c4ee22e73a30fd656bf42c3e818e3f566937f56f
[libav.git] / libavformat / ffmdec.c
1 /*
2 * FFM (avserver live feed) demuxer
3 * Copyright (c) 2001 Fabrice Bellard
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 "libavutil/intfloat.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "ffm.h"
27 #if CONFIG_AVSERVER
28 #include <unistd.h>
29
30 int64_t ffm_read_write_index(int fd)
31 {
32 uint8_t buf[8];
33
34 lseek(fd, 8, SEEK_SET);
35 if (read(fd, buf, 8) != 8)
36 return AVERROR(EIO);
37 return AV_RB64(buf);
38 }
39
40 int ffm_write_write_index(int fd, int64_t pos)
41 {
42 uint8_t buf[8];
43 int i;
44
45 for(i=0;i<8;i++)
46 buf[i] = (pos >> (56 - i * 8)) & 0xff;
47 lseek(fd, 8, SEEK_SET);
48 if (write(fd, buf, 8) != 8)
49 return AVERROR(EIO);
50 return 8;
51 }
52
53 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
54 {
55 FFMContext *ffm = s->priv_data;
56 ffm->write_index = pos;
57 ffm->file_size = file_size;
58 }
59 #endif // CONFIG_AVSERVER
60
61 static int ffm_is_avail_data(AVFormatContext *s, int size)
62 {
63 FFMContext *ffm = s->priv_data;
64 int64_t pos, avail_size;
65 int len;
66
67 len = ffm->packet_end - ffm->packet_ptr;
68 if (size <= len)
69 return 1;
70 pos = avio_tell(s->pb);
71 if (!ffm->write_index) {
72 if (pos == ffm->file_size)
73 return AVERROR_EOF;
74 avail_size = ffm->file_size - pos;
75 } else {
76 if (pos == ffm->write_index) {
77 /* exactly at the end of stream */
78 return AVERROR(EAGAIN);
79 } else if (pos < ffm->write_index) {
80 avail_size = ffm->write_index - pos;
81 } else {
82 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
83 }
84 }
85 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
86 if (size <= avail_size)
87 return 1;
88 else
89 return AVERROR(EAGAIN);
90 }
91
92 static int ffm_resync(AVFormatContext *s, int state)
93 {
94 av_log(s, AV_LOG_ERROR, "resyncing\n");
95 while (state != PACKET_ID) {
96 if (s->pb->eof_reached) {
97 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
98 return -1;
99 }
100 state = (state << 8) | avio_r8(s->pb);
101 }
102 return 0;
103 }
104
105 /* first is true if we read the frame header */
106 static int ffm_read_data(AVFormatContext *s,
107 uint8_t *buf, int size, int header)
108 {
109 FFMContext *ffm = s->priv_data;
110 AVIOContext *pb = s->pb;
111 int len, fill_size, size1, frame_offset, id;
112
113 size1 = size;
114 while (size > 0) {
115 redo:
116 len = ffm->packet_end - ffm->packet_ptr;
117 if (len < 0)
118 return -1;
119 if (len > size)
120 len = size;
121 if (len == 0) {
122 if (avio_tell(pb) == ffm->file_size)
123 avio_seek(pb, ffm->packet_size, SEEK_SET);
124 retry_read:
125 id = avio_rb16(pb); /* PACKET_ID */
126 if (id != PACKET_ID)
127 if (ffm_resync(s, id) < 0)
128 return -1;
129 fill_size = avio_rb16(pb);
130 ffm->dts = avio_rb64(pb);
131 frame_offset = avio_rb16(pb);
132 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
133 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
134 if (ffm->packet_end < ffm->packet || frame_offset < 0)
135 return -1;
136 /* if first packet or resynchronization packet, we must
137 handle it specifically */
138 if (ffm->first_packet || (frame_offset & 0x8000)) {
139 if (!frame_offset) {
140 /* This packet has no frame headers in it */
141 if (avio_tell(pb) >= ffm->packet_size * 3) {
142 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);
143 goto retry_read;
144 }
145 /* This is bad, we cannot find a valid frame header */
146 return 0;
147 }
