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source: vbox/trunk/src/libs/ffmpeg-20060710/libavformat/ffm.c@ 11551

Last change on this file since 11551 was 5776, checked in by vboxsync, 17 years ago

ffmpeg: exported to OSE
File size: 22.7 KB
Line 
1/*
2 * FFM (ffserver live feed) encoder and decoder
3 * Copyright (c) 2001 Fabrice Bellard.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19#include "avformat.h"
20#include <unistd.h>
21
22/* The FFM file is made of blocks of fixed size */
23#define FFM_HEADER_SIZE 14
24#define PACKET_ID 0x666d
25
26/* each packet contains frames (which can span several packets */
27#define FRAME_HEADER_SIZE 8
28#define FLAG_KEY_FRAME 0x01
29
30typedef struct FFMStream {
31 int64_t pts;
32} FFMStream;
33
34enum {
35 READ_HEADER,
36 READ_DATA,
37};
38
39typedef struct FFMContext {
40 /* only reading mode */
41 offset_t write_index, file_size;
42 int read_state;
43 uint8_t header[FRAME_HEADER_SIZE];
44
45 /* read and write */
46 int first_packet; /* true if first packet, needed to set the discontinuity tag */
47 int first_frame_in_packet; /* true if first frame in packet, needed to know if PTS information is valid */
48 int packet_size;
49 int frame_offset;
50 int64_t pts;
51 uint8_t *packet_ptr, *packet_end;
52 uint8_t packet[FFM_PACKET_SIZE];
53} FFMContext;
54
55static int64_t get_pts(AVFormatContext *s, offset_t pos);
56
57/* disable pts hack for testing */
58int ffm_nopts = 0;
59
60#ifdef CONFIG_MUXERS
61static void flush_packet(AVFormatContext *s)
62{
63 FFMContext *ffm = s->priv_data;
64 int fill_size, h;
65 ByteIOContext *pb = &s->pb;
66
67 fill_size = ffm->packet_end - ffm->packet_ptr;
68 memset(ffm->packet_ptr, 0, fill_size);
69
70 if (url_ftell(pb) % ffm->packet_size)
71 av_abort();
72
73 /* put header */
74 put_be16(pb, PACKET_ID);
75 put_be16(pb, fill_size);
76 put_be64(pb, ffm->pts);
77 h = ffm->frame_offset;
78 if (ffm->first_packet)
79 h |= 0x8000;
80 put_be16(pb, h);
81 put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
82 put_flush_packet(pb);
83
84 /* prepare next packet */
85 ffm->frame_offset = 0; /* no key frame */
86 ffm->pts = 0; /* no pts */
87 ffm->packet_ptr = ffm->packet;
88 ffm->first_packet = 0;
89}
90
91/* 'first' is true if first data of a frame */
92static void ffm_write_data(AVFormatContext *s,
93 const uint8_t *buf, int size,
94 int64_t pts, int first)
95{
96 FFMContext *ffm = s->priv_data;
97 int len;
98
99 if (first && ffm->frame_offset == 0)
100 ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
101 if (first && ffm->pts == 0)
102 ffm->pts = pts;
103
104 /* write as many packets as needed */
105 while (size > 0) {
106 len = ffm->packet_end - ffm->packet_ptr;
107 if (len > size)
108 len = size;
109 memcpy(ffm->packet_ptr, buf, len);
110
111 ffm->packet_ptr += len;
112 buf += len;
113 size -= len;
114 if (ffm->packet_ptr >= ffm->packet_end) {
115 /* special case : no pts in packet : we leave the current one */
116 if (ffm->pts == 0)
117 ffm->pts = pts;
118
119 flush_packet(s);
120 }
121 }
122}
123
124static int ffm_write_header(AVFormatContext *s)
125{
126 FFMContext *ffm = s->priv_data;
127 AVStream *st;
128 FFMStream *fst;
129 ByteIOContext *pb = &s->pb;
130 AVCodecContext *codec;
131 int bit_rate, i;
132
133 ffm->packet_size = FFM_PACKET_SIZE;
134
135 /* header */
136 put_le32(pb, MKTAG('F', 'F', 'M', '1'));
137 put_be32(pb, ffm->packet_size);
138 /* XXX: store write position in other file ? */
139 put_be64(pb, ffm->packet_size); /* current write position */
