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
22 #include "libavutil/intreadwrite.h"
23 #include "libavutil/intfloat.h"
30 int64_t ffm_read_write_index(int fd)
34 lseek(fd, 8, SEEK_SET);
35 if (read(fd, buf, 8) != 8)
40 int ffm_write_write_index(int fd, int64_t pos)
46 buf[i] = (pos >> (56 - i * 8)) & 0xff;
47 lseek(fd, 8, SEEK_SET);
48 if (write(fd, buf, 8) != 8)
53 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
55 FFMContext *ffm = s->priv_data;
56 ffm->write_index = pos;
57 ffm->file_size = file_size;
59 #endif // CONFIG_FFSERVER
61 static int ffm_is_avail_data(AVFormatContext *s, int size)
63 FFMContext *ffm = s->priv_data;
64 int64_t pos, avail_size;
67 len = ffm->packet_end - ffm->packet_ptr;
70 pos = avio_tell(s->pb);
71 if (!ffm->write_index) {
72 if (pos == ffm->file_size)
74 avail_size = ffm->file_size - pos;
76 if (pos == ffm->write_index) {
77 /* exactly at the end of stream */
78 return AVERROR(EAGAIN);
79 } else if (pos < ffm->write_index) {
80 avail_size = ffm->write_index - pos;
82 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
85 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
86 if (size <= avail_size)
89 return AVERROR(EAGAIN);
92 static int ffm_resync(AVFormatContext *s, int state)
94 av_log(s, AV_LOG_ERROR, "resyncing\n");
95 while (state != PACKET_ID) {
96 if (url_feof(s->pb)) {
97 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
100 state = (state << 8) | avio_r8(s->pb);
105 /* first is true if we read the frame header */
106 static int ffm_read_data(AVFormatContext *s,
107 uint8_t *buf, int size, int header)
109 FFMContext *ffm = s->priv_data;
110 AVIOContext *pb = s->pb;
111 int len, fill_size, size1, frame_offset, id;
116 len = ffm->packet_end - ffm->packet_ptr;
122 if (avio_tell(pb) == ffm->file_size)
123 avio_seek(pb, ffm->packet_size, SEEK_SET);
125 if (pb->buffer_size != ffm->packet_size) {
126 int64_t tell = avio_tell(pb);
127 url_setbufsize(pb, ffm->packet_size);
128 avio_seek(pb, tell, SEEK_SET);
130 id = avio_rb16(pb); /* PACKET_ID */
132 if (ffm_resync(s, id) < 0)
134 fill_size = avio_rb16(pb);
135 ffm->dts = avio_rb64(pb);
136 frame_offset = avio_rb16(pb);
137 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
138 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
139 if (ffm->packet_end < ffm->packet || frame_offset < 0)
141 /* if first packet or resynchronization packet, we must
142 handle it specifically */
143 if (ffm->first_packet || (frame_offset & 0x8000)) {
145 /* This packet has no frame headers in it */
146 if (avio_tell(pb) >= ffm->packet_size * 3) {
147 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
150 /* This is bad, we cannot find a valid frame header */
153 ffm->first_packet = 0;
154 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
156 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
160 ffm->packet_ptr = ffm->packet;
164 memcpy(buf, ffm->packet_ptr, len);
166 ffm->packet_ptr += len;
173 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
174 and file_size - FFM_PACKET_SIZE */
175 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
177 FFMContext *ffm = s->priv_data;
178 AVIOContext *pb = s->pb;
181 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
182 pos = FFMAX(pos, FFM_PACKET_SIZE);
183 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
184 return avio_seek(pb, pos, SEEK_SET);
187 static int64_t get_dts(AVFormatContext *s, int64_t pos)
189 AVIOContext *pb = s->pb;
195 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
199 static void adjust_write_index(AVFormatContext *s)
201 FFMContext *ffm = s->priv_data;
202 AVIOContext *pb = s->pb;
204 //int64_t orig_write_index = ffm->write_index;
205 int64_t pos_min, pos_max;
207 int64_t ptr = avio_tell(pb);
211 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
213 pts_start = get_dts(s, pos_min);
215 pts = get_dts(s, pos_max);
217 if (pts - 100000 > pts_start)