148 ffm->first_packet = 0;
149 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
150 return -1;
151 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
152 if (!header)
153 break;
154 } else {
155 ffm->packet_ptr = ffm->packet;
156 }
157 goto redo;
158 }
159 memcpy(buf, ffm->packet_ptr, len);
160 buf += len;
161 ffm->packet_ptr += len;
162 size -= len;
163 header = 0;
164 }
165 return size1 - size;
166 }
167
168 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
169 and file_size - FFM_PACKET_SIZE */
170 static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
171 {
172 FFMContext *ffm = s->priv_data;
173 AVIOContext *pb = s->pb;
174 int64_t pos;
175
176 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
177 pos = FFMAX(pos, FFM_PACKET_SIZE);
178 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
179 return avio_seek(pb, pos, SEEK_SET);
180 }
181
182 static int64_t get_dts(AVFormatContext *s, int64_t pos)
183 {
184 AVIOContext *pb = s->pb;
185 int64_t dts;
186
187 ffm_seek1(s, pos);
188 avio_skip(pb, 4);
189 dts = avio_rb64(pb);
190 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
191 return dts;
192 }
193
194 static void adjust_write_index(AVFormatContext *s)
195 {
196 FFMContext *ffm = s->priv_data;
197 AVIOContext *pb = s->pb;
198 int64_t pts;
199 //int64_t orig_write_index = ffm->write_index;
200 int64_t pos_min, pos_max;
201 int64_t pts_start;
202 int64_t ptr = avio_tell(pb);
203
204
205 pos_min = 0;
206 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
207
208 pts_start = get_dts(s, pos_min);
209
210 pts = get_dts(s, pos_max);
211
212 if (pts - 100000 > pts_start)
213 goto end;
214
215 ffm->write_index = FFM_PACKET_SIZE;
216
217 pts_start = get_dts(s, pos_min);
218
219 pts = get_dts(s, pos_max);
220
221 if (pts - 100000 <= pts_start) {
222 while (1) {
223 int64_t newpos;
224 int64_t newpts;
225
226 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
227
228 if (newpos == pos_min)
229 break;
230
231 newpts = get_dts(s, newpos);
232
233 if (newpts - 100000 <= pts) {
234 pos_max = newpos;
235 pts = newpts;
236 } else {
237 pos_min = newpos;
238 }
239 }
240 ffm->write_index += pos_max;
241 }
242
243 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
244 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
245
246 end:
247 avio_seek(pb, ptr, SEEK_SET);
248 }
249
250
251 static int ffm_close(AVFormatContext *s)
252 {
253 int i;
254
255 for (i = 0; i < s->nb_streams; i++)
256 av_freep(&s->streams[i]->codec->rc_eq);
257
258 return 0;
259 }
260
261
262 static int ffm_read_header(AVFormatContext *s)
263 {
264 FFMContext *ffm = s->priv_data;
265 AVStream *st;
266 AVIOContext *pb = s->pb;
267 AVCodecContext *codec;
268 int i, nb_streams;
269 uint32_t tag;
270
271 /* header */
272 tag = avio_rl32(pb);
273 if (tag != MKTAG('F', 'F', 'M', '1'))
274 goto fail;
275 ffm->packet_size = avio_rb32(pb);
276 if (ffm->packet_size != FFM_PACKET_SIZE)
277 goto fail;
278 ffm->write_index = avio_rb64(pb);
279 /* get also filesize */
280 if (pb->seekable) {
281 ffm->file_size = avio_size(pb);
282 if (ffm->write_index)
283 adjust_write_index(s);
284 } else {
285 ffm->file_size = (UINT64_C(1) << 63) - 1;
286 }
287
288 nb_streams = avio_rb32(pb);
289 avio_rb32(pb); /* total bitrate */
290 /* read each stream */
291 for(i=0;i<nb_streams;i++) {
292 char rc_eq_buf[128];
293
294 st = avformat_new_stream(s, NULL);
295 if (!st)
296 goto fail;
297
298 avpriv_set_pts_info(st, 64, 1, 1000000);
