2 * FFM (ffserver live feed) encoder and decoder
3 * Copyright (c) 2001 Fabrice Bellard.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 /* The FFM file is made of blocks of fixed size */
23 #define FFM_HEADER_SIZE 14
24 #define PACKET_ID 0x666d
26 /* each packet contains frames (which can span several packets */
27 #define FRAME_HEADER_SIZE 8
28 #define FLAG_KEY_FRAME 0x01
30 typedef struct FFMStream {
39 typedef struct FFMContext {
40 /* only reading mode */
41 offset_t write_index, file_size;
43 uint8_t header[FRAME_HEADER_SIZE];
46 int first_packet; /* true if first packet, needed to set the discontinuity tag */
50 uint8_t *packet_ptr, *packet_end;
51 uint8_t packet[FFM_PACKET_SIZE];
54 static int64_t get_pts(AVFormatContext *s, offset_t pos);
56 /* disable pts hack for testing */
59 #ifdef CONFIG_ENCODERS
60 static void flush_packet(AVFormatContext *s)
62 FFMContext *ffm = s->priv_data;
64 ByteIOContext *pb = &s->pb;
66 fill_size = ffm->packet_end - ffm->packet_ptr;
67 memset(ffm->packet_ptr, 0, fill_size);
69 if (url_ftell(pb) % ffm->packet_size)
73 put_be16(pb, PACKET_ID);
74 put_be16(pb, fill_size);
75 put_be64(pb, ffm->pts);
76 h = ffm->frame_offset;
77 if (ffm->first_packet)
80 put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
82 /* prepare next packet */
83 ffm->frame_offset = 0; /* no key frame */
84 ffm->pts = 0; /* no pts */
85 ffm->packet_ptr = ffm->packet;
86 ffm->first_packet = 0;
89 /* 'first' is true if first data of a frame */
90 static void ffm_write_data(AVFormatContext *s,
91 const uint8_t *buf, int size,
92 int64_t pts, int first)
94 FFMContext *ffm = s->priv_data;
97 if (first && ffm->frame_offset == 0)
98 ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
99 if (first && ffm->pts == 0)
102 /* write as many packets as needed */
104 len = ffm->packet_end - ffm->packet_ptr;
107 memcpy(ffm->packet_ptr, buf, len);
109 ffm->packet_ptr += len;
112 if (ffm->packet_ptr >= ffm->packet_end) {
113 /* special case : no pts in packet : we leave the current one */
122 static int ffm_write_header(AVFormatContext *s)
124 FFMContext *ffm = s->priv_data;
127 ByteIOContext *pb = &s->pb;
128 AVCodecContext *codec;
131 ffm->packet_size = FFM_PACKET_SIZE;
135 put_be32(pb, ffm->packet_size);
136 /* XXX: store write position in other file ? */
137 put_be64(pb, ffm->packet_size); /* current write position */
139 put_be32(pb, s->nb_streams);
141 for(i=0;i<s->nb_streams;i++) {
143 bit_rate += st->codec.bit_rate;
145 put_be32(pb, bit_rate);
147 /* list of streams */
148 for(i=0;i<s->nb_streams;i++) {
150 fst = av_mallocz(sizeof(FFMStream));
157 put_be32(pb, codec->codec_id);
158 put_byte(pb, codec->codec_type);
159 put_be32(pb, codec->bit_rate);
160 put_be32(pb, st->quality);
161 put_be32(pb, codec->flags);
163 switch(codec->codec_type) {
164 case CODEC_TYPE_VIDEO:
165 put_be32(pb, codec->frame_rate_base);
166 put_be32(pb, codec->frame_rate);
167 put_be16(pb, codec->width);
168 put_be16(pb, codec->height);
169 put_be16(pb, codec->gop_size);
170 put_byte(pb, codec->qmin);
171 put_byte(pb, codec->qmax);
172 put_byte(pb, codec->max_qdiff);
173 put_be16(pb, (int) (codec->qcompress * 10000.0));
174 put_be16(pb, (int) (codec->qblur * 10000.0));
175 put_be32(pb, codec->bit_rate_tolerance);
176 put_strz(pb, codec->rc_eq);
177 put_be32(pb, codec->rc_max_rate);
178 put_be32(pb, codec->rc_min_rate);
179 put_be32(pb, codec->rc_buffer_size);
180 put_be64_double(pb, codec->i_quant_factor);
181 put_be64_double(pb, codec->b_quant_factor);
182 put_be64_double(pb, codec->i_quant_offset);
183 put_be64_double(pb, codec->b_quant_offset);
