libavcodec/dvdec.c

   1 /*
   2  * DV decoder
   3  * Copyright (c) 2002 Fabrice Bellard
   4  * Copyright (c) 2004 Roman Shaposhnik
   5  *
   6  * 50 Mbps (DVCPRO50) support
   7  * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
   8  *
   9  * 100 Mbps (DVCPRO HD) support
  10  * Initial code by Daniel Maas <dmaas@maasdigital.com> (funded by BBC R&D)
  11  * Final code by Roman Shaposhnik
  12  *
  13  * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
  14  * of DV technical info.
  15  *
  16  * This file is part of Libav.
  17  *
  18  * Libav is free software; you can redistribute it and/or
  19  * modify it under the terms of the GNU Lesser General Public
  20  * License as published by the Free Software Foundation; either
  21  * version 2.1 of the License, or (at your option) any later version.
  22  *
  23  * Libav is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  26  * Lesser General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU Lesser General Public
  29  * License along with Libav; if not, write to the Free Software
  30  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  31  */
  32
  33 /**
  34  * @file
  35  * DV decoder
  36  */
  37
  38 #include "libavutil/pixdesc.h"
  39 #include "avcodec.h"
  40 #include "dsputil.h"
  41 #include "get_bits.h"
  42 #include "put_bits.h"
  43 #include "simple_idct.h"
  44 #include "dvdata.h"
  45
  46 typedef struct BlockInfo {
  47     const uint32_t *factor_table;
  48     const uint8_t *scan_table;
  49     uint8_t pos; /* position in block */
  50     void (*idct_put)(uint8_t *dest, int line_size, DCTELEM *block);
  51     uint8_t partial_bit_count;
  52     uint32_t partial_bit_buffer;
  53     int shift_offset;
  54 } BlockInfo;
  55
  56 static const int dv_iweight_bits = 14;
  57
  58 /* decode AC coefficients */
  59 static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, DCTELEM *block)
  60 {
  61     int last_index = gb->size_in_bits;
  62     const uint8_t  *scan_table   = mb->scan_table;
  63     const uint32_t *factor_table = mb->factor_table;
  64     int pos               = mb->pos;
  65     int partial_bit_count = mb->partial_bit_count;
  66     int level, run, vlc_len, index;
  67
  68     OPEN_READER(re, gb);
  69     UPDATE_CACHE(re, gb);
  70
  71     /* if we must parse a partial VLC, we do it here */
  72     if (partial_bit_count > 0) {
  73         re_cache = re_cache >> partial_bit_count | mb->partial_bit_buffer;
  74         re_index -= partial_bit_count;
  75         mb->partial_bit_count = 0;
  76     }
  77
  78     /* get the AC coefficients until last_index is reached */
  79     for (;;) {
  80         av_dlog(NULL, "%2d: bits=%04x index=%d\n", pos, SHOW_UBITS(re, gb, 16),
  81                 re_index);
  82         /* our own optimized GET_RL_VLC */
  83         index   = NEG_USR32(re_cache, TEX_VLC_BITS);
  84         vlc_len = ff_dv_rl_vlc[index].len;
  85         if (vlc_len < 0) {
  86             index = NEG_USR32((unsigned)re_cache << TEX_VLC_BITS, -vlc_len) +
  87                     ff_dv_rl_vlc[index].level;
  88             vlc_len = TEX_VLC_BITS - vlc_len;
  89         }
  90         level = ff_dv_rl_vlc[index].level;
  91         run   = ff_dv_rl_vlc[index].run;
  92
  93         /* gotta check if we're still within gb boundaries */
  94         if (re_index + vlc_len > last_index) {
  95             /* should be < 16 bits otherwise a codeword could have been parsed */
  96             mb->partial_bit_count = last_index - re_index;
  97             mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
  98             re_index = last_index;
  99             break;
 100         }
 101         re_index += vlc_len;
 102
 103         av_dlog(NULL, "run=%d level=%d\n", run, level);
 104         pos += run;
 105         if (pos >= 64)
 106             break;
 107
 108         level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >> dv_iweight_bits;
 109         block[scan_table[pos]] = level;
 110
 111         UPDATE_CACHE(re, gb);