299
300 codec = st->codec;
301 /* generic info */
302 codec->codec_id = avio_rb32(pb);
303 codec->codec_type = avio_r8(pb); /* codec_type */
304 codec->bit_rate = avio_rb32(pb);
305 codec->flags = avio_rb32(pb);
306 codec->flags2 = avio_rb32(pb);
307 codec->debug = avio_rb32(pb);
308 /* specific info */
309 switch(codec->codec_type) {
310 case AVMEDIA_TYPE_VIDEO:
311 codec->time_base.num = avio_rb32(pb);
312 codec->time_base.den = avio_rb32(pb);
313 codec->width = avio_rb16(pb);
314 codec->height = avio_rb16(pb);
315 codec->gop_size = avio_rb16(pb);
316 codec->pix_fmt = avio_rb32(pb);
317 codec->qmin = avio_r8(pb);
318 codec->qmax = avio_r8(pb);
319 codec->max_qdiff = avio_r8(pb);
320 codec->qcompress = avio_rb16(pb) / 10000.0;
321 codec->qblur = avio_rb16(pb) / 10000.0;
322 codec->bit_rate_tolerance = avio_rb32(pb);
323 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
324 codec->rc_eq = av_strdup(rc_eq_buf);
325 codec->rc_max_rate = avio_rb32(pb);
326 codec->rc_min_rate = avio_rb32(pb);
327 codec->rc_buffer_size = avio_rb32(pb);
328 codec->i_quant_factor = av_int2double(avio_rb64(pb));
329 codec->b_quant_factor = av_int2double(avio_rb64(pb));
330 codec->i_quant_offset = av_int2double(avio_rb64(pb));
331 codec->b_quant_offset = av_int2double(avio_rb64(pb));
332 codec->dct_algo = avio_rb32(pb);
333 codec->strict_std_compliance = avio_rb32(pb);
334 codec->max_b_frames = avio_rb32(pb);
335 codec->mpeg_quant = avio_rb32(pb);
336 codec->intra_dc_precision = avio_rb32(pb);
337 codec->me_method = avio_rb32(pb);
338 codec->mb_decision = avio_rb32(pb);
339 codec->nsse_weight = avio_rb32(pb);
340 codec->frame_skip_cmp = avio_rb32(pb);
341 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
342 codec->codec_tag = avio_rb32(pb);
343 codec->thread_count = avio_r8(pb);
344 codec->coder_type = avio_rb32(pb);
345 codec->me_cmp = avio_rb32(pb);
346 codec->me_subpel_quality = avio_rb32(pb);
347 codec->me_range = avio_rb32(pb);
348 codec->keyint_min = avio_rb32(pb);
349 codec->scenechange_threshold = avio_rb32(pb);
350 codec->b_frame_strategy = avio_rb32(pb);
351 codec->qcompress = av_int2double(avio_rb64(pb));
352 codec->qblur = av_int2double(avio_rb64(pb));
353 codec->max_qdiff = avio_rb32(pb);
354 codec->refs = avio_rb32(pb);
355 break;
356 case AVMEDIA_TYPE_AUDIO:
357 codec->sample_rate = avio_rb32(pb);
358 codec->channels = avio_rl16(pb);
359 codec->frame_size = avio_rl16(pb);
360 codec->sample_fmt = (int16_t) avio_rl16(pb);
361 break;
362 default:
363 goto fail;
364 }
365 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
366 codec->extradata_size = avio_rb32(pb);
367 codec->extradata = av_malloc(codec->extradata_size);
368 if (!codec->extradata)
369 return AVERROR(ENOMEM);
370 avio_read(pb, codec->extradata, codec->extradata_size);
371 }
372 }
373
374 /* get until end of block reached */
375 while ((avio_tell(pb) % ffm->packet_size) != 0)
376 avio_r8(pb);
377
378 /* init packet demux */
379 ffm->packet_ptr = ffm->packet;
380 ffm->packet_end = ffm->packet;
381 ffm->frame_offset = 0;
382 ffm->dts = 0;
383 ffm->read_state = READ_HEADER;
384 ffm->first_packet = 1;
385 return 0;
386 fail:
387 ffm_close(s);
388 return -1;
389 }
390
391 /* return < 0 if eof */
392 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
393 {
394 int size;
395 FFMContext *ffm = s->priv_data;
396 int duration, ret;
397
398 switch(ffm->read_state) {
399 case READ_HEADER:
400 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
