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 "libavutil/intreadwrite.h"
  35 #include "dv.h"
  36
  37 struct DVDemuxContext {
  38     const DVprofile*  sys;    /* Current DV profile. E.g.: 525/60, 625/50 */
  39     AVFormatContext*  fctx;
  40     AVStream*         vst;
  41     AVStream*         ast[4];
  42     AVPacket          audio_pkt[4];
  43     uint8_t           audio_buf[4][8192];
  44     int               ach;
  45     int               frames;
  46     uint64_t          abytes;
  47 };
  48
  49 static inline uint16_t dv_audio_12to16(uint16_t sample)
  50 {
  51     uint16_t shift, result;
  52
  53     sample = (sample < 0x800) ? sample : sample | 0xf000;
  54     shift  = (sample & 0xf00) >> 8;
  55
  56     if (shift < 0x2 || shift > 0xd) {
  57         result = sample;
  58     } else if (shift < 0x8) {
  59         shift--;
  60         result = (sample - (256 * shift)) << shift;
  61     } else {
  62         shift = 0xe - shift;
  63         result = ((sample + ((256 * shift) + 1)) << shift) - 1;
  64     }
  65
  66     return result;
  67 }
  68
  69 /*
  70  * This is the dumbest implementation of all -- it simply looks at
  71  * a fixed offset and if pack isn't there -- fails. We might want
  72  * to have a fallback mechanism for complete search of missing packs.
  73  */
  74 static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t)
  75 {
  76     int offs;
  77
  78     switch (t) {
  79     case dv_audio_source:
  80         offs = (80*6 + 80*16*3 + 3);
  81         break;
  82     case dv_audio_control:
  83         offs = (80*6 + 80*16*4 + 3);
  84         break;
  85     case dv_video_control:
  86         offs = (80*5 + 48 + 5);
  87         break;
  88     default:
  89         return NULL;
  90     }
  91
  92     return frame[offs] == t ? &frame[offs] : NULL;
  93 }
  94
  95 /*
  96  * There's a couple of assumptions being made here:
  97  * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.
  98  *    We can pass them upwards when ffmpeg will be ready to deal with them.
  99  * 2. We don't do software emphasis.
 100  * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
 101  *    are converted into 16bit linear ones.
 102  */
 103 static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4],
 104                             const DVprofile *sys)
 105 {
 106     int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
 107     uint16_t lc, rc;
 108     const uint8_t* as_pack;
 109     uint8_t *pcm, ipcm;
 110
 111     as_pack = dv_extract_pack(frame, dv_audio_source);
 112     if (!as_pack)    /* No audio ? */
 113         return 0;
 114
 115     smpls =  as_pack[1] & 0x3f;       /* samples in this frame - min. samples */
 116     freq  = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
 117     quant =  as_pack[4] & 0x07;       /* 0 - 16bit linear, 1 - 12bit nonlinear */
 118
 119     if (quant > 1)
 120         return -1; /* unsupported quantization */
 121
 122     size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
 123     half_ch = sys->difseg_size / 2;
 124
 125     /* We work with 720p frames split in half, thus even frames have
 126      * channels 0,1 and odd 2,3. */
 127     ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 2 : 0;
 128     pcm  = ppcm[ipcm++];
 129
 130     /* for each DIF channel */
 131     for (chan = 0; chan < sys->n_difchan; chan++) {
 132         /* for each DIF segment */
 133         for (i = 0; i < sys->difseg_size; i++) {
 134             frame += 6 * 80; /* skip DIF segment header */
 135             if (quant == 1 && i == half_ch) {
 136                 /* next stereo channel (12bit mode only) */
 137                 pcm = ppcm[ipcm++];
 138                 if (!pcm)
 139                     break;
 140             }
 141
 142             /* for each AV sequence */
 143             for (j = 0; j < 9; j++) {
 144                 for (d = 8; d < 80; d += 2) {
 145                     if (quant == 0) {  /* 16bit quantization */
 146                         of = sys->audio_shuffle[i][j] + (d - 8) / 2 * sys->audio_stride;
 147                         if (of*2 >= size)
 148                             continue;
 149
 150                         pcm[of*2]   = frame[d+1]; // FIXME: maybe we have to admit
 151                         pcm[of*2+1] = frame[d];   //        that DV is a big-endian PCM
