libhb/decsub.c

   1 /* $Id: decsub.c,v 1.12 2005/04/14 17:37:54 titer Exp $
   2
   3    This file is part of the HandBrake source code.
   4    Homepage: <http://handbrake.m0k.org/>.
   5    It may be used under the terms of the GNU General Public License. */
   6
   7 #include "hb.h"
   8
   9 struct hb_work_private_s
  10 {
  11     hb_job_t * job;
  12
  13     uint8_t    buf[0xFFFF];
  14     int        size_sub;
  15     int        size_got;
  16     int        size_rle;
  17     int64_t    pts;
  18     int64_t    pts_start;
  19     int64_t    pts_stop;
  20     int        pts_forced;
  21     int        x;
  22     int        y;
  23     int        width;
  24     int        height;
  25     int        stream_id;
  26
  27     int        offsets[2];
  28     uint8_t    lum[4];
  29     uint8_t    chromaU[4];
  30     uint8_t    chromaV[4];
  31     uint8_t    alpha[4];
  32 };
  33
  34 static hb_buffer_t * Decode( hb_work_object_t * );
  35
  36 int decsubInit( hb_work_object_t * w, hb_job_t * job )
  37 {
  38     hb_work_private_t * pv;
  39
  40     pv              = calloc( 1, sizeof( hb_work_private_t ) );
  41     w->private_data = pv;
  42
  43     pv->job = job;
  44     pv->pts = -1;
  45
  46     return 0;
  47 }
  48
  49 int decsubWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
  50                 hb_buffer_t ** buf_out )
  51 {
  52     hb_work_private_t * pv = w->private_data;
  53     hb_buffer_t * in = *buf_in;
  54
  55     int size_sub, size_rle;
  56
  57     pv->stream_id = in->id;
  58
  59     size_sub = ( in->data[0] << 8 ) | in->data[1];
  60     size_rle = ( in->data[2] << 8 ) | in->data[3];
  61
  62     if( !pv->size_sub )
  63     {
  64         /* We are looking for the start of a new subtitle */
  65         if( size_sub && size_rle && size_sub > size_rle &&
  66             in->size <= size_sub )
  67         {
  68             /* Looks all right so far */
  69             pv->size_sub = size_sub;
  70             pv->size_rle = size_rle;
  71
  72             memcpy( pv->buf, in->data, in->size );
  73             pv->size_got = in->size;
  74             pv->pts      = in->start;
  75         }
  76     }
  77     else
  78     {
  79         /* We are waiting for the end of the current subtitle */
  80         if( in->size <= pv->size_sub - pv->size_got )
  81         {
  82             memcpy( pv->buf + pv->size_got, in->data, in->size );
  83             pv->size_got += in->size;
  84             if( in->start >= 0 )
  85             {
  86                 pv->pts = in->start;
  87             }
  88         }
  89     }
  90
  91     *buf_out = NULL;
  92
  93     if( pv->size_sub && pv->size_sub == pv->size_got )
  94     {
  95         /* We got a complete subtitle, decode it */
  96         *buf_out = Decode( w );
  97
  98         if( buf_out && *buf_out )
  99         {
 100             (*buf_out)->sequence = in->sequence;
 101         }
 102
 103         /* Wait for the next one */
 104         pv->size_sub = 0;
 105         pv->size_got = 0;
 106         pv->size_rle = 0;
 107         pv->pts      = -1;
 108     }
 109
 110     return HB_WORK_OK;
 111 }
 112
 113 void decsubClose( hb_work_object_t * w )
 114 {
 115     free( w->private_data );
 116 }
 117
 118 hb_work_object_t hb_decsub =
 119 {
 120     WORK_DECSUB,
 121     "Subtitle decoder",
 122     decsubInit,
 123     decsubWork,
 124     decsubClose
 125 };
 126
 127
 128 /***********************************************************************
 129  * ParseControls
 130  ***********************************************************************
 131  * Get the start and end dates (relative to the PTS from the PES
 132  * header), the width and height of the subpicture and the colors and
 133  * alphas used in it
 134  **********************************************************************/
 135 static void ParseControls( hb_work_object_t * w )
 136 {
 137     hb_work_private_t * pv = w->private_data;
 138     hb_job_t * job = pv->job;
 139     hb_title_t * title = job->title;
 140     hb_subtitle_t * subtitle;
 141
 142     int i, n;
 143     int command;
 144     int date, next;
 145
 146     pv->pts_start = 0;
 147     pv->pts_stop  = 0;
 148     pv->pts_forced  = 0;
 149
 150     pv->alpha[3] = 0;
 151     pv->alpha[2] = 0;
 152     pv->alpha[1] = 0;
 153     pv->alpha[0] = 0;
 154
 155     for( i = pv->size_rle; ; )
 156     {
 157         date = ( pv->buf[i] << 8 ) | pv->buf[i+1]; i += 2;
 158         next = ( pv->buf[i] << 8 ) | pv->buf[i+1]; i += 2;
 159
 160         for( ;; )
 161         {
 162             command = pv->buf[i++];
 163
 164             /*
 165              * There are eight commands available for
 166              * Sub-Pictures. The first SP_DCSQ should contain, as a
 167              * minimum, SET_COLOR, SET_CONTR, SET_DAREA, and
 168              * SET_DSPXA
 169              */
 170
 171             if( command == 0xFF ) // 0xFF - CMD_END - ends one SP_DCSQ
 172             {
 173                 break;
 174             }
 175
 176             switch( command )
 177             {
 178                 case 0x00: // 0x00 - FSTA_DSP - Forced Start Display, no arguments
 179                     pv->pts_start = pv->pts + date * 900;
 180                     pv->pts_forced = 1;
 181
 182                     /*
 183                      * If we are doing a subtitle scan then note down
 184                      */
 185                     if( job->indepth_scan )
 186                     {
 187                         for( n=0; n < hb_list_count(title->list_subtitle); n++ )
 188                         {
 189                             subtitle = hb_list_item( title->list_subtitle, n);
 190                             if( pv->stream_id == subtitle->id ) {
 191                                 /*
 192                                  * A hit, count it.
