modules/codec/cdg.c

   1 /*****************************************************************************
   2  * cdg.c: CDG decoder module
   3  *****************************************************************************
   4  * Copyright (C) 2007 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir # via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_codec.h>
  34
  35 /*****************************************************************************
  36  * decoder_sys_t : decoder descriptor
  37  *****************************************************************************/
  38
  39 /* The screen size */
  40 #define CDG_SCREEN_WIDTH 300u
  41 #define CDG_SCREEN_HEIGHT 216u
  42
  43 /* The border of the screen size */
  44 #define CDG_SCREEN_BORDER_WIDTH 6u
  45 #define CDG_SCREEN_BORDER_HEIGHT 12u
  46
  47 /* The display part */
  48 #define CDG_DISPLAY_WIDTH  (CDG_SCREEN_WIDTH-2*CDG_SCREEN_BORDER_WIDTH)
  49 #define CDG_DISPLAY_HEIGHT (CDG_SCREEN_HEIGHT-2*CDG_SCREEN_BORDER_HEIGHT)
  50
  51 #define CDG_SCREEN_PITCH CDG_SCREEN_WIDTH
  52
  53 typedef struct
  54 {
  55     uint8_t  color[16][3];
  56     unsigned i_offseth;
  57     unsigned i_offsetv;
  58     uint8_t  screen[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
  59     uint8_t  *p_screen;
  60
  61     int      i_packet;
  62 } decoder_sys_t;
  63
  64 #define CDG_PACKET_SIZE 24u
  65
  66 #define CDG_COLOR_R_SHIFT  0
  67 #define CDG_COLOR_G_SHIFT  8
  68 #define CDG_COLOR_B_SHIFT 16
  69
  70 /*****************************************************************************
  71  * Local prototypes
  72  *****************************************************************************/
  73 static int  Open ( vlc_object_t * );
  74 static void Close( vlc_object_t * );
  75
  76 static int Decode( decoder_t *, block_t * );
  77
  78 static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer );
  79 static void Flush( decoder_t * );
  80 static int Render( decoder_sys_t *p_cdg, picture_t *p_picture );
  81
  82 /*****************************************************************************
  83  * Module descriptor
  84  *****************************************************************************/
  85 vlc_module_begin ()
  86     set_category( CAT_INPUT )
  87     set_subcategory( SUBCAT_INPUT_VCODEC )
  88     set_description( N_("CDG video decoder") )
  89     set_capability( "video decoder", 1000 )
  90     set_callbacks( Open, Close )
  91     add_shortcut( "cdg" )
  92 vlc_module_end ()
  93
  94 /*****************************************************************************
  95  * Open: probe the decoder and return score
  96  *****************************************************************************/
  97 static int Open( vlc_object_t *p_this )
  98 {
  99     decoder_t *p_dec = (decoder_t*)p_this;
 100     decoder_sys_t *p_sys;
 101
 102     if( p_dec->fmt_in.i_codec != VLC_CODEC_CDG )
 103         return VLC_EGENERIC;
 104
 105     /* Allocate the memory needed to store the decoder's structure */
 106     p_dec->p_sys = p_sys = calloc( 1, sizeof(decoder_sys_t) );
 107     if( !p_sys )
 108         return VLC_ENOMEM;
 109
 110     /* Init */
 111     p_sys->p_screen = p_sys->screen;
 112     p_sys->i_packet = 0;
 113
 114     /* Set output properties
 115      * TODO maybe it would be better to use RV16 or RV24 ? */
 116     p_dec->fmt_out.i_codec = VLC_CODEC_RGB32;
 117     p_dec->fmt_out.video.i_width = CDG_DISPLAY_WIDTH;
 118     p_dec->fmt_out.video.i_height = CDG_DISPLAY_HEIGHT;
 119     p_dec->fmt_out.video.i_sar_num = 1;
 120     p_dec->fmt_out.video.i_sar_den = 1;
 121     p_dec->fmt_out.video.i_rmask = 0xff << CDG_COLOR_R_SHIFT;
 122     p_dec->fmt_out.video.i_gmask = 0xff << CDG_COLOR_G_SHIFT;
 123     p_dec->fmt_out.video.i_bmask = 0xff << CDG_COLOR_B_SHIFT;
 124
 125     /* Set callbacks */
 126     p_dec->pf_decode = Decode;
 127     p_dec->pf_flush  = Flush;
 128
 129     return VLC_SUCCESS;
 130 }
 131
 132 /*****************************************************************************
 133  * Flush:
 134  *****************************************************************************/
 135 static void Flush( decoder_t *p_dec )
 136 {
 137     decoder_sys_t *p_sys = p_dec->p_sys;
 138
 139     p_sys->i_packet = 0;
 140 }
 141
 142 /****************************************************************************
 143  * Decode: the whole thing
 144  ****************************************************************************
 145  * This function must be fed with a complete compressed frame.
