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));
153 av_set_pts_info(st, 64, 1, 1000000);
158 put_be32(pb, codec->codec_id);
159 put_byte(pb, codec->codec_type);
160 put_be32(pb, codec->bit_rate);
161 put_be32(pb, st->quality);
162 put_be32(pb, codec->flags);
164 switch(codec->codec_type) {
165 case CODEC_TYPE_VIDEO:
166 put_be32(pb, codec->time_base.num);
167 put_be32(pb, codec->time_base.den);
168 put_be16(pb, codec->width);
169 put_be16(pb, codec->height);
170 put_be16(pb, codec->gop_size);
171 put_byte(pb, codec->qmin);
172 put_byte(pb, codec->qmax);
173 put_byte(pb, codec->max_qdiff);
174 put_be16(pb, (int) (codec->qcompress * 10000.0));
175 put_be16(pb, (int) (codec->qblur * 10000.0));
176 put_be32(pb, codec->bit_rate_tolerance);
177 put_strz(pb, codec->rc_eq);
178 put_be32(pb, codec->rc_max_rate);
179 put_be32(pb, codec->rc_min_rate);
180 put_be32(pb, codec->rc_buffer_size);
181 put_be64_double(pb, codec->i_quant_factor);
182 put_be64_double(pb, codec->b_quant_factor);
183 put_be64_double(pb, codec->i_quant_offset);
184 put_be64_double(pb, codec->b_quant_offset);
185 put_be32(pb, codec->dct_algo);
187 case CODEC_TYPE_AUDIO:
188 put_be32(pb, codec->sample_rate);
189 put_le16(pb, codec->channels);
190 put_le16(pb, codec->frame_size);
195 /* hack to have real time */
199 fst->pts = av_gettime();
202 /* flush until end of block reached */
203 while ((url_ftell(pb) % ffm->packet_size) != 0)
206 put_flush_packet(pb);
208 /* init packet mux */
209 ffm->packet_ptr = ffm->packet;
210 ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
211 assert(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, AVPacket *pkt)
227 AVStream *st = s->streams[pkt->stream_index];
228 FFMStream *fst = st->priv_data;
230 uint8_t header[FRAME_HEADER_SIZE];
234 //XXX/FIXME use duration from pkt
235 if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
236 duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
238 duration = (1000000.0 * st->codec.time_base.num / (float)st->codec.time_base.den);
242 /* packet size & key_frame */
243 header[0] = pkt->stream_index;
245 if (pkt->flags & PKT_FLAG_KEY)
246 header[1] |= FLAG_KEY_FRAME;
247 header[2] = (size >> 16) & 0xff;
248 header[3] = (size >> 8) & 0xff;
249 header[4] = size & 0xff;
250 header[5] = (duration >> 16) & 0xff;
251 header[6] = (duration >> 8) & 0xff;
252 header[7] = duration & 0xff;
253 ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
254 ffm_write_data(s, pkt->data, size, pts, 0);
256 fst->pts += duration;
260 static int ffm_write_trailer(AVFormatContext *s)
262 ByteIOContext *pb = &s->pb;
263 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);
282 #endif //CONFIG_ENCODERS
286 static int ffm_is_avail_data(AVFormatContext *s, int size)
288 FFMContext *ffm = s->priv_data;
289 offset_t pos, avail_size;
292 len = ffm->packet_end - ffm->packet_ptr;
294 /* XXX: I don't understand this test, so I disabled it for testing */
298 pos = url_ftell(&s->pb);
299 if (pos == ffm->write_index) {
300 /* exactly at the end of stream */
302 } else if (pos < ffm->write_index) {
303 avail_size = ffm->write_index - pos;
305 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
307 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
308 if (size <= avail_size)
314 /* first is true if we read the frame header */
315 static int ffm_read_data(AVFormatContext *s,
316 uint8_t *buf, int size, int first)
318 FFMContext *ffm = s->priv_data;
319 ByteIOContext *pb = &s->pb;
320 int len, fill_size, size1, frame_offset;
325 len = ffm->packet_end - ffm->packet_ptr;
329 if (url_ftell(pb) == ffm->file_size)
330 url_fseek(pb, ffm->packet_size, SEEK_SET);
332 get_be16(pb); /* PACKET_ID */
333 fill_size = get_be16(pb);
334 ffm->pts = get_be64(pb);
335 frame_offset = get_be16(pb);
336 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