140
141 put_be32(pb, s->nb_streams);
142 bit_rate = 0;
143 for(i=0;i<s->nb_streams;i++) {
144 st = s->streams[i];
145 bit_rate += st->codec->bit_rate;
146 }
147 put_be32(pb, bit_rate);
148
149 /* list of streams */
150 for(i=0;i<s->nb_streams;i++) {
151 st = s->streams[i];
152 fst = av_mallocz(sizeof(FFMStream));
153 if (!fst)
154 goto fail;
155 av_set_pts_info(st, 64, 1, 1000000);
156 st->priv_data = fst;
157
158 codec = st->codec;
159 /* generic info */
160 put_be32(pb, codec->codec_id);
161 put_byte(pb, codec->codec_type);
162 put_be32(pb, codec->bit_rate);
163 put_be32(pb, st->quality);
164 put_be32(pb, codec->flags);
165 put_be32(pb, codec->flags2);
166 put_be32(pb, codec->debug);
167 /* specific info */
168 switch(codec->codec_type) {
169 case CODEC_TYPE_VIDEO:
170 put_be32(pb, codec->time_base.num);
171 put_be32(pb, codec->time_base.den);
172 put_be16(pb, codec->width);
173 put_be16(pb, codec->height);
174 put_be16(pb, codec->gop_size);
175 put_be32(pb, codec->pix_fmt);
176 put_byte(pb, codec->qmin);
177 put_byte(pb, codec->qmax);
178 put_byte(pb, codec->max_qdiff);
179 put_be16(pb, (int) (codec->qcompress * 10000.0));
180 put_be16(pb, (int) (codec->qblur * 10000.0));
181 put_be32(pb, codec->bit_rate_tolerance);
182 put_strz(pb, codec->rc_eq);
183 put_be32(pb, codec->rc_max_rate);
184 put_be32(pb, codec->rc_min_rate);
185 put_be32(pb, codec->rc_buffer_size);
186 put_be64(pb, av_dbl2int(codec->i_quant_factor));
187 put_be64(pb, av_dbl2int(codec->b_quant_factor));
188 put_be64(pb, av_dbl2int(codec->i_quant_offset));
189 put_be64(pb, av_dbl2int(codec->b_quant_offset));
190 put_be32(pb, codec->dct_algo);
191 put_be32(pb, codec->strict_std_compliance);
192 put_be32(pb, codec->max_b_frames);
193 put_be32(pb, codec->luma_elim_threshold);
194 put_be32(pb, codec->chroma_elim_threshold);
195 put_be32(pb, codec->mpeg_quant);
196 put_be32(pb, codec->intra_dc_precision);
197 put_be32(pb, codec->me_method);
198 put_be32(pb, codec->mb_decision);
199 put_be32(pb, codec->nsse_weight);
200 put_be32(pb, codec->frame_skip_cmp);
201 put_be64(pb, av_dbl2int(codec->rc_buffer_aggressivity));
202 break;
203 case CODEC_TYPE_AUDIO:
204 put_be32(pb, codec->sample_rate);
205 put_le16(pb, codec->channels);
206 put_le16(pb, codec->frame_size);
207 break;
208 default:
209 return -1;
210 }
211 /* hack to have real time */
212 if (ffm_nopts)
213 fst->pts = 0;
214 else
215 fst->pts = av_gettime();
216 }
217
218 /* flush until end of block reached */
219 while ((url_ftell(pb) % ffm->packet_size) != 0)
220 put_byte(pb, 0);
221
222 put_flush_packet(pb);
223
224 /* init packet mux */
225 ffm->packet_ptr = ffm->packet;
226 ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
227 assert(ffm->packet_end >= ffm->packet);
228 ffm->frame_offset = 0;
229 ffm->pts = 0;
230 ffm->first_packet = 1;
231
232 return 0;
233 fail:
234 for(i=0;i<s->nb_streams;i++) {
235 st = s->streams[i];
236 av_freep(&st->priv_data);
237 }
238 return -1;
239}
240
241static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
242{
243 AVStream *st = s->streams[pkt->stream_index];
244 FFMStream *fst = st->priv_data;
245 int64_t pts;
246 uint8_t header[FRAME_HEADER_SIZE];
247 int duration;
248 int size= pkt->size;
249
250 //XXX/FIXME use duration from pkt
251 if (st->codec->codec_type == CODEC_TYPE_AUDIO) {
252 duration = ((float)st->codec->frame_size / st->codec->sample_rate * 1000000.0);
253 } else {
254 duration = (1000000.0 * st->codec->time_base.num / (float)st->codec->time_base.den);
