffer) {
410 ret = AVERROR(ENOMEM);
411 goto fail;
412 }
413 avio_get_str(pb, INT_MAX, buffer, size);
414 av_set_options_string(codec, buffer, "=", ",");
415 if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
416 goto fail;
417 break;
418 case MKBETAG('S', '2', 'A', 'U'):
419 if (f_stau++) {
420 ret = AVERROR(EINVAL);
421 goto fail;
422 }
423 buffer = av_malloc(size);
424 if (!buffer) {
425 ret = AVERROR(ENOMEM);
426 goto fail;
2ba45a60 427 }
f6fa7814
DM		 428 avio_get_str(pb, INT_MAX, buffer, size);
429 av_set_options_string(codec, buffer, "=", ",");
430 ffm_append_recommended_configuration(st, &buffer);
2ba45a60
DM		 431 break;
432 }
433 avio_seek(pb, next, SEEK_SET);
434 }
435
436 /* get until end of block reached */
437 while ((avio_tell(pb) % ffm->packet_size) != 0)
438 avio_r8(pb);
439
440 /* init packet demux */
441 ffm->packet_ptr = ffm->packet;
442 ffm->packet_end = ffm->packet;
443 ffm->frame_offset = 0;
444 ffm->dts = 0;
445 ffm->read_state = READ_HEADER;
446 ffm->first_packet = 1;
447 return 0;
448 fail:
449 ffm_close(s);
450 return ret;
451}
452
453static int ffm_read_header(AVFormatContext *s)
454{
455 FFMContext *ffm = s->priv_data;
456 AVStream *st;
457 AVIOContext *pb = s->pb;
458 AVCodecContext *codec;
459 int i, nb_streams;
460 uint32_t tag;
461
462 /* header */
463 tag = avio_rl32(pb);
464 if (tag == MKTAG('F', 'F', 'M', '2'))
465 return ffm2_read_header(s);
466 if (tag != MKTAG('F', 'F', 'M', '1'))
467 goto fail;
468 ffm->packet_size = avio_rb32(pb);
469 if (ffm->packet_size != FFM_PACKET_SIZE)
470 goto fail;
471 ffm->write_index = avio_rb64(pb);
472 /* get also filesize */
473 if (pb->seekable) {
474 ffm->file_size = avio_size(pb);
475 if (ffm->write_index && 0)
476 adjust_write_index(s);
477 } else {
478 ffm->file_size = (UINT64_C(1) << 63) - 1;
479 }
480
481 nb_streams = avio_rb32(pb);
482 avio_rb32(pb); /* total bitrate */
483 /* read each stream */
484 for(i=0;i<nb_streams;i++) {
485 char rc_eq_buf[128];
486
487 st = avformat_new_stream(s, NULL);
488 if (!st)
489 goto fail;
490
491 avpriv_set_pts_info(st, 64, 1, 1000000);
492
493 codec = st->codec;
494 /* generic info */
495 codec->codec_id = avio_rb32(pb);
496 codec->codec_type = avio_r8(pb); /* codec_type */
497 codec->bit_rate = avio_rb32(pb);
498 codec->flags = avio_rb32(pb);
499 codec->flags2 = avio_rb32(pb);
500 codec->debug = avio_rb32(pb);
501 /* specific info */
502 switch(codec->codec_type) {
503 case AVMEDIA_TYPE_VIDEO:
504 codec->time_base.num = avio_rb32(pb);
505 codec->time_base.den = avio_rb32(pb);
506 codec->width = avio_rb16(pb);
507 codec->height = avio_rb16(pb);
508 codec->gop_size = avio_rb16(pb);
509 codec->pix_fmt = avio_rb32(pb);
510 codec->qmin = avio_r8(pb);
511 codec->qmax = avio_r8(pb);
512 codec->max_qdiff = avio_r8(pb);
513 codec->qcompress = avio_rb16(pb) / 10000.0;
514 codec->qblur = avio_rb16(pb) / 10000.0;
515 codec->bit_rate_tolerance = avio_rb32(pb);
516 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
517 codec->rc_eq = av_strdup(rc_eq_buf);
518 codec->rc_max_rate = avio_rb32(pb);
519 codec->rc_min_rate = avio_rb32(pb);
520 codec->rc_buffer_size = avio_rb32(pb);
521 codec->i_quant_factor = av_int2double(avio_rb64(pb));
522 codec->b_quant_factor = av_int2double(avio_rb64(pb));
523 codec->i_quant_offset = av_int2double(avio_rb64(pb));
524 codec->b_quant_offset = av_int2double(avio_rb64(pb));
525 codec->dct_algo = avio_rb32(pb);
526 codec->strict_std_compliance = avio_rb32(pb);
527 codec->max_b_frames = avio_rb32(pb);
528 codec->mpeg_quant = avio_rb32(pb);
529 codec->intra_dc_precision = avio_rb32(pb);
530 codec->me_method = avio_rb32(pb);
531 codec->mb_decision = avio_rb32(pb);
532 codec->nsse_weight = avio_rb32(pb);
533 codec->frame_skip_cmp = avio_rb32(pb);
534 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
535 codec->codec_tag = avio_rb32(pb);
536 codec->thread_count = avio_r8(pb);
537 codec->coder_type = avio_rb32(pb);
538 codec->me_cmp = avio_rb32(pb);
539 codec->me_subpel_quality = avio_rb32(pb);
540 codec->me_range = avio_rb32(pb);
541 codec->keyint_min = avio_rb32(pb);
542 codec->scenechange_threshold = avio_rb32(pb);
543 codec->b_frame_strategy = avio_rb32(pb);
544 codec->qcompress = av_int2double(avio_rb64(pb));
545 codec->qblur = av_int2double(avio_rb64(pb));
546 codec->max_qdiff = avio_rb32(pb);
547 codec->refs = avio_rb32(pb);
548 break;
549 case AVMEDIA_TYPE_AUDIO:
550 codec->sample_rate = avio_rb32(pb);
551 codec->channels = avio_rl16(pb);
552 codec->frame_size = avio_rl16(pb);
553 break;
554 default:
555 goto fail;
556 }
557 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
558 if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)
559 return AVERROR(ENOMEM);
