Fix random typos.
[libav.git] / libavformat / ffm.c
1 /*
2 * FFM (ffserver live feed) muxer and 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 #include "avformat.h"
22 #include <unistd.h>
23
24 /* The FFM file is made of blocks of fixed size */
25 #define FFM_HEADER_SIZE 14
26 #define PACKET_ID 0x666d
27
28 /* each packet contains frames (which can span several packets */
29 #define FRAME_HEADER_SIZE 8
30 #define FLAG_KEY_FRAME 0x01
31
32 typedef struct FFMStream {
33 int64_t pts;
34 } FFMStream;
35
36 enum {
37 READ_HEADER,
38 READ_DATA,
39 };
40
41 typedef struct FFMContext {
42 /* only reading mode */
43 offset_t write_index, file_size;
44 int read_state;
45 uint8_t header[FRAME_HEADER_SIZE];
46
47 /* read and write */
48 int first_packet; /* true if first packet, needed to set the discontinuity tag */
49 int first_frame_in_packet; /* true if first frame in packet, needed to know if PTS information is valid */
50 int packet_size;
51 int frame_offset;
52 int64_t pts;
53 uint8_t *packet_ptr, *packet_end;
54 uint8_t packet[FFM_PACKET_SIZE];
55 } FFMContext;
56
57 static int64_t get_pts(AVFormatContext *s, offset_t pos);
58
59 /* disable pts hack for testing */
60 int ffm_nopts = 0;
61
62 #ifdef CONFIG_MUXERS
63 static void flush_packet(AVFormatContext *s)
64 {
65 FFMContext *ffm = s->priv_data;
66 int fill_size, h;
67 ByteIOContext *pb = s->pb;
68
69 fill_size = ffm->packet_end - ffm->packet_ptr;
70 memset(ffm->packet_ptr, 0, fill_size);
71
72 if (url_ftell(pb) % ffm->packet_size)
73 av_abort();
74
75 /* put header */
76 put_be16(pb, PACKET_ID);
77 put_be16(pb, fill_size);
78 put_be64(pb, ffm->pts);
79 h = ffm->frame_offset;
80 if (ffm->first_packet)
81 h |= 0x8000;
82 put_be16(pb, h);
83 put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
84 put_flush_packet(pb);
85
86 /* prepare next packet */
87 ffm->frame_offset = 0; /* no key frame */
88 ffm->pts = 0; /* no pts */
89 ffm->packet_ptr = ffm->packet;
90 ffm->first_packet = 0;
91 }
92
93 /* 'first' is true if first data of a frame */
94 static void ffm_write_data(AVFormatContext *s,
95 const uint8_t *buf, int size,
96 int64_t pts, int first)
97 {
98 FFMContext *ffm = s->priv_data;
99 int len;
100
101 if (first && ffm->frame_offset == 0)
102 ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
103 if (first && ffm->pts == 0)
104 ffm->pts = pts;
105
106 /* write as many packets as needed */
107 while (size > 0) {
108 len = ffm->packet_end - ffm->packet_ptr;
109 if (len > size)
110 len = size;
111 memcpy(ffm->packet_ptr, buf, len);
112
113 ffm->packet_ptr += len;
114 buf += len;
115 size -= len;
116 if (ffm->packet_ptr >= ffm->packet_end) {
117 /* special case : no pts in packet : we leave the current one */
118 if (ffm->pts == 0)
119 ffm->pts = pts;
120
121 flush_packet(s);
122 }
123 }
124 }
125
126 static int ffm_write_header(AVFormatContext *s)
127 {
128 FFMContext *ffm = s->priv_data;
129 AVStream *st;
130 FFMStream *fst;
131 ByteIOContext *pb = s->pb;
132 AVCodecContext *codec;
133 int bit_rate, i;
134
135 ffm->packet_size = FFM_PACKET_SIZE;
136
137 /* header */
138 put_le32(pb, MKTAG('F', 'F', 'M', '1'));
139 put_be32(pb, ffm->packet_size);
140 /* XXX: store write position in other file ? */
141 put_be64(pb, ffm->packet_size); /* current write position */
142
143 put_be32(pb, s->nb_streams);
144 bit_rate = 0;
