2 * FFM (ffserver live feed) demuxer
3 * Copyright (c) 2001 Fabrice Bellard
5 * This file is part of FFmpeg.
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.
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.
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
24 #include "libavutil/internal.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/intfloat.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/avassert.h"
29 #include "libavutil/avstring.h"
33 #include "avio_internal.h"
35 static int ffm_is_avail_data(AVFormatContext *s, int size)
37 FFMContext *ffm = s->priv_data;
38 int64_t pos, avail_size;
41 len = ffm->packet_end - ffm->packet_ptr;
44 pos = avio_tell(s->pb);
45 if (!ffm->write_index) {
46 if (pos == ffm->file_size)
48 avail_size = ffm->file_size - pos;
50 if (pos == ffm->write_index) {
51 /* exactly at the end of stream */
52 if (ffm->server_attached)
53 return AVERROR(EAGAIN);
55 return AVERROR_INVALIDDATA;
56 } else if (pos < ffm->write_index) {
57 avail_size = ffm->write_index - pos;
59 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
62 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
63 if (size <= avail_size)
65 else if (ffm->server_attached)
66 return AVERROR(EAGAIN);
68 return AVERROR_INVALIDDATA;
71 static int ffm_resync(AVFormatContext *s, int state)
73 av_log(s, AV_LOG_ERROR, "resyncing\n");
74 while (state != PACKET_ID) {
75 if (avio_feof(s->pb)) {
76 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
79 state = (state << 8) | avio_r8(s->pb);
84 /* first is true if we read the frame header */
85 static int ffm_read_data(AVFormatContext *s,
86 uint8_t *buf, int size, int header)
88 FFMContext *ffm = s->priv_data;
89 AVIOContext *pb = s->pb;
90 int len, fill_size, size1, frame_offset, id;
91 int64_t last_pos = -1;
96 len = ffm->packet_end - ffm->packet_ptr;
102 if (avio_tell(pb) == ffm->file_size)
103 if (ffm->server_attached)
104 avio_seek(pb, ffm->packet_size, SEEK_SET);
108 if (pb->buffer_size != ffm->packet_size) {
109 int64_t tell = avio_tell(pb);
110 int ret = ffio_set_buf_size(pb, ffm->packet_size);
113 avio_seek(pb, tell, SEEK_SET);
115 id = avio_rb16(pb); /* PACKET_ID */
116 if (id != PACKET_ID) {
117 if (ffm_resync(s, id) < 0)
119 last_pos = avio_tell(pb);
121 fill_size = avio_rb16(pb);
122 ffm->dts = avio_rb64(pb);
123 frame_offset = avio_rb16(pb);
124 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
125 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
126 if (ffm->packet_end < ffm->packet || frame_offset < 0)
128 /* if first packet or resynchronization packet, we must
129 handle it specifically */
130 if (ffm->first_packet || (frame_offset & 0x8000)) {
132 /* This packet has no frame headers in it */
133 if (avio_tell(pb) >= ffm->packet_size * 3LL) {
134 int64_t seekback = FFMIN(ffm->packet_size * 2LL, avio_tell(pb) - last_pos);
135 seekback = FFMAX(seekback, 0);
136 avio_seek(pb, -seekback, SEEK_CUR);
139 /* This is bad, we cannot find a valid frame header */
142 ffm->first_packet = 0;
143 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
145 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
149 ffm->packet_ptr = ffm->packet;
153 memcpy(buf, ffm->packet_ptr, len);
155 ffm->packet_ptr += len;
162 /* ensure that actual seeking happens between FFM_PACKET_SIZE
163 and file_size - FFM_PACKET_SIZE */
164 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
166 FFMContext *ffm = s->priv_data;
167 AVIOContext *pb = s->pb;
170 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
171 pos = FFMAX(pos, FFM_PACKET_SIZE);
172 ff_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
173 return avio_seek(pb, pos, SEEK_SET);
176 static int64_t get_dts(AVFormatContext *s, int64_t pos)
178 AVIOContext *pb = s->pb;
184 ff_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
