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);
83 /* prepare next packet */
84 ffm->frame_offset = 0; /* no key frame */
85 ffm->pts = 0; /* no pts */
86 ffm->packet_ptr = ffm->packet;
87 ffm->first_packet = 0;
90 /* 'first' is true if first data of a frame */
91 static void ffm_write_data(AVFormatContext *s,
92 const uint8_t *buf, int size,
93 int64_t pts, int first)
95 FFMContext *ffm = s->priv_data;
98 if (first && ffm->frame_offset == 0)
99 ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
100 if (first && ffm->pts == 0)
103 /* write as many packets as needed */
105 len = ffm->packet_end - ffm->packet_ptr;
108 memcpy(ffm->packet_ptr, buf, len);
110 ffm->packet_ptr += len;
113 if (ffm->packet_ptr >= ffm->packet_end) {
114 /* special case : no pts in packet : we leave the current one */
123 static int ffm_write_header(AVFormatContext *s)
125 FFMContext *ffm = s->priv_data;
128 ByteIOContext *pb = &s->pb;
129 AVCodecContext *codec;
132 ffm->packet_size = FFM_PACKET_SIZE;
136 put_be32(pb, ffm->packet_size);
137 /* XXX: store write position in other file ? */
138 put_be64(pb, ffm->packet_size); /* current write position */
140 put_be32(pb, s->nb_streams);
142 for(i=0;i<s->nb_streams;i++) {
144 bit_rate += st->codec.bit_rate;
146 put_be32(pb, bit_rate);
148 /* list of streams */
149 for(i=0;i<s->nb_streams;i++) {
151 fst = av_mallocz(sizeof(FFMStream));
154 av_set_pts_info(st, 64, 1, 1000000);
159 put_be32(pb, codec->codec_id);
160 put_byte(pb, codec->codec_type);
161 put_be32(pb, codec->bit_rate);
162 put_be32(pb, st->quality);
163 put_be32(pb, codec->flags);
164 put_be32(pb, codec->flags2);
165 put_be32(pb, codec->debug);
167 switch(codec->codec_type) {
168 case CODEC_TYPE_VIDEO:
169 put_be32(pb, codec->time_base.num);
170 put_be32(pb, codec->time_base.den);
171 put_be16(pb, codec->width);
172 put_be16(pb, codec->height);
173 put_be16(pb, codec->gop_size);
174 put_be32(pb, codec->pix_fmt);
175 put_byte(pb, codec->qmin);
176 put_byte(pb, codec->qmax);
177 put_byte(pb, codec->max_qdiff);
178 put_be16(pb, (int) (codec->qcompress * 10000.0));
179 put_be16(pb, (int) (codec->qblur * 10000.0));
180 put_be32(pb, codec->bit_rate_tolerance);
181 put_strz(pb, codec->rc_eq);
182 put_be32(pb, codec->rc_max_rate);
183 put_be32(pb, codec->rc_min_rate);
184 put_be32(pb, codec->rc_buffer_size);
185 put_be64_double(pb, codec->i_quant_factor);
186 put_be64_double(pb, codec->b_quant_factor);
187 put_be64_double(pb, codec->i_quant_offset);
188 put_be64_double(pb, codec->b_quant_offset);
189 put_be32(pb, codec->dct_algo);
190 put_be32(pb, codec->strict_std_compliance);
191 put_be32(pb, codec->max_b_frames);
192 put_be32(pb, codec->luma_elim_threshold);
193 put_be32(pb, codec->chroma_elim_threshold);
194 put_be32(pb, codec->mpeg_quant);
195 put_be32(pb, codec->intra_dc_precision);
196 put_be32(pb, codec->me_method);
197 put_be32(pb, codec->mb_decision);
198 put_be32(pb, codec->nsse_weight);
199 put_be32(pb, codec->frame_skip_cmp);
200 put_be64_double(pb, codec->rc_buffer_aggressivity);
202 case CODEC_TYPE_AUDIO:
203 put_be32(pb, codec->sample_rate);
204 put_le16(pb, codec->channels);
205 put_le16(pb, codec->frame_size);
210 /* hack to have real time */
214 fst->pts = av_gettime();
217 /* flush until end of block reached */
218 while ((url_ftell(pb) % ffm->packet_size) != 0)
221 put_flush_packet(pb);
223 /* init packet mux */
224 ffm->packet_ptr = ffm->packet;
225 ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
226 assert(ffm->packet_end >= ffm->packet);
227 ffm->frame_offset = 0;
229 ffm->first_packet = 1;