 146  ****************************************************************************/
 147 static int Decode( decoder_t *p_dec, block_t *p_block )
 148 {
 149     decoder_sys_t *p_sys = p_dec->p_sys;
 150     picture_t *p_pic = NULL;
 151
 152     if( !p_block ) /* No Drain */
 153         return VLCDEC_SUCCESS;
 154
 155     if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
 156     {
 157         Flush( p_dec );
 158         goto exit;
 159     }
 160
 161     /* Decode packet */
 162     while( p_block->i_buffer >= CDG_PACKET_SIZE )
 163     {
 164         DecodePacket( p_sys, p_block->p_buffer, CDG_PACKET_SIZE );
 165         p_block->i_buffer -= CDG_PACKET_SIZE;
 166         p_block->p_buffer += CDG_PACKET_SIZE;
 167     }
 168
 169     /* Only display 25 frame per second (there is 75 packets per second) */
 170     if( (p_sys->i_packet%3) == 1 && p_block->i_pts == p_block->i_dts )
 171     {
 172         /* Get a new picture */
 173         if( decoder_UpdateVideoFormat( p_dec ) )
 174             goto exit;
 175         p_pic = decoder_NewPicture( p_dec );
 176         if( !p_pic )
 177             goto exit;
 178
 179         Render( p_sys, p_pic );
 180         p_pic->date = p_block->i_pts != VLC_TICK_INVALID ? p_block->i_pts : p_block->i_dts;
 181     }
 182
 183 exit:
 184     block_Release( p_block );
 185     if( p_pic != NULL )
 186         decoder_QueueVideo( p_dec, p_pic );
 187     return VLCDEC_SUCCESS;
 188 }
 189
 190 /*****************************************************************************
 191  * Close: decoder destruction
 192  *****************************************************************************/
 193 static void Close( vlc_object_t *p_this )
 194 {
 195     decoder_t *p_dec = (decoder_t *)p_this;
 196     decoder_sys_t *p_sys = p_dec->p_sys;
 197
 198     free( p_sys );
 199 }
 200
 201 /*****************************************************************************
 202  * Decoder
 203  *****************************************************************************/
 204 static void ScreenFill( decoder_sys_t *p_cdg, int sx, int sy, int dx, int dy, int c )
 205 {
 206     int x, y;
 207     for( y = sy; y < sy+dy; y++ )
 208         for( x = sx; x < sx+dx; x++ )
 209             p_cdg->p_screen[y*CDG_SCREEN_PITCH+x] = c;
 210 }
 211 static int DecodeMemoryPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
 212 {
 213     const int i_color = p_data[0]&0x0f;
 214 #if 0
 215     const int i_repeat= p_data[1]&0x0f;
 216 #endif
 217     /* if i_repeat > 0 we could ignore it if we have a reliable stream */
 218     ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, i_color );
 219     return 0;
 220 }
 221 static int DecodeBorderPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
 222 {
 223     const int i_color = p_data[0]&0x0f;
 224
 225     /* */
 226     ScreenFill( p_cdg,   0,   0,
 227                 CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
 228     ScreenFill( p_cdg,   0, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT,
 229                 CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
 230     ScreenFill( p_cdg,   0, CDG_SCREEN_BORDER_HEIGHT,
 231                 CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
 232     ScreenFill( p_cdg,   CDG_SCREEN_WIDTH-CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_BORDER_HEIGHT,