 193                                  */
 194                                 subtitle->forced_hits++;
 195                             }
 196                         }
 197                     }
 198                     break;
 199
 200                 case 0x01: // 0x01 - STA_DSP - Start Display, no arguments
 201                     pv->pts_start = pv->pts + date * 900;
 202                     pv->pts_forced  = 0;
 203                     break;
 204
 205                 case 0x02: // 0x02 - STP_DSP - Stop Display, no arguments
 206                     if(!pv->pts_stop)
 207                         pv->pts_stop = pv->pts + date * 900;
 208                     break;
 209
 210                 case 0x03: // 0x03 - SET_COLOR - Set Colour indices
 211                 {
 212                     /*
 213                      * SET_COLOR - provides four indices into the CLUT
 214                      * for the current PGC to associate with the four
 215                      * pixel values
 216                      */
 217                     int colors[4];
 218                     int j;
 219
 220                     colors[0] = (pv->buf[i+0]>>4)&0x0f;
 221                     colors[1] = (pv->buf[i+0])&0x0f;
 222                     colors[2] = (pv->buf[i+1]>>4)&0x0f;
 223                     colors[3] = (pv->buf[i+1])&0x0f;
 224
 225                     for( j = 0; j < 4; j++ )
 226                     {
 227                         /*
 228                          * Not sure what is happening here, in theory
 229                          * the palette is in YCbCr. And we want YUV.
 230                          *
 231                          * However it looks more like YCrCb (according
 232                          * to pgcedit). And the scalers for YCrCb don't
 233                          * work, but I get the right colours by doing
 234                          * no conversion.
 235                          */
 236                         uint32_t color = title->palette[colors[j]];
 237                         uint8_t Cr, Cb, y;
 238                         y = (color>>16) & 0xff;
 239                         Cr = (color>>8) & 0xff;
 240                         Cb = (color) & 0xff;
 241                         pv->lum[3-j] = y;
 242                         pv->chromaU[3-j] = Cb;
 243                         pv->chromaV[3-j] = Cr;
 244                         /* hb_log("color[%d] y = %d, u = %d, v = %d",
 245                                3-j,
 246                                pv->lum[3-j],
 247                                pv->chromaU[3-j],
 248                                pv->chromaV[3-j]);
 249                         */
 250                     }
 251                     i += 2;
 252                     break;
 253                 }
 254                 case 0x04: // 0x04 - SET_CONTR - Set Contrast
 255                 {
 256                     /*
 257                      * SET_CONTR - directly provides the four contrast
 258                      * (alpha blend) values to associate with the four
 259                      * pixel values
 260                      */
 261                     uint8_t    alpha[4];
 262
 263                     alpha[3] = (pv->buf[i+0]>>4)&0x0f;
 264                     alpha[2] = (pv->buf[i+0])&0x0f;
 265                     alpha[1] = (pv->buf[i+1]>>4)&0x0f;
 266                     alpha[0] = (pv->buf[i+1])&0x0f;
 267
 268
 269                     int lastAlpha = pv->alpha[3] + pv->alpha[2] + pv->alpha[1] + pv->alpha[0];
 270                     int currAlpha = alpha[3] + alpha[2] + alpha[1] + alpha[0];
 271
 272                     // fading-in, save the highest alpha value
 273                     if( currAlpha > lastAlpha )
 274                     {
 275                         pv->alpha[3] = alpha[3];
 276                         pv->alpha[2] = alpha[2];
 277                         pv->alpha[1] = alpha[1];
 278                         pv->alpha[0] = alpha[0];
 279                     }
 280
 281                     // fading-out
 282                     if( currAlpha < lastAlpha && !pv->pts_stop )
 283                     {
 284                         pv->pts_stop = pv->pts + date * 900;
 285                     }
