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"
28 int64_t ffm_read_write_index(int fd)
32 lseek(fd, 8, SEEK_SET);
33 if (read(fd, buf, 8) != 8)
38 int ffm_write_write_index(int fd, int64_t pos)
44 buf[i] = (pos >> (56 - i * 8)) & 0xff;
45 lseek(fd, 8, SEEK_SET);
46 if (write(fd, buf, 8) != 8)
51 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
53 FFMContext *ffm = s->priv_data;
54 ffm->write_index = pos;
55 ffm->file_size = file_size;
57 #endif // CONFIG_FFSERVER
59 static int ffm_is_avail_data(AVFormatContext *s, int size)
61 FFMContext *ffm = s->priv_data;
62 int64_t pos, avail_size;
65 len = ffm->packet_end - ffm->packet_ptr;
68 pos = avio_tell(s->pb);
69 if (!ffm->write_index) {
70 if (pos == ffm->file_size)
72 avail_size = ffm->file_size - pos;
74 if (pos == ffm->write_index) {
75 /* exactly at the end of stream */
76 return AVERROR(EAGAIN);
77 } else if (pos < ffm->write_index) {
78 avail_size = ffm->write_index - pos;
80 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
83 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
84 if (size <= avail_size)
87 return AVERROR(EAGAIN);
90 static int ffm_resync(AVFormatContext *s, int state)
92 av_log(s, AV_LOG_ERROR, "resyncing\n");
93 while (state != PACKET_ID) {
94 if (url_feof(s->pb)) {
95 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
98 state = (state << 8) | avio_r8(s->pb);
103 /* first is true if we read the frame header */
104 static int ffm_read_data(AVFormatContext *s,
105 uint8_t *buf, int size, int header)
107 FFMContext *ffm = s->priv_data;
108 AVIOContext *pb = s->pb;
109 int len, fill_size, size1, frame_offset, id;
114 len = ffm->packet_end - ffm->packet_ptr;
120 if (avio_tell(pb) == ffm->file_size)
121 avio_seek(pb, ffm->packet_size, SEEK_SET);
123 id = avio_rb16(pb); /* PACKET_ID */
125 if (ffm_resync(s, id) < 0)
127 fill_size = avio_rb16(pb);
128 ffm->dts = avio_rb64(pb);
129 frame_offset = avio_rb16(pb);
130 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
131 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
132 if (ffm->packet_end < ffm->packet || frame_offset < 0)
134 /* if first packet or resynchronization packet, we must
135 handle it specifically */
136 if (ffm->first_packet || (frame_offset & 0x8000)) {
138 /* This packet has no frame headers in it */
139 if (avio_tell(pb) >= ffm->packet_size * 3) {
140 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
143 /* This is bad, we cannot find a valid frame header */
146 ffm->first_packet = 0;
147 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
149 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
153 ffm->packet_ptr = ffm->packet;
157 memcpy(buf, ffm->packet_ptr, len);
159 ffm->packet_ptr += len;
166 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
167 and file_size - FFM_PACKET_SIZE */
168 static void ffm_seek1(AVFormatContext *s, int64_t pos1)
170 FFMContext *ffm = s->priv_data;
171 AVIOContext *pb = s->pb;
174 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
175 pos = FFMAX(pos, FFM_PACKET_SIZE);
176 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
177 avio_seek(pb, pos, SEEK_SET);
180 static int64_t get_dts(AVFormatContext *s, int64_t pos)
182 AVIOContext *pb = s->pb;
188 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
192 static void adjust_write_index(AVFormatContext *s)
194 FFMContext *ffm = s->priv_data;
195 AVIOContext *pb = s->pb;
197 //int64_t orig_write_index = ffm->write_index;
198 int64_t pos_min, pos_max;
200 int64_t ptr = avio_tell(pb);
204 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
206 pts_start = get_dts(s, pos_min);
208 pts = get_dts(s, pos_max);
210 if (pts - 100000 > pts_start)
213 ffm->write_index = FFM_PACKET_SIZE;
215 pts_start = get_dts(s, pos_min);
217 pts = get_dts(s, pos_max);
219 if (pts - 100000 <= pts_start) {
224 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
226 if (newpos == pos_min)
229 newpts = get_dts(s, newpos);
231 if (newpts - 100000 <= pts) {
238 ffm->write_index += pos_max;
241 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
242 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
245 avio_seek(pb, ptr, SEEK_SET);
249 static int ffm_close(AVFormatContext *s)
253 for (i = 0; i < s->nb_streams; i++)
254 av_freep(&s->streams[i]->codec->rc_eq);