337 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
338 if (ffm->packet_end < ffm->packet)
340 /* if first packet or resynchronization packet, we must
341 handle it specifically */
342 if (ffm->first_packet || (frame_offset & 0x8000)) {
344 /* This packet has no frame headers in it */
345 if (url_ftell(pb) >= ffm->packet_size * 3) {
346 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
349 /* This is bad, we cannot find a valid frame header */
352 ffm->first_packet = 0;
353 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
355 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
359 ffm->packet_ptr = ffm->packet;
363 memcpy(buf, ffm->packet_ptr, len);
365 ffm->packet_ptr += len;
373 static void adjust_write_index(AVFormatContext *s)
375 FFMContext *ffm = s->priv_data;
376 ByteIOContext *pb = &s->pb;
378 //offset_t orig_write_index = ffm->write_index;
379 offset_t pos_min, pos_max;
381 offset_t ptr = url_ftell(pb);
385 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
387 pts_start = get_pts(s, pos_min);
389 pts = get_pts(s, pos_max);
391 if (pts - 100000 > pts_start)
394 ffm->write_index = FFM_PACKET_SIZE;
396 pts_start = get_pts(s, pos_min);
398 pts = get_pts(s, pos_max);
400 if (pts - 100000 <= pts_start) {
405 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
407 if (newpos == pos_min)
410 newpts = get_pts(s, newpos);
412 if (newpts - 100000 <= pts) {
419 ffm->write_index += pos_max;
422 //printf("Adjusted write index from %lld to %lld: pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
423 //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
426 url_fseek(pb, ptr, SEEK_SET);
430 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
432 FFMContext *ffm = s->priv_data;
435 ByteIOContext *pb = &s->pb;
436 AVCodecContext *codec;
442 if (tag != MKTAG('F', 'F', 'M', '1'))
444 ffm->packet_size = get_be32(pb);
445 if (ffm->packet_size != FFM_PACKET_SIZE)
447 ffm->write_index = get_be64(pb);
448 /* get also filesize */
449 if (!url_is_streamed(pb)) {
450 ffm->file_size = url_filesize(url_fileno(pb));
451 adjust_write_index(s);
453 ffm->file_size = (uint64_t_C(1) << 63) - 1;
456 nb_streams = get_be32(pb);
457 get_be32(pb); /* total bitrate */
458 /* read each stream */
459 for(i=0;i<nb_streams;i++) {
462 st = av_new_stream(s, 0);
465 fst = av_mallocz(sizeof(FFMStream));
469 av_set_pts_info(st, 64, 1, 1000000);
475 st->codec.codec_id = get_be32(pb);
476 st->codec.codec_type = get_byte(pb); /* codec_type */
477 codec->bit_rate = get_be32(pb);
478 st->quality = get_be32(pb);
479 codec->flags = get_be32(pb);
481 switch(codec->codec_type) {
482 case CODEC_TYPE_VIDEO:
483 codec->time_base.num = get_be32(pb);
484 codec->time_base.den = get_be32(pb);
485 codec->width = get_be16(pb);
486 codec->height = get_be16(pb);
487 codec->gop_size = get_be16(pb);
488 codec->qmin = get_byte(pb);
489 codec->qmax = get_byte(pb);
490 codec->max_qdiff = get_byte(pb);
491 codec->qcompress = get_be16(pb) / 10000.0;
492 codec->qblur = get_be16(pb) / 10000.0;
493 codec->bit_rate_tolerance = get_be32(pb);
494 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
495 codec->rc_max_rate = get_be32(pb);
496 codec->rc_min_rate = get_be32(pb);
497 codec->rc_buffer_size = get_be32(pb);
498 codec->i_quant_factor = get_be64_double(pb);
499 codec->b_quant_factor = get_be64_double(pb);
500 codec->i_quant_offset = get_be64_double(pb);
501 codec->b_quant_offset = get_be64_double(pb);
502 codec->dct_algo = get_be32(pb);
504 case CODEC_TYPE_AUDIO:
505 codec->sample_rate = get_be32(pb);
506 codec->channels = get_le16(pb);
507 codec->frame_size = get_le16(pb);
515 /* get until end of block reached */
516 while ((url_ftell(pb) % ffm->packet_size) != 0)
519 /* init packet demux */
520 ffm->packet_ptr = ffm->packet;
521 ffm->packet_end = ffm->packet;