255 }
256
257 pts = fst->pts;
258 /* packet size & key_frame */
259 header[0] = pkt->stream_index;
260 header[1] = 0;
261 if (pkt->flags & PKT_FLAG_KEY)
262 header[1] |= FLAG_KEY_FRAME;
263 header[2] = (size >> 16) & 0xff;
264 header[3] = (size >> 8) & 0xff;
265 header[4] = size & 0xff;
266 header[5] = (duration >> 16) & 0xff;
267 header[6] = (duration >> 8) & 0xff;
268 header[7] = duration & 0xff;
269 ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
270 ffm_write_data(s, pkt->data, size, pts, 0);
271
272 fst->pts += duration;
273 return 0;
274}
275
276static int ffm_write_trailer(AVFormatContext *s)
277{
278 ByteIOContext *pb = &s->pb;
279 FFMContext *ffm = s->priv_data;
280
281 /* flush packets */
282 if (ffm->packet_ptr > ffm->packet)
283 flush_packet(s);
284
285 put_flush_packet(pb);
286
287 if (!url_is_streamed(pb)) {
288 int64_t size;
289 /* update the write offset */
290 size = url_ftell(pb);
291 url_fseek(pb, 8, SEEK_SET);
292 put_be64(pb, size);
293 put_flush_packet(pb);
294 }
295
296 return 0;
297}
298#endif //CONFIG_MUXERS
299
300/* ffm demux */
301
302static int ffm_is_avail_data(AVFormatContext *s, int size)
303{
304 FFMContext *ffm = s->priv_data;
305 offset_t pos, avail_size;
306 int len;
307
308 len = ffm->packet_end - ffm->packet_ptr;
309 if (!ffm_nopts) {
310 /* XXX: I don't understand this test, so I disabled it for testing */
311 if (size <= len)
312 return 1;
313 }
314 pos = url_ftell(&s->pb);
315 if (pos == ffm->write_index) {
316 /* exactly at the end of stream */
317 return 0;
318 } else if (pos < ffm->write_index) {
319 avail_size = ffm->write_index - pos;
320 } else {
321 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
322 }
323 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
324 if (size <= avail_size)
325 return 1;
326 else
327 return 0;
328}
329
330/* first is true if we read the frame header */
331static int ffm_read_data(AVFormatContext *s,
332 uint8_t *buf, int size, int first)
333{
334 FFMContext *ffm = s->priv_data;
335 ByteIOContext *pb = &s->pb;
336 int len, fill_size, size1, frame_offset;
337
338 size1 = size;
339 while (size > 0) {
340 redo:
341 len = ffm->packet_end - ffm->packet_ptr;
342 if (len > size)
343 len = size;
344 if (len == 0) {
345 if (url_ftell(pb) == ffm->file_size)
346 url_fseek(pb, ffm->packet_size, SEEK_SET);
347 retry_read:
348 get_be16(pb); /* PACKET_ID */
349 fill_size = get_be16(pb);
350 ffm->pts = get_be64(pb);
351 ffm->first_frame_in_packet = 1;
352 frame_offset = get_be16(pb);
353 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
354 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
355 if (ffm->packet_end < ffm->packet)
356 return -1;
357 /* if first packet or resynchronization packet, we must
358 handle it specifically */
359 if (ffm->first_packet || (frame_offset & 0x8000)) {
360 if (!frame_offset) {
361 /* This packet has no frame headers in it */
362 if (url_ftell(pb) >= ffm->packet_size * 3) {
363 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
364 goto retry_read;
365 }
366 /* This is bad, we cannot find a valid frame header */
367 return 0;
368 }
369 ffm->first_packet = 0;
370 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
371 return -1;
372 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
373 if (!first)
374 break;
375 } else {
376 ffm->packet_ptr = ffm->packet;
377 }
378 goto redo;
379 }
380 memcpy(buf, ffm->packet_ptr, len);
381 buf += len;
382 ffm->packet_ptr += len;
