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
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/intfloat.h"
30 static int ffm_is_avail_data(AVFormatContext *s, int size)
32 FFMContext *ffm = s->priv_data;
33 int64_t pos, avail_size;
36 len = ffm->packet_end - ffm->packet_ptr;
39 pos = avio_tell(s->pb);
40 if (!ffm->write_index) {
41 if (pos == ffm->file_size)
43 avail_size = ffm->file_size - pos;
45 if (pos == ffm->write_index) {
46 /* exactly at the end of stream */
47 return AVERROR(EAGAIN);
48 } else if (pos < ffm->write_index) {
49 avail_size = ffm->write_index - pos;
51 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
54 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
55 if (size <= avail_size)
58 return AVERROR(EAGAIN);
61 static int ffm_resync(AVFormatContext *s, int state)
63 av_log(s, AV_LOG_ERROR, "resyncing\n");
64 while (state != PACKET_ID) {
65 if (s->pb->eof_reached) {
66 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
69 state = (state << 8) | avio_r8(s->pb);
74 /* first is true if we read the frame header */
75 static int ffm_read_data(AVFormatContext *s,
76 uint8_t *buf, int size, int header)
78 FFMContext *ffm = s->priv_data;
79 AVIOContext *pb = s->pb;
80 int len, fill_size, size1, frame_offset, id;
85 len = ffm->packet_end - ffm->packet_ptr;
91 if (avio_tell(pb) == ffm->file_size)
92 avio_seek(pb, ffm->packet_size, SEEK_SET);
94 id = avio_rb16(pb); /* PACKET_ID */
96 if (ffm_resync(s, id) < 0)
98 fill_size = avio_rb16(pb);
99 ffm->dts = avio_rb64(pb);
100 frame_offset = avio_rb16(pb);
101 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
102 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
103 if (ffm->packet_end < ffm->packet || frame_offset < 0)
105 /* if first packet or resynchronization packet, we must
106 handle it specifically */
107 if (ffm->first_packet || (frame_offset & 0x8000)) {
109 /* This packet has no frame headers in it */
110 if (avio_tell(pb) >= ffm->packet_size * 3) {
111 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
114 /* This is bad, we cannot find a valid frame header */
117 ffm->first_packet = 0;
118 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
120 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
124 ffm->packet_ptr = ffm->packet;
128 memcpy(buf, ffm->packet_ptr, len);
130 ffm->packet_ptr += len;
137 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
138 and file_size - FFM_PACKET_SIZE */
139 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
141 FFMContext *ffm = s->priv_data;
142 AVIOContext *pb = s->pb;
145 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
146 pos = FFMAX(pos, FFM_PACKET_SIZE);
147 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
148 return avio_seek(pb, pos, SEEK_SET);
151 static int64_t get_dts(AVFormatContext *s, int64_t pos)
153 AVIOContext *pb = s->pb;
159 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
163 static void adjust_write_index(AVFormatContext *s)
165 FFMContext *ffm = s->priv_data;
166 AVIOContext *pb = s->pb;
168 //int64_t orig_write_index = ffm->write_index;
169 int64_t pos_min, pos_max;
171 int64_t ptr = avio_tell(pb);
175 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
177 pts_start = get_dts(s, pos_min);
179 pts = get_dts(s, pos_max);
181 if (pts - 100000 > pts_start)
184 ffm->write_index = FFM_PACKET_SIZE;
186 pts_start = get_dts(s, pos_min);
188 pts = get_dts(s, pos_max);
190 if (pts - 100000 <= pts_start) {