184 put_be32(pb, codec->dct_algo);
186 case CODEC_TYPE_AUDIO:
187 put_be32(pb, codec->sample_rate);
188 put_le16(pb, codec->channels);
189 put_le16(pb, codec->frame_size);
194 /* hack to have real time */
198 fst->pts = av_gettime();
201 /* flush until end of block reached */
202 while ((url_ftell(pb) % ffm->packet_size) != 0)
205 put_flush_packet(pb);
207 /* init packet mux */
208 ffm->packet_ptr = ffm->packet;
209 ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
210 if (ffm->packet_end < ffm->packet)
212 ffm->frame_offset = 0;
214 ffm->first_packet = 1;
218 for(i=0;i<s->nb_streams;i++) {
220 av_freep(&st->priv_data);
225 static int ffm_write_packet(AVFormatContext *s, int stream_index,
226 const uint8_t *buf, int size, int64_t force_pts)
228 AVStream *st = s->streams[stream_index];
229 FFMStream *fst = st->priv_data;
231 uint8_t header[FRAME_HEADER_SIZE];
234 if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
235 duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
237 duration = (1000000.0 * st->codec.frame_rate_base / (float)st->codec.frame_rate);
241 /* packet size & key_frame */
242 header[0] = stream_index;
244 if (st->codec.coded_frame->key_frame) //if st->codec.coded_frame==NULL then there is a bug somewhere else
245 header[1] |= FLAG_KEY_FRAME;
246 header[2] = (size >> 16) & 0xff;
247 header[3] = (size >> 8) & 0xff;
248 header[4] = size & 0xff;
249 header[5] = (duration >> 16) & 0xff;
250 header[6] = (duration >> 8) & 0xff;
251 header[7] = duration & 0xff;
252 ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
253 ffm_write_data(s, buf, size, pts, 0);
255 fst->pts += duration;
259 static int ffm_write_trailer(AVFormatContext *s)
261 ByteIOContext *pb = &s->pb;
262 FFMContext *ffm = s->priv_data;
266 if (ffm->packet_ptr > ffm->packet)
269 put_flush_packet(pb);
271 if (!url_is_streamed(pb)) {
273 /* update the write offset */
274 size = url_ftell(pb);
275 url_fseek(pb, 8, SEEK_SET);
277 put_flush_packet(pb);
280 for(i=0;i<s->nb_streams;i++)
281 av_freep(&s->streams[i]->priv_data);
284 #endif //CONFIG_ENCODERS
288 static int ffm_is_avail_data(AVFormatContext *s, int size)
290 FFMContext *ffm = s->priv_data;
291 offset_t pos, avail_size;
294 len = ffm->packet_end - ffm->packet_ptr;
296 /* XXX: I don't understand this test, so I disabled it for testing */
300 pos = url_ftell(&s->pb);
301 if (pos == ffm->write_index) {
302 /* exactly at the end of stream */
304 } else if (pos < ffm->write_index) {
305 avail_size = ffm->write_index - pos;
307 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
309 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
310 if (size <= avail_size)
316 /* first is true if we read the frame header */
317 static int ffm_read_data(AVFormatContext *s,
318 uint8_t *buf, int size, int first)
320 FFMContext *ffm = s->priv_data;
321 ByteIOContext *pb = &s->pb;
322 int len, fill_size, size1, frame_offset;
327 len = ffm->packet_end - ffm->packet_ptr;
331 if (url_ftell(pb) == ffm->file_size)
332 url_fseek(pb, ffm->packet_size, SEEK_SET);
334 get_be16(pb); /* PACKET_ID */
335 fill_size = get_be16(pb);
336 ffm->pts = get_be64(pb);
337 frame_offset = get_be16(pb);
338 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
339 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
340 if (ffm->packet_end < ffm->packet)
342 /* if first packet or resynchronization packet, we must
343 handle it specifically */
344 if (ffm->first_packet || (frame_offset & 0x8000)) {
346 /* This packet has no frame headers in it */
347 if (url_ftell(pb) >= ffm->packet_size * 3) {
