* clarifying the AVInputFormat::read_seek return value
[libav.git] / libavformat / dv.c
1 /*
2 * General DV muxer/demuxer
3 * Copyright (c) 2003 Roman Shaposhnik
4 *
5 * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
6 * of DV technical info.
7 *
8 * Raw DV format
9 * Copyright (c) 2002 Fabrice Bellard.
10 *
11 * 50 Mbps (DVCPRO50) support
12 * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
13 *
14 * This file is part of FFmpeg.
15 *
16 * FFmpeg is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU Lesser General Public
18 * License as published by the Free Software Foundation; either
19 * version 2.1 of the License, or (at your option) any later version.
20 *
21 * FFmpeg is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 * Lesser General Public License for more details.
25 *
26 * You should have received a copy of the GNU Lesser General Public
27 * License along with FFmpeg; if not, write to the Free Software
28 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 */
30 #include <time.h>
31 #include "avformat.h"
32 #include "dvdata.h"
33 #include "dv.h"
34
35 struct DVDemuxContext {
36 const DVprofile* sys; /* Current DV profile. E.g.: 525/60, 625/50 */
37 AVFormatContext* fctx;
38 AVStream* vst;
39 AVStream* ast[2];
40 AVPacket audio_pkt[2];
41 uint8_t audio_buf[2][8192];
42 int ach;
43 int frames;
44 uint64_t abytes;
45 };
46
47 static inline uint16_t dv_audio_12to16(uint16_t sample)
48 {
49 uint16_t shift, result;
50
51 sample = (sample < 0x800) ? sample : sample | 0xf000;
52 shift = (sample & 0xf00) >> 8;
53
54 if (shift < 0x2 || shift > 0xd) {
55 result = sample;
56 } else if (shift < 0x8) {
57 shift--;
58 result = (sample - (256 * shift)) << shift;
59 } else {
60 shift = 0xe - shift;
61 result = ((sample + ((256 * shift) + 1)) << shift) - 1;
62 }
63
64 return result;
65 }
66
67 /*
68 * This is the dumbest implementation of all -- it simply looks at
69 * a fixed offset and if pack isn't there -- fails. We might want
70 * to have a fallback mechanism for complete search of missing packs.
71 */
72 static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t)
73 {
74 int offs;
75
76 switch (t) {
77 case dv_audio_source:
78 offs = (80*6 + 80*16*3 + 3);
79 break;
80 case dv_audio_control:
81 offs = (80*6 + 80*16*4 + 3);
82 break;
83 case dv_video_control:
84 offs = (80*5 + 48 + 5);
85 break;
86 default:
87 return NULL;
88 }
89
90 return (frame[offs] == t ? &frame[offs] : NULL);
91 }
92
93 /*
94 * There's a couple of assumptions being made here:
95 * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.
96 * We can pass them upwards when ffmpeg will be ready to deal with them.
97 * 2. We don't do software emphasis.
98 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
99 * are converted into 16bit linear ones.
100 */
101 static int dv_extract_audio(uint8_t* frame, uint8_t* pcm, uint8_t* pcm2,
102 const DVprofile *sys)
103 {
104 int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
105 uint16_t lc, rc;
106 const uint8_t* as_pack;
107
108 as_pack = dv_extract_pack(frame, dv_audio_source);
109 if (!as_pack) /* No audio ? */
110 return 0;
111
112 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
113 freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
114 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
115
116 if (quant > 1)
117 return -1; /* Unsupported quantization */
118
119 size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
120 half_ch = sys->difseg_size/2;
121
122 /* for each DIF channel */
123 for (chan = 0; chan < sys->n_difchan; chan++) {
124 /* for each DIF segment */
125 for (i = 0; i < sys->difseg_size; i++) {
126 frame += 6 * 80; /* skip DIF segment header */
127 if (quant == 1 && i == half_ch) {
128 /* next stereo channel (12bit mode only) */
129 if (!pcm2)
130 break;
131 else
132 pcm = pcm2;
133 }
134
135 /* for each AV sequence */
136 for (j = 0; j < 9; j++) {
137 for (d = 8; d < 80; d += 2) {
138 if (quant == 0) { /* 16bit quantization */
139 of = sys->audio_shuffle[i][j] + (d - 8)/2 * sys->audio_stride;
140 if (of*2 >= size)
141 continue;
142
143 pcm[of*2] = frame[d+1]; // FIXME: may be we have to admit
144 pcm[of*2+1] = frame[d]; // that DV is a big endian PCM
