resync ffm if error in stream
[libav.git] / libavformat / ffmdec.c
1 /*
2 * FFM (ffserver live feed) demuxer
3 * Copyright (c) 2001 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 #include "libavutil/intreadwrite.h"
23 #include "avformat.h"
24 #include "ffm.h"
25 #if CONFIG_FFSERVER
26 #include <unistd.h>
27
28 int64_t ffm_read_write_index(int fd)
29 {
30 uint8_t buf[8];
31
32 lseek(fd, 8, SEEK_SET);
33 if (read(fd, buf, 8) != 8)
34 return AVERROR(EIO);
35 return AV_RB64(buf);
36 }
37
38 int ffm_write_write_index(int fd, int64_t pos)
39 {
40 uint8_t buf[8];
41 int i;
42
43 for(i=0;i<8;i++)
44 buf[i] = (pos >> (56 - i * 8)) & 0xff;
45 lseek(fd, 8, SEEK_SET);
46 if (write(fd, buf, 8) != 8)
47 return AVERROR(EIO);
48 return 8;
49 }
50
51 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
52 {
53 FFMContext *ffm = s->priv_data;
54 ffm->write_index = pos;
55 ffm->file_size = file_size;
56 }
57 #endif // CONFIG_FFSERVER
58
59 static int ffm_is_avail_data(AVFormatContext *s, int size)
60 {
61 FFMContext *ffm = s->priv_data;
62 int64_t pos, avail_size;
63 int len;
64
65 len = ffm->packet_end - ffm->packet_ptr;
66 if (size <= len)
67 return 1;
68 pos = url_ftell(s->pb);
69 if (!ffm->write_index) {
70 if (pos == ffm->file_size)
71 return AVERROR_EOF;
72 avail_size = ffm->file_size - pos;
73 } else {
74 if (pos == ffm->write_index) {
75 /* exactly at the end of stream */
76 return AVERROR(EAGAIN);
77 } else if (pos < ffm->write_index) {
78 avail_size = ffm->write_index - pos;
79 } else {
80 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
81 }
82 }
83 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
84 if (size <= avail_size)
85 return 1;
86 else
87 return AVERROR(EAGAIN);
88 }
89
90 static int ffm_resync(AVFormatContext *s, int state)
91 {
92 av_log(s, AV_LOG_ERROR, "resyncing\n");
93 while (state != PACKET_ID) {
94 if (url_feof(s->pb)) {
95 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
96 return -1;
97 }
98 state = (state << 8) | get_byte(s->pb);
99 }
100 return 0;
101 }
102
103 /* first is true if we read the frame header */
104 static int ffm_read_data(AVFormatContext *s,
105 uint8_t *buf, int size, int header)
106 {
107 FFMContext *ffm = s->priv_data;
108 ByteIOContext *pb = s->pb;
109 int len, fill_size, size1, frame_offset, id;
110
111 size1 = size;
112 while (size > 0) {
113 redo:
114 len = ffm->packet_end - ffm->packet_ptr;
115 if (len < 0)
116 return -1;
117 if (len > size)
118 len = size;
119 if (len == 0) {
120 if (url_ftell(pb) == ffm->file_size)
121 url_fseek(pb, ffm->packet_size, SEEK_SET);
122 retry_read:
123 id = get_be16(pb); /* PACKET_ID */
124 if (id != PACKET_ID)
125 if (ffm_resync(s, id) < 0)
126 return -1;
127 fill_size = get_be16(pb);
128 ffm->dts = get_be64(pb);
129 frame_offset = get_be16(pb);
130 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
131 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
132 if (ffm->packet_end < ffm->packet || frame_offset < 0)
133 return -1;
134 /* if first packet or resynchronization packet, we must
135 handle it specifically */
136 if (ffm->first_packet || (frame_offset & 0x8000)) {
137 if (!frame_offset) {
138 /* This packet has no frame headers in it */
139 if (url_ftell(pb) >= ffm->packet_size * 3) {
140 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
141 goto retry_read;
142 }