348 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
351 /* This is bad, we cannot find a valid frame header */
354 ffm->first_packet = 0;
355 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
357 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
361 ffm->packet_ptr = ffm->packet;
365 memcpy(buf, ffm->packet_ptr, len);
367 ffm->packet_ptr += len;
375 static void adjust_write_index(AVFormatContext *s)
377 FFMContext *ffm = s->priv_data;
378 ByteIOContext *pb = &s->pb;
380 //offset_t orig_write_index = ffm->write_index;
381 offset_t pos_min, pos_max;
383 offset_t ptr = url_ftell(pb);
387 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
389 pts_start = get_pts(s, pos_min);
391 pts = get_pts(s, pos_max);
393 if (pts - 100000 > pts_start)
396 ffm->write_index = FFM_PACKET_SIZE;
398 pts_start = get_pts(s, pos_min);
400 pts = get_pts(s, pos_max);
402 if (pts - 100000 <= pts_start) {
407 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
409 if (newpos == pos_min)
412 newpts = get_pts(s, newpos);
414 if (newpts - 100000 <= pts) {
421 ffm->write_index += pos_max;
424 //printf("Adjusted write index from %lld to %lld: pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
425 //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
428 url_fseek(pb, ptr, SEEK_SET);
432 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
434 FFMContext *ffm = s->priv_data;
437 ByteIOContext *pb = &s->pb;
438 AVCodecContext *codec;
444 if (tag != MKTAG('F', 'F', 'M', '1'))
446 ffm->packet_size = get_be32(pb);
447 if (ffm->packet_size != FFM_PACKET_SIZE)
449 ffm->write_index = get_be64(pb);
450 /* get also filesize */
451 if (!url_is_streamed(pb)) {
452 ffm->file_size = url_filesize(url_fileno(pb));
453 adjust_write_index(s);
455 ffm->file_size = (uint64_t_C(1) << 63) - 1;
458 nb_streams = get_be32(pb);
459 get_be32(pb); /* total bitrate */
460 /* read each stream */
461 for(i=0;i<nb_streams;i++) {
464 st = av_new_stream(s, 0);
467 fst = av_mallocz(sizeof(FFMStream));
474 st->codec.codec_id = get_be32(pb);
475 st->codec.codec_type = get_byte(pb); /* codec_type */
476 codec->bit_rate = get_be32(pb);
477 st->quality = get_be32(pb);
478 codec->flags = get_be32(pb);
480 switch(codec->codec_type) {
481 case CODEC_TYPE_VIDEO:
482 codec->frame_rate_base = get_be32(pb);
483 codec->frame_rate = get_be32(pb);
484 codec->width = get_be16(pb);
485 codec->height = get_be16(pb);
486 codec->gop_size = get_be16(pb);
487 codec->qmin = get_byte(pb);
488 codec->qmax = get_byte(pb);
489 codec->max_qdiff = get_byte(pb);
490 codec->qcompress = get_be16(pb) / 10000.0;
491 codec->qblur = get_be16(pb) / 10000.0;
492 codec->bit_rate_tolerance = get_be32(pb);
493 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
494 codec->rc_max_rate = get_be32(pb);
495 codec->rc_min_rate = get_be32(pb);
496 codec->rc_buffer_size = get_be32(pb);
497 codec->i_quant_factor = get_be64_double(pb);
498 codec->b_quant_factor = get_be64_double(pb);
499 codec->i_quant_offset = get_be64_double(pb);
500 codec->b_quant_offset = get_be64_double(pb);
501 codec->dct_algo = get_be32(pb);
503 case CODEC_TYPE_AUDIO:
504 codec->sample_rate = get_be32(pb);
505 codec->channels = get_le16(pb);
506 codec->frame_size = get_le16(pb);
514 /* get until end of block reached */
515 while ((url_ftell(pb) % ffm->packet_size) != 0)
518 /* init packet demux */
519 ffm->packet_ptr = ffm->packet;
520 ffm->packet_end = ffm->packet;
521 ffm->frame_offset = 0;
523 ffm->read_state = READ_HEADER;
524 ffm->first_packet = 1;
527 for(i=0;i<s->nb_streams;i++) {
530 av_freep(&st->priv_data);
537 /* return < 0 if eof */