188 static void adjust_write_index(AVFormatContext *s)
190 FFMContext *ffm = s->priv_data;
191 AVIOContext *pb = s->pb;
193 //int64_t orig_write_index = ffm->write_index;
194 int64_t pos_min, pos_max;
196 int64_t ptr = avio_tell(pb);
200 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
202 pts_start = get_dts(s, pos_min);
204 pts = get_dts(s, pos_max);
206 if (pts - 100000 > pts_start)
209 ffm->write_index = FFM_PACKET_SIZE;
211 pts_start = get_dts(s, pos_min);
213 pts = get_dts(s, pos_max);
215 if (pts - 100000 <= pts_start) {
220 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
222 if (newpos == pos_min)
225 newpts = get_dts(s, newpos);
227 if (newpts - 100000 <= pts) {
234 ffm->write_index += pos_max;
238 avio_seek(pb, ptr, SEEK_SET);
242 static int ffm_close(AVFormatContext *s)
246 for (i = 0; i < s->nb_streams; i++)
247 av_freep(&s->streams[i]->codec->rc_eq);
252 static int ffm_append_recommended_configuration(AVStream *st, char **conf)
256 av_assert0(conf && st);
259 if (!st->recommended_encoder_configuration) {
260 st->recommended_encoder_configuration = *conf;
264 newsize = strlen(*conf) + strlen(st->recommended_encoder_configuration) + 2;
265 if ((ret = av_reallocp(&st->recommended_encoder_configuration, newsize)) < 0)
267 av_strlcat(st->recommended_encoder_configuration, ",", newsize);
268 av_strlcat(st->recommended_encoder_configuration, *conf, newsize);
273 static int ffm2_read_header(AVFormatContext *s)
275 FFMContext *ffm = s->priv_data;
277 AVIOContext *pb = s->pb;
278 AVCodecContext *codec;
279 const AVCodecDescriptor *codec_desc;
281 int f_main = 0, f_cprv = -1, f_stvi = -1, f_stau = -1;
285 ffm->packet_size = avio_rb32(pb);
286 if (ffm->packet_size != FFM_PACKET_SIZE) {
287 av_log(s, AV_LOG_ERROR, "Invalid packet size %d, expected size was %d\n",
288 ffm->packet_size, FFM_PACKET_SIZE);
289 ret = AVERROR_INVALIDDATA;
293 ffm->write_index = avio_rb64(pb);
294 /* get also filesize */
296 ffm->file_size = avio_size(pb);
297 if (ffm->write_index && 0)
298 adjust_write_index(s);
300 ffm->file_size = (UINT64_C(1) << 63) - 1;
303 while(!avio_feof(pb)) {
304 unsigned id = avio_rb32(pb);
305 unsigned size = avio_rb32(pb);
306 int64_t next = avio_tell(pb) + size;
313 case MKBETAG('M', 'A', 'I', 'N'):
315 ret = AVERROR(EINVAL);
318 avio_rb32(pb); /* nb_streams */
319 avio_rb32(pb); /* total bitrate */
321 case MKBETAG('C', 'O', 'M', 'M'):
322 f_cprv = f_stvi = f_stau = 0;
323 st = avformat_new_stream(s, NULL);
325 ret = AVERROR(ENOMEM);
329 avpriv_set_pts_info(st, 64, 1, 1000000);
333 codec->codec_id = avio_rb32(pb);
334 codec_desc = avcodec_descriptor_get(codec->codec_id);
336 av_log(s, AV_LOG_ERROR, "Invalid codec id: %d\n", codec->codec_id);
337 codec->codec_id = AV_CODEC_ID_NONE;
340 codec->codec_type = avio_r8(pb);
341 if (codec->codec_type != codec_desc->type) {
342 av_log(s, AV_LOG_ERROR, "Codec type mismatch: expected %d, found %d\n",
343 codec_desc->type, codec->codec_type);
344 codec->codec_id = AV_CODEC_ID_NONE;
345 codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
348 codec->bit_rate = avio_rb32(pb);
349 codec->flags = avio_rb32(pb);
350 codec->flags2 = avio_rb32(pb);
351 codec->debug = avio_rb32(pb);
352 if (codec->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {
353 if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)
354 return AVERROR(ENOMEM);
357 case MKBETAG('S', 'T', 'V', 'I'):
359 ret = AVERROR(EINVAL);
362 codec->time_base.num = avio_rb32(pb);
363 codec->time_base.den = avio_rb32(pb);
364 if (codec->time_base.num <= 0 || codec->time_base.den <= 0) {
365 av_log(s, AV_LOG_ERROR, "Invalid time base %d/%d\n",
366 codec->time_base.num, codec->time_base.den);
367 ret = AVERROR_INVALIDDATA;
370 codec->width = avio_rb16(pb);
371 codec->height = avio_rb16(pb);
372 codec->gop_size = avio_rb16(pb);
373 codec->pix_fmt = avio_rb32(pb);