145 for(i=0;i<s->nb_streams;i++) {
146 st = s->streams[i];
147 bit_rate += st->codec->bit_rate;
148 }
149 put_be32(pb, bit_rate);
150
151 /* list of streams */
152 for(i=0;i<s->nb_streams;i++) {
153 st = s->streams[i];
154 fst = av_mallocz(sizeof(FFMStream));
155 if (!fst)
156 goto fail;
157 av_set_pts_info(st, 64, 1, 1000000);
158 st->priv_data = fst;
159
160 codec = st->codec;
161 /* generic info */
162 put_be32(pb, codec->codec_id);
163 put_byte(pb, codec->codec_type);
164 put_be32(pb, codec->bit_rate);
165 put_be32(pb, st->quality);
166 put_be32(pb, codec->flags);
167 put_be32(pb, codec->flags2);
168 put_be32(pb, codec->debug);
169 /* specific info */
170 switch(codec->codec_type) {
171 case CODEC_TYPE_VIDEO:
172 put_be32(pb, codec->time_base.num);
173 put_be32(pb, codec->time_base.den);
174 put_be16(pb, codec->width);
175 put_be16(pb, codec->height);
176 put_be16(pb, codec->gop_size);
177 put_be32(pb, codec->pix_fmt);
178 put_byte(pb, codec->qmin);
179 put_byte(pb, codec->qmax);
180 put_byte(pb, codec->max_qdiff);
181 put_be16(pb, (int) (codec->qcompress * 10000.0));
182 put_be16(pb, (int) (codec->qblur * 10000.0));
183 put_be32(pb, codec->bit_rate_tolerance);
184 put_strz(pb, codec->rc_eq);
185 put_be32(pb, codec->rc_max_rate);
186 put_be32(pb, codec->rc_min_rate);
187 put_be32(pb, codec->rc_buffer_size);
188 put_be64(pb, av_dbl2int(codec->i_quant_factor));
189 put_be64(pb, av_dbl2int(codec->b_quant_factor));
190 put_be64(pb, av_dbl2int(codec->i_quant_offset));
191 put_be64(pb, av_dbl2int(codec->b_quant_offset));
192 put_be32(pb, codec->dct_algo);
193 put_be32(pb, codec->strict_std_compliance);
194 put_be32(pb, codec->max_b_frames);
195 put_be32(pb, codec->luma_elim_threshold);
196 put_be32(pb, codec->chroma_elim_threshold);
197 put_be32(pb, codec->mpeg_quant);
198 put_be32(pb, codec->intra_dc_precision);
199 put_be32(pb, codec->me_method);
200 put_be32(pb, codec->mb_decision);
201 put_be32(pb, codec->nsse_weight);
202 put_be32(pb, codec->frame_skip_cmp);
203 put_be64(pb, av_dbl2int(codec->rc_buffer_aggressivity));
204 put_be32(pb, codec->codec_tag);
205 break;
206 case CODEC_TYPE_AUDIO:
207 put_be32(pb, codec->sample_rate);
208 put_le16(pb, codec->channels);
209 put_le16(pb, codec->frame_size);
210 break;
211 default:
212 return -1;
213 }
214 /* hack to have real time */
215 if (ffm_nopts)
216 fst->pts = 0;
217 else
218 fst->pts = av_gettime();
219 }
220
221 /* flush until end of block reached */
222 while ((url_ftell(pb) % ffm->packet_size) != 0)
223 put_byte(pb, 0);
224
225 put_flush_packet(pb);
226
227 /* init packet mux */
228 ffm->packet_ptr = ffm->packet;
229 ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
230 assert(ffm->packet_end >= ffm->packet);
231 ffm->frame_offset = 0;
232 ffm->pts = 0;
233 ffm->first_packet = 1;
234
235 return 0;
236 fail:
237 for(i=0;i<s->nb_streams;i++) {
238 st = s->streams[i];
239 av_freep(&st->priv_data);
240 }
241 return -1;
242 }
243
244 static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
245 {
246 AVStream *st = s->streams[pkt->stream_index];
247 FFMStream *fst = st->priv_data;
248 int64_t pts;
249 uint8_t header[FRAME_HEADER_SIZE];
250 int duration;
251 int size= pkt->size;
252
253 //XXX/FIXME use duration from pkt
254 if (st->codec->codec_type == CODEC_TYPE_AUDIO) {
255 duration = ((float)st->codec->frame_size / st->codec->sample_rate * 1000000.0);