538 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
541 FFMContext *ffm = s->priv_data;
544 switch(ffm->read_state) {
546 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
550 printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
551 url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
553 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
559 for(i=0;i<FRAME_HEADER_SIZE;i++)
560 printf("%02x ", ffm->header[i]);
564 ffm->read_state = READ_DATA;
567 size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
568 if (!ffm_is_avail_data(s, size)) {
572 duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
574 av_new_packet(pkt, size);
575 pkt->stream_index = ffm->header[0];
576 if (ffm->header[1] & FLAG_KEY_FRAME)
577 pkt->flags |= PKT_FLAG_KEY;
579 ffm->read_state = READ_HEADER;
580 if (ffm_read_data(s, pkt->data, size, 0) != size) {
581 /* bad case: desynchronized packet. we cancel all the packet loading */
586 pkt->duration = duration;
594 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
595 by the write position inside this function */
596 static void ffm_seek1(AVFormatContext *s, offset_t pos1)
598 FFMContext *ffm = s->priv_data;
599 ByteIOContext *pb = &s->pb;
602 pos = pos1 + ffm->write_index;
603 if (pos >= ffm->file_size)
604 pos -= (ffm->file_size - FFM_PACKET_SIZE);
606 printf("seek to %Lx -> %Lx\n", pos1, pos);
608 url_fseek(pb, pos, SEEK_SET);
611 static int64_t get_pts(AVFormatContext *s, offset_t pos)
613 ByteIOContext *pb = &s->pb;
620 printf("pts=%0.6f\n", pts / 1000000.0);
625 /* seek to a given time in the file. The file read pointer is
626 positionned at or before pts. XXX: the following code is quite
628 static int ffm_seek(AVFormatContext *s, int64_t wanted_pts)
630 FFMContext *ffm = s->priv_data;
631 offset_t pos_min, pos_max, pos;
632 int64_t pts_min, pts_max, pts;
636 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
638 /* find the position using linear interpolation (better than
639 dichotomy in typical cases) */
641 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
642 while (pos_min <= pos_max) {
643 pts_min = get_pts(s, pos_min);
644 pts_max = get_pts(s, pos_max);
645 /* linear interpolation */
646 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
647 (double)(pts_max - pts_min);
648 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
651 else if (pos >= pos_max)
653 pts = get_pts(s, pos);
654 /* check if we are lucky */
655 if (pts == wanted_pts) {
657 } else if (pts > wanted_pts) {
658 pos_max = pos - FFM_PACKET_SIZE;
660 pos_min = pos + FFM_PACKET_SIZE;
665 pos -= FFM_PACKET_SIZE;
671 offset_t ffm_read_write_index(int fd)
677 lseek(fd, 8, SEEK_SET);
681 pos |= (int64_t)buf[i] << (56 - i * 8);
685 void ffm_write_write_index(int fd, offset_t pos)
691 buf[i] = (pos >> (56 - i * 8)) & 0xff;
692 lseek(fd, 8, SEEK_SET);
696 void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
698 FFMContext *ffm = s->priv_data;
699 ffm->write_index = pos;
700 ffm->file_size = file_size;
703 static int ffm_read_close(AVFormatContext *s)
708 for(i=0;i<s->nb_streams;i++) {
710 av_freep(&st->priv_data);
715 static int ffm_probe(AVProbeData *p)
717 if (p->buf_size >= 4 &&
718 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
720 return AVPROBE_SCORE_MAX + 1;
724 static AVInputFormat ffm_iformat = {
735 #ifdef CONFIG_ENCODERS
736 static AVOutputFormat ffm_oformat = {
742 /* not really used */
749 #endif //CONFIG_ENCODERS
753 av_register_input_format(&ffm_iformat);
754 #ifdef CONFIG_ENCODERS
755 av_register_output_format(&ffm_oformat);
756 #endif //CONFIG_ENCODERS