 112     }
 113     CLOSE_READER(re, gb);
 114     mb->pos = pos;
 115 }
 116
 117 static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)
 118 {
 119     int bits_left = get_bits_left(gb);
 120     while (bits_left >= MIN_CACHE_BITS) {
 121         put_bits(pb, MIN_CACHE_BITS, get_bits(gb, MIN_CACHE_BITS));
 122         bits_left -= MIN_CACHE_BITS;
 123     }
 124     if (bits_left > 0) {
 125         put_bits(pb, bits_left, get_bits(gb, bits_left));
 126     }
 127 }
 128
 129 /* mb_x and mb_y are in units of 8 pixels */
 130 static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
 131 {
 132     DVVideoContext *s = avctx->priv_data;
 133     DVwork_chunk *work_chunk = arg;
 134     int quant, dc, dct_mode, class1, j;
 135     int mb_index, mb_x, mb_y, last_index;
 136     int y_stride, linesize;
 137     DCTELEM *block, *block1;
 138     int c_offset;
 139     uint8_t *y_ptr;
 140     const uint8_t *buf_ptr;
 141     PutBitContext pb, vs_pb;
 142     GetBitContext gb;
 143     BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;
 144     LOCAL_ALIGNED_16(DCTELEM, sblock, [5*DV_MAX_BPM], [64]);
 145     LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [  80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
 146     LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [5*80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
 147     const int log2_blocksize = 3;
 148     int is_field_mode[5];
 149
 150     assert((((int)mb_bit_buffer) & 7) == 0);
 151     assert((((int)vs_bit_buffer) & 7) == 0);
 152
 153     memset(sblock, 0, 5*DV_MAX_BPM*sizeof(*sblock));
 154
 155     /* pass 1: read DC and AC coefficients in blocks */
 156     buf_ptr = &s->buf[work_chunk->buf_offset*80];
 157     block1  = &sblock[0][0];
 158     mb1     = mb_data;
 159     init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);
 160     for (mb_index = 0; mb_index < 5; mb_index++, mb1 += s->sys->bpm, block1 += s->sys->bpm * 64) {
 161         /* skip header */
 162         quant = buf_ptr[3] & 0x0f;
 163         buf_ptr += 4;
 164         init_put_bits(&pb, mb_bit_buffer, 80);
 165         mb    = mb1;
 166         block = block1;
 167         is_field_mode[mb_index] = 0;
 168         for (j = 0; j < s->sys->bpm; j++) {
 169             last_index = s->sys->block_sizes[j];
 170             init_get_bits(&gb, buf_ptr, last_index);
 171
 172             /* get the DC */
 173             dc       = get_sbits(&gb, 9);
 174             dct_mode = get_bits1(&gb);
 175             class1   = get_bits(&gb, 2);
 176             if (DV_PROFILE_IS_HD(s->sys)) {
 177                 mb->idct_put     = s->idct_put[0];
 178                 mb->scan_table   = s->dv_zigzag[0];
 179                 mb->factor_table = &s->sys->idct_factor[(j >= 4)*4*16*64 + class1*16*64 + quant*64];
 180                 is_field_mode[mb_index] |= !j && dct_mode;
 181             } else {
 182                 mb->idct_put     = s->idct_put[dct_mode && log2_blocksize == 3];
 183                 mb->scan_table   = s->dv_zigzag[dct_mode];
 184                 mb->factor_table = &s->sys->idct_factor[(class1 == 3)*2*22*64 + dct_mode*22*64 +
 185                                                         (quant + ff_dv_quant_offset[class1])*64];
 186             }
 187             dc = dc << 2;
 188             /* convert to unsigned because 128 is not added in the
 189                standard IDCT */
 190             dc += 1024;
 191             block[0] = dc;
 192             buf_ptr += last_index >> 3;
 193             mb->pos               = 0;
 194             mb->partial_bit_count = 0;
 195
 196             av_dlog(avctx, "MB block: %d, %d ", mb_index, j);
 197             dv_decode_ac(&gb, mb, block);
 198
 199             /* write the remaining bits in a new buffer only if the
 200                block is finished */
 201             if (mb->pos >= 64)
 202                 bit_copy(&pb, &gb);
 203
 204             block += 64;
 205             mb++;
 206         }
 207
 208         /* pass 2: we can do it just after */