256 } else {
257 duration = (1000000.0 * st->codec->time_base.num / (float)st->codec->time_base.den);
258 }
259
260 pts = fst->pts;
261 /* packet size & key_frame */
262 header[0] = pkt->stream_index;
263 header[1] = 0;
264 if (pkt->flags & PKT_FLAG_KEY)
265 header[1] |= FLAG_KEY_FRAME;
266 header[2] = (size >> 16) & 0xff;
267 header[3] = (size >> 8) & 0xff;
268 header[4] = size & 0xff;
269 header[5] = (duration >> 16) & 0xff;
270 header[6] = (duration >> 8) & 0xff;
271 header[7] = duration & 0xff;
272 ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
273 ffm_write_data(s, pkt->data, size, pts, 0);
274
275 fst->pts += duration;
276 return 0;
277 }
278
279 static int ffm_write_trailer(AVFormatContext *s)
280 {
281 ByteIOContext *pb = s->pb;
282 FFMContext *ffm = s->priv_data;
283
284 /* flush packets */
285 if (ffm->packet_ptr > ffm->packet)
286 flush_packet(s);
287
288 put_flush_packet(pb);
289
290 if (!url_is_streamed(pb)) {
291 int64_t size;
292 /* update the write offset */
293 size = url_ftell(pb);
294 url_fseek(pb, 8, SEEK_SET);
295 put_be64(pb, size);
296 put_flush_packet(pb);
297 }
298
299 return 0;
300 }
301 #endif //CONFIG_MUXERS
302
303 /* ffm demux */
304
305 static int ffm_is_avail_data(AVFormatContext *s, int size)
306 {
307 FFMContext *ffm = s->priv_data;
308 offset_t pos, avail_size;
309 int len;
310
311 len = ffm->packet_end - ffm->packet_ptr;
312 if (!ffm_nopts) {
313 /* XXX: I don't understand this test, so I disabled it for testing */
314 if (size <= len)
315 return 1;
316 }
317 pos = url_ftell(s->pb);
318 if (pos == ffm->write_index) {
319 /* exactly at the end of stream */
320 return 0;
321 } else if (pos < ffm->write_index) {
322 avail_size = ffm->write_index - pos;
323 } else {
324 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
325 }
326 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
327 if (size <= avail_size)
328 return 1;
329 else
330 return 0;
331 }
332
333 /* first is true if we read the frame header */
334 static int ffm_read_data(AVFormatContext *s,
335 uint8_t *buf, int size, int first)
336 {
337 FFMContext *ffm = s->priv_data;
338 ByteIOContext *pb = s->pb;
339 int len, fill_size, size1, frame_offset;
340
341 size1 = size;
342 while (size > 0) {
343 redo:
344 len = ffm->packet_end - ffm->packet_ptr;
345 if (len > size)
346 len = size;
347 if (len == 0) {
348 if (url_ftell(pb) == ffm->file_size)
349 url_fseek(pb, ffm->packet_size, SEEK_SET);
350 retry_read:
351 get_be16(pb); /* PACKET_ID */
352 fill_size = get_be16(pb);
353 ffm->pts = get_be64(pb);
354 ffm->first_frame_in_packet = 1;
355 frame_offset = get_be16(pb);
356 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
357 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
358 if (ffm->packet_end < ffm->packet)
359 return -1;
360 /* if first packet or resynchronization packet, we must
361 handle it specifically */
362 if (ffm->first_packet || (frame_offset & 0x8000)) {
363 if (!frame_offset) {
364 /* This packet has no frame headers in it */
365 if (url_ftell(pb) >= ffm->packet_size * 3) {
366 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
367 goto retry_read;
368 }
369 /* This is bad, we cannot find a valid frame header */
370 return 0;
371 }
372 ffm->first_packet = 0;
373 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
374 return -1;