145 if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
146 pcm[of*2+1] = 0;
147 } else { /* 12bit quantization */
148 lc = ((uint16_t)frame[d] << 4) |
149 ((uint16_t)frame[d+2] >> 4);
150 rc = ((uint16_t)frame[d+1] << 4) |
151 ((uint16_t)frame[d+2] & 0x0f);
152 lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
153 rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
154
155 of = sys->audio_shuffle[i%half_ch][j] + (d - 8)/3 * sys->audio_stride;
156 if (of*2 >= size)
157 continue;
158
159 pcm[of*2] = lc & 0xff; // FIXME: may be we have to admit
160 pcm[of*2+1] = lc >> 8; // that DV is a big endian PCM
161 of = sys->audio_shuffle[i%half_ch+half_ch][j] +
162 (d - 8)/3 * sys->audio_stride;
163 pcm[of*2] = rc & 0xff; // FIXME: may be we have to admit
164 pcm[of*2+1] = rc >> 8; // that DV is a big endian PCM
165 ++d;
166 }
167 }
168
169 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
170 }
171 }
172
173 /* next stereo channel (50Mbps only) */
174 if(!pcm2)
175 break;
176 pcm = pcm2;
177 }
178
179 return size;
180 }
181
182 static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
183 {
184 const uint8_t* as_pack;
185 int freq, stype, smpls, quant, i, ach;
186
187 as_pack = dv_extract_pack(frame, dv_audio_source);
188 if (!as_pack || !c->sys) { /* No audio ? */
189 c->ach = 0;
190 return 0;
191 }
192
193 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
194 freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
195 stype = (as_pack[3] & 0x1f); /* 0 - 2CH, 2 - 4CH */
196 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
197
198 /* note: ach counts PAIRS of channels (i.e. stereo channels) */
199 ach = (stype == 2 || (quant && (freq == 2))) ? 2 : 1;
200
201 /* Dynamic handling of the audio streams in DV */
202 for (i=0; i<ach; i++) {
203 if (!c->ast[i]) {
204 c->ast[i] = av_new_stream(c->fctx, 0);
205 if (!c->ast[i])
206 break;
207 av_set_pts_info(c->ast[i], 64, 1, 30000);
208 c->ast[i]->codec->codec_type = CODEC_TYPE_AUDIO;
209 c->ast[i]->codec->codec_id = CODEC_ID_PCM_S16LE;
210
211 av_init_packet(&c->audio_pkt[i]);
212 c->audio_pkt[i].size = 0;
213 c->audio_pkt[i].data = c->audio_buf[i];
214 c->audio_pkt[i].stream_index = c->ast[i]->index;
215 c->audio_pkt[i].flags |= PKT_FLAG_KEY;
216 }
217 c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
218 c->ast[i]->codec->channels = 2;
219 c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16;
220 c->ast[i]->start_time = 0;
221 }
222 c->ach = i;
223
224 return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
225 }
226
227 static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
228 {
229 const uint8_t* vsc_pack;
230 AVCodecContext* avctx;
231 int apt, is16_9;
232 int size = 0;
233
234 if (c->sys) {
235 avctx = c->vst->codec;
236
237 av_set_pts_info(c->vst, 64, c->sys->frame_rate_base, c->sys->frame_rate);
238 avctx->time_base= (AVRational){c->sys->frame_rate_base, c->sys->frame_rate};
239 if(!avctx->width){
240 avctx->width = c->sys->width;
241 avctx->height = c->sys->height;
242 }
243 avctx->pix_fmt = c->sys->pix_fmt;
244
245 /* finding out SAR is a little bit messy */
246 vsc_pack = dv_extract_pack(frame, dv_video_control);
247 apt = frame[4] & 0x07;
248 is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
249 (!apt && (vsc_pack[2] & 0x07) == 0x07)));
250 avctx->sample_aspect_ratio = c->sys->sar[is16_9];
251 avctx->bit_rate = av_rescale(c->sys->frame_size * 8,
252 c->sys->frame_rate,
253 c->sys->frame_rate_base);
254 size = c->sys->frame_size;
255 }
256 return size;
257 }
258
259 /*
260 * The following 3 functions constitute our interface to the world
261 */
262
263 DVDemuxContext* dv_init_demux(AVFormatContext *s)
264 {
265 DVDemuxContext *c;
266
267 c = av_mallocz(sizeof(DVDemuxContext));
268 if (!c)
269 return NULL;
270
271 c->vst = av_new_stream(s, 0);
272 if (!c->vst) {
273 av_free(c);
274 return NULL;
275 }
276
277 c->sys = NULL;
278 c->fctx = s;
279 c->ast[0] = c->ast[1] = NULL;
280 c->ach = 0;
281 c->frames = 0;
282 c->abytes = 0;
283
284 c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
285 c->vst->codec->codec_id = CODEC_ID_DVVIDEO;
286 c->vst->codec->bit_rate = 25000000;
287 c->vst->start_time = 0;
288
289 return c;
290 }
291