143 /* This is bad, we cannot find a valid frame header */
144 return 0;
145 }
146 ffm->first_packet = 0;
147 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
148 return -1;
149 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
150 if (!header)
151 break;
152 } else {
153 ffm->packet_ptr = ffm->packet;
154 }
155 goto redo;
156 }
157 memcpy(buf, ffm->packet_ptr, len);
158 buf += len;
159 ffm->packet_ptr += len;
160 size -= len;
161 header = 0;
162 }
163 return size1 - size;
164 }
165
166 //#define DEBUG_SEEK
167
168 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
169 by the write position inside this function */
170 static void ffm_seek1(AVFormatContext *s, int64_t pos1)
171 {
172 FFMContext *ffm = s->priv_data;
173 ByteIOContext *pb = s->pb;
174 int64_t pos;
175
176 pos = pos1 + ffm->write_index;
177 if (pos >= ffm->file_size)
178 pos -= (ffm->file_size - FFM_PACKET_SIZE);
179 #ifdef DEBUG_SEEK
180 av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
181 #endif
182 url_fseek(pb, pos, SEEK_SET);
183 }
184
185 static int64_t get_dts(AVFormatContext *s, int64_t pos)
186 {
187 ByteIOContext *pb = s->pb;
188 int64_t dts;
189
190 ffm_seek1(s, pos);
191 url_fskip(pb, 4);
192 dts = get_be64(pb);
193 #ifdef DEBUG_SEEK
194 av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
195 #endif
196 return dts;
197 }
198
199 static void adjust_write_index(AVFormatContext *s)
200 {
201 FFMContext *ffm = s->priv_data;
202 ByteIOContext *pb = s->pb;
203 int64_t pts;
204 //int64_t orig_write_index = ffm->write_index;
205 int64_t pos_min, pos_max;
206 int64_t pts_start;
207 int64_t ptr = url_ftell(pb);
208
209
210 pos_min = 0;
211 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
212
213 pts_start = get_dts(s, pos_min);
214
215 pts = get_dts(s, pos_max);
216
217 if (pts - 100000 > pts_start)
218 goto end;
219
220 ffm->write_index = FFM_PACKET_SIZE;
221
222 pts_start = get_dts(s, pos_min);
223
224 pts = get_dts(s, pos_max);
225
226 if (pts - 100000 <= pts_start) {
227 while (1) {
228 int64_t newpos;
229 int64_t newpts;
230
231 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
232
233 if (newpos == pos_min)
234 break;
235
236 newpts = get_dts(s, newpos);
237
238 if (newpts - 100000 <= pts) {
239 pos_max = newpos;
240 pts = newpts;
241 } else {
242 pos_min = newpos;
243 }
244 }
245 ffm->write_index += pos_max;
246 }
247
248 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
249 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
250
251 end:
252 url_fseek(pb, ptr, SEEK_SET);
253 }
254
255
256 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
257 {
258 FFMContext *ffm = s->priv_data;
259 AVStream *st;
260 ByteIOContext *pb = s->pb;
261 AVCodecContext *codec;
262 int i, nb_streams;
263 uint32_t tag;
264
265 /* header */
266 tag = get_le32(pb);
267 if (tag != MKTAG('F', 'F', 'M', '1'))
268 goto fail;
269 ffm->packet_size = get_be32(pb);
270 if (ffm->packet_size != FFM_PACKET_SIZE)
271 goto fail;
272 ffm->write_index = get_be64(pb);
273 /* get also filesize */
274 if (!url_is_streamed(pb)) {
275 ffm->file_size = url_fsize(pb);
276 if (ffm->write_index)
277 adjust_write_index(s);
278 } else {
279 ffm->file_size = (UINT64_C(1) << 63) - 1;
280 }
281
282 nb_streams = get_be32(pb);
283 get_be32(pb); /* total bitrate */
284 /* read each stream */
285 for(i=0;i<nb_streams;i++) {