195 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
197 if (newpos == pos_min)
200 newpts = get_dts(s, newpos);
202 if (newpts - 100000 <= pts) {
209 ffm->write_index += pos_max;
213 avio_seek(pb, ptr, SEEK_SET);
217 static int ffm_close(AVFormatContext *s)
221 for (i = 0; i < s->nb_streams; i++)
222 av_freep(&s->streams[i]->codec->rc_eq);
228 static int ffm_read_header(AVFormatContext *s)
230 FFMContext *ffm = s->priv_data;
232 AVIOContext *pb = s->pb;
233 AVCodecContext *codec;
239 if (tag != MKTAG('F', 'F', 'M', '1'))
241 ffm->packet_size = avio_rb32(pb);
242 if (ffm->packet_size != FFM_PACKET_SIZE)
244 ffm->write_index = avio_rb64(pb);
245 /* get also filesize */
247 ffm->file_size = avio_size(pb);
248 if (ffm->write_index)
249 adjust_write_index(s);
251 ffm->file_size = (UINT64_C(1) << 63) - 1;
254 nb_streams = avio_rb32(pb);
255 avio_rb32(pb); /* total bitrate */
256 /* read each stream */
257 for(i=0;i<nb_streams;i++) {
260 st = avformat_new_stream(s, NULL);
264 avpriv_set_pts_info(st, 64, 1, 1000000);
268 codec->codec_id = avio_rb32(pb);
269 codec->codec_type = avio_r8(pb); /* codec_type */
270 codec->bit_rate = avio_rb32(pb);
271 codec->flags = avio_rb32(pb);
272 codec->flags2 = avio_rb32(pb);
273 codec->debug = avio_rb32(pb);
275 switch(codec->codec_type) {
276 case AVMEDIA_TYPE_VIDEO:
277 codec->time_base.num = avio_rb32(pb);
278 codec->time_base.den = avio_rb32(pb);
279 codec->width = avio_rb16(pb);
280 codec->height = avio_rb16(pb);
281 codec->gop_size = avio_rb16(pb);
282 codec->pix_fmt = avio_rb32(pb);
283 codec->qmin = avio_r8(pb);
284 codec->qmax = avio_r8(pb);
285 codec->max_qdiff = avio_r8(pb);
286 codec->qcompress = avio_rb16(pb) / 10000.0;
287 codec->qblur = avio_rb16(pb) / 10000.0;
288 codec->bit_rate_tolerance = avio_rb32(pb);
289 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
290 codec->rc_eq = av_strdup(rc_eq_buf);
291 codec->rc_max_rate = avio_rb32(pb);
292 codec->rc_min_rate = avio_rb32(pb);
293 codec->rc_buffer_size = avio_rb32(pb);
294 codec->i_quant_factor = av_int2double(avio_rb64(pb));
295 codec->b_quant_factor = av_int2double(avio_rb64(pb));
296 codec->i_quant_offset = av_int2double(avio_rb64(pb));
297 codec->b_quant_offset = av_int2double(avio_rb64(pb));
298 codec->dct_algo = avio_rb32(pb);
299 codec->strict_std_compliance = avio_rb32(pb);
300 codec->max_b_frames = avio_rb32(pb);
301 codec->mpeg_quant = avio_rb32(pb);
302 codec->intra_dc_precision = avio_rb32(pb);
303 codec->me_method = avio_rb32(pb);
304 codec->mb_decision = avio_rb32(pb);
305 codec->nsse_weight = avio_rb32(pb);
306 codec->frame_skip_cmp = avio_rb32(pb);
307 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
308 codec->codec_tag = avio_rb32(pb);
309 codec->thread_count = avio_r8(pb);
310 codec->coder_type = avio_rb32(pb);
311 codec->me_cmp = avio_rb32(pb);
312 codec->me_subpel_quality = avio_rb32(pb);
313 codec->me_range = avio_rb32(pb);
314 codec->keyint_min = avio_rb32(pb);
315 codec->scenechange_threshold = avio_rb32(pb);
316 codec->b_frame_strategy = avio_rb32(pb);
317 codec->qcompress = av_int2double(avio_rb64(pb));
318 codec->qblur = av_int2double(avio_rb64(pb));
319 codec->max_qdiff = avio_rb32(pb);
320 codec->refs = avio_rb32(pb);
322 case AVMEDIA_TYPE_AUDIO:
323 codec->sample_rate = avio_rb32(pb);
324 codec->channels = avio_rl16(pb);
325 codec->frame_size = avio_rl16(pb);
330 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
331 codec->extradata_size = avio_rb32(pb);
