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"
28 static int ffm_is_avail_data(AVFormatContext *s, int size)
30 FFMContext *ffm = s->priv_data;
31 int64_t pos, avail_size;
34 len = ffm->packet_end - ffm->packet_ptr;
37 pos = avio_tell(s->pb);
38 if (!ffm->write_index) {
39 if (pos == ffm->file_size)
41 avail_size = ffm->file_size - pos;
43 if (pos == ffm->write_index) {
44 /* exactly at the end of stream */
45 return AVERROR(EAGAIN);
46 } else if (pos < ffm->write_index) {
47 avail_size = ffm->write_index - pos;
49 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
52 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
53 if (size <= avail_size)
56 return AVERROR(EAGAIN);
59 static int ffm_resync(AVFormatContext *s, int state)
61 av_log(s, AV_LOG_ERROR, "resyncing\n");
62 while (state != PACKET_ID) {
63 if (s->pb->eof_reached) {
64 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
67 state = (state << 8) | avio_r8(s->pb);
72 /* first is true if we read the frame header */
73 static int ffm_read_data(AVFormatContext *s,
74 uint8_t *buf, int size, int header)
76 FFMContext *ffm = s->priv_data;
77 AVIOContext *pb = s->pb;
78 int len, fill_size, size1, frame_offset, id;
83 len = ffm->packet_end - ffm->packet_ptr;
89 if (avio_tell(pb) == ffm->file_size)
90 avio_seek(pb, ffm->packet_size, SEEK_SET);
92 id = avio_rb16(pb); /* PACKET_ID */
94 if (ffm_resync(s, id) < 0)
96 fill_size = avio_rb16(pb);
97 ffm->dts = avio_rb64(pb);
98 frame_offset = avio_rb16(pb);
99 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
100 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
101 if (ffm->packet_end < ffm->packet || frame_offset < 0)
103 /* if first packet or resynchronization packet, we must
104 handle it specifically */
105 if (ffm->first_packet || (frame_offset & 0x8000)) {
107 /* This packet has no frame headers in it */
108 if (avio_tell(pb) >= ffm->packet_size * 3) {
109 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
112 /* This is bad, we cannot find a valid frame header */
115 ffm->first_packet = 0;
116 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
118 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
122 ffm->packet_ptr = ffm->packet;
126 memcpy(buf, ffm->packet_ptr, len);
128 ffm->packet_ptr += len;
135 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
136 and file_size - FFM_PACKET_SIZE */
137 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
139 FFMContext *ffm = s->priv_data;
140 AVIOContext *pb = s->pb;
143 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
144 pos = FFMAX(pos, FFM_PACKET_SIZE);
145 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
146 return avio_seek(pb, pos, SEEK_SET);
149 static int64_t get_dts(AVFormatContext *s, int64_t pos)
151 AVIOContext *pb = s->pb;
157 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
161 static void adjust_write_index(AVFormatContext *s)
163 FFMContext *ffm = s->priv_data;
164 AVIOContext *pb = s->pb;
166 //int64_t orig_write_index = ffm->write_index;
167 int64_t pos_min, pos_max;
169 int64_t ptr = avio_tell(pb);
173 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
175 pts_start = get_dts(s, pos_min);
177 pts = get_dts(s, pos_max);
179 if (pts - 100000 > pts_start)
182 ffm->write_index = FFM_PACKET_SIZE;
184 pts_start = get_dts(s, pos_min);
186 pts = get_dts(s, pos_max);
188 if (pts - 100000 <= pts_start) {
193 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