 152                         if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
 153                             pcm[of*2+1] = 0;
 154                     } else {           /* 12bit quantization */
 155                         lc = ((uint16_t)frame[d]   << 4) |
 156                              ((uint16_t)frame[d+2] >> 4);
 157                         rc = ((uint16_t)frame[d+1] << 4) |
 158                              ((uint16_t)frame[d+2] & 0x0f);
 159                         lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
 160                         rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
 161
 162                         of = sys->audio_shuffle[i%half_ch][j] + (d - 8) / 3 * sys->audio_stride;
 163                         if (of*2 >= size)
 164                             continue;
 165
 166                         pcm[of*2]   = lc & 0xff; // FIXME: maybe we have to admit
 167                         pcm[of*2+1] = lc >> 8;   //        that DV is a big-endian PCM
 168                         of = sys->audio_shuffle[i%half_ch+half_ch][j] +
 169                             (d - 8) / 3 * sys->audio_stride;
 170                         pcm[of*2]   = rc & 0xff; // FIXME: maybe we have to admit
 171                         pcm[of*2+1] = rc >> 8;   //        that DV is a big-endian PCM
 172                         ++d;
 173                     }
 174                 }
 175
 176                 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
 177             }
 178         }
 179
 180         /* next stereo channel (50Mbps and 100Mbps only) */
 181         pcm = ppcm[ipcm++];
 182         if (!pcm)
 183             break;
 184     }
 185
 186     return size;
 187 }
 188
 189 static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
 190 {
 191     const uint8_t* as_pack;
 192     int freq, stype, smpls, quant, i, ach;
 193
 194     as_pack = dv_extract_pack(frame, dv_audio_source);
 195     if (!as_pack || !c->sys) {    /* No audio ? */
 196         c->ach = 0;
 197         return 0;
 198     }
 199
 200     smpls =  as_pack[1] & 0x3f;       /* samples in this frame - min. samples */
 201     freq  = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
 202     stype = (as_pack[3] & 0x1f);      /* 0 - 2CH, 2 - 4CH, 3 - 8CH */
 203     quant =  as_pack[4] & 0x07;       /* 0 - 16bit linear, 1 - 12bit nonlinear */
 204
 205     /* note: ach counts PAIRS of channels (i.e. stereo channels) */
 206     ach = ((int[4]){  1,  0,  2,  4})[stype];
 207     if (ach == 1 && quant && freq == 2)
 208         ach = 2;
 209
 210     /* Dynamic handling of the audio streams in DV */
 211     for (i = 0; i < ach; i++) {
 212        if (!c->ast[i]) {
 213            c->ast[i] = av_new_stream(c->fctx, 0);
 214            if (!c->ast[i])
 215                break;
 216            av_set_pts_info(c->ast[i], 64, 1, 30000);
 217            c->ast[i]->codec->codec_type = CODEC_TYPE_AUDIO;
 218            c->ast[i]->codec->codec_id   = CODEC_ID_PCM_S16LE;
 219
 220            av_init_packet(&c->audio_pkt[i]);
 221            c->audio_pkt[i].size         = 0;
 222            c->audio_pkt[i].data         = c->audio_buf[i];
 223            c->audio_pkt[i].stream_index = c->ast[i]->index;
 224            c->audio_pkt[i].flags       |= PKT_FLAG_KEY;
 225        }
 226        c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
 227        c->ast[i]->codec->channels    = 2;
 228        c->ast[i]->codec->bit_rate    = 2 * dv_audio_frequency[freq] * 16;
 229        c->ast[i]->start_time         = 0;
 230     }
 231     c->ach = i;
 232
 233     return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
 234 }
 235
 236 static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
 237 {
 238     const uint8_t* vsc_pack;
 239     AVCodecContext* avctx;
 240     int apt, is16_9;
 241     int size = 0;
 242
 243     if (c->sys) {
 244         avctx = c->vst->codec;
 245
 246         av_set_pts_info(c->vst, 64, c->sys->time_base.num,
 247                         c->sys->time_base.den);
 248         avctx->time_base= c->sys->time_base;
 249         if (!avctx->width){
 250             avctx->width = c->sys->width;
 251             avctx->height = c->sys->height;
 252         }
 253         avctx->pix_fmt = c->sys->pix_fmt;
 254
 255         /* finding out SAR is a little bit messy */
 256         vsc_pack = dv_extract_pack(frame, dv_video_control);
 257         apt      = frame[4] & 0x07;