220 ffm->write_index = FFM_PACKET_SIZE;
222 pts_start = get_dts(s, pos_min);
224 pts = get_dts(s, pos_max);
226 if (pts - 100000 <= pts_start) {
231 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
233 if (newpos == pos_min)
236 newpts = get_dts(s, newpos);
238 if (newpts - 100000 <= pts) {
245 ffm->write_index += pos_max;
248 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
249 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
252 avio_seek(pb, ptr, SEEK_SET);
256 static int ffm_close(AVFormatContext *s)
260 for (i = 0; i < s->nb_streams; i++)
261 av_freep(&s->streams[i]->codec->rc_eq);
267 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
269 FFMContext *ffm = s->priv_data;
271 AVIOContext *pb = s->pb;
272 AVCodecContext *codec;
278 if (tag != MKTAG('F', 'F', 'M', '1'))
280 ffm->packet_size = avio_rb32(pb);
281 if (ffm->packet_size != FFM_PACKET_SIZE)
283 ffm->write_index = avio_rb64(pb);
284 /* get also filesize */
286 ffm->file_size = avio_size(pb);
287 if (ffm->write_index)
288 adjust_write_index(s);
290 ffm->file_size = (UINT64_C(1) << 63) - 1;
293 nb_streams = avio_rb32(pb);
294 avio_rb32(pb); /* total bitrate */
295 /* read each stream */
296 for(i=0;i<nb_streams;i++) {
299 st = avformat_new_stream(s, NULL);
303 avpriv_set_pts_info(st, 64, 1, 1000000);
307 codec->codec_id = avio_rb32(pb);
308 codec->codec_type = avio_r8(pb); /* codec_type */
309 codec->bit_rate = avio_rb32(pb);
310 codec->flags = avio_rb32(pb);
311 codec->flags2 = avio_rb32(pb);
312 codec->debug = avio_rb32(pb);
314 switch(codec->codec_type) {
315 case AVMEDIA_TYPE_VIDEO:
316 codec->time_base.num = avio_rb32(pb);
317 codec->time_base.den = avio_rb32(pb);
318 codec->width = avio_rb16(pb);
319 codec->height = avio_rb16(pb);
320 codec->gop_size = avio_rb16(pb);
321 codec->pix_fmt = avio_rb32(pb);
322 codec->qmin = avio_r8(pb);
323 codec->qmax = avio_r8(pb);
324 codec->max_qdiff = avio_r8(pb);
325 codec->qcompress = avio_rb16(pb) / 10000.0;
326 codec->qblur = avio_rb16(pb) / 10000.0;
327 codec->bit_rate_tolerance = avio_rb32(pb);
328 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
329 codec->rc_max_rate = avio_rb32(pb);
330 codec->rc_min_rate = avio_rb32(pb);
331 codec->rc_buffer_size = avio_rb32(pb);
332 codec->i_quant_factor = av_int2double(avio_rb64(pb));
333 codec->b_quant_factor = av_int2double(avio_rb64(pb));
334 codec->i_quant_offset = av_int2double(avio_rb64(pb));
335 codec->b_quant_offset = av_int2double(avio_rb64(pb));
336 codec->dct_algo = avio_rb32(pb);
337 codec->strict_std_compliance = avio_rb32(pb);
338 codec->max_b_frames = avio_rb32(pb);
339 codec->luma_elim_threshold = avio_rb32(pb);
340 codec->chroma_elim_threshold = avio_rb32(pb);
341 codec->mpeg_quant = avio_rb32(pb);
342 codec->intra_dc_precision = avio_rb32(pb);
343 codec->me_method = avio_rb32(pb);
344 codec->mb_decision = avio_rb32(pb);
345 codec->nsse_weight = avio_rb32(pb);
346 codec->frame_skip_cmp = avio_rb32(pb);
347 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
348 codec->codec_tag = avio_rb32(pb);
349 codec->thread_count = avio_r8(pb);
350 codec->coder_type = avio_rb32(pb);
351 codec->me_cmp = avio_rb32(pb);
352 codec->partitions = avio_rb32(pb);
353 codec->me_subpel_quality = avio_rb32(pb);
354 codec->me_range = avio_rb32(pb);
355 codec->keyint_min = avio_rb32(pb);
356 codec->scenechange_threshold = avio_rb32(pb);
357 codec->b_frame_strategy = avio_rb32(pb);
358 codec->qcompress = av_int2double(avio_rb64(pb));
359 codec->qblur = av_int2double(avio_rb64(pb));
360 codec->max_qdiff = avio_rb32(pb);
361 codec->refs = avio_rb32(pb);
362 codec->directpred = avio_rb32(pb);
364 case AVMEDIA_TYPE_AUDIO:
365 codec->sample_rate = avio_rb32(pb);
366 codec->channels = avio_rl16(pb);
367 codec->frame_size = avio_rl16(pb);
368 codec->sample_fmt = (int16_t) avio_rl16(pb);
373 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