375 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
376 if (!first)
377 break;
378 } else {
379 ffm->packet_ptr = ffm->packet;
380 }
381 goto redo;
382 }
383 memcpy(buf, ffm->packet_ptr, len);
384 buf += len;
385 ffm->packet_ptr += len;
386 size -= len;
387 first = 0;
388 }
389 return size1 - size;
390 }
391
392
393 static void adjust_write_index(AVFormatContext *s)
394 {
395 FFMContext *ffm = s->priv_data;
396 ByteIOContext *pb = s->pb;
397 int64_t pts;
398 //offset_t orig_write_index = ffm->write_index;
399 offset_t pos_min, pos_max;
400 int64_t pts_start;
401 offset_t ptr = url_ftell(pb);
402
403
404 pos_min = 0;
405 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
406
407 pts_start = get_pts(s, pos_min);
408
409 pts = get_pts(s, pos_max);
410
411 if (pts - 100000 > pts_start)
412 goto end;
413
414 ffm->write_index = FFM_PACKET_SIZE;
415
416 pts_start = get_pts(s, pos_min);
417
418 pts = get_pts(s, pos_max);
419
420 if (pts - 100000 <= pts_start) {
421 while (1) {
422 offset_t newpos;
423 int64_t newpts;
424
425 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
426
427 if (newpos == pos_min)
428 break;
429
430 newpts = get_pts(s, newpos);
431
432 if (newpts - 100000 <= pts) {
433 pos_max = newpos;
434 pts = newpts;
435 } else {
436 pos_min = newpos;
437 }
438 }
439 ffm->write_index += pos_max;
440 }
441
442 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
443 //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
444
445 end:
446 url_fseek(pb, ptr, SEEK_SET);
447 }
448
449
450 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
451 {
452 FFMContext *ffm = s->priv_data;
453 AVStream *st;
454 FFMStream *fst;
455 ByteIOContext *pb = s->pb;
456 AVCodecContext *codec;
457 int i, nb_streams;
458 uint32_t tag;
459
460 /* header */
461 tag = get_le32(pb);
462 if (tag != MKTAG('F', 'F', 'M', '1'))
463 goto fail;
464 ffm->packet_size = get_be32(pb);
465 if (ffm->packet_size != FFM_PACKET_SIZE)
466 goto fail;
467 ffm->write_index = get_be64(pb);
468 /* get also filesize */
469 if (!url_is_streamed(pb)) {
470 ffm->file_size = url_fsize(pb);
471 adjust_write_index(s);
472 } else {
473 ffm->file_size = (UINT64_C(1) << 63) - 1;
474 }
475
476 nb_streams = get_be32(pb);
477 get_be32(pb); /* total bitrate */
478 /* read each stream */
479 for(i=0;i<nb_streams;i++) {
480 char rc_eq_buf[128];
481
482 st = av_new_stream(s, 0);
483 if (!st)
484 goto fail;
485 fst = av_mallocz(sizeof(FFMStream));
486 if (!fst)
487 goto fail;
488 s->streams[i] = st;
489
490 av_set_pts_info(st, 64, 1, 1000000);
491
492 st->priv_data = fst;
493
494 codec = st->codec;
495 /* generic info */
496 codec->codec_id = get_be32(pb);
497 codec->codec_type = get_byte(pb); /* codec_type */
498 codec->bit_rate = get_be32(pb);
499 st->quality = get_be32(pb);
500 codec->flags = get_be32(pb);
501 codec->flags2 = get_be32(pb);
502 codec->debug = get_be32(pb);
503 /* specific info */
504 switch(codec->codec_type) {
505 case CODEC_TYPE_VIDEO:
506 codec->time_base.num = get_be32(pb);
507 codec->time_base.den = get_be32(pb);
508 codec->width = get_be16(pb);
509 codec->height = get_be16(pb);
510 codec->gop_size = get_be16(pb);
511 codec->pix_fmt = get_be32(pb);
512 codec->qmin = get_byte(pb);
513 codec->qmax = get_byte(pb);
514 codec->max_qdiff = get_byte(pb);
515 codec->qcompress = get_be16(pb) / 10000.0;
