Statistics
| Branch: | Revision:

ffmpeg / libavformat / dv.c @ 75f2c209

History | View | Annotate | Download (14.4 KB)

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) and 100 Mbps (DVCPRO HD) support
12
 * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
13
 * Funded by BBC Research & Development
14
 *
15
 * This file is part of FFmpeg.
16
 *
17
 * FFmpeg is free software; you can redistribute it and/or
18
 * modify it under the terms of the GNU Lesser General Public
19
 * License as published by the Free Software Foundation; either
20
 * version 2.1 of the License, or (at your option) any later version.
21
 *
22
 * FFmpeg is distributed in the hope that it will be useful,
23
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
25
 * Lesser General Public License for more details.
26
 *
27
 * You should have received a copy of the GNU Lesser General Public
28
 * License along with FFmpeg; if not, write to the Free Software
29
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30
 */
31
#include <time.h>
32
#include "avformat.h"
33
#include "libavcodec/dvdata.h"
34
#include "dv.h"
35

    
36
struct DVDemuxContext {
37
    const DVprofile*  sys;    /* Current DV profile. E.g.: 525/60, 625/50 */
38
    AVFormatContext* fctx;
39
    AVStream*        vst;
40
    AVStream*        ast[4];
41
    AVPacket         audio_pkt[4];
42
    uint8_t          audio_buf[4][8192];
43
    int              ach;
44
    int              frames;
45
    uint64_t         abytes;
46
};
47

    
48
static inline uint16_t dv_audio_12to16(uint16_t sample)
49
{
50
    uint16_t shift, result;
51

    
52
    sample = (sample < 0x800) ? sample : sample | 0xf000;
53
    shift = (sample & 0xf00) >> 8;
54

    
55
    if (shift < 0x2 || shift > 0xd) {
56
        result = sample;
57
    } else if (shift < 0x8) {
58
        shift--;
59
        result = (sample - (256 * shift)) << shift;
60
    } else {
61
        shift = 0xe - shift;
62
        result = ((sample + ((256 * shift) + 1)) << shift) - 1;
63
    }
64

    
65
    return result;
66
}
67

    
68
/*
69
 * This is the dumbest implementation of all -- it simply looks at
70
 * a fixed offset and if pack isn't there -- fails. We might want
71
 * to have a fallback mechanism for complete search of missing packs.
72
 */
73
static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t)
74
{
75
    int offs;
76

    
77
    switch (t) {
78
    case dv_audio_source:
79
          offs = (80*6 + 80*16*3 + 3);
80
          break;
81
    case dv_audio_control:
82
          offs = (80*6 + 80*16*4 + 3);
83
          break;
84
    case dv_video_control:
85
          offs = (80*5 + 48 + 5);
86
          break;
87
    default:
88
          return NULL;
89
    }
90

    
91
    return frame[offs] == t ? &frame[offs] : NULL;
92
}
93

    
94
/*
95
 * There's a couple of assumptions being made here:
96
 * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.
97
 *    We can pass them upwards when ffmpeg will be ready to deal with them.
98
 * 2. We don't do software emphasis.
99
 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
100
 *    are converted into 16bit linear ones.
101
 */
102
static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4],
103
                            const DVprofile *sys)
104
{
105
    int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
106
    uint16_t lc, rc;
107
    const uint8_t* as_pack;
108
    uint8_t *pcm, ipcm;
109

    
110
    as_pack = dv_extract_pack(frame, dv_audio_source);
111
    if (!as_pack)    /* No audio ? */
112
        return 0;
113

    
114
    smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
115
    freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
116
    quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
117

    
118
    if (quant > 1)
119
        return -1; /* unsupported quantization */
120

    
121
    size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
122
    half_ch = sys->difseg_size/2;
123

    
124
    /* We work with 720p frames split in half, thus even frames have
125
     * channels 0,1 and odd 2,3 */
126
    ipcm = (sys->height == 720 && !(frame[1]&0x0C))?2:0;
127
    pcm = ppcm[ipcm++];
128