 258         is16_9   = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
 259                                 (!apt && (vsc_pack[2] & 0x07) == 0x07)));
 260         c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
 261         avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1},
 262                                        c->sys->time_base);
 263         size = c->sys->frame_size;
 264     }
 265     return size;
 266 }
 267
 268 /*
 269  * The following 3 functions constitute our interface to the world
 270  */
 271
 272 DVDemuxContext* dv_init_demux(AVFormatContext *s)
 273 {
 274     DVDemuxContext *c;
 275
 276     c = av_mallocz(sizeof(DVDemuxContext));
 277     if (!c)
 278         return NULL;
 279
 280     c->vst = av_new_stream(s, 0);
 281     if (!c->vst) {
 282         av_free(c);
 283         return NULL;
 284     }
 285
 286     c->sys  = NULL;
 287     c->fctx = s;
 288     memset(c->ast, 0, sizeof(c->ast));
 289     c->ach    = 0;
 290     c->frames = 0;
 291     c->abytes = 0;
 292
 293     c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
 294     c->vst->codec->codec_id   = CODEC_ID_DVVIDEO;
 295     c->vst->codec->bit_rate   = 25000000;
 296     c->vst->start_time        = 0;
 297
 298     return c;
 299 }
 300
 301 int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
 302 {
 303     int size = -1;
 304     int i;
 305
 306     for (i = 0; i < c->ach; i++) {
 307        if (c->ast[i] && c->audio_pkt[i].size) {
 308            *pkt = c->audio_pkt[i];
 309            c->audio_pkt[i].size = 0;
 310            size = pkt->size;
 311            break;
 312        }
 313     }
 314
 315     return size;
 316 }
 317
 318 int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
 319                       uint8_t* buf, int buf_size)
 320 {
 321     int size, i;
 322     uint8_t *ppcm[4] = {0};
 323
 324     if (buf_size < DV_PROFILE_BYTES ||
 325         !(c->sys = dv_frame_profile(buf)) ||
 326         buf_size < c->sys->frame_size) {
 327           return -1;   /* Broken frame, or not enough data */
 328     }
 329
 330     /* Queueing audio packet */
 331     /* FIXME: in case of no audio/bad audio we have to do something */
 332     size = dv_extract_audio_info(c, buf);
 333     for (i = 0; i < c->ach; i++) {
 334        c->audio_pkt[i].size = size;
 335        c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
 336        ppcm[i] = c->audio_buf[i];
 337     }
 338     dv_extract_audio(buf, ppcm, c->sys);
 339     c->abytes += size;
 340
 341     /* We work with 720p frames split in half, thus even frames have
 342      * channels 0,1 and odd 2,3. */
 343     if (c->sys->height == 720) {
 344         if (buf[1] & 0x0C)
 345             c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
 346         else
 347             c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
 348     }
 349
 350     /* Now it's time to return video packet */
 351     size = dv_extract_video_info(c, buf);
 352     av_init_packet(pkt);
 353     pkt->data         = buf;
 354     pkt->size         = size;
 355     pkt->flags       |= PKT_FLAG_KEY;
 356     pkt->stream_index = c->vst->id;
 357     pkt->pts          = c->frames;
 358
 359     c->frames++;
 360
 361     return size;
 362 }
 363
 364 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
 365                               int64_t timestamp, int flags)
 366 {
 367     // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
 368     const DVprofile* sys = dv_codec_profile(c->vst->codec);
 369     int64_t offset;
 370     int64_t size = url_fsize(s->pb);
 371     int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
 372
 373     offset = sys->frame_size * timestamp;
 374
 375     if (offset > max_offset) offset = max_offset;
 376     else if (offset < 0) offset = 0;
 377
 378     return offset;
 379 }
 380
 381 void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
 382 {
 383     c->frames= frame_offset;
 384     if (c->ach)
 385         c->abytes= av_rescale_q(c->frames, c->sys->time_base,
 386                                 (AVRational){8, c->ast[0]->codec->bit_rate});
 387     c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
 388     c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
 389 }
 390
 391 /************************************************************
 392  * Implementation of the easiest DV storage of all -- raw DV.