233 for(i=0;i<s->nb_streams;i++) {
235 av_freep(&st->priv_data);
240 static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
242 AVStream *st = s->streams[pkt->stream_index];
243 FFMStream *fst = st->priv_data;
245 uint8_t header[FRAME_HEADER_SIZE];
249 //XXX/FIXME use duration from pkt
250 if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
251 duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
253 duration = (1000000.0 * st->codec.time_base.num / (float)st->codec.time_base.den);
257 /* packet size & key_frame */
258 header[0] = pkt->stream_index;
260 if (pkt->flags & PKT_FLAG_KEY)
261 header[1] |= FLAG_KEY_FRAME;
262 header[2] = (size >> 16) & 0xff;
263 header[3] = (size >> 8) & 0xff;
264 header[4] = size & 0xff;
265 header[5] = (duration >> 16) & 0xff;
266 header[6] = (duration >> 8) & 0xff;
267 header[7] = duration & 0xff;
268 ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
269 ffm_write_data(s, pkt->data, size, pts, 0);
271 fst->pts += duration;
275 static int ffm_write_trailer(AVFormatContext *s)
277 ByteIOContext *pb = &s->pb;
278 FFMContext *ffm = s->priv_data;
281 if (ffm->packet_ptr > ffm->packet)
284 put_flush_packet(pb);
286 if (!url_is_streamed(pb)) {
288 /* update the write offset */
289 size = url_ftell(pb);
290 url_fseek(pb, 8, SEEK_SET);
292 put_flush_packet(pb);
297 #endif //CONFIG_ENCODERS
301 static int ffm_is_avail_data(AVFormatContext *s, int size)
303 FFMContext *ffm = s->priv_data;
304 offset_t pos, avail_size;
307 len = ffm->packet_end - ffm->packet_ptr;
309 /* XXX: I don't understand this test, so I disabled it for testing */
313 pos = url_ftell(&s->pb);
314 if (pos == ffm->write_index) {
315 /* exactly at the end of stream */
317 } else if (pos < ffm->write_index) {
318 avail_size = ffm->write_index - pos;
320 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
322 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
323 if (size <= avail_size)
329 /* first is true if we read the frame header */
330 static int ffm_read_data(AVFormatContext *s,
331 uint8_t *buf, int size, int first)
333 FFMContext *ffm = s->priv_data;
334 ByteIOContext *pb = &s->pb;
335 int len, fill_size, size1, frame_offset;
340 len = ffm->packet_end - ffm->packet_ptr;
344 if (url_ftell(pb) == ffm->file_size)
345 url_fseek(pb, ffm->packet_size, SEEK_SET);
347 get_be16(pb); /* PACKET_ID */
348 fill_size = get_be16(pb);
349 ffm->pts = get_be64(pb);
350 frame_offset = get_be16(pb);
351 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
352 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
353 if (ffm->packet_end < ffm->packet)
355 /* if first packet or resynchronization packet, we must
356 handle it specifically */
357 if (ffm->first_packet || (frame_offset & 0x8000)) {
359 /* This packet has no frame headers in it */
360 if (url_ftell(pb) >= ffm->packet_size * 3) {
361 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
364 /* This is bad, we cannot find a valid frame header */
367 ffm->first_packet = 0;
368 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
370 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
374 ffm->packet_ptr = ffm->packet;
378 memcpy(buf, ffm->packet_ptr, len);
380 ffm->packet_ptr += len;
388 static void adjust_write_index(AVFormatContext *s)
390 FFMContext *ffm = s->priv_data;
391 ByteIOContext *pb = &s->pb;
393 //offset_t orig_write_index = ffm->write_index;
394 offset_t pos_min, pos_max;
396 offset_t ptr = url_ftell(pb);
400 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
402 pts_start = get_pts(s, pos_min);
404 pts = get_pts(s, pos_max);
