modules/codec/cdg.c

   1 /*****************************************************************************
   2  * cdg.c: CDG decoder module
   3  *****************************************************************************
   4  * Copyright (C) 2007 Laurent Aimar
   5  *
   6  * Authors: Laurent Aimar <fenrir # via.ecp.fr>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24  * Preamble
  25  *****************************************************************************/
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <vlc_common.h>
  31 #include <vlc_plugin.h>
  32 #include <vlc_codec.h>
  33
  34 /*****************************************************************************
  35  * decoder_sys_t : decoder descriptor
  36  *****************************************************************************/
  37
  38 /* The screen size */
  39 #define CDG_SCREEN_WIDTH 300u
  40 #define CDG_SCREEN_HEIGHT 216u
  41
  42 /* The border of the screen size */
  43 #define CDG_SCREEN_BORDER_WIDTH 6u
  44 #define CDG_SCREEN_BORDER_HEIGHT 12u
  45
  46 /* The display part */
  47 #define CDG_DISPLAY_WIDTH  (CDG_SCREEN_WIDTH-2*CDG_SCREEN_BORDER_WIDTH)
  48 #define CDG_DISPLAY_HEIGHT (CDG_SCREEN_HEIGHT-2*CDG_SCREEN_BORDER_HEIGHT)
  49
  50 #define CDG_SCREEN_PITCH CDG_SCREEN_WIDTH
  51
  52 typedef struct
  53 {
  54     uint8_t  color[16][3];
  55     unsigned i_offseth;
  56     unsigned i_offsetv;
  57     uint8_t  screen[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
  58     uint8_t  *p_screen;
  59
  60     int      i_packet;
  61 } decoder_sys_t;
  62
  63 #define CDG_PACKET_SIZE 24u
  64
  65 #define CDG_COLOR_R_SHIFT  0
  66 #define CDG_COLOR_G_SHIFT  8
  67 #define CDG_COLOR_B_SHIFT 16
  68
  69 /*****************************************************************************
  70  * Local prototypes
  71  *****************************************************************************/
  72 static int  Open ( vlc_object_t * );
  73 static void Close( vlc_object_t * );
  74
  75 static int Decode( decoder_t *, block_t * );
  76
  77 static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer );
  78 static void Flush( decoder_t * );
  79 static int Render( decoder_sys_t *p_cdg, picture_t *p_picture );
  80
  81 /*****************************************************************************
  82  * Module descriptor
  83  *****************************************************************************/
  84 vlc_module_begin ()
  85     set_category( CAT_INPUT )
  86     set_subcategory( SUBCAT_INPUT_VCODEC )
  87     set_description( N_("CDG video decoder") )
  88     set_capability( "video decoder", 1000 )
  89     set_callbacks( Open, Close )
  90     add_shortcut( "cdg" )
  91 vlc_module_end ()
  92
  93 /*****************************************************************************
  94  * Open: probe the decoder and return score
  95  *****************************************************************************/
  96 static int Open( vlc_object_t *p_this )
  97 {
  98     decoder_t *p_dec = (decoder_t*)p_this;
  99     decoder_sys_t *p_sys;
 100
 101     if( p_dec->fmt_in.i_codec != VLC_CODEC_CDG )
 102         return VLC_EGENERIC;
 103
 104     /* Allocate the memory needed to store the decoder's structure */
 105     p_dec->p_sys = p_sys = calloc( 1, sizeof(decoder_sys_t) );
 106     if( !p_sys )
 107         return VLC_ENOMEM;
 108
 109     /* Init */
 110     p_sys->p_screen = p_sys->screen;
 111     p_sys->i_packet = 0;
 112
 113     /* Set output properties
 114      * TODO maybe it would be better to use RV16 or RV24 ? */
 115     p_dec->fmt_out.i_codec = VLC_CODEC_RGB32;
 116     p_dec->fmt_out.video.i_width = CDG_DISPLAY_WIDTH;
 117     p_dec->fmt_out.video.i_height = CDG_DISPLAY_HEIGHT;
 118     p_dec->fmt_out.video.i_sar_num = 1;
 119     p_dec->fmt_out.video.i_sar_den = 1;
 120     p_dec->fmt_out.video.i_rmask = 0xff << CDG_COLOR_R_SHIFT;
 121     p_dec->fmt_out.video.i_gmask = 0xff << CDG_COLOR_G_SHIFT;
 122     p_dec->fmt_out.video.i_bmask = 0xff << CDG_COLOR_B_SHIFT;
 123
 124     /* Set callbacks */
 125     p_dec->pf_decode = Decode;
 126     p_dec->pf_flush  = Flush;
 127
 128     return VLC_SUCCESS;
 129 }
 130
 131 /*****************************************************************************
 132  * Flush:
 133  *****************************************************************************/
 134 static void Flush( decoder_t *p_dec )
 135 {
 136     decoder_sys_t *p_sys = p_dec->p_sys;
 137
 138     p_sys->i_packet = 0;
 139 }
 140
 141 /****************************************************************************
 142  * Decode: the whole thing
 143  ****************************************************************************
 144  * This function must be fed with a complete compressed frame.