 233                 CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
 234     return 0;
 235 }
 236
 237 static int DecodeLoadColorTable( decoder_sys_t *p_cdg, const uint8_t *p_data, int i_base )
 238 {
 239     int n;
 240     for( n = 0; n < 8; n++ )
 241     {
 242         const int c = ((p_data[2*n+0] << 8) | p_data[2*n+1]);
 243         const int r = (c >> 10)&0x0f;
 244         const int g = ((c >> 6)&0x0c) | ((c >> 4)&0x03);
 245         const int b = c &0x0f;
 246
 247         p_cdg->color[i_base+n][0] = r << 4;
 248         p_cdg->color[i_base+n][1] = g << 4;
 249         p_cdg->color[i_base+n][2] = b << 4;
 250     }
 251     return 0;
 252 }
 253 static int DecodeTileBlock( decoder_sys_t *p_cdg, const uint8_t *p_data, int doXor )
 254 {
 255     int p_color[2];
 256     int sx, sy;
 257     int x, y;
 258
 259     p_color[0] = p_data[0] & 0x0f;
 260     p_color[1] = p_data[1] & 0x0f;
 261
 262     sy = (p_data[2] & 0x1f)*12;
 263     sx = (p_data[3] & 0x3f)*6;
 264
 265     for( y = 0; y < 12; y++ )
 266     {
 267         for( x = 0; x < 6; x++ )
 268         {
 269             const int idx = ( p_data[4+y] >> (5-x) ) & 0x01;
 270
 271             unsigned index = (sy+y)*CDG_SCREEN_PITCH+(sx+x);
 272             if( index >= CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT )
 273                 return 0;
 274
 275             uint8_t *p = &p_cdg->p_screen[index];
 276
 277             if( doXor )
 278                 *p ^= p_color[idx];
 279             else
 280                 *p = p_color[idx];
 281         }
 282     }
 283     return 0;
 284 }
 285
 286 static int DecodeScroll( decoder_sys_t *p_cdg, const uint8_t *p_data, int b_copy )
 287 {
 288     uint8_t copy[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
 289
 290     uint8_t color = p_data[0]&0x0f;
 291     int i_shifth;
 292     int i_shiftv;
 293
 294     /* */
 295     p_cdg->i_offseth = p_data[1]&0x7;
 296     if( p_cdg->i_offseth >= CDG_SCREEN_BORDER_WIDTH )
 297         p_cdg->i_offseth = CDG_SCREEN_BORDER_WIDTH-1;
 298
 299     p_cdg->i_offsetv = p_data[2]&0xf;
 300     if( p_cdg->i_offsetv >= CDG_SCREEN_BORDER_HEIGHT )
 301         p_cdg->i_offsetv = CDG_SCREEN_BORDER_HEIGHT-1;
 302
 303     /* */
 304     switch( (p_data[1] >> 4)&0x3 )
 305     {
 306     case 0x01: i_shifth =  6; break;
 307     case 0x02: i_shifth = -6; break;
 308     default:
 309         i_shifth = 0;
 310         break;
 311     }
 312     switch( (p_data[2] >> 4)&0x3 )
 313     {
 314     case 0x01: i_shiftv = 12; break;
 315     case 0x02: i_shiftv =-12; break;
 316     default:
 317         i_shiftv = 0;
 318         break;
 319     }
 320
 321     if( i_shifth == 0 && i_shiftv == 0 )
 322         return 0;
 323
 324     /* Make a copy of the screen */
 325     memcpy( copy, p_cdg->screen, sizeof(p_cdg->screen) );
 326
 327     /* Fill the uncovered part XXX way too much */
 328     ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, color );
 329
 330     /* Copy back */
 331     for( unsigned y = 0; y < CDG_SCREEN_HEIGHT; y++ )
 332     {
 333         int dy = i_shiftv + y;
 334         for( unsigned x = 0; x < CDG_SCREEN_WIDTH; x++ )
 335         {
 336             int dx = i_shifth + x;
 337
 338             if( b_copy )
 339             {
 340                 dy = (dy + CDG_SCREEN_HEIGHT) % CDG_SCREEN_HEIGHT;