    
129
    /* for each DIF channel */
130
    for (chan = 0; chan < sys->n_difchan; chan++) {
131
        /* for each DIF segment */
132
        for (i = 0; i < sys->difseg_size; i++) {
133
            frame += 6 * 80; /* skip DIF segment header */
134
            if (quant == 1 && i == half_ch) {
135
                /* next stereo channel (12bit mode only) */
136
                pcm = ppcm[ipcm++];
137
                if (!pcm)
138
                    break;
139
            }
140

    
141
            /* for each AV sequence */
142
            for (j = 0; j < 9; j++) {
143
                for (d = 8; d < 80; d += 2) {
144
                    if (quant == 0) {  /* 16bit quantization */
145
                        of = sys->audio_shuffle[i][j] + (d - 8)/2 * sys->audio_stride;
146
                        if (of*2 >= size)
147
                            continue;
148

    
149
                        pcm[of*2]   = frame[d+1]; // FIXME: maybe we have to admit
150
                        pcm[of*2+1] = frame[d];   //        that DV is a big-endian PCM
151
                        if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
152
                            pcm[of*2+1] = 0;
153
                    } else {           /* 12bit quantization */
154
                        lc = ((uint16_t)frame[d] << 4) |
155
                             ((uint16_t)frame[d+2] >> 4);
156
                        rc = ((uint16_t)frame[d+1] << 4) |
157
                             ((uint16_t)frame[d+2] & 0x0f);
158
                        lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
159
                        rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
160

    
161
                        of = sys->audio_shuffle[i%half_ch][j] + (d - 8)/3 * sys->audio_stride;
162
                        if (of*2 >= size)
163
                            continue;
164

    
165
                        pcm[of*2]   = lc & 0xff; // FIXME: maybe we have to admit
166
                        pcm[of*2+1] = lc >> 8;   //        that DV is a big-endian PCM
167
                        of = sys->audio_shuffle[i%half_ch+half_ch][j] +
168
                            (d - 8)/3 * sys->audio_stride;
169
                        pcm[of*2]   = rc & 0xff; // FIXME: maybe we have to admit
170
                        pcm[of*2+1] = rc >> 8;   //        that DV is a big-endian PCM
171
                        ++d;
172
                    }
173
                }
174

    
175
                frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
176
            }
177
        }
178

    
179
        /* next stereo channel (50Mbps and 100Mbps only) */
180
        pcm = ppcm[ipcm++];
181
        if (!pcm)
182
            break;
183
    }
184

    
185
    return size;
186
}
187

    
188
static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
189
{
190
    const uint8_t* as_pack;
191
    int freq, stype, smpls, quant, i, ach;
192

    
193
    as_pack = dv_extract_pack(frame, dv_audio_source);
194
    if (!as_pack || !c->sys) {    /* No audio ? */
195
        c->ach = 0;
196
        return 0;
197
    }
198

    
199
    smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
200
    freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
201
    stype = (as_pack[3] & 0x1f); /* 0 - 2CH, 2 - 4CH, 3 - 8CH */
202
    quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
203

    
204
    /* note: ach counts PAIRS of channels (i.e. stereo channels) */
205
    ach = ((int[4]){  1,  0,  2,  4})[stype];
206
    if (ach == 1 && quant && freq == 2)
207
        ach = 2;
208

    
209
    /* Dynamic handling of the audio streams in DV */
210
    for (i=0; i<ach; i++) {
211
       if (!c->ast[i]) {
212
           c->ast[i] = av_new_stream(c->fctx, 0);
213
           if (!c->ast[i])
214
               break;
215
           av_set_pts_info(c->ast[i], 64, 1, 30000);
216
           c->ast[i]->codec->codec_type = CODEC_TYPE_AUDIO;
217
           c->ast[i]->codec->codec_id = CODEC_ID_PCM_S16LE;
218