374 codec->qmin = avio_r8(pb);
375 codec->qmax = avio_r8(pb);
376 codec->max_qdiff = avio_r8(pb);
377 codec->qcompress = avio_rb16(pb) / 10000.0;
378 codec->qblur = avio_rb16(pb) / 10000.0;
379 codec->bit_rate_tolerance = avio_rb32(pb);
380 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
381 codec->rc_eq = av_strdup(rc_eq_buf);
382 codec->rc_max_rate = avio_rb32(pb);
383 codec->rc_min_rate = avio_rb32(pb);
384 codec->rc_buffer_size = avio_rb32(pb);
385 codec->i_quant_factor = av_int2double(avio_rb64(pb));
386 codec->b_quant_factor = av_int2double(avio_rb64(pb));
387 codec->i_quant_offset = av_int2double(avio_rb64(pb));
388 codec->b_quant_offset = av_int2double(avio_rb64(pb));
389 codec->dct_algo = avio_rb32(pb);
390 codec->strict_std_compliance = avio_rb32(pb);
391 codec->max_b_frames = avio_rb32(pb);
392 codec->mpeg_quant = avio_rb32(pb);
393 codec->intra_dc_precision = avio_rb32(pb);
394 codec->me_method = avio_rb32(pb);
395 codec->mb_decision = avio_rb32(pb);
396 codec->nsse_weight = avio_rb32(pb);
397 codec->frame_skip_cmp = avio_rb32(pb);
398 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
399 codec->codec_tag = avio_rb32(pb);
400 codec->thread_count = avio_r8(pb);
401 codec->coder_type = avio_rb32(pb);
402 codec->me_cmp = avio_rb32(pb);
403 codec->me_subpel_quality = avio_rb32(pb);
404 codec->me_range = avio_rb32(pb);
405 codec->keyint_min = avio_rb32(pb);
406 codec->scenechange_threshold = avio_rb32(pb);
407 codec->b_frame_strategy = avio_rb32(pb);
408 codec->qcompress = av_int2double(avio_rb64(pb));
409 codec->qblur = av_int2double(avio_rb64(pb));
410 codec->max_qdiff = avio_rb32(pb);
411 codec->refs = avio_rb32(pb);
413 case MKBETAG('S', 'T', 'A', 'U'):
415 ret = AVERROR(EINVAL);
418 codec->sample_rate = avio_rb32(pb);
419 codec->channels = avio_rl16(pb);
420 codec->frame_size = avio_rl16(pb);
422 case MKBETAG('C', 'P', 'R', 'V'):
424 ret = AVERROR(EINVAL);
427 enc = avcodec_find_encoder(codec->codec_id);
428 if (enc && enc->priv_data_size && enc->priv_class) {
429 buffer = av_malloc(size + 1);
431 ret = AVERROR(ENOMEM);
434 avio_get_str(pb, size, buffer, size + 1);
435 if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
439 case MKBETAG('S', '2', 'V', 'I'):
440 if (f_stvi++ || !size) {
441 ret = AVERROR(EINVAL);
444 buffer = av_malloc(size);
446 ret = AVERROR(ENOMEM);
449 avio_get_str(pb, INT_MAX, buffer, size);
450 av_set_options_string(codec, buffer, "=", ",");
451 if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
454 case MKBETAG('S', '2', 'A', 'U'):
455 if (f_stau++ || !size) {
456 ret = AVERROR(EINVAL);
459 buffer = av_malloc(size);
461 ret = AVERROR(ENOMEM);
464 avio_get_str(pb, INT_MAX, buffer, size);
465 av_set_options_string(codec, buffer, "=", ",");
466 if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
470 avio_seek(pb, next, SEEK_SET);
473 /* get until end of block reached */
474 while ((avio_tell(pb) % ffm->packet_size) != 0 && !pb->eof_reached)
477 /* init packet demux */
478 ffm->packet_ptr = ffm->packet;
479 ffm->packet_end = ffm->packet;
480 ffm->frame_offset = 0;
482 ffm->read_state = READ_HEADER;
483 ffm->first_packet = 1;
490 static int ffm_read_header(AVFormatContext *s)
492 FFMContext *ffm = s->priv_data;
494 AVIOContext *pb = s->pb;
495 AVCodecContext *codec;
496 const AVCodecDescriptor *codec_desc;
502 if (tag == MKTAG('F', 'F', 'M', '2'))
503 return ffm2_read_header(s);
504 if (tag != MKTAG('F', 'F', 'M', '1'))
506 ffm->packet_size = avio_rb32(pb);
507 if (ffm->packet_size != FFM_PACKET_SIZE)
509 ffm->write_index = avio_rb64(pb);
510 /* get also filesize */
512 ffm->file_size = avio_size(pb);
513 if (ffm->write_index && 0)
514 adjust_write_index(s);
516 ffm->file_size = (UINT64_C(1) << 63) - 1;
519 nb_streams = avio_rb32(pb);
520 avio_rb32(pb); /* total bitrate */
521 /* read each stream */
522 for(i=0;i<nb_streams;i++) {