406 if (pts - 100000 > pts_start)
409 ffm->write_index = FFM_PACKET_SIZE;
411 pts_start = get_pts(s, pos_min);
413 pts = get_pts(s, pos_max);
415 if (pts - 100000 <= pts_start) {
420 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
422 if (newpos == pos_min)
425 newpts = get_pts(s, newpos);
427 if (newpts - 100000 <= pts) {
434 ffm->write_index += pos_max;
437 //printf("Adjusted write index from %lld to %lld: pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
438 //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
441 url_fseek(pb, ptr, SEEK_SET);
445 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
447 FFMContext *ffm = s->priv_data;
450 ByteIOContext *pb = &s->pb;
451 AVCodecContext *codec;
457 if (tag != MKTAG('F', 'F', 'M', '1'))
459 ffm->packet_size = get_be32(pb);
460 if (ffm->packet_size != FFM_PACKET_SIZE)
462 ffm->write_index = get_be64(pb);
463 /* get also filesize */
464 if (!url_is_streamed(pb)) {
465 ffm->file_size = url_filesize(url_fileno(pb));
466 adjust_write_index(s);
468 ffm->file_size = (uint64_t_C(1) << 63) - 1;
471 nb_streams = get_be32(pb);
472 get_be32(pb); /* total bitrate */
473 /* read each stream */
474 for(i=0;i<nb_streams;i++) {
477 st = av_new_stream(s, 0);
480 fst = av_mallocz(sizeof(FFMStream));
484 av_set_pts_info(st, 64, 1, 1000000);
490 st->codec.codec_id = get_be32(pb);
491 st->codec.codec_type = get_byte(pb); /* codec_type */
492 codec->bit_rate = get_be32(pb);
493 st->quality = get_be32(pb);
494 codec->flags = get_be32(pb);
495 codec->flags2 = get_be32(pb);
496 codec->debug = get_be32(pb);
498 switch(codec->codec_type) {
499 case CODEC_TYPE_VIDEO:
500 codec->time_base.num = get_be32(pb);
501 codec->time_base.den = get_be32(pb);
502 codec->width = get_be16(pb);
503 codec->height = get_be16(pb);
504 codec->gop_size = get_be16(pb);
505 codec->pix_fmt = get_be32(pb);
506 codec->qmin = get_byte(pb);
507 codec->qmax = get_byte(pb);
508 codec->max_qdiff = get_byte(pb);
509 codec->qcompress = get_be16(pb) / 10000.0;
510 codec->qblur = get_be16(pb) / 10000.0;
511 codec->bit_rate_tolerance = get_be32(pb);
512 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
513 codec->rc_max_rate = get_be32(pb);
514 codec->rc_min_rate = get_be32(pb);
515 codec->rc_buffer_size = get_be32(pb);
516 codec->i_quant_factor = get_be64_double(pb);
517 codec->b_quant_factor = get_be64_double(pb);
518 codec->i_quant_offset = get_be64_double(pb);
519 codec->b_quant_offset = get_be64_double(pb);
520 codec->dct_algo = get_be32(pb);
521 codec->strict_std_compliance = get_be32(pb);
522 codec->max_b_frames = get_be32(pb);
523 codec->luma_elim_threshold = get_be32(pb);
524 codec->chroma_elim_threshold = get_be32(pb);
525 codec->mpeg_quant = get_be32(pb);
526 codec->intra_dc_precision = get_be32(pb);
527 codec->me_method = get_be32(pb);
528 codec->mb_decision = get_be32(pb);
529 codec->nsse_weight = get_be32(pb);
530 codec->frame_skip_cmp = get_be32(pb);
531 codec->rc_buffer_aggressivity = get_be64_double(pb);
533 case CODEC_TYPE_AUDIO:
534 codec->sample_rate = get_be32(pb);
535 codec->channels = get_le16(pb);
536 codec->frame_size = get_le16(pb);
544 /* get until end of block reached */
545 while ((url_ftell(pb) % ffm->packet_size) != 0)
548 /* init packet demux */
549 ffm->packet_ptr = ffm->packet;
550 ffm->packet_end = ffm->packet;
551 ffm->frame_offset = 0;
553 ffm->read_state = READ_HEADER;
554 ffm->first_packet = 1;
557 for(i=0;i<s->nb_streams;i++) {
560 av_freep(&st->priv_data);
567 /* return < 0 if eof */
568 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
