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"
27 #include "avio_internal.h"
31 int64_t ffm_read_write_index(int fd)
35 lseek(fd, 8, SEEK_SET);
36 if (read(fd, buf, 8) != 8)
41 int ffm_write_write_index(int fd, int64_t pos)
47 buf[i] = (pos >> (56 - i * 8)) & 0xff;
48 lseek(fd, 8, SEEK_SET);
49 if (write(fd, buf, 8) != 8)
54 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
56 FFMContext *ffm = s->priv_data;
57 ffm->write_index = pos;
58 ffm->file_size = file_size;
60 #endif // CONFIG_FFSERVER
62 static int ffm_is_avail_data(AVFormatContext *s, int size)
64 FFMContext *ffm = s->priv_data;
65 int64_t pos, avail_size;
68 len = ffm->packet_end - ffm->packet_ptr;
71 pos = avio_tell(s->pb);
72 if (!ffm->write_index) {
73 if (pos == ffm->file_size)
75 avail_size = ffm->file_size - pos;
77 if (pos == ffm->write_index) {
78 /* exactly at the end of stream */
79 return AVERROR(EAGAIN);
80 } else if (pos < ffm->write_index) {
81 avail_size = ffm->write_index - pos;
83 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
86 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
87 if (size <= avail_size)
90 return AVERROR(EAGAIN);
93 static int ffm_resync(AVFormatContext *s, int state)
95 av_log(s, AV_LOG_ERROR, "resyncing\n");
96 while (state != PACKET_ID) {
97 if (url_feof(s->pb)) {
98 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
101 state = (state << 8) | avio_r8(s->pb);
106 /* first is true if we read the frame header */
107 static int ffm_read_data(AVFormatContext *s,
108 uint8_t *buf, int size, int header)
110 FFMContext *ffm = s->priv_data;
111 AVIOContext *pb = s->pb;
112 int len, fill_size, size1, frame_offset, id;
117 len = ffm->packet_end - ffm->packet_ptr;
123 if (avio_tell(pb) == ffm->file_size)
124 avio_seek(pb, ffm->packet_size, SEEK_SET);
126 if (pb->buffer_size != ffm->packet_size) {
127 int64_t tell = avio_tell(pb);
128 ffio_set_buf_size(pb, ffm->packet_size);
129 avio_seek(pb, tell, SEEK_SET);
131 id = avio_rb16(pb); /* PACKET_ID */
133 if (ffm_resync(s, id) < 0)
135 fill_size = avio_rb16(pb);
136 ffm->dts = avio_rb64(pb);
137 frame_offset = avio_rb16(pb);
138 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
139 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
140 if (ffm->packet_end < ffm->packet || frame_offset < 0)
142 /* if first packet or resynchronization packet, we must
143 handle it specifically */
144 if (ffm->first_packet || (frame_offset & 0x8000)) {
146 /* This packet has no frame headers in it */
147 if (avio_tell(pb) >= ffm->packet_size * 3) {
148 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
151 /* This is bad, we cannot find a valid frame header */
154 ffm->first_packet = 0;
155 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
157 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
161 ffm->packet_ptr = ffm->packet;
165 memcpy(buf, ffm->packet_ptr, len);
167 ffm->packet_ptr += len;
174 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
175 and file_size - FFM_PACKET_SIZE */
176 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
178 FFMContext *ffm = s->priv_data;
179 AVIOContext *pb = s->pb;
182 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
183 pos = FFMAX(pos, FFM_PACKET_SIZE);
184 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
185 return avio_seek(pb, pos, SEEK_SET);
188 static int64_t get_dts(AVFormatContext *s, int64_t pos)
190 AVIOContext *pb = s->pb;
196 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
200 static void adjust_write_index(AVFormatContext *s)
202 FFMContext *ffm = s->priv_data;
203 AVIOContext *pb = s->pb;
205 //int64_t orig_write_index = ffm->write_index;
206 int64_t pos_min, pos_max;
208 int64_t ptr = avio_tell(pb);
212 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
214 pts_start = get_dts(s, pos_min);