 145  ****************************************************************************/
 146 static int Decode( decoder_t *p_dec, block_t *p_block )
 147 {
 148     decoder_sys_t *p_sys = p_dec->p_sys;
 149     picture_t *p_pic = NULL;
 150
 151     if( !p_block ) /* No Drain */
 152         return VLCDEC_SUCCESS;
 153
 154     if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
 155     {
 156         Flush( p_dec );
 157         goto exit;
 158     }
 159
 160     /* Decode packet */
 161     while( p_block->i_buffer >= CDG_PACKET_SIZE )
 162     {
 163         DecodePacket( p_sys, p_block->p_buffer, CDG_PACKET_SIZE );
 164         p_block->i_buffer -= CDG_PACKET_SIZE;
 165         p_block->p_buffer += CDG_PACKET_SIZE;
 166     }
 167
 168     /* Only display 25 frame per second (there is 75 packets per second) */
 169     if( (p_sys->i_packet%3) == 1 && p_block->i_pts == p_block->i_dts )
 170     {
 171         /* Get a new picture */
 172         if( decoder_UpdateVideoFormat( p_dec ) )
 173             goto exit;
 174         p_pic = decoder_NewPicture( p_dec );
 175         if( !p_pic )
 176             goto exit;
 177
 178         Render( p_sys, p_pic );
 179         p_pic->date = p_block->i_pts != VLC_TICK_INVALID ? p_block->i_pts : p_block->i_dts;
 180     }
 181
 182 exit:
 183     block_Release( p_block );
 184     if( p_pic != NULL )
 185         decoder_QueueVideo( p_dec, p_pic );
 186     return VLCDEC_SUCCESS;
 187 }
 188
 189 /*****************************************************************************
 190  * Close: decoder destruction
 191  *****************************************************************************/
 192 static void Close( vlc_object_t *p_this )
 193 {
 194     decoder_t *p_dec = (decoder_t *)p_this;
 195     decoder_sys_t *p_sys = p_dec->p_sys;
 196
 197     free( p_sys );
 198 }
 199
 200 /*****************************************************************************
 201  * Decoder
 202  *****************************************************************************/
 203 static void ScreenFill( decoder_sys_t *p_cdg, int sx, int sy, int dx, int dy, int c )
 204 {
 205     int x, y;
 206     for( y = sy; y < sy+dy; y++ )
 207         for( x = sx; x < sx+dx; x++ )
 208             p_cdg->p_screen[y*CDG_SCREEN_PITCH+x] = c;
 209 }
 210 static int DecodeMemoryPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
 211 {
 212     const int i_color = p_data[0]&0x0f;
 213 #if 0
 214     const int i_repeat= p_data[1]&0x0f;
 215 #endif
 216     /* if i_repeat > 0 we could ignore it if we have a reliable stream */
 217     ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, i_color );
 218     return 0;
 219 }
 220 static int DecodeBorderPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
 221 {
 222     const int i_color = p_data[0]&0x0f;
 223
 224     /* */
 225     ScreenFill( p_cdg,   0,   0,
 226                 CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
 227     ScreenFill( p_cdg,   0, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT,
 228                 CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
 229     ScreenFill( p_cdg,   0, CDG_SCREEN_BORDER_HEIGHT,
 230                 CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
 231     ScreenFill( p_cdg,   CDG_SCREEN_WIDTH-CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_BORDER_HEIGHT,
 232                 CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