    
219
           av_init_packet(&c->audio_pkt[i]);
220
           c->audio_pkt[i].size     = 0;
221
           c->audio_pkt[i].data     = c->audio_buf[i];
222
           c->audio_pkt[i].stream_index = c->ast[i]->index;
223
           c->audio_pkt[i].flags |= PKT_FLAG_KEY;
224
       }
225
       c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
226
       c->ast[i]->codec->channels = 2;
227
       c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16;
228
       c->ast[i]->start_time = 0;
229
    }
230
    c->ach = i;
231

    
232
    return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
233
}
234

    
235
static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
236
{
237
    const uint8_t* vsc_pack;
238
    AVCodecContext* avctx;
239
    int apt, is16_9;
240
    int size = 0;
241

    
242
    if (c->sys) {
243
        avctx = c->vst->codec;
244

    
245
        av_set_pts_info(c->vst, 64, c->sys->time_base.num, c->sys->time_base.den);
246
        avctx->time_base= c->sys->time_base;
247
        if(!avctx->width){
248
            avctx->width = c->sys->width;
249
            avctx->height = c->sys->height;
250
        }
251
        avctx->pix_fmt = c->sys->pix_fmt;
252

    
253
        /* finding out SAR is a little bit messy */
254
        vsc_pack = dv_extract_pack(frame, dv_video_control);
255
        apt = frame[4] & 0x07;
256
        is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
257
                               (!apt && (vsc_pack[2] & 0x07) == 0x07)));
258
        c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
259
        avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1},
260
                                       c->sys->time_base);
261
        size = c->sys->frame_size;
262
    }
263
    return size;
264
}
265

    
266
/*
267
 * The following 3 functions constitute our interface to the world
268
 */
269

    
270
DVDemuxContext* dv_init_demux(AVFormatContext *s)
271
{
272
    DVDemuxContext *c;
273

    
274
    c = av_mallocz(sizeof(DVDemuxContext));
275
    if (!c)
276
        return NULL;
277

    
278
    c->vst = av_new_stream(s, 0);
279
    if (!c->vst) {
280
        av_free(c);
281
        return NULL;
282
    }
283

    
284
    c->sys = NULL;
285
    c->fctx = s;
286
    memset(c->ast, 0, sizeof(c->ast));
287
    c->ach = 0;
288
    c->frames = 0;
289
    c->abytes = 0;
290

    
291
    c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
292
    c->vst->codec->codec_id = CODEC_ID_DVVIDEO;
293
    c->vst->codec->bit_rate = 25000000;
294
    c->vst->start_time = 0;
295

    
296
    return c;
297
}
298

    
299
int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
300
{
301
    int size = -1;
302
    int i;
303

    
304
    for (i=0; i<c->ach; i++) {
305
       if (c->ast[i] && c->audio_pkt[i].size) {
306
           *pkt = c->audio_pkt[i];
307
           c->audio_pkt[i].size = 0;
308
           size = pkt->size;
309
           break;
310
       }
311
    }
312

    
313
    return size;
314
}
315

    
316
int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
317
                      uint8_t* buf, int buf_size)
318
{
319
    int size, i;
320
    uint8_t *ppcm[4] = {0};
321

    
322
    if (buf_size < DV_PROFILE_BYTES ||
323
        !(c->sys = dv_frame_profile(buf)) ||
324
        buf_size < c->sys->frame_size) {
325
          return -1;   /* Broken frame, or not enough data */
326
    }
327

    
328
    /* Queueing audio packet */
329
    /* FIXME: in case of no audio/bad audio we have to do something */
330
    size = dv_extract_audio_info(c, buf);
331
    for (i=0; i<c->ach; i++) {
332
       c->audio_pkt[i].size = size;
333
       c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
334
       ppcm[i] = c->audio_buf[i];
335
    }
336
    dv_extract_audio(buf, ppcm, c->sys);
337
    c->abytes += size;
338

    
339
    /* We work with 720p frames split in half, thus even frames have
340
     * channels 0,1 and odd 2,3. */
341
    if (c->sys->height == 720) {
342
        if (buf[1]&0x0C)
343
            c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
344
        else
345
            c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
346
    }
347

