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) 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,
 246                         c->sys->time_base.den);
 247         avctx->time_base= c->sys->time_base;
 248         if (!avctx->width){
 249             avctx->width = c->sys->width;
 250             avctx->height = c->sys->height;
 251         }
 252         avctx->pix_fmt = c->sys->pix_fmt;
 253
 254         /* finding out SAR is a little bit messy */
 255         vsc_pack = dv_extract_pack(frame, dv_video_control);
 256         apt      = frame[4] & 0x07;
 257         is16_9   = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
 258                                 (!apt && (vsc_pack[2] & 0x07) == 0x07)));
 259         c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
 260         avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1},
 261                                        c->sys->time_base);
 262         size = c->sys->frame_size;
 263     }
 264     return size;
 265 }
 266
 267 /*
 268  * The following 3 functions constitute our interface to the world
 269  */
 270
 271 DVDemuxContext* dv_init_demux(AVFormatContext *s)
 272 {
 273     DVDemuxContext *c;
 274
 275     c = av_mallocz(sizeof(DVDemuxContext));
 276     if (!c)
 277         return NULL;
 278
 279     c->vst = av_new_stream(s, 0);
 280     if (!c->vst) {
 281         av_free(c);
 282         return NULL;
 283     }
 284
 285     c->sys  = NULL;
 286     c->fctx = s;
 287     memset(c->ast, 0, sizeof(c->ast));
 288     c->ach    = 0;
 289     c->frames = 0;
 290     c->abytes = 0;
 291
 292     c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
 293     c->vst->codec->codec_id   = CODEC_ID_DVVIDEO;
 294     c->vst->codec->bit_rate   = 25000000;
 295     c->vst->start_time        = 0;
 296
 297     return c;
 298 }
 299
 300 int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
 301 {
 302     int size = -1;
 303     int i;
 304
 305     for (i = 0; i < c->ach; i++) {
 306        if (c->ast[i] && c->audio_pkt[i].size) {
 307            *pkt = c->audio_pkt[i];
 308            c->audio_pkt[i].size = 0;
 309            size = pkt->size;
 310            break;
 311        }
 312     }
 313
 314     return size;
 315 }
 316
 317 int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
 318                       uint8_t* buf, int buf_size)
 319 {
 320     int size, i;
 321     uint8_t *ppcm[4] = {0};
 322
 323     if (buf_size < DV_PROFILE_BYTES ||
 324         !(c->sys = dv_frame_profile(buf)) ||
 325         buf_size < c->sys->frame_size) {
 326           return -1;   /* Broken frame, or not enough data */
 327     }
 328
 329     /* Queueing audio packet */
 330     /* FIXME: in case of no audio/bad audio we have to do something */
 331     size = dv_extract_audio_info(c, buf);
 332     for (i = 0; i < c->ach; i++) {
 333        c->audio_pkt[i].size = size;
 334        c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
 335        ppcm[i] = c->audio_buf[i];
 336     }
 337     dv_extract_audio(buf, ppcm, c->sys);
 338     c->abytes += size;
 339
 340     /* We work with 720p frames split in half, thus even frames have
 341      * channels 0,1 and odd 2,3. */
 342     if (c->sys->height == 720) {
 343         if (buf[1] & 0x0C)
 344             c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
 345         else
 346             c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
 347     }
 348
 349     /* Now it's time to return video packet */
 350     size = dv_extract_video_info(c, buf);
 351     av_init_packet(pkt);
 352     pkt->data         = buf;
 353     pkt->size         = size;
 354     pkt->flags       |= PKT_FLAG_KEY;
 355     pkt->stream_index = c->vst->id;
 356     pkt->pts          = c->frames;
 357
 358     c->frames++;
 359
 360     return size;
 361 }
 362
 363 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
 364                               int64_t timestamp, int flags)
 365 {
 366     // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
 367     const DVprofile* sys = dv_codec_profile(c->vst->codec);
 368     int64_t offset;
 369     int64_t size = url_fsize(s->pb);
 370     int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
 371
 372     offset = sys->frame_size * timestamp;
 373
 374     if (offset > max_offset) offset = max_offset;
 375     else if (offset < 0) offset = 0;
 376
 377     return offset;
 378 }
 379
 380 void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
 381 {
 382     c->frames= frame_offset;
 383     if (c->ach)
 384         c->abytes= av_rescale_q(c->frames, c->sys->time_base,
 385                                 (AVRational){8, c->ast[0]->codec->bit_rate});
 386     c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
 387     c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
 388 }
 389
 390 /************************************************************
 391  * Implementation of the easiest DV storage of all -- raw DV.
 392  ************************************************************/
 393
 394 typedef struct RawDVContext {
 395     DVDemuxContext* dv_demux;
 396     uint8_t         buf[DV_MAX_FRAME_SIZE];
 397 } RawDVContext;
 398
 399 static int dv_read_header(AVFormatContext *s,
 400                           AVFormatParameters *ap)
 401 {
 402     RawDVContext *c = s->priv_data;
 403
 404     c->dv_demux = dv_init_demux(s);
 405     if (!c->dv_demux)
 406         return -1;
 407
 408     if (get_buffer(s->pb, c->buf, DV_PROFILE_BYTES) <= 0 ||
 409         url_fseek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
 410         return AVERROR(EIO);
 411
 412     c->dv_demux->sys = dv_frame_profile(c->buf);
 413     if (!c->dv_demux->sys) {
 414         av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
 415         return -1;
 416     }
 417
 418     s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1},
 419                                c->dv_demux->sys->time_base);
 420
 421     return 0;
 422 }
 423
 424
 425 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
 426 {
 427     int size;
 428     RawDVContext *c = s->priv_data;
 429
 430     size = dv_get_packet(c->dv_demux, pkt);
 431
 432     if (size < 0) {
 433         size = c->dv_demux->sys->frame_size;
 434         if (get_buffer(s->pb, c->buf, size) <= 0)
 435             return AVERROR(EIO);
 436
 437         size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
 438     }
 439
 440     return size;
 441 }
 442
 443 static int dv_read_seek(AVFormatContext *s, int stream_index,
 444                        int64_t timestamp, int flags)
 445 {
 446     RawDVContext *r   = s->priv_data;
 447     DVDemuxContext *c = r->dv_demux;
 448     int64_t offset    = dv_frame_offset(s, c, timestamp, flags);
 449
 450     dv_offset_reset(c, offset / c->sys->frame_size);
 451
 452     offset = url_fseek(s->pb, offset, SEEK_SET);
 453     return (offset < 0) ? offset : 0;
 454 }
 455
 456 static int dv_read_close(AVFormatContext *s)
 457 {
 458     RawDVContext *c = s->priv_data;
 459     av_free(c->dv_demux);
 460     return 0;
 461 }
 462
 463 #ifdef CONFIG_DV_DEMUXER
 464 AVInputFormat dv_demuxer = {
 465     "dv",
 466     NULL_IF_CONFIG_SMALL("DV video format"),
 467     sizeof(RawDVContext),
 468     NULL,
 469     dv_read_header,
 470     dv_read_packet,
 471     dv_read_close,
 472     dv_read_seek,
 473     .extensions = "dv,dif",
 474 };
 475 #endif