571 FFMContext *ffm = s->priv_data;
574 switch(ffm->read_state) {
576 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
580 printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
581 url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
583 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
589 for(i=0;i<FRAME_HEADER_SIZE;i++)
590 printf("%02x ", ffm->header[i]);
594 ffm->read_state = READ_DATA;
597 size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
598 if (!ffm_is_avail_data(s, size)) {
602 duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
604 av_new_packet(pkt, size);
605 pkt->stream_index = ffm->header[0];
606 if (ffm->header[1] & FLAG_KEY_FRAME)
607 pkt->flags |= PKT_FLAG_KEY;
609 ffm->read_state = READ_HEADER;
610 if (ffm_read_data(s, pkt->data, size, 0) != size) {
611 /* bad case: desynchronized packet. we cancel all the packet loading */
616 pkt->duration = duration;
624 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
625 by the write position inside this function */
626 static void ffm_seek1(AVFormatContext *s, offset_t pos1)
628 FFMContext *ffm = s->priv_data;
629 ByteIOContext *pb = &s->pb;
632 pos = pos1 + ffm->write_index;
633 if (pos >= ffm->file_size)
634 pos -= (ffm->file_size - FFM_PACKET_SIZE);
636 printf("seek to %Lx -> %Lx\n", pos1, pos);
638 url_fseek(pb, pos, SEEK_SET);
641 static int64_t get_pts(AVFormatContext *s, offset_t pos)
643 ByteIOContext *pb = &s->pb;
650 printf("pts=%0.6f\n", pts / 1000000.0);
655 /* seek to a given time in the file. The file read pointer is
656 positionned at or before pts. XXX: the following code is quite
658 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
660 FFMContext *ffm = s->priv_data;
661 offset_t pos_min, pos_max, pos;
662 int64_t pts_min, pts_max, pts;
666 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
668 /* find the position using linear interpolation (better than
669 dichotomy in typical cases) */
671 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
672 while (pos_min <= pos_max) {
673 pts_min = get_pts(s, pos_min);
674 pts_max = get_pts(s, pos_max);
675 /* linear interpolation */
676 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
677 (double)(pts_max - pts_min);
678 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
681 else if (pos >= pos_max)
683 pts = get_pts(s, pos);
684 /* check if we are lucky */
685 if (pts == wanted_pts) {
687 } else if (pts > wanted_pts) {
688 pos_max = pos - FFM_PACKET_SIZE;
690 pos_min = pos + FFM_PACKET_SIZE;
693 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
695 pos -= FFM_PACKET_SIZE;
701 offset_t ffm_read_write_index(int fd)
707 lseek(fd, 8, SEEK_SET);
711 pos |= (int64_t)buf[i] << (56 - i * 8);
715 void ffm_write_write_index(int fd, offset_t pos)
721 buf[i] = (pos >> (56 - i * 8)) & 0xff;
722 lseek(fd, 8, SEEK_SET);
726 void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
728 FFMContext *ffm = s->priv_data;
729 ffm->write_index = pos;
730 ffm->file_size = file_size;
733 static int ffm_read_close(AVFormatContext *s)
738 for(i=0;i<s->nb_streams;i++) {
740 av_freep(&st->priv_data);
745 static int ffm_probe(AVProbeData *p)
747 if (p->buf_size >= 4 &&
748 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
750 return AVPROBE_SCORE_MAX + 1;
754 static AVInputFormat ffm_iformat = {
765 #ifdef CONFIG_ENCODERS
766 static AVOutputFormat ffm_oformat = {
772 /* not really used */
779 #endif //CONFIG_ENCODERS
783 av_register_input_format(&ffm_iformat);
784 #ifdef CONFIG_ENCODERS
785 av_register_output_format(&ffm_oformat);
786 #endif //CONFIG_ENCODERS