 233     return 0;
 234 }
 235
 236 static int DecodeLoadColorTable( decoder_sys_t *p_cdg, const uint8_t *p_data, int i_base )
 237 {
 238     int n;
 239     for( n = 0; n < 8; n++ )
 240     {
 241         const int c = ((p_data[2*n+0] << 8) | p_data[2*n+1]);
 242         const int r = (c >> 10)&0x0f;
 243         const int g = ((c >> 6)&0x0c) | ((c >> 4)&0x03);
 244         const int b = c &0x0f;
 245
 246         p_cdg->color[i_base+n][0] = r << 4;
 247         p_cdg->color[i_base+n][1] = g << 4;
 248         p_cdg->color[i_base+n][2] = b << 4;
 249     }
 250     return 0;
 251 }
 252 static int DecodeTileBlock( decoder_sys_t *p_cdg, const uint8_t *p_data, int doXor )
 253 {
 254     int p_color[2];
 255     int sx, sy;
 256     int x, y;
 257
 258     p_color[0] = p_data[0] & 0x0f;
 259     p_color[1] = p_data[1] & 0x0f;
 260
 261     sy = (p_data[2] & 0x1f)*12;
 262     sx = (p_data[3] & 0x3f)*6;
 263
 264     for( y = 0; y < 12; y++ )
 265     {
 266         for( x = 0; x < 6; x++ )
 267         {
 268             const int idx = ( p_data[4+y] >> (5-x) ) & 0x01;
 269
 270             unsigned index = (sy+y)*CDG_SCREEN_PITCH+(sx+x);
 271             if( index >= CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT )
 272                 return 0;
 273
 274             uint8_t *p = &p_cdg->p_screen[index];
 275
 276             if( doXor )
 277                 *p ^= p_color[idx];
 278             else
 279                 *p = p_color[idx];
 280         }
 281     }
 282     return 0;
 283 }
 284
 285 static int DecodeScroll( decoder_sys_t *p_cdg, const uint8_t *p_data, int b_copy )
 286 {
 287     uint8_t copy[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
 288
 289     uint8_t color = p_data[0]&0x0f;
 290     int i_shifth;
 291     int i_shiftv;
 292
 293     /* */
 294     p_cdg->i_offseth = p_data[1]&0x7;
 295     if( p_cdg->i_offseth >= CDG_SCREEN_BORDER_WIDTH )
 296         p_cdg->i_offseth = CDG_SCREEN_BORDER_WIDTH-1;
 297
 298     p_cdg->i_offsetv = p_data[2]&0xf;
 299     if( p_cdg->i_offsetv >= CDG_SCREEN_BORDER_HEIGHT )
 300         p_cdg->i_offsetv = CDG_SCREEN_BORDER_HEIGHT-1;
 301
 302     /* */
 303     switch( (p_data[1] >> 4)&0x3 )
 304     {
 305     case 0x01: i_shifth =  6; break;
 306     case 0x02: i_shifth = -6; break;
 307     default:
 308         i_shifth = 0;
 309         break;
 310     }
 311     switch( (p_data[2] >> 4)&0x3 )
 312     {
 313     case 0x01: i_shiftv = 12; break;
 314     case 0x02: i_shiftv =-12; break;
 315     default:
 316         i_shiftv = 0;
 317         break;
 318     }
 319
 320     if( i_shifth == 0 && i_shiftv == 0 )
 321         return 0;
 322
 323     /* Make a copy of the screen */
 324     memcpy( copy, p_cdg->screen, sizeof(p_cdg->screen) );
 325
 326     /* Fill the uncovered part XXX way too much */
 327     ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, color );
 328
 329     /* Copy back */
 330     for( unsigned y = 0; y < CDG_SCREEN_HEIGHT; y++ )
 331     {
 332         int dy = i_shiftv + y;
 333         for( unsigned x = 0; x < CDG_SCREEN_WIDTH; x++ )
 334         {
 335             int dx = i_shifth + x;
 336
 337             if( b_copy )
 338             {
 339                 dy = (dy + CDG_SCREEN_HEIGHT) % CDG_SCREEN_HEIGHT;
 340                 dx = (dx + CDG_SCREEN_WIDTH ) % CDG_SCREEN_WIDTH;
 341             }