286 char rc_eq_buf[128];
287
288 st = av_new_stream(s, 0);
289 if (!st)
290 goto fail;
291 s->streams[i] = st;
292
293 av_set_pts_info(st, 64, 1, 1000000);
294
295 codec = st->codec;
296 /* generic info */
297 codec->codec_id = get_be32(pb);
298 codec->codec_type = get_byte(pb); /* codec_type */
299 codec->bit_rate = get_be32(pb);
300 st->quality = get_be32(pb);
301 codec->flags = get_be32(pb);
302 codec->flags2 = get_be32(pb);
303 codec->debug = get_be32(pb);
304 /* specific info */
305 switch(codec->codec_type) {
306 case CODEC_TYPE_VIDEO:
307 codec->time_base.num = get_be32(pb);
308 codec->time_base.den = get_be32(pb);
309 codec->width = get_be16(pb);
310 codec->height = get_be16(pb);
311 codec->gop_size = get_be16(pb);
312 codec->pix_fmt = get_be32(pb);
313 codec->qmin = get_byte(pb);
314 codec->qmax = get_byte(pb);
315 codec->max_qdiff = get_byte(pb);
316 codec->qcompress = get_be16(pb) / 10000.0;
317 codec->qblur = get_be16(pb) / 10000.0;
318 codec->bit_rate_tolerance = get_be32(pb);
319 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
320 codec->rc_max_rate = get_be32(pb);
321 codec->rc_min_rate = get_be32(pb);
322 codec->rc_buffer_size = get_be32(pb);
323 codec->i_quant_factor = av_int2dbl(get_be64(pb));
324 codec->b_quant_factor = av_int2dbl(get_be64(pb));
325 codec->i_quant_offset = av_int2dbl(get_be64(pb));
326 codec->b_quant_offset = av_int2dbl(get_be64(pb));
327 codec->dct_algo = get_be32(pb);
328 codec->strict_std_compliance = get_be32(pb);
329 codec->max_b_frames = get_be32(pb);
330 codec->luma_elim_threshold = get_be32(pb);
331 codec->chroma_elim_threshold = get_be32(pb);
332 codec->mpeg_quant = get_be32(pb);
333 codec->intra_dc_precision = get_be32(pb);
334 codec->me_method = get_be32(pb);
335 codec->mb_decision = get_be32(pb);
336 codec->nsse_weight = get_be32(pb);
337 codec->frame_skip_cmp = get_be32(pb);
338 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
339 codec->codec_tag = get_be32(pb);
340 codec->thread_count = get_byte(pb);
341 break;
342 case CODEC_TYPE_AUDIO:
343 codec->sample_rate = get_be32(pb);
344 codec->channels = get_le16(pb);
345 codec->frame_size = get_le16(pb);
346 break;
347 default:
348 goto fail;
349 }
350 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
351 codec->extradata_size = get_be32(pb);
352 codec->extradata = av_malloc(codec->extradata_size);
353 if (!codec->extradata)
354 return AVERROR(ENOMEM);
355 get_buffer(pb, codec->extradata, codec->extradata_size);
356 }
357 }
358
359 /* get until end of block reached */
360 while ((url_ftell(pb) % ffm->packet_size) != 0)
361 get_byte(pb);
362
363 /* init packet demux */
364 ffm->packet_ptr = ffm->packet;
365 ffm->packet_end = ffm->packet;
366 ffm->frame_offset = 0;
367 ffm->dts = 0;
368 ffm->read_state = READ_HEADER;
369 ffm->first_packet = 1;
370 return 0;
371 fail:
372 for(i=0;i<s->nb_streams;i++) {
373 st = s->streams[i];
374 if (st) {
375 av_free(st);
376 }
377 }
378 return -1;
379 }
380
381 /* return < 0 if eof */
382 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
383 {
384 int size;
385 FFMContext *ffm = s->priv_data;
386 int duration, ret;
387
388 switch(ffm->read_state) {
389 case READ_HEADER:
390 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
391 return ret;
392
393 dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