 341                 dx = (dx + CDG_SCREEN_WIDTH ) % CDG_SCREEN_WIDTH;
 342             }
 343             else
 344             {
 345                 if( dy < 0 || (unsigned)dy >= CDG_SCREEN_HEIGHT ||
 346                     dx < 0 || (unsigned)dx >= CDG_SCREEN_WIDTH )
 347                     continue;
 348             }
 349             p_cdg->screen[dy*CDG_SCREEN_PITCH+dx] = copy[y*CDG_SCREEN_PITCH+x];
 350         }
 351     }
 352     /* */
 353     //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 );
 354     return 0;
 355 }
 356
 357 static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer )
 358 {
 359     const int i_cmd = p_buffer[0] & 0x3f;
 360     const int i_instruction = p_buffer[1] & 0x3f;
 361     const uint8_t *p_data = &p_buffer[4];
 362
 363     if( i_buffer != CDG_PACKET_SIZE )
 364         return -1;
 365
 366     p_cdg->i_packet++;
 367
 368     /* Handle CDG command only */
 369     if( i_cmd != 0x09 )
 370         return 0;
 371
 372     switch( i_instruction )
 373     {
 374         case 1:
 375             DecodeMemoryPreset( p_cdg, p_data );
 376             break;
 377         case 2:
 378             DecodeBorderPreset( p_cdg, p_data );
 379             break;
 380         case 6:
 381             DecodeTileBlock( p_cdg, p_data, 0 );
 382             break;
 383         case 20:
 384             DecodeScroll( p_cdg, p_data, 0 );
 385             break;
 386         case 24:
 387             DecodeScroll( p_cdg, p_data, 1 );
 388             break;
 389         case 28:
 390             /* FIXME what to do about that one ? */
 391             //CdgDebug( CDG_LOG_WARNING, "DecodeDefineTransparentColor not implemented\n" );
 392             //DecodeDefineTransparentColor( p_cdg, p_data );
 393             break;
 394         case 30:
 395             DecodeLoadColorTable( p_cdg, p_data, 0 );
 396             break;
 397         case 31:
 398             DecodeLoadColorTable( p_cdg, p_data, 8 );
 399             break;
 400         case 38:
 401             DecodeTileBlock( p_cdg, p_data, 1 );
 402             break;
 403         default:
 404             break;
 405     }
 406     return 0;
 407 }
 408
 409 static void RenderPixel( picture_t *p_picture, int x, int y, uint32_t c )
 410 {
 411     const int i_plane = 0;
 412     const int i_pitch = p_picture->p[i_plane].i_pitch;
 413     uint32_t *s = (uint32_t*)&p_picture->p[i_plane].p_pixels[y*i_pitch + x*sizeof(uint32_t)];
 414     *s = c;
 415 }
 416 static uint32_t RenderRGB( int r, int g, int b )
 417 {
 418     return ( r << CDG_COLOR_R_SHIFT ) | ( g << CDG_COLOR_G_SHIFT ) | ( b << CDG_COLOR_B_SHIFT );
 419 }
 420
 421 static int Render( decoder_sys_t *p_cdg, picture_t *p_picture )
 422 {
 423     for( unsigned y = 0; y < CDG_DISPLAY_HEIGHT; y++ )
 424     {
 425         for( unsigned x = 0; x < CDG_DISPLAY_WIDTH; x++ )
 426         {
 427             const int sx = x + p_cdg->i_offseth + CDG_SCREEN_BORDER_WIDTH;
 428             const int sy = y + p_cdg->i_offsetv + CDG_SCREEN_BORDER_HEIGHT;
 429             uint8_t cidx = p_cdg->p_screen[sy*CDG_SCREEN_PITCH +sx];
 430             uint8_t r = p_cdg->color[cidx][0];
 431             uint8_t g = p_cdg->color[cidx][1];
 432             uint8_t b = p_cdg->color[cidx][2];
 433
 434             RenderPixel( p_picture, x, y, RenderRGB( r, g, b ) );
 435         }
 436     }
 437     return 0;
 438 }
 439