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 header[FRAME_HEADER_SIZE];
46 int first_packet; /* true if first packet, needed to set the discontinuity tag */
50 UINT8 *packet_ptr, *packet_end;
51 UINT8 packet[FFM_PACKET_SIZE];
54 /* disable pts hack for testing */
57 static void flush_packet(AVFormatContext *s)
59 FFMContext *ffm = s->priv_data;
61 ByteIOContext *pb = &s->pb;
63 fill_size = ffm->packet_end - ffm->packet_ptr;
64 memset(ffm->packet_ptr, 0, fill_size);
67 put_be16(pb, PACKET_ID);
68 put_be16(pb, fill_size);
69 put_be64(pb, ffm->pts);
70 h = ffm->frame_offset;
71 if (ffm->first_packet)
74 put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
76 /* prepare next packet */
77 ffm->frame_offset = 0; /* no key frame */
78 ffm->pts = 0; /* no pts */
79 ffm->packet_ptr = ffm->packet;
80 ffm->first_packet = 0;
83 /* 'first' is true if first data of a frame */
84 static void ffm_write_data(AVFormatContext *s,
88 FFMContext *ffm = s->priv_data;
91 if (first && ffm->frame_offset == 0)
92 ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
93 if (first && ffm->pts == 0)
96 /* write as many packets as needed */
98 len = ffm->packet_end - ffm->packet_ptr;
101 memcpy(ffm->packet_ptr, buf, len);
103 ffm->packet_ptr += len;
106 if (ffm->packet_ptr >= ffm->packet_end) {
107 /* special case : no pts in packet : we leave the current one */
116 static int ffm_write_header(AVFormatContext *s)
118 FFMContext *ffm = s->priv_data;
121 ByteIOContext *pb = &s->pb;
122 AVCodecContext *codec;
125 ffm->packet_size = FFM_PACKET_SIZE;
129 put_be32(pb, ffm->packet_size);
130 /* XXX: store write position in other file ? */
131 put_be64(pb, ffm->packet_size); /* current write position */
133 put_be32(pb, s->nb_streams);
135 for(i=0;i<s->nb_streams;i++) {
137 bit_rate += st->codec.bit_rate;
139 put_be32(pb, bit_rate);
141 /* list of streams */
142 for(i=0;i<s->nb_streams;i++) {
144 fst = av_mallocz(sizeof(FFMStream) + ffm->packet_size);
151 put_be32(pb, codec->codec_id);
152 put_byte(pb, codec->codec_type);
153 put_be32(pb, codec->bit_rate);
154 put_be32(pb, codec->flags);
156 switch(codec->codec_type) {
157 case CODEC_TYPE_VIDEO:
158 put_be32(pb, (codec->frame_rate * 1000) / FRAME_RATE_BASE);
159 put_be16(pb, codec->width);
160 put_be16(pb, codec->height);
161 put_be16(pb, codec->gop_size);
162 put_byte(pb, codec->qmin);
163 put_byte(pb, codec->qmax);
164 put_byte(pb, codec->max_qdiff);
165 put_be16(pb, (int) (codec->qcompress * 10000.0));
166 put_be16(pb, (int) (codec->qblur * 10000.0));
167 put_be32(pb, codec->bit_rate_tolerance);
169 case CODEC_TYPE_AUDIO:
170 put_be32(pb, codec->sample_rate);
171 put_le16(pb, codec->channels);
172 put_le16(pb, codec->frame_size);
177 /* hack to have real time */
181 fst->pts = gettime();
184 /* flush until end of block reached */
185 while ((url_ftell(pb) % ffm->packet_size) != 0)
188 put_flush_packet(pb);
190 /* init packet mux */
191 ffm->packet_ptr = ffm->packet;
192 ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
193 ffm->frame_offset = 0;
195 ffm->first_packet = 1;
199 for(i=0;i<s->nb_streams;i++) {
201 av_freep(&st->priv_data);
206 static int ffm_write_packet(AVFormatContext *s, int stream_index,
207 UINT8 *buf, int size, int force_pts)
209 AVStream *st = s->streams[stream_index];
210 FFMStream *fst = st->priv_data;
212 UINT8 header[FRAME_HEADER_SIZE];
215 if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
216 duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
218 duration = (1000000.0 * FRAME_RATE_BASE / (float)st->codec.frame_rate);
222 /* packet size & key_frame */
223 header[0] = stream_index;
225 if (st->codec.key_frame)
226 header[1] |= FLAG_KEY_FRAME;
227 header[2] = (size >> 16) & 0xff;
228 header[3] = (size >> 8) & 0xff;
229 header[4] = size & 0xff;
230 header[5] = (duration >> 16) & 0xff;
231 header[6] = (duration >> 8) & 0xff;