394 url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
395 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
396 FRAME_HEADER_SIZE)
397 return -1;
398 if (ffm->header[1] & FLAG_DTS)
399 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
400 return -1;
401 #if 0
402 av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
403 #endif
404 ffm->read_state = READ_DATA;
405 /* fall thru */
406 case READ_DATA:
407 size = AV_RB24(ffm->header + 2);
408 if ((ret = ffm_is_avail_data(s, size)) < 0)
409 return ret;
410
411 duration = AV_RB24(ffm->header + 5);
412
413 av_new_packet(pkt, size);
414 pkt->stream_index = ffm->header[0];
415 if ((unsigned)pkt->stream_index >= s->nb_streams) {
416 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
417 av_free_packet(pkt);
418 ffm->read_state = READ_HEADER;
419 return -1;
420 }
421 pkt->pos = url_ftell(s->pb);
422 if (ffm->header[1] & FLAG_KEY_FRAME)
423 pkt->flags |= PKT_FLAG_KEY;
424
425 ffm->read_state = READ_HEADER;
426 if (ffm_read_data(s, pkt->data, size, 0) != size) {
427 /* bad case: desynchronized packet. we cancel all the packet loading */
428 av_free_packet(pkt);
429 return -1;
430 }
431 pkt->pts = AV_RB64(ffm->header+8);
432 if (ffm->header[1] & FLAG_DTS)
433 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
434 else
435 pkt->dts = pkt->pts;
436 pkt->duration = duration;
437 break;
438 }
439 return 0;
440 }
441
442 /* seek to a given time in the file. The file read pointer is
443 positioned at or before pts. XXX: the following code is quite
444 approximative */
445 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
446 {
447 FFMContext *ffm = s->priv_data;
448 int64_t pos_min, pos_max, pos;
449 int64_t pts_min, pts_max, pts;
450 double pos1;
451
452 #ifdef DEBUG_SEEK
453 av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
454 #endif
455 /* find the position using linear interpolation (better than
456 dichotomy in typical cases) */
457 pos_min = 0;
458 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
459 while (pos_min <= pos_max) {
460 pts_min = get_dts(s, pos_min);
461 pts_max = get_dts(s, pos_max);
462 /* linear interpolation */
463 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
464 (double)(pts_max - pts_min);
465 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
466 if (pos <= pos_min)
467 pos = pos_min;
468 else if (pos >= pos_max)
469 pos = pos_max;
470 pts = get_dts(s, pos);
471 /* check if we are lucky */
472 if (pts == wanted_pts) {
473 goto found;
474 } else if (pts > wanted_pts) {
475 pos_max = pos - FFM_PACKET_SIZE;
476 } else {
477 pos_min = pos + FFM_PACKET_SIZE;
478 }
479 }
480 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
481 if (pos > 0)
482 pos -= FFM_PACKET_SIZE;
483 found:
484 ffm_seek1(s, pos);
485
486 /* reset read state */
487 ffm->read_state = READ_HEADER;
488 ffm->packet_ptr = ffm->packet;
489 ffm->packet_end = ffm->packet;
490 ffm->first_packet = 1;
491
492 return 0;
493 }
494
495 static int ffm_probe(AVProbeData *p)
496 {
497 if (
498 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
499 p->buf[3] == '1')
500 return AVPROBE_SCORE_MAX + 1;
501 return 0;
502 }
503
504 AVInputFormat ffm_demuxer = {
505 "ffm",
506 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),
507 sizeof(FFMContext),
508 ffm_probe,
509 ffm_read_header,
510 ffm_read_packet,
511 NULL,
512 ffm_seek,
513 };