525 st = avformat_new_stream(s, NULL);
529 avpriv_set_pts_info(st, 64, 1, 1000000);
533 codec->codec_id = avio_rb32(pb);
534 codec_desc = avcodec_descriptor_get(codec->codec_id);
536 av_log(s, AV_LOG_ERROR, "Invalid codec id: %d\n", codec->codec_id);
537 codec->codec_id = AV_CODEC_ID_NONE;
540 codec->codec_type = avio_r8(pb); /* codec_type */
541 if (codec->codec_type != codec_desc->type) {
542 av_log(s, AV_LOG_ERROR, "Codec type mismatch: expected %d, found %d\n",
543 codec_desc->type, codec->codec_type);
544 codec->codec_id = AV_CODEC_ID_NONE;
545 codec->codec_type = AVMEDIA_TYPE_UNKNOWN;
548 codec->bit_rate = avio_rb32(pb);
549 codec->flags = avio_rb32(pb);
550 codec->flags2 = avio_rb32(pb);
551 codec->debug = avio_rb32(pb);
553 switch(codec->codec_type) {
554 case AVMEDIA_TYPE_VIDEO:
555 codec->time_base.num = avio_rb32(pb);
556 codec->time_base.den = avio_rb32(pb);
557 if (codec->time_base.num <= 0 || codec->time_base.den <= 0) {
558 av_log(s, AV_LOG_ERROR, "Invalid time base %d/%d\n",
559 codec->time_base.num, codec->time_base.den);
562 codec->width = avio_rb16(pb);
563 codec->height = avio_rb16(pb);
564 codec->gop_size = avio_rb16(pb);
565 codec->pix_fmt = avio_rb32(pb);
566 codec->qmin = avio_r8(pb);
567 codec->qmax = avio_r8(pb);
568 codec->max_qdiff = avio_r8(pb);
569 codec->qcompress = avio_rb16(pb) / 10000.0;
570 codec->qblur = avio_rb16(pb) / 10000.0;
571 codec->bit_rate_tolerance = avio_rb32(pb);
572 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
573 codec->rc_eq = av_strdup(rc_eq_buf);
574 codec->rc_max_rate = avio_rb32(pb);
575 codec->rc_min_rate = avio_rb32(pb);
576 codec->rc_buffer_size = avio_rb32(pb);
577 codec->i_quant_factor = av_int2double(avio_rb64(pb));
578 codec->b_quant_factor = av_int2double(avio_rb64(pb));
579 codec->i_quant_offset = av_int2double(avio_rb64(pb));
580 codec->b_quant_offset = av_int2double(avio_rb64(pb));
581 codec->dct_algo = avio_rb32(pb);
582 codec->strict_std_compliance = avio_rb32(pb);
583 codec->max_b_frames = avio_rb32(pb);
584 codec->mpeg_quant = avio_rb32(pb);
585 codec->intra_dc_precision = avio_rb32(pb);
586 codec->me_method = avio_rb32(pb);
587 codec->mb_decision = avio_rb32(pb);
588 codec->nsse_weight = avio_rb32(pb);
589 codec->frame_skip_cmp = avio_rb32(pb);
590 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
591 codec->codec_tag = avio_rb32(pb);
592 codec->thread_count = avio_r8(pb);
593 codec->coder_type = avio_rb32(pb);
594 codec->me_cmp = avio_rb32(pb);
595 codec->me_subpel_quality = avio_rb32(pb);
596 codec->me_range = avio_rb32(pb);
597 codec->keyint_min = avio_rb32(pb);
598 codec->scenechange_threshold = avio_rb32(pb);
599 codec->b_frame_strategy = avio_rb32(pb);
600 codec->qcompress = av_int2double(avio_rb64(pb));
601 codec->qblur = av_int2double(avio_rb64(pb));
602 codec->max_qdiff = avio_rb32(pb);
603 codec->refs = avio_rb32(pb);
605 case AVMEDIA_TYPE_AUDIO:
606 codec->sample_rate = avio_rb32(pb);
607 codec->channels = avio_rl16(pb);
608 codec->frame_size = avio_rl16(pb);
613 if (codec->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {
614 if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)
615 return AVERROR(ENOMEM);
619 /* get until end of block reached */
620 while ((avio_tell(pb) % ffm->packet_size) != 0 && !pb->eof_reached)
623 /* init packet demux */
624 ffm->packet_ptr = ffm->packet;
625 ffm->packet_end = ffm->packet;
626 ffm->frame_offset = 0;
628 ffm->read_state = READ_HEADER;
629 ffm->first_packet = 1;
636 /* return < 0 if eof */
637 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
640 FFMContext *ffm = s->priv_data;
643 switch(ffm->read_state) {
645 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
648 ff_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
649 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
650 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