232 header[7] = duration & 0xff;
233 ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
234 ffm_write_data(s, buf, size, pts, 0);
236 fst->pts += duration;
240 static int ffm_write_trailer(AVFormatContext *s)
242 ByteIOContext *pb = &s->pb;
243 FFMContext *ffm = s->priv_data;
247 if (ffm->packet_ptr > ffm->packet)
250 put_flush_packet(pb);
252 if (!url_is_streamed(pb)) {
254 /* update the write offset */
255 size = url_ftell(pb);
256 url_fseek(pb, 8, SEEK_SET);
258 put_flush_packet(pb);
261 for(i=0;i<s->nb_streams;i++)
262 av_freep(&s->streams[i]->priv_data);
268 static int ffm_is_avail_data(AVFormatContext *s, int size)
270 FFMContext *ffm = s->priv_data;
271 offset_t pos, avail_size;
274 len = ffm->packet_end - ffm->packet_ptr;
276 /* XXX: I don't understand this test, so I disabled it for testing */
280 pos = url_ftell(&s->pb);
281 if (pos == ffm->write_index) {
282 /* exactly at the end of stream */
284 } else if (pos < ffm->write_index) {
285 avail_size = ffm->write_index - pos;
287 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
289 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
290 if (size <= avail_size)
296 /* first is true if we read the frame header */
297 static int ffm_read_data(AVFormatContext *s,
298 UINT8 *buf, int size, int first)
300 FFMContext *ffm = s->priv_data;
301 ByteIOContext *pb = &s->pb;
302 int len, fill_size, size1, frame_offset;
307 len = ffm->packet_end - ffm->packet_ptr;
311 if (url_ftell(pb) == ffm->file_size)
312 url_fseek(pb, ffm->packet_size, SEEK_SET);
314 get_be16(pb); /* PACKET_ID */
315 fill_size = get_be16(pb);
316 ffm->pts = get_be64(pb);
317 frame_offset = get_be16(pb);
318 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
319 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
320 /* if first packet or resynchronization packet, we must
321 handle it specifically */
322 if (ffm->first_packet || (frame_offset & 0x8000)) {
324 /* This packet has no frame headers in it */
325 if (url_ftell(pb) >= ffm->packet_size * 3) {
326 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
329 /* This is bad, we cannot find a valid frame header */
332 ffm->first_packet = 0;
333 if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
335 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
339 ffm->packet_ptr = ffm->packet;
343 memcpy(buf, ffm->packet_ptr, len);
345 ffm->packet_ptr += len;
353 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
355 FFMContext *ffm = s->priv_data;
358 ByteIOContext *pb = &s->pb;
359 AVCodecContext *codec;
365 if (tag != MKTAG('F', 'F', 'M', '1'))
367 ffm->packet_size = get_be32(pb);
368 if (ffm->packet_size != FFM_PACKET_SIZE)
370 ffm->write_index = get_be64(pb);
371 /* get also filesize */
372 if (!url_is_streamed(pb)) {
373 ffm->file_size = url_filesize(url_fileno(pb));
375 ffm->file_size = (UINT64_C(1) << 63) - 1;
378 s->nb_streams = get_be32(pb);
379 get_be32(pb); /* total bitrate */
380 /* read each stream */
381 for(i=0;i<s->nb_streams;i++) {
382 st = av_mallocz(sizeof(AVStream));
386 fst = av_mallocz(sizeof(FFMStream) + ffm->packet_size);
393 st->codec.codec_id = get_be32(pb);
394 st->codec.codec_type = get_byte(pb); /* codec_type */
395 codec->bit_rate = get_be32(pb);
396 codec->flags = get_be32(pb);
398 switch(codec->codec_type) {
399 case CODEC_TYPE_VIDEO:
400 codec->frame_rate = ((INT64)get_be32(pb) * FRAME_RATE_BASE) / 1000;
401 codec->width = get_be16(pb);
402 codec->height = get_be16(pb);
403 codec->gop_size = get_be16(pb);
404 codec->qmin = get_byte(pb);
405 codec->qmax = get_byte(pb);
406 codec->max_qdiff = get_byte(pb);
407 codec->qcompress = get_be16(pb) / 10000.0;
408 codec->qblur = get_be16(pb) / 10000.0;
409 codec->bit_rate_tolerance = get_be32(pb);
411 case CODEC_TYPE_AUDIO:
412 codec->sample_rate = get_be32(pb);
413 codec->channels = get_le16(pb);