401 return ret;
402
403 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
404 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
405 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
406 FRAME_HEADER_SIZE)
407 return -1;
408 if (ffm->header[1] & FLAG_DTS)
409 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
410 return -1;
411 ffm->read_state = READ_DATA;
412 /* fall thru */
413 case READ_DATA:
414 size = AV_RB24(ffm->header + 2);
415 if ((ret = ffm_is_avail_data(s, size)) < 0)
416 return ret;
417
418 duration = AV_RB24(ffm->header + 5);
419
420 av_new_packet(pkt, size);
421 pkt->stream_index = ffm->header[0];
422 if ((unsigned)pkt->stream_index >= s->nb_streams) {
423 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
424 av_free_packet(pkt);
425 ffm->read_state = READ_HEADER;
426 return -1;
427 }
428 pkt->pos = avio_tell(s->pb);
429 if (ffm->header[1] & FLAG_KEY_FRAME)
430 pkt->flags |= AV_PKT_FLAG_KEY;
431
432 ffm->read_state = READ_HEADER;
433 if (ffm_read_data(s, pkt->data, size, 0) != size) {
434 /* bad case: desynchronized packet. we cancel all the packet loading */
435 av_free_packet(pkt);
436 return -1;
437 }
438 pkt->pts = AV_RB64(ffm->header+8);
439 if (ffm->header[1] & FLAG_DTS)
440 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
441 else
442 pkt->dts = pkt->pts;
443 pkt->duration = duration;
444 break;
445 }
446 return 0;
447 }
448
449 /* seek to a given time in the file. The file read pointer is
450 positioned at or before pts. XXX: the following code is quite
451 approximative */
452 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
453 {
454 FFMContext *ffm = s->priv_data;
455 int64_t pos_min, pos_max, pos;
456 int64_t pts_min, pts_max, pts;
457 double pos1;
458
459 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
460 /* find the position using linear interpolation (better than
461 dichotomy in typical cases) */
462 pos_min = FFM_PACKET_SIZE;
463 pos_max = ffm->file_size - FFM_PACKET_SIZE;
464 while (pos_min <= pos_max) {
465 pts_min = get_dts(s, pos_min);
466 pts_max = get_dts(s, pos_max);
467 /* linear interpolation */
468 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
469 (double)(pts_max - pts_min);
470 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
471 if (pos <= pos_min)
472 pos = pos_min;
473 else if (pos >= pos_max)
474 pos = pos_max;
475 pts = get_dts(s, pos);
476 /* check if we are lucky */
477 if (pts == wanted_pts) {
478 goto found;
479 } else if (pts > wanted_pts) {
480 pos_max = pos - FFM_PACKET_SIZE;
481 } else {
482 pos_min = pos + FFM_PACKET_SIZE;
483 }
484 }
485 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
486
487 found:
488 if (ffm_seek1(s, pos) < 0)
489 return -1;
490
491 /* reset read state */
492 ffm->read_state = READ_HEADER;
493 ffm->packet_ptr = ffm->packet;
494 ffm->packet_end = ffm->packet;
495 ffm->first_packet = 1;
496
497 return 0;
498 }
499
500 static int ffm_probe(AVProbeData *p)
501 {
502 if (
503 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
504 p->buf[3] == '1')
505 return AVPROBE_SCORE_MAX + 1;
506 return 0;
507 }
508
509 AVInputFormat ff_ffm_demuxer = {
510 .name = "ffm",
511 .long_name = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed)"),
512 .priv_data_size = sizeof(FFMContext),
513 .read_probe = ffm_probe,
514 .read_header = ffm_read_header,
515 .read_packet = ffm_read_packet,
516 .read_close = ffm_close,
517 .read_seek = ffm_seek,
518 };