522 ffm->frame_offset = 0;
524 ffm->read_state = READ_HEADER;
525 ffm->first_packet = 1;
528 for(i=0;i<s->nb_streams;i++) {
531 av_freep(&st->priv_data);
538 /* return < 0 if eof */
539 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
542 FFMContext *ffm = s->priv_data;
545 switch(ffm->read_state) {
547 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
551 printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
552 url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
554 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
560 for(i=0;i<FRAME_HEADER_SIZE;i++)
561 printf("%02x ", ffm->header[i]);
565 ffm->read_state = READ_DATA;
568 size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
569 if (!ffm_is_avail_data(s, size)) {
573 duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
575 av_new_packet(pkt, size);
576 pkt->stream_index = ffm->header[0];
577 if (ffm->header[1] & FLAG_KEY_FRAME)
578 pkt->flags |= PKT_FLAG_KEY;
580 ffm->read_state = READ_HEADER;
581 if (ffm_read_data(s, pkt->data, size, 0) != size) {
582 /* bad case: desynchronized packet. we cancel all the packet loading */
587 pkt->duration = duration;
595 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
596 by the write position inside this function */
597 static void ffm_seek1(AVFormatContext *s, offset_t pos1)
599 FFMContext *ffm = s->priv_data;
600 ByteIOContext *pb = &s->pb;
603 pos = pos1 + ffm->write_index;
604 if (pos >= ffm->file_size)
605 pos -= (ffm->file_size - FFM_PACKET_SIZE);
607 printf("seek to %Lx -> %Lx\n", pos1, pos);
609 url_fseek(pb, pos, SEEK_SET);
612 static int64_t get_pts(AVFormatContext *s, offset_t pos)
614 ByteIOContext *pb = &s->pb;
621 printf("pts=%0.6f\n", pts / 1000000.0);
626 /* seek to a given time in the file. The file read pointer is
627 positionned at or before pts. XXX: the following code is quite
629 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
631 FFMContext *ffm = s->priv_data;
632 offset_t pos_min, pos_max, pos;
633 int64_t pts_min, pts_max, pts;
637 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
639 /* find the position using linear interpolation (better than
640 dichotomy in typical cases) */
642 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
643 while (pos_min <= pos_max) {
644 pts_min = get_pts(s, pos_min);
645 pts_max = get_pts(s, pos_max);
646 /* linear interpolation */
647 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
648 (double)(pts_max - pts_min);
649 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
652 else if (pos >= pos_max)
654 pts = get_pts(s, pos);
655 /* check if we are lucky */
656 if (pts == wanted_pts) {
658 } else if (pts > wanted_pts) {
659 pos_max = pos - FFM_PACKET_SIZE;
661 pos_min = pos + FFM_PACKET_SIZE;
664 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
666 pos -= FFM_PACKET_SIZE;
672 offset_t ffm_read_write_index(int fd)
678 lseek(fd, 8, SEEK_SET);
682 pos |= (int64_t)buf[i] << (56 - i * 8);
686 void ffm_write_write_index(int fd, offset_t pos)
692 buf[i] = (pos >> (56 - i * 8)) & 0xff;
693 lseek(fd, 8, SEEK_SET);
697 void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
699 FFMContext *ffm = s->priv_data;
700 ffm->write_index = pos;
701 ffm->file_size = file_size;
704 static int ffm_read_close(AVFormatContext *s)
709 for(i=0;i<s->nb_streams;i++) {
711 av_freep(&st->priv_data);
716 static int ffm_probe(AVProbeData *p)
718 if (p->buf_size >= 4 &&
719 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
721 return AVPROBE_SCORE_MAX + 1;
725 static AVInputFormat ffm_iformat = {
736 #ifdef CONFIG_ENCODERS
737 static AVOutputFormat ffm_oformat = {
743 /* not really used */
750 #endif //CONFIG_ENCODERS
754 av_register_input_format(&ffm_iformat);
755 #ifdef CONFIG_ENCODERS
756 av_register_output_format(&ffm_oformat);
757 #endif //CONFIG_ENCODERS