216 pts = get_dts(s, pos_max);
218 if (pts - 100000 > pts_start)
221 ffm->write_index = FFM_PACKET_SIZE;
223 pts_start = get_dts(s, pos_min);
225 pts = get_dts(s, pos_max);
227 if (pts - 100000 <= pts_start) {
232 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
234 if (newpos == pos_min)
237 newpts = get_dts(s, newpos);
239 if (newpts - 100000 <= pts) {
246 ffm->write_index += pos_max;
250 avio_seek(pb, ptr, SEEK_SET);
254 static int ffm_close(AVFormatContext *s)
258 for (i = 0; i < s->nb_streams; i++)
259 av_freep(&s->streams[i]->codec->rc_eq);
265 static int ffm_read_header(AVFormatContext *s)
267 FFMContext *ffm = s->priv_data;
269 AVIOContext *pb = s->pb;
270 AVCodecContext *codec;
276 if (tag != MKTAG('F', 'F', 'M', '1'))
278 ffm->packet_size = avio_rb32(pb);
279 if (ffm->packet_size != FFM_PACKET_SIZE)
281 ffm->write_index = avio_rb64(pb);
282 /* get also filesize */
284 ffm->file_size = avio_size(pb);
285 if (ffm->write_index && 0)
286 adjust_write_index(s);
288 ffm->file_size = (UINT64_C(1) << 63) - 1;
291 nb_streams = avio_rb32(pb);
292 avio_rb32(pb); /* total bitrate */
293 /* read each stream */
294 for(i=0;i<nb_streams;i++) {
297 st = avformat_new_stream(s, NULL);
301 avpriv_set_pts_info(st, 64, 1, 1000000);
305 codec->codec_id = avio_rb32(pb);
306 codec->codec_type = avio_r8(pb); /* codec_type */
307 codec->bit_rate = avio_rb32(pb);
308 codec->flags = avio_rb32(pb);
309 codec->flags2 = avio_rb32(pb);
310 codec->debug = avio_rb32(pb);
312 switch(codec->codec_type) {
313 case AVMEDIA_TYPE_VIDEO:
314 codec->time_base.num = avio_rb32(pb);
315 codec->time_base.den = avio_rb32(pb);
316 codec->width = avio_rb16(pb);
317 codec->height = avio_rb16(pb);
318 codec->gop_size = avio_rb16(pb);
319 codec->pix_fmt = avio_rb32(pb);
320 codec->qmin = avio_r8(pb);
321 codec->qmax = avio_r8(pb);
322 codec->max_qdiff = avio_r8(pb);
323 codec->qcompress = avio_rb16(pb) / 10000.0;
324 codec->qblur = avio_rb16(pb) / 10000.0;
325 codec->bit_rate_tolerance = avio_rb32(pb);
326 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
327 codec->rc_eq = av_strdup(rc_eq_buf);
328 codec->rc_max_rate = avio_rb32(pb);
329 codec->rc_min_rate = avio_rb32(pb);
330 codec->rc_buffer_size = avio_rb32(pb);
331 codec->i_quant_factor = av_int2double(avio_rb64(pb));
332 codec->b_quant_factor = av_int2double(avio_rb64(pb));
333 codec->i_quant_offset = av_int2double(avio_rb64(pb));
334 codec->b_quant_offset = av_int2double(avio_rb64(pb));
335 codec->dct_algo = avio_rb32(pb);
336 codec->strict_std_compliance = avio_rb32(pb);
337 codec->max_b_frames = avio_rb32(pb);
338 codec->mpeg_quant = avio_rb32(pb);
339 codec->intra_dc_precision = avio_rb32(pb);
340 codec->me_method = avio_rb32(pb);
341 codec->mb_decision = avio_rb32(pb);
342 codec->nsse_weight = avio_rb32(pb);
343 codec->frame_skip_cmp = avio_rb32(pb);
344 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
345 codec->codec_tag = avio_rb32(pb);
346 codec->thread_count = avio_r8(pb);
347 codec->coder_type = avio_rb32(pb);
348 codec->me_cmp = avio_rb32(pb);
349 codec->me_subpel_quality = avio_rb32(pb);
350 codec->me_range = avio_rb32(pb);
351 codec->keyint_min = avio_rb32(pb);
352 codec->scenechange_threshold = avio_rb32(pb);
353 codec->b_frame_strategy = avio_rb32(pb);
354 codec->qcompress = av_int2double(avio_rb64(pb));
355 codec->qblur = av_int2double(avio_rb64(pb));
356 codec->max_qdiff = avio_rb32(pb);
357 codec->refs = avio_rb32(pb);
359 case AVMEDIA_TYPE_AUDIO:
360 codec->sample_rate = avio_rb32(pb);
361 codec->channels = avio_rl16(pb);
362 codec->frame_size = avio_rl16(pb);
367 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
368 codec->extradata_size = avio_rb32(pb);
369 codec->extradata = av_malloc(codec->extradata_size);
370 if (!codec->extradata)