195 if (newpos == pos_min)
198 newpts = get_dts(s, newpos);
200 if (newpts - 100000 <= pts) {
207 ffm->write_index += pos_max;
211 avio_seek(pb, ptr, SEEK_SET);
215 static int ffm_close(AVFormatContext *s)
219 for (i = 0; i < s->nb_streams; i++)
220 av_freep(&s->streams[i]->codec->rc_eq);
226 static int ffm_read_header(AVFormatContext *s)
228 FFMContext *ffm = s->priv_data;
230 AVIOContext *pb = s->pb;
231 AVCodecContext *codec;
237 if (tag != MKTAG('F', 'F', 'M', '1'))
239 ffm->packet_size = avio_rb32(pb);
240 if (ffm->packet_size != FFM_PACKET_SIZE)
242 ffm->write_index = avio_rb64(pb);
243 /* get also filesize */
245 ffm->file_size = avio_size(pb);
246 if (ffm->write_index)
247 adjust_write_index(s);
249 ffm->file_size = (UINT64_C(1) << 63) - 1;
252 nb_streams = avio_rb32(pb);
253 avio_rb32(pb); /* total bitrate */
254 /* read each stream */
255 for(i=0;i<nb_streams;i++) {
258 st = avformat_new_stream(s, NULL);
262 avpriv_set_pts_info(st, 64, 1, 1000000);
266 codec->codec_id = avio_rb32(pb);
267 codec->codec_type = avio_r8(pb); /* codec_type */
268 codec->bit_rate = avio_rb32(pb);
269 codec->flags = avio_rb32(pb);
270 codec->flags2 = avio_rb32(pb);
271 codec->debug = avio_rb32(pb);
273 switch(codec->codec_type) {
274 case AVMEDIA_TYPE_VIDEO:
275 codec->time_base.num = avio_rb32(pb);
276 codec->time_base.den = avio_rb32(pb);
277 codec->width = avio_rb16(pb);
278 codec->height = avio_rb16(pb);
279 codec->gop_size = avio_rb16(pb);
280 codec->pix_fmt = avio_rb32(pb);
281 codec->qmin = avio_r8(pb);
282 codec->qmax = avio_r8(pb);
283 codec->max_qdiff = avio_r8(pb);
284 codec->qcompress = avio_rb16(pb) / 10000.0;
285 codec->qblur = avio_rb16(pb) / 10000.0;
286 codec->bit_rate_tolerance = avio_rb32(pb);
287 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
288 codec->rc_eq = av_strdup(rc_eq_buf);
289 codec->rc_max_rate = avio_rb32(pb);
290 codec->rc_min_rate = avio_rb32(pb);
291 codec->rc_buffer_size = avio_rb32(pb);
292 codec->i_quant_factor = av_int2double(avio_rb64(pb));
293 codec->b_quant_factor = av_int2double(avio_rb64(pb));
294 codec->i_quant_offset = av_int2double(avio_rb64(pb));
295 codec->b_quant_offset = av_int2double(avio_rb64(pb));
296 codec->dct_algo = avio_rb32(pb);
297 codec->strict_std_compliance = avio_rb32(pb);
298 codec->max_b_frames = avio_rb32(pb);
299 codec->mpeg_quant = avio_rb32(pb);
300 codec->intra_dc_precision = avio_rb32(pb);
301 codec->me_method = avio_rb32(pb);
302 codec->mb_decision = avio_rb32(pb);
303 codec->nsse_weight = avio_rb32(pb);
304 codec->frame_skip_cmp = avio_rb32(pb);
305 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
306 codec->codec_tag = avio_rb32(pb);
307 codec->thread_count = avio_r8(pb);
308 codec->coder_type = avio_rb32(pb);
309 codec->me_cmp = avio_rb32(pb);
310 codec->me_subpel_quality = avio_rb32(pb);
311 codec->me_range = avio_rb32(pb);
312 codec->keyint_min = avio_rb32(pb);
313 codec->scenechange_threshold = avio_rb32(pb);
314 codec->b_frame_strategy = avio_rb32(pb);
315 codec->qcompress = av_int2double(avio_rb64(pb));
316 codec->qblur = av_int2double(avio_rb64(pb));
317 codec->max_qdiff = avio_rb32(pb);
318 codec->refs = avio_rb32(pb);
320 case AVMEDIA_TYPE_AUDIO:
321 codec->sample_rate = avio_rb32(pb);
322 codec->channels = avio_rl16(pb);
323 codec->frame_size = avio_rl16(pb);
328 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
329 codec->extradata_size = avio_rb32(pb);
330 codec->extradata = av_malloc(codec->extradata_size);