383 size -= len;
384 first = 0;
385 }
386 return size1 - size;
387}
388
389
390static void adjust_write_index(AVFormatContext *s)
391{
392 FFMContext *ffm = s->priv_data;
393 ByteIOContext *pb = &s->pb;
394 int64_t pts;
395 //offset_t orig_write_index = ffm->write_index;
396 offset_t pos_min, pos_max;
397 int64_t pts_start;
398 offset_t ptr = url_ftell(pb);
399
400
401 pos_min = 0;
402 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
403
404 pts_start = get_pts(s, pos_min);
405
406 pts = get_pts(s, pos_max);
407
408 if (pts - 100000 > pts_start)
409 goto end;
410
411 ffm->write_index = FFM_PACKET_SIZE;
412
413 pts_start = get_pts(s, pos_min);
414
415 pts = get_pts(s, pos_max);
416
417 if (pts - 100000 <= pts_start) {
418 while (1) {
419 offset_t newpos;
420 int64_t newpts;
421
422 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
423
424 if (newpos == pos_min)
425 break;
426
427 newpts = get_pts(s, newpos);
428
429 if (newpts - 100000 <= pts) {
430 pos_max = newpos;
431 pts = newpts;
432 } else {
433 pos_min = newpos;
434 }
435 }
436 ffm->write_index += pos_max;
437 }
438
439 //printf("Adjusted write index from %lld to %lld: pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
440 //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
441
442 end:
443 url_fseek(pb, ptr, SEEK_SET);
444}
445
446
447static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
448{
449 FFMContext *ffm = s->priv_data;
450 AVStream *st;
451 FFMStream *fst;
452 ByteIOContext *pb = &s->pb;
453 AVCodecContext *codec;
454 int i, nb_streams;
455 uint32_t tag;
456
457 /* header */
458 tag = get_le32(pb);
459 if (tag != MKTAG('F', 'F', 'M', '1'))
460 goto fail;
461 ffm->packet_size = get_be32(pb);
462 if (ffm->packet_size != FFM_PACKET_SIZE)
463 goto fail;
464 ffm->write_index = get_be64(pb);
465 /* get also filesize */
466 if (!url_is_streamed(pb)) {
467 ffm->file_size = url_fsize(pb);
468 adjust_write_index(s);
469 } else {
470 ffm->file_size = (uint64_t_C(1) << 63) - 1;
471 }
472
473 nb_streams = get_be32(pb);
474 get_be32(pb); /* total bitrate */
475 /* read each stream */
476 for(i=0;i<nb_streams;i++) {
477 char rc_eq_buf[128];
478
479 st = av_new_stream(s, 0);
480 if (!st)
481 goto fail;
482 fst = av_mallocz(sizeof(FFMStream));
483 if (!fst)
484 goto fail;
485 s->streams[i] = st;
486
487 av_set_pts_info(st, 64, 1, 1000000);
488
489 st->priv_data = fst;
490
491 codec = st->codec;
492 /* generic info */
493 codec->codec_id = get_be32(pb);
494 codec->codec_type = get_byte(pb); /* codec_type */
495 codec->bit_rate = get_be32(pb);
496 st->quality = get_be32(pb);
497 codec->flags = get_be32(pb);
498 codec->flags2 = get_be32(pb);
499 codec->debug = get_be32(pb);
500 /* specific info */
501 switch(codec->codec_type) {
502 case CODEC_TYPE_VIDEO:
503 codec->time_base.num = get_be32(pb);
504 codec->time_base.den = get_be32(pb);
505 codec->width = get_be16(pb);
506 codec->height = get_be16(pb);
507 codec->gop_size = get_be16(pb);
508 codec->pix_fmt = get_be32(pb);
509 codec->qmin = get_byte(pb);
510 codec->qmax = get_byte(pb);
511 codec->max_qdiff = get_byte(pb);
512 codec->qcompress = get_be16(pb) / 10000.0;
513 codec->qblur = get_be16(pb) / 10000.0;
514 codec->bit_rate_tolerance = get_be32(pb);
515 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
516 codec->rc_max_rate = get_be32(pb);
517 codec->rc_min_rate = get_be32(pb);
518 codec->rc_buffer_size = get_be32(pb);
519 codec->i_quant_factor = av_int2dbl(get_be64(pb));