374 codec->extradata_size = avio_rb32(pb);
375 codec->extradata = av_malloc(codec->extradata_size);
376 if (!codec->extradata)
377 return AVERROR(ENOMEM);
378 avio_read(pb, codec->extradata, codec->extradata_size);
382 /* get until end of block reached */
383 while ((avio_tell(pb) % ffm->packet_size) != 0)
386 /* init packet demux */
387 ffm->packet_ptr = ffm->packet;
388 ffm->packet_end = ffm->packet;
389 ffm->frame_offset = 0;
391 ffm->read_state = READ_HEADER;
392 ffm->first_packet = 1;
399 /* return < 0 if eof */
400 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
403 FFMContext *ffm = s->priv_data;
406 switch(ffm->read_state) {
408 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
411 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
412 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
413 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
416 if (ffm->header[1] & FLAG_DTS)
417 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
419 ffm->read_state = READ_DATA;
422 size = AV_RB24(ffm->header + 2);
423 if ((ret = ffm_is_avail_data(s, size)) < 0)
426 duration = AV_RB24(ffm->header + 5);
428 av_new_packet(pkt, size);
429 pkt->stream_index = ffm->header[0];
430 if ((unsigned)pkt->stream_index >= s->nb_streams) {
431 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
433 ffm->read_state = READ_HEADER;
436 pkt->pos = avio_tell(s->pb);
437 if (ffm->header[1] & FLAG_KEY_FRAME)
438 pkt->flags |= AV_PKT_FLAG_KEY;
440 ffm->read_state = READ_HEADER;
441 if (ffm_read_data(s, pkt->data, size, 0) != size) {
442 /* bad case: desynchronized packet. we cancel all the packet loading */
446 pkt->pts = AV_RB64(ffm->header+8);
447 if (ffm->header[1] & FLAG_DTS)
448 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
451 pkt->duration = duration;
457 /* seek to a given time in the file. The file read pointer is
458 positioned at or before pts. XXX: the following code is quite
460 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
462 FFMContext *ffm = s->priv_data;
463 int64_t pos_min, pos_max, pos;
464 int64_t pts_min, pts_max, pts;
467 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
468 /* find the position using linear interpolation (better than
469 dichotomy in typical cases) */
470 if (ffm->write_index && ffm->write_index < ffm->file_size) {
471 if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
472 pos_min = FFM_PACKET_SIZE;
473 pos_max = ffm->write_index - FFM_PACKET_SIZE;
475 pos_min = ffm->write_index;
476 pos_max = ffm->file_size - FFM_PACKET_SIZE;
479 pos_min = FFM_PACKET_SIZE;
480 pos_max = ffm->file_size - FFM_PACKET_SIZE;
482 while (pos_min <= pos_max) {
483 pts_min = get_dts(s, pos_min);
484 pts_max = get_dts(s, pos_max);
485 if (pts_min > wanted_pts || pts_max < wanted_pts) {
486 pos = pts_min > wanted_pts ? pos_min : pos_max;
489 /* linear interpolation */
490 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
491 (double)(pts_max - pts_min);
492 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
495 else if (pos >= pos_max)
497 pts = get_dts(s, pos);
498 /* check if we are lucky */
499 if (pts == wanted_pts) {
501 } else if (pts > wanted_pts) {
502 pos_max = pos - FFM_PACKET_SIZE;
504 pos_min = pos + FFM_PACKET_SIZE;
507 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
510 if (ffm_seek1(s, pos) < 0)
513 /* reset read state */
514 ffm->read_state = READ_HEADER;
515 ffm->packet_ptr = ffm->packet;
516 ffm->packet_end = ffm->packet;
517 ffm->first_packet = 1;
522 static int ffm_probe(AVProbeData *p)
525 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
527 return AVPROBE_SCORE_MAX + 1;
531 AVInputFormat ff_ffm_demuxer = {
533 .long_name = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),
534 .priv_data_size = sizeof(FFMContext),
535 .read_probe = ffm_probe,
536 .read_header = ffm_read_header,
537 .read_packet = ffm_read_packet,
538 .read_close = ffm_close,
539 .read_seek = ffm_seek,