371 return AVERROR(ENOMEM);
372 avio_read(pb, codec->extradata, codec->extradata_size);
376 /* get until end of block reached */
377 while ((avio_tell(pb) % ffm->packet_size) != 0)
380 /* init packet demux */
381 ffm->packet_ptr = ffm->packet;
382 ffm->packet_end = ffm->packet;
383 ffm->frame_offset = 0;
385 ffm->read_state = READ_HEADER;
386 ffm->first_packet = 1;
393 /* return < 0 if eof */
394 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
397 FFMContext *ffm = s->priv_data;
400 switch(ffm->read_state) {
402 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
405 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
406 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
407 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
410 if (ffm->header[1] & FLAG_DTS)
411 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
413 ffm->read_state = READ_DATA;
416 size = AV_RB24(ffm->header + 2);
417 if ((ret = ffm_is_avail_data(s, size)) < 0)
420 duration = AV_RB24(ffm->header + 5);
422 av_new_packet(pkt, size);
423 pkt->stream_index = ffm->header[0];
424 if ((unsigned)pkt->stream_index >= s->nb_streams) {
425 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
427 ffm->read_state = READ_HEADER;
430 pkt->pos = avio_tell(s->pb);
431 if (ffm->header[1] & FLAG_KEY_FRAME)
432 pkt->flags |= AV_PKT_FLAG_KEY;
434 ffm->read_state = READ_HEADER;
435 if (ffm_read_data(s, pkt->data, size, 0) != size) {
436 /* bad case: desynchronized packet. we cancel all the packet loading */
440 pkt->pts = AV_RB64(ffm->header+8);
441 if (ffm->header[1] & FLAG_DTS)
442 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
445 pkt->duration = duration;
451 /* seek to a given time in the file. The file read pointer is
452 positioned at or before pts. XXX: the following code is quite
454 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
456 FFMContext *ffm = s->priv_data;
457 int64_t pos_min, pos_max, pos;
458 int64_t pts_min, pts_max, pts;
461 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
462 /* find the position using linear interpolation (better than
463 dichotomy in typical cases) */
464 if (ffm->write_index && ffm->write_index < ffm->file_size) {
465 if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
466 pos_min = FFM_PACKET_SIZE;
467 pos_max = ffm->write_index - FFM_PACKET_SIZE;
469 pos_min = ffm->write_index;
470 pos_max = ffm->file_size - FFM_PACKET_SIZE;
473 pos_min = FFM_PACKET_SIZE;
474 pos_max = ffm->file_size - FFM_PACKET_SIZE;
476 while (pos_min <= pos_max) {
477 pts_min = get_dts(s, pos_min);
478 pts_max = get_dts(s, pos_max);
479 if (pts_min > wanted_pts || pts_max < wanted_pts) {
480 pos = pts_min > wanted_pts ? pos_min : pos_max;
483 /* linear interpolation */
484 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
485 (double)(pts_max - pts_min);
486 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
489 else if (pos >= pos_max)
491 pts = get_dts(s, pos);
492 /* check if we are lucky */
493 if (pts == wanted_pts) {
495 } else if (pts > wanted_pts) {
496 pos_max = pos - FFM_PACKET_SIZE;
498 pos_min = pos + FFM_PACKET_SIZE;
501 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
504 if (ffm_seek1(s, pos) < 0)
507 /* reset read state */
508 ffm->read_state = READ_HEADER;
509 ffm->packet_ptr = ffm->packet;
510 ffm->packet_end = ffm->packet;
511 ffm->first_packet = 1;
516 static int ffm_probe(AVProbeData *p)
519 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
521 return AVPROBE_SCORE_MAX + 1;
525 AVInputFormat ff_ffm_demuxer = {
527 .long_name = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),
528 .priv_data_size = sizeof(FFMContext),
529 .read_probe = ffm_probe,
530 .read_header = ffm_read_header,
531 .read_packet = ffm_read_packet,
532 .read_close = ffm_close,
533 .read_seek = ffm_seek,