332 codec->extradata = av_malloc(codec->extradata_size);
333 if (!codec->extradata)
334 return AVERROR(ENOMEM);
335 avio_read(pb, codec->extradata, codec->extradata_size);
339 /* get until end of block reached */
340 while ((avio_tell(pb) % ffm->packet_size) != 0)
343 /* init packet demux */
344 ffm->packet_ptr = ffm->packet;
345 ffm->packet_end = ffm->packet;
346 ffm->frame_offset = 0;
348 ffm->read_state = READ_HEADER;
349 ffm->first_packet = 1;
356 /* return < 0 if eof */
357 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
360 FFMContext *ffm = s->priv_data;
363 switch(ffm->read_state) {
365 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
368 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
369 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
370 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
373 if (ffm->header[1] & FLAG_DTS)
374 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
376 ffm->read_state = READ_DATA;
379 size = AV_RB24(ffm->header + 2);
380 if ((ret = ffm_is_avail_data(s, size)) < 0)
383 duration = AV_RB24(ffm->header + 5);
385 av_new_packet(pkt, size);
386 pkt->stream_index = ffm->header[0];
387 if ((unsigned)pkt->stream_index >= s->nb_streams) {
388 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
390 ffm->read_state = READ_HEADER;
393 pkt->pos = avio_tell(s->pb);
394 if (ffm->header[1] & FLAG_KEY_FRAME)
395 pkt->flags |= AV_PKT_FLAG_KEY;
397 ffm->read_state = READ_HEADER;
398 if (ffm_read_data(s, pkt->data, size, 0) != size) {
399 /* bad case: desynchronized packet. we cancel all the packet loading */
403 pkt->pts = AV_RB64(ffm->header+8);
404 if (ffm->header[1] & FLAG_DTS)
405 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
408 pkt->duration = duration;
414 /* seek to a given time in the file. The file read pointer is
415 positioned at or before pts. XXX: the following code is quite
417 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
419 FFMContext *ffm = s->priv_data;
420 int64_t pos_min, pos_max, pos;
421 int64_t pts_min, pts_max, pts;
424 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
425 /* find the position using linear interpolation (better than
426 dichotomy in typical cases) */
427 pos_min = FFM_PACKET_SIZE;
428 pos_max = ffm->file_size - FFM_PACKET_SIZE;
429 while (pos_min <= pos_max) {
430 pts_min = get_dts(s, pos_min);
431 pts_max = get_dts(s, pos_max);
432 /* linear interpolation */
433 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
434 (double)(pts_max - pts_min);
435 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
438 else if (pos >= pos_max)
440 pts = get_dts(s, pos);
441 /* check if we are lucky */
442 if (pts == wanted_pts) {
444 } else if (pts > wanted_pts) {
445 pos_max = pos - FFM_PACKET_SIZE;
447 pos_min = pos + FFM_PACKET_SIZE;
450 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
453 if (ffm_seek1(s, pos) < 0)
456 /* reset read state */
457 ffm->read_state = READ_HEADER;
458 ffm->packet_ptr = ffm->packet;
459 ffm->packet_end = ffm->packet;
460 ffm->first_packet = 1;
465 static int ffm_probe(AVProbeData *p)
468 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
470 return AVPROBE_SCORE_MAX + 1;
474 AVInputFormat ff_ffm_demuxer = {
476 .long_name = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed)"),
477 .priv_data_size = sizeof(FFMContext),
478 .read_probe = ffm_probe,
479 .read_header = ffm_read_header,
480 .read_packet = ffm_read_packet,
481 .read_close = ffm_close,
482 .read_seek = ffm_seek,