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
26 static int ffm_is_avail_data(AVFormatContext *s, int size)
28 FFMContext *ffm = s->priv_data;
29 offset_t pos, avail_size;
32 len = ffm->packet_end - ffm->packet_ptr;
35 pos = url_ftell(s->pb);
36 if (pos == ffm->write_index) {
37 /* exactly at the end of stream */
39 } else if (pos < ffm->write_index) {
40 avail_size = ffm->write_index - pos;
42 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
44 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
45 if (size <= avail_size)
51 /* first is true if we read the frame header */
52 static int ffm_read_data(AVFormatContext *s,
53 uint8_t *buf, int size, int first)
55 FFMContext *ffm = s->priv_data;
56 ByteIOContext *pb = s->pb;
57 int len, fill_size, size1, frame_offset;
62 len = ffm->packet_end - ffm->packet_ptr;
66 if (url_ftell(pb) == ffm->file_size)
67 url_fseek(pb, ffm->packet_size, SEEK_SET);
69 get_be16(pb); /* PACKET_ID */
70 fill_size = get_be16(pb);
71 ffm->pts = get_be64(pb);
72 ffm->first_frame_in_packet = 1;
73 frame_offset = get_be16(pb);
74 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
75 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
76 if (ffm->packet_end < ffm->packet)
78 /* if first packet or resynchronization packet, we must
79 handle it specifically */
80 if (ffm->first_packet || (frame_offset & 0x8000)) {
82 /* This packet has no frame headers in it */
83 if (url_ftell(pb) >= ffm->packet_size * 3) {
84 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
87 /* This is bad, we cannot find a valid frame header */
90 ffm->first_packet = 0;
91 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
93 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
97 ffm->packet_ptr = ffm->packet;
101 memcpy(buf, ffm->packet_ptr, len);
103 ffm->packet_ptr += len;
112 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
113 by the write position inside this function */
114 static void ffm_seek1(AVFormatContext *s, offset_t pos1)
116 FFMContext *ffm = s->priv_data;
117 ByteIOContext *pb = s->pb;
120 pos = pos1 + ffm->write_index;
121 if (pos >= ffm->file_size)
122 pos -= (ffm->file_size - FFM_PACKET_SIZE);
124 printf("seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
126 url_fseek(pb, pos, SEEK_SET);
129 static int64_t get_pts(AVFormatContext *s, offset_t pos)
131 ByteIOContext *pb = s->pb;
138 printf("pts=%0.6f\n", pts / 1000000.0);
143 static void adjust_write_index(AVFormatContext *s)
145 FFMContext *ffm = s->priv_data;
146 ByteIOContext *pb = s->pb;
148 //offset_t orig_write_index = ffm->write_index;
149 offset_t pos_min, pos_max;
151 offset_t ptr = url_ftell(pb);
155 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
157 pts_start = get_pts(s, pos_min);
159 pts = get_pts(s, pos_max);
161 if (pts - 100000 > pts_start)
164 ffm->write_index = FFM_PACKET_SIZE;
166 pts_start = get_pts(s, pos_min);
168 pts = get_pts(s, pos_max);
170 if (pts - 100000 <= pts_start) {
175 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
177 if (newpos == pos_min)
180 newpts = get_pts(s, newpos);
182 if (newpts - 100000 <= pts) {
189 ffm->write_index += pos_max;
192 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
193 //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
196 url_fseek(pb, ptr, SEEK_SET);
200 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
202 FFMContext *ffm = s->priv_data;
205 ByteIOContext *pb = s->pb;
206 AVCodecContext *codec;
212 if (tag != MKTAG('F', 'F', 'M', '1'))
214 ffm->packet_size = get_be32(pb);
215 if (ffm->packet_size != FFM_PACKET_SIZE)
217 ffm->write_index = get_be64(pb);
218 /* get also filesize */
219 if (!url_is_streamed(pb)) {
220 ffm->file_size = url_fsize(pb);
221 adjust_write_index(s);
223 ffm->file_size = (UINT64_C(1) << 63) - 1;
226 nb_streams = get_be32(pb);
227 get_be32(pb); /* total bitrate */
228 /* read each stream */
229 for(i=0;i<nb_streams;i++) {
232 st = av_new_stream(s, 0);
235 fst = av_mallocz(sizeof(FFMStream));
240 av_set_pts_info(st, 64, 1, 1000000);
246 codec->codec_id = get_be32(pb);
247 codec->codec_type = get_byte(pb); /* codec_type */
248 codec->bit_rate = get_be32(pb);
249 st->quality = get_be32(pb);
250 codec->flags = get_be32(pb);
251 codec->flags2 = get_be32(pb);
252 codec->debug = get_be32(pb);
254 switch(codec->codec_type) {
255 case CODEC_TYPE_VIDEO:
256 codec->time_base.num = get_be32(pb);
257 codec->time_base.den = get_be32(pb);
258 codec->width = get_be16(pb);
259 codec->height = get_be16(pb);
260 codec->gop_size = get_be16(pb);
261 codec->pix_fmt = get_be32(pb);
262 codec->qmin = get_byte(pb);
263 codec->qmax = get_byte(pb);
264 codec->max_qdiff = get_byte(pb);
265 codec->qcompress = get_be16(pb) / 10000.0;