    
348
    /* Now it's time to return video packet */
349
    size = dv_extract_video_info(c, buf);
350
    av_init_packet(pkt);
351
    pkt->data     = buf;
352
    pkt->size     = size;
353
    pkt->flags   |= PKT_FLAG_KEY;
354
    pkt->stream_index = c->vst->id;
355
    pkt->pts      = c->frames;
356

    
357
    c->frames++;
358

    
359
    return size;
360
}
361

    
362
static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
363
                              int64_t timestamp, int flags)
364
{
365
    // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
366
    const DVprofile* sys = dv_codec_profile(c->vst->codec);
367
    int64_t offset;
368
    int64_t size = url_fsize(s->pb);
369
    int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
370

    
371
    offset = sys->frame_size * timestamp;
372

    
373
    if (offset > max_offset) offset = max_offset;
374
    else if (offset < 0) offset = 0;
375

    
376
    return offset;
377
}
378

    
379
void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
380
{
381
    c->frames= frame_offset;
382
    if (c->ach)
383
        c->abytes= av_rescale_q(c->frames, c->sys->time_base,
384
                                (AVRational){8, c->ast[0]->codec->bit_rate});
385
    c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
386
    c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
387
}
388

    
389
/************************************************************
390
 * Implementation of the easiest DV storage of all -- raw DV.
391
 ************************************************************/
392

    
393
typedef struct RawDVContext {
394
    DVDemuxContext* dv_demux;
395
    uint8_t         buf[DV_MAX_FRAME_SIZE];
396
} RawDVContext;
397

    
398
static int dv_read_header(AVFormatContext *s,
399
                          AVFormatParameters *ap)
400
{
401
    RawDVContext *c = s->priv_data;
402

    
403
    c->dv_demux = dv_init_demux(s);
404
    if (!c->dv_demux)
405
        return -1;
406

    
407
    if (get_buffer(s->pb, c->buf, DV_PROFILE_BYTES) <= 0 ||
408
        url_fseek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
409
        return AVERROR(EIO);
410

    
411
    c->dv_demux->sys = dv_frame_profile(c->buf);
412
    if (!c->dv_demux->sys) {
413
        av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
414
        return -1;
415
    }
416

    
417
    s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1},
418
                               c->dv_demux->sys->time_base);
419

    
420
    return 0;
421
}
422

    
423

    
424
static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
425
{
426
    int size;
427
    RawDVContext *c = s->priv_data;
428

    
429
    size = dv_get_packet(c->dv_demux, pkt);
430

    
431
    if (size < 0) {
432
        size = c->dv_demux->sys->frame_size;
433
        if (get_buffer(s->pb, c->buf, size) <= 0)
434
            return AVERROR(EIO);
435

    
436
        size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
437
    }
438

    
439
    return size;
440
}
441

    
442
static int dv_read_seek(AVFormatContext *s, int stream_index,
443
                       int64_t timestamp, int flags)
444
{
445
    RawDVContext *r = s->priv_data;
446
    DVDemuxContext *c = r->dv_demux;
447
    int64_t offset= dv_frame_offset(s, c, timestamp, flags);
448

    
449
    dv_offset_reset(c, offset / c->sys->frame_size);
450

    
451
    offset = url_fseek(s->pb, offset, SEEK_SET);
452
    return (offset < 0)?offset:0;
453
}
454

    
455
static int dv_read_close(AVFormatContext *s)
456
{
457
    RawDVContext *c = s->priv_data;
458
    av_free(c->dv_demux);
459
    return 0;
460
}
461

    
462
#ifdef CONFIG_DV_DEMUXER
463
AVInputFormat dv_demuxer = {
464
    "dv",
465
    NULL_IF_CONFIG_SMALL("DV video format"),
466
    sizeof(RawDVContext),
467
    NULL,
468
    dv_read_header,
469
    dv_read_packet,
470
    dv_read_close,
471
    dv_read_seek,
472
    .extensions = "dv,dif",
473
};
474
#endif