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;
243 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
244 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
247 avio_seek(pb, ptr, SEEK_SET);
251 static int ffm_close(AVFormatContext *s)
255 for (i = 0; i < s->nb_streams; i++)
256 av_freep(&s->streams[i]->codec->rc_eq);
262 static int ffm_read_header(AVFormatContext *s)
264 FFMContext *ffm = s->priv_data;
266 AVIOContext *pb = s->pb;
267 AVCodecContext *codec;
273 if (tag != MKTAG('F', 'F', 'M', '1'))
275 ffm->packet_size = avio_rb32(pb);
276 if (ffm->packet_size != FFM_PACKET_SIZE)
278 ffm->write_index = avio_rb64(pb);
279 /* get also filesize */
281 ffm->file_size = avio_size(pb);
282 if (ffm->write_index)
283 adjust_write_index(s);
285 ffm->file_size = (UINT64_C(1) << 63) - 1;
288 nb_streams = avio_rb32(pb);
289 avio_rb32(pb); /* total bitrate */
290 /* read each stream */
291 for(i=0;i<nb_streams;i++) {
294 st = avformat_new_stream(s, NULL);
298 avpriv_set_pts_info(st, 64, 1, 1000000);
302 codec->codec_id = avio_rb32(pb);
303 codec->codec_type = avio_r8(pb); /* codec_type */
304 codec->bit_rate = avio_rb32(pb);
305 codec->flags = avio_rb32(pb);
306 codec->flags2 = avio_rb32(pb);
307 codec->debug = avio_rb32(pb);
309 switch(codec->codec_type) {
310 case AVMEDIA_TYPE_VIDEO:
311 codec->time_base.num = avio_rb32(pb);
312 codec->time_base.den = avio_rb32(pb);
313 codec->width = avio_rb16(pb);
314 codec->height = avio_rb16(pb);
315 codec->gop_size = avio_rb16(pb);
316 codec->pix_fmt = avio_rb32(pb);
317 codec->qmin = avio_r8(pb);
318 codec->qmax = avio_r8(pb);
319 codec->max_qdiff = avio_r8(pb);
320 codec->qcompress = avio_rb16(pb) / 10000.0;
321 codec->qblur = avio_rb16(pb) / 10000.0;
322 codec->bit_rate_tolerance = avio_rb32(pb);
323 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
324 codec->rc_eq = av_strdup(rc_eq_buf);
325 codec->rc_max_rate = avio_rb32(pb);
326 codec->rc_min_rate = avio_rb32(pb);
327 codec->rc_buffer_size = avio_rb32(pb);
328 codec->i_quant_factor = av_int2double(avio_rb64(pb));
329 codec->b_quant_factor = av_int2double(avio_rb64(pb));
330 codec->i_quant_offset = av_int2double(avio_rb64(pb));
331 codec->b_quant_offset = av_int2double(avio_rb64(pb));
332 codec->dct_algo = avio_rb32(pb);
333 codec->strict_std_compliance = avio_rb32(pb);
334 codec->max_b_frames = 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_int2double(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->me_subpel_quality = avio_rb32(pb);
347 codec->me_range = avio_rb32(pb);
348 codec->keyint_min = avio_rb32(pb);
349 codec->scenechange_threshold = avio_rb32(pb);
350 codec->b_frame_strategy = avio_rb32(pb);
351 codec->qcompress = av_int2double(avio_rb64(pb));
352 codec->qblur = av_int2double(avio_rb64(pb));
353 codec->max_qdiff = avio_rb32(pb);
354 codec->refs = avio_rb32(pb);
356 case AVMEDIA_TYPE_AUDIO:
357 codec->sample_rate = avio_rb32(pb);
358 codec->channels = avio_rl16(pb);
359 codec->frame_size = avio_rl16(pb);
360 codec->sample_fmt = (int16_t) avio_rl16(pb);
365 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
366 codec->extradata_size = avio_rb32(pb);
367 codec->extradata = av_malloc(codec->extradata_size);
368 if (!codec->extradata)
369 return AVERROR(ENOMEM);
370 avio_read(pb, codec->extradata, codec->extradata_size);
374 /* get until end of block reached */
375 while ((avio_tell(pb) % ffm->packet_size) != 0)
378 /* init packet demux */
379 ffm->packet_ptr = ffm->packet;
380 ffm->packet_end = ffm->packet;
381 ffm->frame_offset = 0;
383 ffm->read_state = READ_HEADER;
384 ffm->first_packet = 1;
391 /* return < 0 if eof */
392 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
395 FFMContext *ffm = s->priv_data;
398 switch(ffm->read_state) {
400 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
403 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
404 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
405 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
408 if (ffm->header[1] & FLAG_DTS)
409 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
411 ffm->read_state = READ_DATA;
414 size = AV_RB24(ffm->header + 2);
415 if ((ret = ffm_is_avail_data(s, size)) < 0)
418 duration = AV_RB24(ffm->header + 5);
420 av_new_packet(pkt, size);
421 pkt->stream_index = ffm->header[0];
422 if ((unsigned)pkt->stream_index >= s->nb_streams) {
423 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
425 ffm->read_state = READ_HEADER;
428 pkt->pos = avio_tell(s->pb);
429 if (ffm->header[1] & FLAG_KEY_FRAME)
430 pkt->flags |= AV_PKT_FLAG_KEY;
432 ffm->read_state = READ_HEADER;
433 if (ffm_read_data(s, pkt->data, size, 0) != size) {
434 /* bad case: desynchronized packet. we cancel all the packet loading */
438 pkt->pts = AV_RB64(ffm->header+8);
439 if (ffm->header[1] & FLAG_DTS)
440 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
443 pkt->duration = duration;
449 /* seek to a given time in the file. The file read pointer is
450 positioned at or before pts. XXX: the following code is quite
452 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
454 FFMContext *ffm = s->priv_data;
455 int64_t pos_min, pos_max, pos;
456 int64_t pts_min, pts_max, pts;
459 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
460 /* find the position using linear interpolation (better than
461 dichotomy in typical cases) */
462 pos_min = FFM_PACKET_SIZE;
463 pos_max = ffm->file_size - FFM_PACKET_SIZE;
464 while (pos_min <= pos_max) {
465 pts_min = get_dts(s, pos_min);
466 pts_max = get_dts(s, pos_max);
467 /* linear interpolation */
468 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
469 (double)(pts_max - pts_min);
470 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
473 else if (pos >= pos_max)
475 pts = get_dts(s, pos);
476 /* check if we are lucky */
477 if (pts == wanted_pts) {
479 } else if (pts > wanted_pts) {
480 pos_max = pos - FFM_PACKET_SIZE;
482 pos_min = pos + FFM_PACKET_SIZE;
485 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
488 if (ffm_seek1(s, pos) < 0)
491 /* reset read state */
492 ffm->read_state = READ_HEADER;
493 ffm->packet_ptr = ffm->packet;
494 ffm->packet_end = ffm->packet;
495 ffm->first_packet = 1;
500 static int ffm_probe(AVProbeData *p)
503 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
505 return AVPROBE_SCORE_MAX + 1;
509 AVInputFormat ff_ffm_demuxer = {
511 .long_name = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed) format"),
512 .priv_data_size = sizeof(FFMContext),
513 .read_probe = ffm_probe,
514 .read_header = ffm_read_header,
515 .read_packet = ffm_read_packet,
516 .read_close = ffm_close,
517 .read_seek = ffm_seek,