520 codec->b_quant_factor = av_int2dbl(get_be64(pb));
521 codec->i_quant_offset = av_int2dbl(get_be64(pb));
522 codec->b_quant_offset = av_int2dbl(get_be64(pb));
523 codec->dct_algo = get_be32(pb);
524 codec->strict_std_compliance = get_be32(pb);
525 codec->max_b_frames = get_be32(pb);
526 codec->luma_elim_threshold = get_be32(pb);
527 codec->chroma_elim_threshold = get_be32(pb);
528 codec->mpeg_quant = get_be32(pb);
529 codec->intra_dc_precision = get_be32(pb);
530 codec->me_method = get_be32(pb);
531 codec->mb_decision = get_be32(pb);
532 codec->nsse_weight = get_be32(pb);
533 codec->frame_skip_cmp = get_be32(pb);
534 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
535 break;
536 case CODEC_TYPE_AUDIO:
537 codec->sample_rate = get_be32(pb);
538 codec->channels = get_le16(pb);
539 codec->frame_size = get_le16(pb);
540 break;
541 default:
542 goto fail;
543 }
544
545 }
546
547 /* get until end of block reached */
548 while ((url_ftell(pb) % ffm->packet_size) != 0)
549 get_byte(pb);
550
551 /* init packet demux */
552 ffm->packet_ptr = ffm->packet;
553 ffm->packet_end = ffm->packet;
554 ffm->frame_offset = 0;
555 ffm->pts = 0;
556 ffm->read_state = READ_HEADER;
557 ffm->first_packet = 1;
558 return 0;
559 fail:
560 for(i=0;i<s->nb_streams;i++) {
561 st = s->streams[i];
562 if (st) {
563 av_freep(&st->priv_data);
564 av_free(st);
565 }
566 }
567 return -1;
568}
569
570/* return < 0 if eof */
571static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
572{
573 int size;
574 FFMContext *ffm = s->priv_data;
575 int duration;
576
577 switch(ffm->read_state) {
578 case READ_HEADER:
579 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
580 return -EAGAIN;
581 }
582#if 0
583 printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
584 url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
585#endif
586 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
587 FRAME_HEADER_SIZE)
588 return -EAGAIN;
589#if 0
590 {
591 int i;
592 for(i=0;i<FRAME_HEADER_SIZE;i++)
593 printf("%02x ", ffm->header[i]);
594 printf("\n");
595 }
596#endif
597 ffm->read_state = READ_DATA;
598 /* fall thru */
599 case READ_DATA:
600 size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
601 if (!ffm_is_avail_data(s, size)) {
602 return -EAGAIN;
603 }
604
605 duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
606
607 av_new_packet(pkt, size);
608 pkt->stream_index = ffm->header[0];
609 pkt->pos = url_ftell(&s->pb);
610 if (ffm->header[1] & FLAG_KEY_FRAME)
611 pkt->flags |= PKT_FLAG_KEY;
612
613 ffm->read_state = READ_HEADER;
614 if (ffm_read_data(s, pkt->data, size, 0) != size) {
615 /* bad case: desynchronized packet. we cancel all the packet loading */
616 av_free_packet(pkt);
617 return -EAGAIN;
618 }
619 if (ffm->first_frame_in_packet)
620 {
621 pkt->pts = ffm->pts;
622 ffm->first_frame_in_packet = 0;
623 }
624 pkt->duration = duration;
625 break;
626 }
627 return 0;
628}
629
630//#define DEBUG_SEEK
631
632/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
633 by the write position inside this function */
634static void ffm_seek1(AVFormatContext *s, offset_t pos1)
635{
636 FFMContext *ffm = s->priv_data;
637 ByteIOContext *pb = &s->pb;
638 offset_t pos;
639
640 pos = pos1 + ffm->write_index;
641 if (pos >= ffm->file_size)
642 pos -= (ffm->file_size - FFM_PACKET_SIZE);
643#ifdef DEBUG_SEEK
644 printf("seek to %Lx -> %Lx\n", pos1, pos);
645#endif
646 url_fseek(pb, pos, SEEK_SET);
647}
648
649static int64_t get_pts(AVFormatContext *s, offset_t pos)