 209         av_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);
 210         block = block1;
 211         mb    = mb1;
 212         init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));
 213         put_bits32(&pb, 0); // padding must be zeroed
 214         flush_put_bits(&pb);
 215         for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {
 216             if (mb->pos < 64 && get_bits_left(&gb) > 0) {
 217                 dv_decode_ac(&gb, mb, block);
 218                 /* if still not finished, no need to parse other blocks */
 219                 if (mb->pos < 64)
 220                     break;
 221             }
 222         }
 223         /* all blocks are finished, so the extra bytes can be used at
 224            the video segment level */
 225         if (j >= s->sys->bpm)
 226             bit_copy(&vs_pb, &gb);
 227     }
 228
 229     /* we need a pass over the whole video segment */
 230     av_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));
 231     block = &sblock[0][0];
 232     mb    = mb_data;
 233     init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));
 234     put_bits32(&vs_pb, 0); // padding must be zeroed
 235     flush_put_bits(&vs_pb);
 236     for (mb_index = 0; mb_index < 5; mb_index++) {
 237         for (j = 0; j < s->sys->bpm; j++) {
 238             if (mb->pos < 64) {
 239                 av_dlog(avctx, "start %d:%d\n", mb_index, j);
 240                 dv_decode_ac(&gb, mb, block);
 241             }
 242             if (mb->pos >= 64 && mb->pos < 127)
 243                 av_log(avctx, AV_LOG_ERROR, "AC EOB marker is absent pos=%d\n", mb->pos);
 244             block += 64;
 245             mb++;
 246         }
 247     }
 248
 249     /* compute idct and place blocks */
 250     block = &sblock[0][0];
 251     mb    = mb_data;
 252     for (mb_index = 0; mb_index < 5; mb_index++) {
 253         dv_calculate_mb_xy(s, work_chunk, mb_index, &mb_x, &mb_y);
 254
 255         /* idct_put'ting luminance */
 256         if ((s->sys->pix_fmt == PIX_FMT_YUV420P) ||
 257             (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x >= (704 / 8)) ||
 258             (s->sys->height >= 720 && mb_y != 134)) {
 259             y_stride = (s->picture.linesize[0] << ((!is_field_mode[mb_index]) * log2_blocksize));
 260         } else {
 261             y_stride = (2 << log2_blocksize);
 262         }
 263         y_ptr = s->picture.data[0] + ((mb_y * s->picture.linesize[0] + mb_x) << log2_blocksize);
 264         linesize = s->picture.linesize[0] << is_field_mode[mb_index];
 265         mb[0]    .idct_put(y_ptr                                   , linesize, block + 0*64);
 266         if (s->sys->video_stype == 4) { /* SD 422 */
 267             mb[2].idct_put(y_ptr + (1 << log2_blocksize)           , linesize, block + 2*64);
 268         } else {
 269             mb[1].idct_put(y_ptr + (1 << log2_blocksize)           , linesize, block + 1*64);
 270             mb[2].idct_put(y_ptr                         + y_stride, linesize, block + 2*64);
 271             mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride, linesize, block + 3*64);
 272         }
 273         mb += 4;
 274         block += 4*64;
 275
 276         /* idct_put'ting chrominance */
 277         c_offset = (((mb_y >>  (s->sys->pix_fmt == PIX_FMT_YUV420P)) * s->picture.linesize[1] +
 278                      (mb_x >> ((s->sys->pix_fmt == PIX_FMT_YUV411P) ? 2 : 1))) << log2_blocksize);
 279         for (j = 2; j; j--) {
 280             uint8_t *c_ptr = s->picture.data[j] + c_offset;
 281             if (s->sys->pix_fmt == PIX_FMT_YUV411P && mb_x >= (704 / 8)) {
 282                   uint64_t aligned_pixels[64/8];
 283                   uint8_t *pixels = (uint8_t*)aligned_pixels;
 284                   uint8_t *c_ptr1, *ptr1;
 285                   int x, y;
 286                   mb->idct_put(pixels, 8, block);
 287                   for (y = 0; y < (1 << log2_blocksize); y++, c_ptr += s->picture.linesize[j], pixels += 8) {