260 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
262 FFMContext *ffm = s->priv_data;
264 AVIOContext *pb = s->pb;
265 AVCodecContext *codec;
271 if (tag != MKTAG('F', 'F', 'M', '1'))
273 ffm->packet_size = avio_rb32(pb);
274 if (ffm->packet_size != FFM_PACKET_SIZE)
276 ffm->write_index = avio_rb64(pb);
277 /* get also filesize */
279 ffm->file_size = avio_size(pb);
280 if (ffm->write_index)
281 adjust_write_index(s);
283 ffm->file_size = (UINT64_C(1) << 63) - 1;
286 nb_streams = avio_rb32(pb);
287 avio_rb32(pb); /* total bitrate */
288 /* read each stream */
289 for(i=0;i<nb_streams;i++) {
292 st = av_new_stream(s, 0);
296 av_set_pts_info(st, 64, 1, 1000000);
300 codec->codec_id = avio_rb32(pb);
301 codec->codec_type = avio_r8(pb); /* codec_type */
302 codec->bit_rate = avio_rb32(pb);
303 st->quality = avio_rb32(pb);
304 codec->flags = avio_rb32(pb);
305 codec->flags2 = avio_rb32(pb);
306 codec->debug = avio_rb32(pb);
308 switch(codec->codec_type) {
309 case AVMEDIA_TYPE_VIDEO:
310 codec->time_base.num = avio_rb32(pb);
311 codec->time_base.den = avio_rb32(pb);
312 codec->width = avio_rb16(pb);
313 codec->height = avio_rb16(pb);
314 codec->gop_size = avio_rb16(pb);
315 codec->pix_fmt = avio_rb32(pb);
316 codec->qmin = avio_r8(pb);
317 codec->qmax = avio_r8(pb);
318 codec->max_qdiff = avio_r8(pb);
319 codec->qcompress = avio_rb16(pb) / 10000.0;
320 codec->qblur = avio_rb16(pb) / 10000.0;
321 codec->bit_rate_tolerance = avio_rb32(pb);
322 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
323 codec->rc_max_rate = avio_rb32(pb);
324 codec->rc_min_rate = avio_rb32(pb);
325 codec->rc_buffer_size = avio_rb32(pb);
326 codec->i_quant_factor = av_int2dbl(avio_rb64(pb));
327 codec->b_quant_factor = av_int2dbl(avio_rb64(pb));
328 codec->i_quant_offset = av_int2dbl(avio_rb64(pb));
329 codec->b_quant_offset = av_int2dbl(avio_rb64(pb));
330 codec->dct_algo = avio_rb32(pb);
331 codec->strict_std_compliance = avio_rb32(pb);
332 codec->max_b_frames = avio_rb32(pb);
333 codec->luma_elim_threshold = avio_rb32(pb);
334 codec->chroma_elim_threshold = avio_rb32(pb);
335 codec->mpeg_quant = avio_rb32(pb);
336 codec->intra_dc_precision = avio_rb32(pb);
337 codec->me_method = avio_rb32(pb);
338 codec->mb_decision = avio_rb32(pb);
339 codec->nsse_weight = avio_rb32(pb);
340 codec->frame_skip_cmp = avio_rb32(pb);
341 codec->rc_buffer_aggressivity = av_int2dbl(avio_rb64(pb));
342 codec->codec_tag = avio_rb32(pb);
343 codec->thread_count = avio_r8(pb);
344 codec->coder_type = avio_rb32(pb);
345 codec->me_cmp = avio_rb32(pb);
346 codec->partitions = avio_rb32(pb);
347 codec->me_subpel_quality = avio_rb32(pb);
348 codec->me_range = avio_rb32(pb);
349 codec->keyint_min = avio_rb32(pb);
350 codec->scenechange_threshold = avio_rb32(pb);
351 codec->b_frame_strategy = avio_rb32(pb);
352 codec->qcompress = av_int2dbl(avio_rb64(pb));
353 codec->qblur = av_int2dbl(avio_rb64(pb));
354 codec->max_qdiff = avio_rb32(pb);
355 codec->refs = avio_rb32(pb);
356 codec->directpred = avio_rb32(pb);
358 case AVMEDIA_TYPE_AUDIO:
359 codec->sample_rate = avio_rb32(pb);
360 codec->channels = avio_rl16(pb);
361 codec->frame_size = avio_rl16(pb);
362 codec->sample_fmt = (int16_t) 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 pos_min = FFM_PACKET_SIZE;
465 pos_max = ffm->file_size - FFM_PACKET_SIZE;
466 while (pos_min <= pos_max) {
467 pts_min = get_dts(s, pos_min);
468 pts_max = get_dts(s, pos_max);
469 /* linear interpolation */
470 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
471 (double)(pts_max - pts_min);
472 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
475 else if (pos >= pos_max)
477 pts = get_dts(s, pos);
478 /* check if we are lucky */
479 if (pts == wanted_pts) {
481 } else if (pts > wanted_pts) {
482 pos_max = pos - FFM_PACKET_SIZE;
484 pos_min = pos + FFM_PACKET_SIZE;
487 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
492 /* reset read state */
493 ffm->read_state = READ_HEADER;
494 ffm->packet_ptr = ffm->packet;
495 ffm->packet_end = ffm->packet;
496 ffm->first_packet = 1;
501 static int ffm_probe(AVProbeData *p)
504 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
506 return AVPROBE_SCORE_MAX + 1;
510 AVInputFormat ff_ffm_demuxer = {
512 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),