 342             else
 343             {
 344                 if( dy < 0 || (unsigned)dy >= CDG_SCREEN_HEIGHT ||
 345                     dx < 0 || (unsigned)dx >= CDG_SCREEN_WIDTH )
 346                     continue;
 347             }
 348             p_cdg->screen[dy*CDG_SCREEN_PITCH+dx] = copy[y*CDG_SCREEN_PITCH+x];
 349         }
 350     }
 351     /* */
 352     //CdgDebug( CDG_LOG_WARNING, "DecodeScroll: color=%d ch=%d oh=%d cv=%d ov=%d\n copy=%d\n", color, i_shifth, p_cdg->i_offseth, i_shiftv, p_cdg->i_offsetv, b_copy );
 353     return 0;
 354 }
 355
 356 static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer )
 357 {
 358     const int i_cmd = p_buffer[0] & 0x3f;
 359     const int i_instruction = p_buffer[1] & 0x3f;
 360     const uint8_t *p_data = &p_buffer[4];
 361
 362     if( i_buffer != CDG_PACKET_SIZE )
 363         return -1;
 364
 365     p_cdg->i_packet++;
 366
 367     /* Handle CDG command only */
 368     if( i_cmd != 0x09 )
 369         return 0;
 370
 371     switch( i_instruction )
 372     {
 373         case 1:
 374             DecodeMemoryPreset( p_cdg, p_data );
 375             break;
 376         case 2:
 377             DecodeBorderPreset( p_cdg, p_data );
 378             break;
 379         case 6:
 380             DecodeTileBlock( p_cdg, p_data, 0 );
 381             break;
 382         case 20:
 383             DecodeScroll( p_cdg, p_data, 0 );
 384             break;
 385         case 24:
 386             DecodeScroll( p_cdg, p_data, 1 );
 387             break;
 388         case 28:
 389             /* FIXME what to do about that one ? */
 390             //CdgDebug( CDG_LOG_WARNING, "DecodeDefineTransparentColor not implemented\n" );
 391             //DecodeDefineTransparentColor( p_cdg, p_data );
 392             break;
 393         case 30:
 394             DecodeLoadColorTable( p_cdg, p_data, 0 );
 395             break;
 396         case 31:
 397             DecodeLoadColorTable( p_cdg, p_data, 8 );
 398             break;
 399         case 38:
 400             DecodeTileBlock( p_cdg, p_data, 1 );
 401             break;
 402         default:
 403             break;
 404     }
 405     return 0;
 406 }
 407
 408 static void RenderPixel( picture_t *p_picture, int x, int y, uint32_t c )
 409 {
 410     const int i_plane = 0;
 411     const int i_pitch = p_picture->p[i_plane].i_pitch;
 412     uint32_t *s = (uint32_t*)&p_picture->p[i_plane].p_pixels[y*i_pitch + x*sizeof(uint32_t)];
 413     *s = c;
 414 }
 415 static uint32_t RenderRGB( int r, int g, int b )
 416 {
 417     return ( r << CDG_COLOR_R_SHIFT ) | ( g << CDG_COLOR_G_SHIFT ) | ( b << CDG_COLOR_B_SHIFT );
 418 }
 419
 420 static int Render( decoder_sys_t *p_cdg, picture_t *p_picture )
 421 {
 422     for( unsigned y = 0; y < CDG_DISPLAY_HEIGHT; y++ )
 423     {
 424         for( unsigned x = 0; x < CDG_DISPLAY_WIDTH; x++ )
 425         {
 426             const int sx = x + p_cdg->i_offseth + CDG_SCREEN_BORDER_WIDTH;
 427             const int sy = y + p_cdg->i_offsetv + CDG_SCREEN_BORDER_HEIGHT;
 428             uint8_t cidx = p_cdg->p_screen[sy*CDG_SCREEN_PITCH +sx];
 429             uint8_t r = p_cdg->color[cidx][0];
 430             uint8_t g = p_cdg->color[cidx][1];
 431             uint8_t b = p_cdg->color[cidx][2];
 432
 433             RenderPixel( p_picture, x, y, RenderRGB( r, g, b ) );
 434         }
 435     }
 436     return 0;
 437 }
 438