 286
 287                     i += 2;
 288                     break;
 289                 }
 290                 case 0x05: // 0x05 - SET_DAREA - defines the display area
 291                 {
 292                     pv->x     = (pv->buf[i+0]<<4) | ((pv->buf[i+1]>>4)&0x0f);
 293                     pv->width = (((pv->buf[i+1]&0x0f)<<8)| pv->buf[i+2]) - pv->x + 1;
 294                     pv->y     = (pv->buf[i+3]<<4)| ((pv->buf[i+4]>>4)&0x0f);
 295                     pv->height = (((pv->buf[i+4]&0x0f)<<8)| pv->buf[i+5]) - pv->y + 1;
 296                     i += 6;
 297                     break;
 298                 }
 299                 case 0x06: // 0x06 - SET_DSPXA - defines the pixel data addresses
 300                 {
 301                     pv->offsets[0] = ( pv->buf[i] << 8 ) | pv->buf[i+1]; i += 2;
 302                     pv->offsets[1] = ( pv->buf[i] << 8 ) | pv->buf[i+1]; i += 2;
 303                     break;
 304                 }
 305             }
 306         }
 307
 308
 309
 310         if( i > next )
 311         {
 312             break;
 313         }
 314         i = next;
 315     }
 316
 317     if( !pv->pts_stop )
 318     {
 319         /* Show it for 3 seconds */
 320         pv->pts_stop = pv->pts_start + 3 * 90000;
 321     }
 322 }
 323
 324 /***********************************************************************
 325  * CropSubtitle
 326  ***********************************************************************
 327  * Given a raw decoded subtitle, detects transparent borders and
 328  * returns a cropped subtitle in a hb_buffer_t ready to be used by
 329  * the renderer, or NULL if the subtitle was completely transparent
 330  **********************************************************************/
 331 static int LineIsTransparent( hb_work_object_t * w, uint8_t * p )
 332 {
 333     hb_work_private_t * pv = w->private_data;
 334     int i;
 335     for( i = 0; i < pv->width; i++ )
 336     {
 337         if( p[i] )
 338         {
 339             return 0;
 340         }
 341     }
 342     return 1;
 343 }
 344 static int ColumnIsTransparent( hb_work_object_t * w, uint8_t * p )
 345 {
 346     hb_work_private_t * pv = w->private_data;
 347     int i;
 348     for( i = 0; i < pv->height; i++ )
 349     {
 350         if( p[i*pv->width] )
 351         {
 352             return 0;
 353         }
 354     }
 355     return 1;
 356 }
 357 static hb_buffer_t * CropSubtitle( hb_work_object_t * w, uint8_t * raw )
 358 {
 359     hb_work_private_t * pv = w->private_data;
 360     int i;
 361     int crop[4] = { -1,-1,-1,-1 };
 362     uint8_t * alpha;
 363     int realwidth, realheight;
 364     hb_buffer_t * buf;
 365     uint8_t * lum_in, * lum_out, * alpha_in, * alpha_out;
 366     uint8_t * u_in, * u_out, * v_in, * v_out;
 367
 368     alpha = raw + pv->width * pv->height;
 369
 370     /* Top */
 371     for( i = 0; i < pv->height; i++ )
 372     {
 373         if( !LineIsTransparent( w, &alpha[i*pv->width] ) )
 374         {
 375             crop[0] = i;
 376             break;
 377         }
 378     }
 379
 380     if( crop[0] < 0 )
 381     {
 382         /* Empty subtitle */
 383         return NULL;
 384     }
 385
 386     /* Bottom */
 387     for( i = pv->height - 1; i >= 0; i-- )
 388     {
 389         if( !LineIsTransparent( w, &alpha[i*pv->width] ) )
 390         {
 391             crop[1] = i;
 392             break;
 393         }
 394     }
 395
 396     /* Left */
 397     for( i = 0; i < pv->width; i++ )
 398     {
 399         if( !ColumnIsTransparent( w, &alpha[i] ) )
 400         {
 401             crop[2] = i;
 402             break;
 403         }
 404     }
 405
 406     /* Right */
 407     for( i = pv->width - 1; i >= 0; i-- )
 408     {
 409         if( !ColumnIsTransparent( w, &alpha[i] ) )
 410         {
 411             crop[3] = i;
 412             break;
 413         }
 414     }
 415
 416     realwidth  = crop[3] - crop[2] + 1;
 417     realheight = crop[1] - crop[0] + 1;
 418
 419     buf         = hb_buffer_init( realwidth * realheight * 4 );
 420     buf->start  = pv->pts_start;
 421     buf->stop   = pv->pts_stop;
 422     buf->x      = pv->x + crop[2];