560 }
561 }
562
563 /* get until end of block reached */
564 while ((avio_tell(pb) % ffm->packet_size) != 0)
565 avio_r8(pb);
566
567 /* init packet demux */
568 ffm->packet_ptr = ffm->packet;
569 ffm->packet_end = ffm->packet;
570 ffm->frame_offset = 0;
571 ffm->dts = 0;
572 ffm->read_state = READ_HEADER;
573 ffm->first_packet = 1;
574 return 0;
575 fail:
576 ffm_close(s);
577 return -1;
578}
579
580/* return < 0 if eof */
581static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
582{
583 int size;
584 FFMContext *ffm = s->priv_data;
585 int duration, ret;
586
587 switch(ffm->read_state) {
588 case READ_HEADER:
589 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
590 return ret;
591
592 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
593 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
594 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
595 FRAME_HEADER_SIZE)
596 return -1;
597 if (ffm->header[1] & FLAG_DTS)
598 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
599 return -1;
600 ffm->read_state = READ_DATA;
601 /* fall through */
602 case READ_DATA:
603 size = AV_RB24(ffm->header + 2);
604 if ((ret = ffm_is_avail_data(s, size)) < 0)
605 return ret;
606
607 duration = AV_RB24(ffm->header + 5);
608
609 if (av_new_packet(pkt, size) < 0) {
610 return AVERROR(ENOMEM);
611 }
612 pkt->stream_index = ffm->header[0];
613 if ((unsigned)pkt->stream_index >= s->nb_streams) {
614 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
615 av_free_packet(pkt);
616 ffm->read_state = READ_HEADER;
617 return -1;
618 }
619 pkt->pos = avio_tell(s->pb);
620 if (ffm->header[1] & FLAG_KEY_FRAME)
621 pkt->flags |= AV_PKT_FLAG_KEY;
622
623 ffm->read_state = READ_HEADER;
624 if (ffm_read_data(s, pkt->data, size, 0) != size) {
625 /* bad case: desynchronized packet. we cancel all the packet loading */
626 av_free_packet(pkt);
627 return -1;
628 }
629 pkt->pts = AV_RB64(ffm->header+8);
630 if (ffm->header[1] & FLAG_DTS)
631 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
632 else
633 pkt->dts = pkt->pts;
634 pkt->duration = duration;
635 break;
636 }
637 return 0;
638}
639
640/* seek to a given time in the file. The file read pointer is
641 positioned at or before pts. XXX: the following code is quite
642 approximative */
643static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
644{
645 FFMContext *ffm = s->priv_data;
646 int64_t pos_min, pos_max, pos;
647 int64_t pts_min, pts_max, pts;
648 double pos1;
649
650 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
651 /* find the position using linear interpolation (better than
652 dichotomy in typical cases) */
653 if (ffm->write_index && ffm->write_index < ffm->file_size) {
654 if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
655 pos_min = FFM_PACKET_SIZE;
656 pos_max = ffm->write_index - FFM_PACKET_SIZE;
657 } else {
658 pos_min = ffm->write_index;
659 pos_max = ffm->file_size - FFM_PACKET_SIZE;
660 }
661 } else {
662 pos_min = FFM_PACKET_SIZE;
663 pos_max = ffm->file_size - FFM_PACKET_SIZE;
664 }
665 while (pos_min <= pos_max) {
666 pts_min = get_dts(s, pos_min);
667 pts_max = get_dts(s, pos_max);
668 if (pts_min > wanted_pts || pts_max <= wanted_pts) {
669 pos = pts_min > wanted_pts ? pos_min : pos_max;
670 goto found;
671 }
672 /* linear interpolation */
673 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
674 (double)(pts_max - pts_min);
675 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
676 if (pos <= pos_min)
677 pos = pos_min;
678 else if (pos >= pos_max)
679 pos = pos_max;
680 pts = get_dts(s, pos);
681 /* check if we are lucky */
682 if (pts == wanted_pts) {
683 goto found;
684 } else if (pts > wanted_pts) {
685 pos_max = pos - FFM_PACKET_SIZE;
686 } else {
687 pos_min = pos + FFM_PACKET_SIZE;
688 }
689 }
690 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
691
692 found:
693 if (ffm_seek1(s, pos) < 0)
694 return -1;
695
696 /* reset read state */
697 ffm->read_state = READ_HEADER;
698 ffm->packet_ptr = ffm->packet;
699 ffm->packet_end = ffm->packet;
700 ffm->first_packet = 1;
701
702 return 0;
703}
704
705static int ffm_probe(AVProbeData *p)
706{
707 if (
708 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
709 (p->buf[3] == '1' || p->buf[3] == '2'))
710 return AVPROBE_SCORE_MAX + 1;
711 return 0;
712}
713
714AVInputFormat ff_ffm_demuxer = {
715 .name = "ffm",
716 .long_name = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),
717 .priv_data_size = sizeof(FFMContext),
718 .read_probe = ffm_probe,
719 .read_header = ffm_read_header,
720 .read_packet = ffm_read_packet,
721 .read_close = ffm_close,
722 .read_seek = ffm_seek,
723};
ffmpeg Piment Noir Debian package repository