2 * FFM (avserver live feed) demuxer
3 * Copyright (c) 2001 Fabrice Bellard
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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_AVSERVER
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 (s->pb->eof_reached) {
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 id = avio_rb16(pb); /* PACKET_ID */
127 if (ffm_resync(s, id) < 0)
129 fill_size = avio_rb16(pb);
130 ffm->dts = avio_rb64(pb);
131 frame_offset = avio_rb16(pb);
132 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
133 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
134 if (ffm->packet_end < ffm->packet || frame_offset < 0)
136 /* if first packet or resynchronization packet, we must
137 handle it specifically */
138 if (ffm->first_packet || (frame_offset & 0x8000)) {
140 /* This packet has no frame headers in it */
141 if (avio_tell(pb) >= ffm->packet_size * 3) {
142 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
145 /* This is bad, we cannot find a valid frame header */
148 ffm->first_packet = 0;
149 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
151 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
155 ffm->packet_ptr = ffm->packet;
159 memcpy(buf, ffm->packet_ptr, len);
161 ffm->packet_ptr += len;
168 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
169 and file_size - FFM_PACKET_SIZE */
170 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
172 FFMContext *ffm = s->priv_data;
173 AVIOContext *pb = s->pb;
176 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
177 pos = FFMAX(pos, FFM_PACKET_SIZE);
178 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
179 return avio_seek(pb, pos, SEEK_SET);
182 static int64_t get_dts(AVFormatContext *s, int64_t pos)
184 AVIOContext *pb = s->pb;
190 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
194 static void adjust_write_index(AVFormatContext *s)
196 FFMContext *ffm = s->priv_data;
197 AVIOContext *pb = s->pb;
199 //int64_t orig_write_index = ffm->write_index;
200 int64_t pos_min, pos_max;
202 int64_t ptr = avio_tell(pb);
206 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
208 pts_start = get_dts(s, pos_min);
210 pts = get_dts(s, pos_max);
212 if (pts - 100000 > pts_start)
215 ffm->write_index = FFM_PACKET_SIZE;
217 pts_start = get_dts(s, pos_min);
219 pts = get_dts(s, pos_max);
221 if (pts - 100000 <= pts_start) {
226 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
228 if (newpos == pos_min)
231 newpts = get_dts(s, newpos);
233 if (newpts - 100000 <= pts) {
240 ffm->write_index += pos_max;
244 avio_seek(pb, ptr, SEEK_SET);
248 static int ffm_close(AVFormatContext *s)
252 for (i = 0; i < s->nb_streams; i++)
253 av_freep(&s->streams[i]->codec->rc_eq);
259 static int ffm_read_header(AVFormatContext *s)
261 FFMContext *ffm = s->priv_data;
263 AVIOContext *pb = s->pb;
264 AVCodecContext *codec;
270 if (tag != MKTAG('F', 'F', 'M', '1'))
272 ffm->packet_size = avio_rb32(pb);
273 if (ffm->packet_size != FFM_PACKET_SIZE)
275 ffm->write_index = avio_rb64(pb);
276 /* get also filesize */
278 ffm->file_size = avio_size(pb);
279 if (ffm->write_index)
280 adjust_write_index(s);
282 ffm->file_size = (UINT64_C(1) << 63) - 1;
285 nb_streams = avio_rb32(pb);
286 avio_rb32(pb); /* total bitrate */
287 /* read each stream */
288 for(i=0;i<nb_streams;i++) {
291 st = avformat_new_stream(s, NULL);
295 avpriv_set_pts_info(st, 64, 1, 1000000);
299 codec->codec_id = avio_rb32(pb);
300 codec->codec_type = avio_r8(pb); /* codec_type */
301 codec->bit_rate = avio_rb32(pb);
302 codec->flags = avio_rb32(pb);
303 codec->flags2 = avio_rb32(pb);
304 codec->debug = avio_rb32(pb);
306 switch(codec->codec_type) {
307 case AVMEDIA_TYPE_VIDEO:
308 codec->time_base.num = avio_rb32(pb);
309 codec->time_base.den = avio_rb32(pb);
310 codec->width = avio_rb16(pb);
311 codec->height = avio_rb16(pb);
312 codec->gop_size = avio_rb16(pb);
313 codec->pix_fmt = avio_rb32(pb);
314 codec->qmin = avio_r8(pb);
315 codec->qmax = avio_r8(pb);
316 codec->max_qdiff = avio_r8(pb);
317 codec->qcompress = avio_rb16(pb) / 10000.0;
318 codec->qblur = avio_rb16(pb) / 10000.0;
319 codec->bit_rate_tolerance = avio_rb32(pb);
320 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
321 codec->rc_eq = av_strdup(rc_eq_buf);
322 codec->rc_max_rate = avio_rb32(pb);
323 codec->rc_min_rate = avio_rb32(pb);
324 codec->rc_buffer_size = avio_rb32(pb);
325 codec->i_quant_factor = av_int2double(avio_rb64(pb));
326 codec->b_quant_factor = av_int2double(avio_rb64(pb));
327 codec->i_quant_offset = av_int2double(avio_rb64(pb));
328 codec->b_quant_offset = av_int2double(avio_rb64(pb));
329 codec->dct_algo = avio_rb32(pb);