 423     buf->y      = pv->y + crop[0];
 424     buf->width  = realwidth;
 425     buf->height = realheight;
 426
 427     lum_in    = raw + crop[0] * pv->width + crop[2];
 428     alpha_in  = lum_in + pv->width * pv->height;
 429     u_in      = alpha_in + pv->width * pv->height;
 430     v_in      = u_in + pv->width * pv->height;
 431
 432     lum_out   = buf->data;
 433     alpha_out = lum_out + realwidth * realheight;
 434     u_out     = alpha_out + realwidth * realheight;
 435     v_out     = u_out + realwidth * realheight;
 436
 437     for( i = 0; i < realheight; i++ )
 438     {
 439         memcpy( lum_out, lum_in, realwidth );
 440         memcpy( alpha_out, alpha_in, realwidth );
 441         memcpy( u_out, u_in, realwidth );
 442         memcpy( v_out, v_in, realwidth );
 443
 444         lum_in    += pv->width;
 445         alpha_in  += pv->width;
 446         u_in      += pv->width;
 447         v_in      += pv->width;
 448
 449         lum_out   += realwidth;
 450         alpha_out += realwidth;
 451         u_out     += realwidth;
 452         v_out     += realwidth;
 453     }
 454
 455     return buf;
 456 }
 457
 458 static hb_buffer_t * Decode( hb_work_object_t * w )
 459 {
 460     hb_work_private_t * pv = w->private_data;
 461     int code, line, col;
 462     int offsets[2];
 463     int * offset;
 464     hb_buffer_t * buf;
 465     uint8_t * buf_raw = NULL;
 466     hb_job_t * job = pv->job;
 467
 468     /* Get infos about the subtitle */
 469     ParseControls( w );
 470
 471     if( job->indepth_scan || ( job->subtitle_force && pv->pts_forced == 0 ) )
 472     {
 473         /*
 474          * Don't encode subtitles when doing a scan.
 475          *
 476          * When forcing subtitles, ignore all those that don't
 477          * have the forced flag set.
 478          */
 479         return NULL;
 480     }
 481
 482     /* Do the actual decoding now */
 483     buf_raw = malloc( ( pv->width * pv->height ) * 4 );
 484
 485 #define GET_NEXT_NIBBLE code = ( code << 4 ) | ( ( ( *offset & 1 ) ? \
 486 ( pv->buf[((*offset)>>1)] & 0xF ) : ( pv->buf[((*offset)>>1)] >> 4 ) ) ); \
 487 (*offset)++
 488
 489     offsets[0] = pv->offsets[0] * 2;
 490     offsets[1] = pv->offsets[1] * 2;
 491
 492     for( line = 0; line < pv->height; line++ )
 493     {
 494         /* Select even or odd field */
 495         offset = ( line & 1 ) ? &offsets[1] : &offsets[0];
 496
 497         for( col = 0; col < pv->width; col += code >> 2 )
 498         {
 499             uint8_t * lum, * alpha,  * chromaU, * chromaV;
 500
 501             code = 0;
 502             GET_NEXT_NIBBLE;
 503             if( code < 0x4 )
 504             {
 505                 GET_NEXT_NIBBLE;
 506                 if( code < 0x10 )
 507                 {
 508                     GET_NEXT_NIBBLE;
 509                     if( code < 0x40 )
 510                     {
 511                         GET_NEXT_NIBBLE;
 512                         if( code < 0x100 )
 513                         {
 514                             /* End of line */
 515                             code |= ( pv->width - col ) << 2;
 516                         }
 517                     }
 518                 }
 519             }
 520
 521             lum   = buf_raw;
 522             alpha = lum + pv->width * pv->height;
 523             chromaU = alpha + pv->width * pv->height;
 524             chromaV = chromaU + pv->width * pv->height;
 525
 526             memset( lum + line * pv->width + col,
 527                     pv->lum[code & 3], code >> 2 );
 528             memset( alpha + line * pv->width + col,
 529                     pv->alpha[code & 3], code >> 2 );
 530             memset( chromaU + line * pv->width + col,
 531                     pv->chromaU[code & 3], code >> 2 );
 532             memset( chromaV + line * pv->width + col,
 533                     pv->chromaV[code & 3], code >> 2 );
 534         }
 535
 536         /* Byte-align */
 537         if( *offset & 1 )
 538         {
 539             (*offset)++;
 540         }
 541     }
 542
 543     /* Crop subtitle (remove transparent borders) */
 544     buf = CropSubtitle( w, buf_raw );
 545
 546     free( buf_raw );
 547
 548     return buf;
 549 }