292 int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
293 {
294 int size = -1;
295 int i;
296
297 for (i=0; i<c->ach; i++) {
298 if (c->ast[i] && c->audio_pkt[i].size) {
299 *pkt = c->audio_pkt[i];
300 c->audio_pkt[i].size = 0;
301 size = pkt->size;
302 break;
303 }
304 }
305
306 return size;
307 }
308
309 int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
310 uint8_t* buf, int buf_size)
311 {
312 int size, i;
313
314 if (buf_size < DV_PROFILE_BYTES ||
315 !(c->sys = dv_frame_profile(buf)) ||
316 buf_size < c->sys->frame_size) {
317 return -1; /* Broken frame, or not enough data */
318 }
319
320 /* Queueing audio packet */
321 /* FIXME: in case of no audio/bad audio we have to do something */
322 size = dv_extract_audio_info(c, buf);
323 for (i=0; i<c->ach; i++) {
324 c->audio_pkt[i].size = size;
325 c->audio_pkt[i].pts = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
326 }
327 dv_extract_audio(buf, c->audio_buf[0], c->audio_buf[1], c->sys);
328 c->abytes += size;
329
330 /* Now it's time to return video packet */
331 size = dv_extract_video_info(c, buf);
332 av_init_packet(pkt);
333 pkt->data = buf;
334 pkt->size = size;
335 pkt->flags |= PKT_FLAG_KEY;
336 pkt->stream_index = c->vst->id;
337 pkt->pts = c->frames;
338
339 c->frames++;
340
341 return size;
342 }
343
344 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
345 int64_t timestamp, int flags)
346 {
347 // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
348 const DVprofile* sys = dv_codec_profile(c->vst->codec);
349 int64_t offset;
350 int64_t size = url_fsize(&s->pb);
351 int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
352
353 offset = sys->frame_size * timestamp;
354
355 if (offset > max_offset) offset = max_offset;
356 else if (offset < 0) offset = 0;
357
358 return offset;
359 }
360
361 void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
362 {
363 c->frames= frame_offset;
364 if (c->ach)
365 c->abytes= av_rescale(c->frames,
366 c->ast[0]->codec->bit_rate * (int64_t)c->sys->frame_rate_base,
367 8*c->sys->frame_rate);
368 c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
369 }
370
371 /************************************************************
372 * Implementation of the easiest DV storage of all -- raw DV.
373 ************************************************************/
374
375 typedef struct RawDVContext {
376 DVDemuxContext* dv_demux;
377 uint8_t buf[DV_MAX_FRAME_SIZE];
378 } RawDVContext;
379
380 static int dv_read_header(AVFormatContext *s,
381 AVFormatParameters *ap)
382 {
383 RawDVContext *c = s->priv_data;
384
385 c->dv_demux = dv_init_demux(s);
386 if (!c->dv_demux)
387 return -1;
388
389 if (get_buffer(&s->pb, c->buf, DV_PROFILE_BYTES) <= 0 ||
390 url_fseek(&s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
391 return AVERROR_IO;
392
393 c->dv_demux->sys = dv_frame_profile(c->buf);
394 s->bit_rate = av_rescale(c->dv_demux->sys->frame_size * 8,
395 c->dv_demux->sys->frame_rate,
396 c->dv_demux->sys->frame_rate_base);
397
398 return 0;
399 }
400
401
402 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
403 {
404 int size;
405 RawDVContext *c = s->priv_data;
406
407 size = dv_get_packet(c->dv_demux, pkt);
408
409 if (size < 0) {
410 size = c->dv_demux->sys->frame_size;
411 if (get_buffer(&s->pb, c->buf, size) <= 0)
412 return AVERROR_IO;
413
414 size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
415 }
416
417 return size;
418 }
419
420 static int dv_read_seek(AVFormatContext *s, int stream_index,
421 int64_t timestamp, int flags)
422 {
423 RawDVContext *r = s->priv_data;
424 DVDemuxContext *c = r->dv_demux;
425 int64_t offset= dv_frame_offset(s, c, timestamp, flags);
426
427 dv_offset_reset(c, offset / c->sys->frame_size);
428
429 offset = url_fseek(&s->pb, offset, SEEK_SET);
430 return (offset < 0)?offset:0;
431 }
432
433 static int dv_read_close(AVFormatContext *s)
434 {
435 RawDVContext *c = s->priv_data;
436 av_free(c->dv_demux);
437 return 0;
438 }
439
440 #ifdef CONFIG_DV_DEMUXER
441 AVInputFormat dv_demuxer = {
442 "dv",
443 "DV video format",
444 sizeof(RawDVContext),
445 NULL,
446 dv_read_header,
447 dv_read_packet,
448 dv_read_close,
449 dv_read_seek,
450 .extensions = "dv,dif",
451 };
452 #endif