330 codec->strict_std_compliance = avio_rb32(pb);
331 codec->max_b_frames = avio_rb32(pb);
332 codec->mpeg_quant = avio_rb32(pb);
333 codec->intra_dc_precision = avio_rb32(pb);
334 codec->me_method = avio_rb32(pb);
335 codec->mb_decision = avio_rb32(pb);
336 codec->nsse_weight = avio_rb32(pb);
337 codec->frame_skip_cmp = avio_rb32(pb);
338 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
339 codec->codec_tag = avio_rb32(pb);
340 codec->thread_count = avio_r8(pb);
341 codec->coder_type = avio_rb32(pb);
342 codec->me_cmp = avio_rb32(pb);
343 codec->me_subpel_quality = avio_rb32(pb);
344 codec->me_range = avio_rb32(pb);
345 codec->keyint_min = avio_rb32(pb);
346 codec->scenechange_threshold = avio_rb32(pb);
347 codec->b_frame_strategy = avio_rb32(pb);
348 codec->qcompress = av_int2double(avio_rb64(pb));
349 codec->qblur = av_int2double(avio_rb64(pb));
350 codec->max_qdiff = avio_rb32(pb);
351 codec->refs = avio_rb32(pb);
353 case AVMEDIA_TYPE_AUDIO:
354 codec->sample_rate = avio_rb32(pb);
355 codec->channels = avio_rl16(pb);
356 codec->frame_size = avio_rl16(pb);
361 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
362 codec->extradata_size = avio_rb32(pb);
363 codec->extradata = av_malloc(codec->extradata_size);
364 if (!codec->extradata)
365 return AVERROR(ENOMEM);
366 avio_read(pb, codec->extradata, codec->extradata_size);
370 /* get until end of block reached */
371 while ((avio_tell(pb) % ffm->packet_size) != 0)
374 /* init packet demux */
375 ffm->packet_ptr = ffm->packet;
376 ffm->packet_end = ffm->packet;
377 ffm->frame_offset = 0;
379 ffm->read_state = READ_HEADER;
380 ffm->first_packet = 1;
387 /* return < 0 if eof */
388 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
391 FFMContext *ffm = s->priv_data;
394 switch(ffm->read_state) {
396 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
399 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
400 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
401 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
404 if (ffm->header[1] & FLAG_DTS)
405 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
407 ffm->read_state = READ_DATA;
410 size = AV_RB24(ffm->header + 2);
411 if ((ret = ffm_is_avail_data(s, size)) < 0)
414 duration = AV_RB24(ffm->header + 5);
416 av_new_packet(pkt, size);
417 pkt->stream_index = ffm->header[0];
418 if ((unsigned)pkt->stream_index >= s->nb_streams) {
419 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
421 ffm->read_state = READ_HEADER;
424 pkt->pos = avio_tell(s->pb);
425 if (ffm->header[1] & FLAG_KEY_FRAME)
426 pkt->flags |= AV_PKT_FLAG_KEY;
428 ffm->read_state = READ_HEADER;
429 if (ffm_read_data(s, pkt->data, size, 0) != size) {
430 /* bad case: desynchronized packet. we cancel all the packet loading */
434 pkt->pts = AV_RB64(ffm->header+8);
435 if (ffm->header[1] & FLAG_DTS)
436 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
439 pkt->duration = duration;
445 /* seek to a given time in the file. The file read pointer is
446 positioned at or before pts. XXX: the following code is quite
448 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
450 FFMContext *ffm = s->priv_data;
451 int64_t pos_min, pos_max, pos;
452 int64_t pts_min, pts_max, pts;
455 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
456 /* find the position using linear interpolation (better than
457 dichotomy in typical cases) */
458 pos_min = FFM_PACKET_SIZE;
459 pos_max = ffm->file_size - FFM_PACKET_SIZE;
460 while (pos_min <= pos_max) {
461 pts_min = get_dts(s, pos_min);
462 pts_max = get_dts(s, pos_max);
463 /* linear interpolation */
464 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
465 (double)(pts_max - pts_min);
466 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
469 else if (pos >= pos_max)
471 pts = get_dts(s, pos);
472 /* check if we are lucky */
473 if (pts == wanted_pts) {
475 } else if (pts > wanted_pts) {
476 pos_max = pos - FFM_PACKET_SIZE;
478 pos_min = pos + FFM_PACKET_SIZE;
481 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
484 if (ffm_seek1(s, pos) < 0)
487 /* reset read state */
488 ffm->read_state = READ_HEADER;
489 ffm->packet_ptr = ffm->packet;
490 ffm->packet_end = ffm->packet;
491 ffm->first_packet = 1;
496 static int ffm_probe(AVProbeData *p)
499 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
501 return AVPROBE_SCORE_MAX + 1;
505 AVInputFormat ff_ffm_demuxer = {
507 .long_name = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed)"),
508 .priv_data_size = sizeof(FFMContext),
509 .read_probe = ffm_probe,
510 .read_header = ffm_read_header,
511 .read_packet = ffm_read_packet,
512 .read_close = ffm_close,
513 .read_seek = ffm_seek,