266 codec->qblur = get_be16(pb) / 10000.0;
267 codec->bit_rate_tolerance = get_be32(pb);
268 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
269 codec->rc_max_rate = get_be32(pb);
270 codec->rc_min_rate = get_be32(pb);
271 codec->rc_buffer_size = get_be32(pb);
272 codec->i_quant_factor = av_int2dbl(get_be64(pb));
273 codec->b_quant_factor = av_int2dbl(get_be64(pb));
274 codec->i_quant_offset = av_int2dbl(get_be64(pb));
275 codec->b_quant_offset = av_int2dbl(get_be64(pb));
276 codec->dct_algo = get_be32(pb);
277 codec->strict_std_compliance = get_be32(pb);
278 codec->max_b_frames = get_be32(pb);
279 codec->luma_elim_threshold = get_be32(pb);
280 codec->chroma_elim_threshold = get_be32(pb);
281 codec->mpeg_quant = get_be32(pb);
282 codec->intra_dc_precision = get_be32(pb);
283 codec->me_method = get_be32(pb);
284 codec->mb_decision = get_be32(pb);
285 codec->nsse_weight = get_be32(pb);
286 codec->frame_skip_cmp = get_be32(pb);
287 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
288 codec->codec_tag = get_be32(pb);
290 case CODEC_TYPE_AUDIO:
291 codec->sample_rate = get_be32(pb);
292 codec->channels = get_le16(pb);
293 codec->frame_size = get_le16(pb);
301 /* get until end of block reached */
302 while ((url_ftell(pb) % ffm->packet_size) != 0)
305 /* init packet demux */
306 ffm->packet_ptr = ffm->packet;
307 ffm->packet_end = ffm->packet;
308 ffm->frame_offset = 0;
310 ffm->read_state = READ_HEADER;
311 ffm->first_packet = 1;
314 for(i=0;i<s->nb_streams;i++) {
317 av_freep(&st->priv_data);
324 /* return < 0 if eof */
325 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
328 FFMContext *ffm = s->priv_data;
331 switch(ffm->read_state) {
333 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
334 return AVERROR(EAGAIN);
337 printf("pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
338 url_ftell(s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
340 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
342 return AVERROR(EAGAIN);
346 for(i=0;i<FRAME_HEADER_SIZE;i++)
347 printf("%02x ", ffm->header[i]);
351 ffm->read_state = READ_DATA;
354 size = AV_RB24(ffm->header + 2);
355 if (!ffm_is_avail_data(s, size)) {
356 return AVERROR(EAGAIN);
359 duration = AV_RB24(ffm->header + 5);
361 av_new_packet(pkt, size);
362 pkt->stream_index = ffm->header[0];
363 if ((unsigned)pkt->stream_index >= s->nb_streams) {
364 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
366 ffm->read_state = READ_HEADER;
367 return AVERROR(EAGAIN);
369 pkt->pos = url_ftell(s->pb);
370 if (ffm->header[1] & FLAG_KEY_FRAME)
371 pkt->flags |= PKT_FLAG_KEY;
373 ffm->read_state = READ_HEADER;
374 if (ffm_read_data(s, pkt->data, size, 0) != size) {
375 /* bad case: desynchronized packet. we cancel all the packet loading */
377 return AVERROR(EAGAIN);
379 if (ffm->first_frame_in_packet)
382 ffm->first_frame_in_packet = 0;
384 pkt->duration = duration;
390 /* seek to a given time in the file. The file read pointer is
391 positioned at or before pts. XXX: the following code is quite
393 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
395 FFMContext *ffm = s->priv_data;
396 offset_t pos_min, pos_max, pos;
397 int64_t pts_min, pts_max, pts;
401 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
403 /* find the position using linear interpolation (better than
404 dichotomy in typical cases) */
406 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
407 while (pos_min <= pos_max) {
408 pts_min = get_pts(s, pos_min);
409 pts_max = get_pts(s, pos_max);
410 /* linear interpolation */
411 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
412 (double)(pts_max - pts_min);
413 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
416 else if (pos >= pos_max)
418 pts = get_pts(s, pos);
419 /* check if we are lucky */
420 if (pts == wanted_pts) {
422 } else if (pts > wanted_pts) {
423 pos_max = pos - FFM_PACKET_SIZE;
425 pos_min = pos + FFM_PACKET_SIZE;
428 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
430 pos -= FFM_PACKET_SIZE;
436 #ifdef CONFIG_FFSERVER
437 offset_t ffm_read_write_index(int fd)
441 lseek(fd, 8, SEEK_SET);
446 void ffm_write_write_index(int fd, offset_t pos)
452 buf[i] = (pos >> (56 - i * 8)) & 0xff;
453 lseek(fd, 8, SEEK_SET);
457 void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
459 FFMContext *ffm = s->priv_data;
460 ffm->write_index = pos;
461 ffm->file_size = file_size;
463 #endif // CONFIG_FFSERVER
465 static int ffm_read_close(AVFormatContext *s)
470 for(i=0;i<s->nb_streams;i++) {
472 av_freep(&st->priv_data);
477 static int ffm_probe(AVProbeData *p)
480 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
482 return AVPROBE_SCORE_MAX + 1;
486 AVInputFormat ffm_demuxer = {