 288                       ptr1   = pixels + (1 << (log2_blocksize - 1));
 289                       c_ptr1 = c_ptr + (s->picture.linesize[j] << log2_blocksize);
 290                       for (x = 0; x < (1 << (log2_blocksize - 1)); x++) {
 291                           c_ptr[x]  = pixels[x];
 292                           c_ptr1[x] = ptr1[x];
 293                       }
 294                   }
 295                   block += 64; mb++;
 296             } else {
 297                   y_stride = (mb_y == 134) ? (1 << log2_blocksize) :
 298                                              s->picture.linesize[j] << ((!is_field_mode[mb_index]) * log2_blocksize);
 299                   linesize = s->picture.linesize[j] << is_field_mode[mb_index];
 300                   (mb++)->    idct_put(c_ptr           , linesize, block); block += 64;
 301                   if (s->sys->bpm == 8) {
 302                       (mb++)->idct_put(c_ptr + y_stride, linesize, block); block += 64;
 303                   }
 304             }
 305         }
 306     }
 307     return 0;
 308 }
 309
 310 /* NOTE: exactly one frame must be given (120000 bytes for NTSC,
 311    144000 bytes for PAL - or twice those for 50Mbps) */
 312 static int dvvideo_decode_frame(AVCodecContext *avctx,
 313                                  void *data, int *data_size,
 314                                  AVPacket *avpkt)
 315 {
 316     uint8_t *buf = avpkt->data;
 317     int buf_size = avpkt->size;
 318     DVVideoContext *s = avctx->priv_data;
 319     const uint8_t* vsc_pack;
 320     int apt, is16_9;
 321
 322     s->sys = avpriv_dv_frame_profile(s->sys, buf, buf_size);
 323     if (!s->sys || buf_size < s->sys->frame_size || ff_dv_init_dynamic_tables(s->sys)) {
 324         av_log(avctx, AV_LOG_ERROR, "could not find dv frame profile\n");
 325         return -1; /* NOTE: we only accept several full frames */
 326     }
 327
 328     if (s->picture.data[0])
 329         avctx->release_buffer(avctx, &s->picture);
 330
 331     s->picture.reference = 0;
 332     s->picture.key_frame = 1;
 333     s->picture.pict_type = AV_PICTURE_TYPE_I;
 334     avctx->pix_fmt   = s->sys->pix_fmt;
 335     avctx->time_base = s->sys->time_base;
 336     avcodec_set_dimensions(avctx, s->sys->width, s->sys->height);
 337     if (avctx->get_buffer(avctx, &s->picture) < 0) {
 338         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 339         return -1;
 340     }
 341     s->picture.interlaced_frame = 1;
 342     s->picture.top_field_first  = 0;
 343
 344     s->buf = buf;
 345     avctx->execute(avctx, dv_decode_video_segment, s->sys->work_chunks, NULL,
 346                    dv_work_pool_size(s->sys), sizeof(DVwork_chunk));
 347
 348     emms_c();
 349
 350     /* return image */
 351     *data_size = sizeof(AVFrame);
 352     *(AVFrame*)data = s->picture;
 353
 354     /* Determine the codec's sample_aspect ratio from the packet */
 355     vsc_pack = buf + 80*5 + 48 + 5;
 356     if ( *vsc_pack == dv_video_control ) {
 357         apt = buf[4] & 0x07;
 358         is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 || (!apt && (vsc_pack[2] & 0x07) == 0x07)));
 359         avctx->sample_aspect_ratio = s->sys->sar[is16_9];
 360     }
 361
 362     return s->sys->frame_size;
 363 }
 364
 365 static int dvvideo_close(AVCodecContext *c)
 366 {
 367     DVVideoContext *s = c->priv_data;
 368
 369     if (s->picture.data[0])
 370         c->release_buffer(c, &s->picture);
 371
 372     return 0;
 373 }
 374
 375 AVCodec ff_dvvideo_decoder = {
 376     .name           = "dvvideo",
 377     .type           = AVMEDIA_TYPE_VIDEO,
 378     .id             = CODEC_ID_DVVIDEO,
 379     .priv_data_size = sizeof(DVVideoContext),
 380     .init           = ff_dvvideo_init,
 381     .close          = dvvideo_close,
 382     .decode         = dvvideo_decode_frame,
 383     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,
 384     .long_name      = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),
 385 };