516 codec->qblur = get_be16(pb) / 10000.0;
517 codec->bit_rate_tolerance = get_be32(pb);
518 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
519 codec->rc_max_rate = get_be32(pb);
520 codec->rc_min_rate = get_be32(pb);
521 codec->rc_buffer_size = get_be32(pb);
522 codec->i_quant_factor = av_int2dbl(get_be64(pb));
523 codec->b_quant_factor = av_int2dbl(get_be64(pb));
524 codec->i_quant_offset = av_int2dbl(get_be64(pb));
525 codec->b_quant_offset = av_int2dbl(get_be64(pb));
526 codec->dct_algo = get_be32(pb);
527 codec->strict_std_compliance = get_be32(pb);
528 codec->max_b_frames = get_be32(pb);
529 codec->luma_elim_threshold = get_be32(pb);
530 codec->chroma_elim_threshold = get_be32(pb);
531 codec->mpeg_quant = get_be32(pb);
532 codec->intra_dc_precision = get_be32(pb);
533 codec->me_method = get_be32(pb);
534 codec->mb_decision = get_be32(pb);
535 codec->nsse_weight = get_be32(pb);
536 codec->frame_skip_cmp = get_be32(pb);
537 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
538 codec->codec_tag = get_be32(pb);
539 break;
540 case CODEC_TYPE_AUDIO:
541 codec->sample_rate = get_be32(pb);
542 codec->channels = get_le16(pb);
543 codec->frame_size = get_le16(pb);
544 break;
545 default:
546 goto fail;
547 }
548
549 }
550
551 /* get until end of block reached */
552 while ((url_ftell(pb) % ffm->packet_size) != 0)
553 get_byte(pb);
554
555 /* init packet demux */
556 ffm->packet_ptr = ffm->packet;
557 ffm->packet_end = ffm->packet;
558 ffm->frame_offset = 0;
559 ffm->pts = 0;
560 ffm->read_state = READ_HEADER;
561 ffm->first_packet = 1;
562 return 0;
563 fail:
564 for(i=0;i<s->nb_streams;i++) {
565 st = s->streams[i];
566 if (st) {
567 av_freep(&st->priv_data);
568 av_free(st);
569 }
570 }
571 return -1;
572 }
573
574 /* return < 0 if eof */
575 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
576 {
577 int size;
578 FFMContext *ffm = s->priv_data;
579 int duration;
580
581 switch(ffm->read_state) {
582 case READ_HEADER:
583 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
584 return AVERROR(EAGAIN);
585 }
586 #if 0
587 printf("pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
588 url_ftell(s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
589 #endif
590 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
591 FRAME_HEADER_SIZE)
592 return AVERROR(EAGAIN);
593 #if 0
594 {
595 int i;
596 for(i=0;i<FRAME_HEADER_SIZE;i++)
597 printf("%02x ", ffm->header[i]);
598 printf("\n");
599 }
600 #endif
601 ffm->read_state = READ_DATA;
602 /* fall thru */
603 case READ_DATA:
604 size = AV_RB24(ffm->header + 2);
605 if (!ffm_is_avail_data(s, size)) {
606 return AVERROR(EAGAIN);
607 }
608
609 duration = AV_RB24(ffm->header + 5);
610
611 av_new_packet(pkt, size);
612 pkt->stream_index = ffm->header[0];
613 pkt->pos = url_ftell(s->pb);
614 if (ffm->header[1] & FLAG_KEY_FRAME)
615 pkt->flags |= PKT_FLAG_KEY;
616
617 ffm->read_state = READ_HEADER;
618 if (ffm_read_data(s, pkt->data, size, 0) != size) {
619 /* bad case: desynchronized packet. we cancel all the packet loading */
620 av_free_packet(pkt);
621 return AVERROR(EAGAIN);
622 }
623 if (ffm->first_frame_in_packet)
624 {
625 pkt->pts = ffm->pts;
626 ffm->first_frame_in_packet = 0;
627 }
628 pkt->duration = duration;
629 break;
630 }
631 return 0;
632 }
633
634 //#define DEBUG_SEEK
635
636 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