414 codec->frame_size = get_le16(pb);
422 /* get until end of block reached */
423 while ((url_ftell(pb) % ffm->packet_size) != 0)
426 /* init packet demux */
427 ffm->packet_ptr = ffm->packet;
428 ffm->packet_end = ffm->packet;
429 ffm->frame_offset = 0;
431 ffm->read_state = READ_HEADER;
432 ffm->first_packet = 1;
435 for(i=0;i<s->nb_streams;i++) {
438 av_freep(&st->priv_data);
445 /* return < 0 if eof */
446 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
449 FFMContext *ffm = s->priv_data;
452 switch(ffm->read_state) {
454 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
458 printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
459 url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
461 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
467 for(i=0;i<FRAME_HEADER_SIZE;i++)
468 printf("%02x ", ffm->header[i]);
472 ffm->read_state = READ_DATA;
475 size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
476 if (!ffm_is_avail_data(s, size)) {
480 duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
482 av_new_packet(pkt, size);
483 pkt->stream_index = ffm->header[0];
484 if (ffm->header[1] & FLAG_KEY_FRAME)
485 pkt->flags |= PKT_FLAG_KEY;
487 ffm->read_state = READ_HEADER;
488 if (ffm_read_data(s, pkt->data, size, 0) != size) {
489 /* bad case: desynchronized packet. we cancel all the packet loading */
494 pkt->duration = duration;
502 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
503 by the write position inside this function */
504 static void ffm_seek1(AVFormatContext *s, offset_t pos1)
506 FFMContext *ffm = s->priv_data;
507 ByteIOContext *pb = &s->pb;
510 pos = pos1 + ffm->write_index;
511 if (pos >= ffm->file_size)
512 pos -= (ffm->file_size - FFM_PACKET_SIZE);
514 printf("seek to %Lx -> %Lx\n", pos1, pos);
516 url_fseek(pb, pos, SEEK_SET);
519 static INT64 get_pts(AVFormatContext *s, offset_t pos)
521 ByteIOContext *pb = &s->pb;
528 printf("pts=%0.6f\n", pts / 1000000.0);
533 /* seek to a given time in the file. The file read pointer is
534 positionned at or before pts. XXX: the following code is quite
536 static int ffm_seek(AVFormatContext *s, INT64 wanted_pts)
538 FFMContext *ffm = s->priv_data;
539 offset_t pos_min, pos_max, pos;
540 INT64 pts_min, pts_max, pts;
544 printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
546 /* find the position using linear interpolation (better than
547 dichotomy in typical cases) */
549 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
550 while (pos_min <= pos_max) {
551 pts_min = get_pts(s, pos_min);
552 pts_max = get_pts(s, pos_max);
553 /* linear interpolation */
554 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
555 (double)(pts_max - pts_min);
556 pos = (((INT64)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
559 else if (pos >= pos_max)
561 pts = get_pts(s, pos);
562 /* check if we are lucky */
563 if (pts == wanted_pts) {
565 } else if (pts > wanted_pts) {
566 pos_max = pos - FFM_PACKET_SIZE;
568 pos_min = pos + FFM_PACKET_SIZE;
573 pos -= FFM_PACKET_SIZE;
579 offset_t ffm_read_write_index(int fd)
585 lseek(fd, 8, SEEK_SET);
589 pos |= buf[i] << (56 - i * 8);
593 void ffm_write_write_index(int fd, offset_t pos)
599 buf[i] = (pos >> (56 - i * 8)) & 0xff;
600 lseek(fd, 8, SEEK_SET);
604 void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
606 FFMContext *ffm = s->priv_data;
607 ffm->write_index = pos;
608 ffm->file_size = file_size;
611 static int ffm_read_close(AVFormatContext *s)
616 for(i=0;i<s->nb_streams;i++) {
618 av_freep(&st->priv_data);
623 static int ffm_probe(AVProbeData *p)
625 if (p->buf_size >= 4 &&
626 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
628 return AVPROBE_SCORE_MAX + 1;
632 AVInputFormat ffm_iformat = {
643 AVOutputFormat ffm_oformat = {
649 /* not really used */
659 av_register_input_format(&ffm_iformat);
660 av_register_output_format(&ffm_oformat);