 393  ************************************************************/
 394
 395 typedef struct RawDVContext {
 396     DVDemuxContext* dv_demux;
 397     uint8_t         buf[DV_MAX_FRAME_SIZE];
 398 } RawDVContext;
 399
 400 static int dv_read_header(AVFormatContext *s,
 401                           AVFormatParameters *ap)
 402 {
 403     unsigned state;
 404     RawDVContext *c = s->priv_data;
 405
 406     c->dv_demux = dv_init_demux(s);
 407     if (!c->dv_demux)
 408         return -1;
 409
 410     state = get_be32(s->pb);
 411     while ((state & 0xffffff7f) != 0x1f07003f) {
 412         if (url_feof(s->pb)) {
 413             av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n");
 414             return -1;
 415         }
 416         state = (state << 8) | get_byte(s->pb);
 417     }
 418     AV_WB32(c->buf, state);
 419
 420     if (get_buffer(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) <= 0 ||
 421         url_fseek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
 422         return AVERROR(EIO);
 423
 424     c->dv_demux->sys = dv_frame_profile(c->buf);
 425     if (!c->dv_demux->sys) {
 426         av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
 427         return -1;
 428     }
 429
 430     s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1},
 431                                c->dv_demux->sys->time_base);
 432
 433     return 0;
 434 }
 435
 436
 437 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
 438 {
 439     int size;
 440     RawDVContext *c = s->priv_data;
 441
 442     size = dv_get_packet(c->dv_demux, pkt);
 443
 444     if (size < 0) {
 445         if (!c->dv_demux->sys)
 446             return AVERROR(EIO);
 447         size = c->dv_demux->sys->frame_size;
 448         if (get_buffer(s->pb, c->buf, size) <= 0)
 449             return AVERROR(EIO);
 450
 451         size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
 452     }
 453
 454     return size;
 455 }
 456
 457 static int dv_read_seek(AVFormatContext *s, int stream_index,
 458                        int64_t timestamp, int flags)
 459 {
 460     RawDVContext *r   = s->priv_data;
 461     DVDemuxContext *c = r->dv_demux;
 462     int64_t offset    = dv_frame_offset(s, c, timestamp, flags);
 463
 464     dv_offset_reset(c, offset / c->sys->frame_size);
 465
 466     offset = url_fseek(s->pb, offset, SEEK_SET);
 467     return (offset < 0) ? offset : 0;
 468 }
 469
 470 static int dv_read_close(AVFormatContext *s)
 471 {
 472     RawDVContext *c = s->priv_data;
 473     av_free(c->dv_demux);
 474     return 0;
 475 }
 476
 477 static int dv_probe(AVProbeData *p)
 478 {
 479     unsigned state;
 480     int i;
 481
 482     if (p->buf_size < 5)
 483         return 0;
 484
 485     state = AV_RB32(p->buf);
 486     for (i = 4; i < p->buf_size; i++) {
 487         if ((state & 0xffffff7f) == 0x1f07003f)
 488             return AVPROBE_SCORE_MAX*3/4; // not max to avoid dv in mov to match
 489         state = (state << 8) | p->buf[i];
 490     }
 491
 492     return 0;
 493 }
 494
 495 #if CONFIG_DV_DEMUXER
 496 AVInputFormat dv_demuxer = {
 497     "dv",
 498     NULL_IF_CONFIG_SMALL("DV video format"),
 499     sizeof(RawDVContext),
 500     dv_probe,
 501     dv_read_header,
 502     dv_read_packet,
 503     dv_read_close,
 504     dv_read_seek,
 505     .extensions = "dv,dif",
 506 };
 507 #endif