637 by the write position inside this function */
638 static void ffm_seek1(AVFormatContext *s, offset_t pos1)
639 {
640 FFMContext *ffm = s->priv_data;
641 ByteIOContext *pb = s->pb;
642 offset_t pos;
643
644 pos = pos1 + ffm->write_index;
645 if (pos >= ffm->file_size)
646 pos -= (ffm->file_size - FFM_PACKET_SIZE);
647 #ifdef DEBUG_SEEK
648 printf("seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
649 #endif
650 url_fseek(pb, pos, SEEK_SET);
651 }
652
653 static int64_t get_pts(AVFormatContext *s, offset_t pos)
654 {
655 ByteIOContext *pb = s->pb;
656 int64_t pts;
657
658 ffm_seek1(s, pos);
659 url_fskip(pb, 4);
660 pts = get_be64(pb);
661 #ifdef DEBUG_SEEK
662 printf("pts=%0.6f\n", pts / 1000000.0);
663 #endif
664 return pts;
665 }
666
667 /* seek to a given time in the file. The file read pointer is
668 positioned at or before pts. XXX: the following code is quite
669 approximative */
670 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
671 {
672 FFMContext *ffm = s->priv_data;
673 offset_t pos_min, pos_max, pos;
674 int64_t pts_min, pts_max, pts;
675 double pos1;
676
677 #ifdef DEBUG_SEEK
678 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
679 #endif
680 /* find the position using linear interpolation (better than
681 dichotomy in typical cases) */
682 pos_min = 0;
683 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
684 while (pos_min <= pos_max) {
685 pts_min = get_pts(s, pos_min);
686 pts_max = get_pts(s, pos_max);
687 /* linear interpolation */
688 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
689 (double)(pts_max - pts_min);
690 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
691 if (pos <= pos_min)
692 pos = pos_min;
693 else if (pos >= pos_max)
694 pos = pos_max;
695 pts = get_pts(s, pos);
696 /* check if we are lucky */
697 if (pts == wanted_pts) {
698 goto found;
699 } else if (pts > wanted_pts) {
700 pos_max = pos - FFM_PACKET_SIZE;
701 } else {
702 pos_min = pos + FFM_PACKET_SIZE;
703 }
704 }
705 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
706 if (pos > 0)
707 pos -= FFM_PACKET_SIZE;
708 found:
709 ffm_seek1(s, pos);
710 return 0;
711 }
712
713 #ifdef CONFIG_FFSERVER
714 offset_t ffm_read_write_index(int fd)
715 {
716 uint8_t buf[8];
717
718 lseek(fd, 8, SEEK_SET);
719 read(fd, buf, 8);
720 return AV_RB64(buf);
721 }
722
723 void ffm_write_write_index(int fd, offset_t pos)
724 {
725 uint8_t buf[8];
726 int i;
727
728 for(i=0;i<8;i++)
729 buf[i] = (pos >> (56 - i * 8)) & 0xff;
730 lseek(fd, 8, SEEK_SET);
731 write(fd, buf, 8);
732 }
733
734 void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
735 {
736 FFMContext *ffm = s->priv_data;
737 ffm->write_index = pos;
738 ffm->file_size = file_size;
739 }
740 #endif // CONFIG_FFSERVER
741
742 static int ffm_read_close(AVFormatContext *s)
743 {
744 AVStream *st;
745 int i;
746
747 for(i=0;i<s->nb_streams;i++) {
748 st = s->streams[i];
749 av_freep(&st->priv_data);
750 }
751 return 0;
752 }
753
754 static int ffm_probe(AVProbeData *p)
755 {
756 if (
757 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
758 p->buf[3] == '1')
759 return AVPROBE_SCORE_MAX + 1;
760 return 0;
761 }
762
763 #ifdef CONFIG_FFM_DEMUXER
764 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 #endif
775 #ifdef CONFIG_FFM_MUXER
776 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_FFM_MUXER