331 if (!codec->extradata)
332 return AVERROR(ENOMEM);
333 avio_read(pb, codec->extradata, codec->extradata_size);
337 /* get until end of block reached */
338 while ((avio_tell(pb) % ffm->packet_size) != 0)
341 /* init packet demux */
342 ffm->packet_ptr = ffm->packet;
343 ffm->packet_end = ffm->packet;
344 ffm->frame_offset = 0;
346 ffm->read_state = READ_HEADER;
347 ffm->first_packet = 1;
354 /* return < 0 if eof */
355 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
358 FFMContext *ffm = s->priv_data;
361 switch(ffm->read_state) {
363 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
366 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
367 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
368 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
371 if (ffm->header[1] & FLAG_DTS)
372 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
374 ffm->read_state = READ_DATA;
377 size = AV_RB24(ffm->header + 2);
378 if ((ret = ffm_is_avail_data(s, size)) < 0)
381 duration = AV_RB24(ffm->header + 5);
383 av_new_packet(pkt, size);
384 pkt->stream_index = ffm->header[0];
385 if ((unsigned)pkt->stream_index >= s->nb_streams) {
386 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
388 ffm->read_state = READ_HEADER;
391 pkt->pos = avio_tell(s->pb);
392 if (ffm->header[1] & FLAG_KEY_FRAME)
393 pkt->flags |= AV_PKT_FLAG_KEY;
395 ffm->read_state = READ_HEADER;
396 if (ffm_read_data(s, pkt->data, size, 0) != size) {
397 /* bad case: desynchronized packet. we cancel all the packet loading */
401 pkt->pts = AV_RB64(ffm->header+8);
402 if (ffm->header[1] & FLAG_DTS)
403 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
406 pkt->duration = duration;
412 /* seek to a given time in the file. The file read pointer is
413 positioned at or before pts. XXX: the following code is quite
415 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
417 FFMContext *ffm = s->priv_data;
418 int64_t pos_min, pos_max, pos;
419 int64_t pts_min, pts_max, pts;
422 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
423 /* find the position using linear interpolation (better than
424 dichotomy in typical cases) */
425 pos_min = FFM_PACKET_SIZE;
426 pos_max = ffm->file_size - FFM_PACKET_SIZE;
427 while (pos_min <= pos_max) {
428 pts_min = get_dts(s, pos_min);
429 pts_max = get_dts(s, pos_max);
430 /* linear interpolation */
431 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
432 (double)(pts_max - pts_min);
433 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
436 else if (pos >= pos_max)
438 pts = get_dts(s, pos);
439 /* check if we are lucky */
440 if (pts == wanted_pts) {
442 } else if (pts > wanted_pts) {
443 pos_max = pos - FFM_PACKET_SIZE;
445 pos_min = pos + FFM_PACKET_SIZE;
448 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
451 if (ffm_seek1(s, pos) < 0)
454 /* reset read state */
455 ffm->read_state = READ_HEADER;
456 ffm->packet_ptr = ffm->packet;
457 ffm->packet_end = ffm->packet;
458 ffm->first_packet = 1;
463 static int ffm_probe(AVProbeData *p)
466 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
468 return AVPROBE_SCORE_MAX + 1;
472 AVInputFormat ff_ffm_demuxer = {
474 .long_name = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed)"),
475 .priv_data_size = sizeof(FFMContext),
476 .read_probe = ffm_probe,
477 .read_header = ffm_read_header,
478 .read_packet = ffm_read_packet,
479 .read_close = ffm_close,
480 .read_seek = ffm_seek,