650{
651 ByteIOContext *pb = &s->pb;
652 int64_t pts;
653
654 ffm_seek1(s, pos);
655 url_fskip(pb, 4);
656 pts = get_be64(pb);
657#ifdef DEBUG_SEEK
658 printf("pts=%0.6f\n", pts / 1000000.0);
659#endif
660 return pts;
661}
662
663/* seek to a given time in the file. The file read pointer is
664 positionned at or before pts. XXX: the following code is quite
665 approximative */
666static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
667{
668 FFMContext *ffm = s->priv_data;
669 offset_t pos_min, pos_max, pos;
670 int64_t pts_min, pts_max, pts;
671 double pos1;
672
673#ifdef DEBUG_SEEK
674 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
675#endif
676 /* find the position using linear interpolation (better than
677 dichotomy in typical cases) */
678 pos_min = 0;
679 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
680 while (pos_min <= pos_max) {
681 pts_min = get_pts(s, pos_min);
682 pts_max = get_pts(s, pos_max);
683 /* linear interpolation */
684 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
685 (double)(pts_max - pts_min);
686 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
687 if (pos <= pos_min)
688 pos = pos_min;
689 else if (pos >= pos_max)
690 pos = pos_max;
691 pts = get_pts(s, pos);
692 /* check if we are lucky */
693 if (pts == wanted_pts) {
694 goto found;
695 } else if (pts > wanted_pts) {
696 pos_max = pos - FFM_PACKET_SIZE;
697 } else {
698 pos_min = pos + FFM_PACKET_SIZE;
699 }
700 }
701 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
702 if (pos > 0)
703 pos -= FFM_PACKET_SIZE;
704 found:
705 ffm_seek1(s, pos);
706 return 0;
707}
708
709#ifdef CONFIG_FFSERVER
710offset_t ffm_read_write_index(int fd)
711{
712 uint8_t buf[8];
713 offset_t pos;
714 int i;
715
716 lseek(fd, 8, SEEK_SET);
717 read(fd, buf, 8);
718 pos = 0;
719 for(i=0;i<8;i++)
720 pos |= (int64_t)buf[i] << (56 - i * 8);
721 return pos;
722}
723
724void ffm_write_write_index(int fd, offset_t pos)
725{
726 uint8_t buf[8];
727 int i;
728
729 for(i=0;i<8;i++)
730 buf[i] = (pos >> (56 - i * 8)) & 0xff;
731 lseek(fd, 8, SEEK_SET);
732 write(fd, buf, 8);
733}
734
735void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
736{
737 FFMContext *ffm = s->priv_data;
738 ffm->write_index = pos;
739 ffm->file_size = file_size;
740}
741#endif // CONFIG_FFSERVER
742
743static int ffm_read_close(AVFormatContext *s)
744{
745 AVStream *st;
746 int i;
747
748 for(i=0;i<s->nb_streams;i++) {
749 st = s->streams[i];
750 av_freep(&st->priv_data);
751 }
752 return 0;
753}
754
755static int ffm_probe(AVProbeData *p)
756{
757 if (p->buf_size >= 4 &&
758 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
759 p->buf[3] == '1')
760 return AVPROBE_SCORE_MAX + 1;
761 return 0;
762}
763
764static AVInputFormat ffm_demuxer = {
765 "ffm",
766 "ffm format",
767 sizeof(FFMContext),
768 ffm_probe,
769 ffm_read_header,
770 ffm_read_packet,
771 ffm_read_close,
772 ffm_seek,
773};
774
775#ifdef CONFIG_MUXERS
776static AVOutputFormat ffm_muxer = {
777 "ffm",
778 "ffm format",
779 "",
780 "ffm",
781 sizeof(FFMContext),
782 /* not really used */
783 CODEC_ID_MP2,
784 CODEC_ID_MPEG1VIDEO,
785 ffm_write_header,
786 ffm_write_packet,
787 ffm_write_trailer,
788};
789#endif //CONFIG_MUXERS
790
791int ffm_init(void)
792{
793 av_register_input_format(&ffm_demuxer);
794#ifdef CONFIG_MUXERS
795 av_register_output_format(&ffm_muxer);
796#endif //CONFIG_MUXERS
797 return 0;
798}
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