653 if (ffm->header[1] & FLAG_DTS)
654 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
656 ffm->read_state = READ_DATA;
659 size = AV_RB24(ffm->header + 2);
660 if ((ret = ffm_is_avail_data(s, size)) < 0)
663 duration = AV_RB24(ffm->header + 5);
665 if (av_new_packet(pkt, size) < 0) {
666 return AVERROR(ENOMEM);
668 pkt->stream_index = ffm->header[0];
669 if ((unsigned)pkt->stream_index >= s->nb_streams) {
670 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
671 av_packet_unref(pkt);
672 ffm->read_state = READ_HEADER;
675 pkt->pos = avio_tell(s->pb);
676 if (ffm->header[1] & FLAG_KEY_FRAME)
677 pkt->flags |= AV_PKT_FLAG_KEY;
679 ffm->read_state = READ_HEADER;
680 if (ffm_read_data(s, pkt->data, size, 0) != size) {
681 /* bad case: desynchronized packet. we cancel all the packet loading */
682 av_packet_unref(pkt);
685 pkt->pts = AV_RB64(ffm->header+8);
686 if (ffm->header[1] & FLAG_DTS)
687 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
690 pkt->duration = duration;
696 /* seek to a given time in the file. The file read pointer is
697 positioned at or before pts. XXX: the following code is quite
699 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
701 FFMContext *ffm = s->priv_data;
702 int64_t pos_min, pos_max, pos;
703 int64_t pts_min, pts_max, pts;
706 ff_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
707 /* find the position using linear interpolation (better than
708 dichotomy in typical cases) */
709 if (ffm->write_index && ffm->write_index < ffm->file_size) {
710 if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
711 pos_min = FFM_PACKET_SIZE;
712 pos_max = ffm->write_index - FFM_PACKET_SIZE;
714 pos_min = ffm->write_index;
715 pos_max = ffm->file_size - FFM_PACKET_SIZE;
718 pos_min = FFM_PACKET_SIZE;
719 pos_max = ffm->file_size - FFM_PACKET_SIZE;
721 while (pos_min <= pos_max) {
722 pts_min = get_dts(s, pos_min);
723 pts_max = get_dts(s, pos_max);
724 if (pts_min > wanted_pts || pts_max <= wanted_pts) {
725 pos = pts_min > wanted_pts ? pos_min : pos_max;
728 /* linear interpolation */
729 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
730 (double)(pts_max - pts_min);
731 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
734 else if (pos >= pos_max)
736 pts = get_dts(s, pos);
737 /* check if we are lucky */
738 if (pts == wanted_pts) {
740 } else if (pts > wanted_pts) {
741 pos_max = pos - FFM_PACKET_SIZE;
743 pos_min = pos + FFM_PACKET_SIZE;
746 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
749 if (ffm_seek1(s, pos) < 0)
752 /* reset read state */
753 ffm->read_state = READ_HEADER;
754 ffm->packet_ptr = ffm->packet;
755 ffm->packet_end = ffm->packet;
756 ffm->first_packet = 1;
761 static int ffm_probe(AVProbeData *p)
764 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
765 (p->buf[3] == '1' || p->buf[3] == '2'))
766 return AVPROBE_SCORE_MAX + 1;
770 static const AVOption options[] = {
771 {"server_attached", NULL, offsetof(FFMContext, server_attached), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_EXPORT },
772 {"ffm_write_index", NULL, offsetof(FFMContext, write_index), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, 1, AV_OPT_FLAG_EXPORT },
773 {"ffm_file_size", NULL, offsetof(FFMContext, file_size), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, 1, AV_OPT_FLAG_EXPORT },
777 static const AVClass ffm_class = {
778 .class_name = "ffm demuxer",
779 .item_name = av_default_item_name,
781 .version = LIBAVUTIL_VERSION_INT,
783 AVInputFormat ff_ffm_demuxer = {
785 .long_name = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),
786 .priv_data_size = sizeof(FFMContext),
787 .read_probe = ffm_probe,
788 .read_header = ffm_read_header,
789 .read_packet = ffm_read_packet,
790 .read_close = ffm_close,
791 .read_seek = ffm_seek,
792 .priv_class = &ffm_class,