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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 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 (300)
  41 #define CDG_SCREEN_HEIGHT (216)
  42
  43 /* The border of the screen size */
  44 #define CDG_SCREEN_BORDER_WIDTH (6)
  45 #define CDG_SCREEN_BORDER_HEIGHT (12)
  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 struct decoder_sys_t
  54 {
  55     uint8_t color[16][3];
  56     int     i_offseth;
  57     int     i_offsetv;
  58     uint8_t screen[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
  59     uint8_t *p_screen;
  60
  61     int     i_packet;
  62 };
  63
  64 #define CDG_PACKET_SIZE (24)
  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 picture_t *Decode( decoder_t *, block_t ** );
  77
  78 static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer );
  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( "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_cat = VIDEO_ES;
 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_video = Decode;
 127
 128     return VLC_SUCCESS;
 129 }
 130
 131 /****************************************************************************
 132  * Decode: the whole thing
 133  ****************************************************************************
 134  * This function must be fed with a complete compressed frame.
 135  ****************************************************************************/
 136 static picture_t *Decode( decoder_t *p_dec, block_t **pp_block )
 137 {
 138     decoder_sys_t *p_sys = p_dec->p_sys;
 139     block_t *p_block;
 140     picture_t *p_pic = NULL;
 141
 142     if( !pp_block || !*pp_block )
 143         return NULL;
 144     p_block = *pp_block;
 145
 146     if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 147     {
 148         p_sys->i_packet = 0;
 149         goto exit;
 150     }
 151
 152     /* Decode packet */
 153     while( p_block->i_buffer >= CDG_PACKET_SIZE )
 154     {
 155         DecodePacket( p_sys, p_block->p_buffer, CDG_PACKET_SIZE );
 156         p_block->i_buffer -= CDG_PACKET_SIZE;
 157         p_block->p_buffer += CDG_PACKET_SIZE;
 158     }
 159
 160     /* Only display 25 frame per second (there is 75 packets per second) */
 161     if( (p_sys->i_packet%3) == 1 )
 162     {
 163         /* Get a new picture */
 164         p_pic = decoder_NewPicture( p_dec );
 165         if( !p_pic )
 166             goto exit;
 167
 168         Render( p_sys, p_pic );
 169         p_pic->date = p_block->i_pts > VLC_TS_INVALID ? p_block->i_pts : p_block->i_dts;
 170     }
 171
 172 exit:
 173     block_Release( p_block ); *pp_block = NULL;
 174     return p_pic;
 175 }
 176
 177 /*****************************************************************************
 178  * Close: decoder destruction
 179  *****************************************************************************/
 180 static void Close( vlc_object_t *p_this )
 181 {
 182     decoder_t *p_dec = (decoder_t *)p_this;
 183     decoder_sys_t *p_sys = p_dec->p_sys;
 184
 185     free( p_sys );
 186 }
 187
 188 /*****************************************************************************
 189  * Decoder
 190  *****************************************************************************/
 191 static void ScreenFill( decoder_sys_t *p_cdg, int sx, int sy, int dx, int dy, int c )
 192 {
 193     int x, y;
 194     for( y = sy; y < sy+dy; y++ )
 195         for( x = sx; x < sx+dx; x++ )
 196             p_cdg->p_screen[y*CDG_SCREEN_PITCH+x] = c;
 197 }
 198 static int DecodeMemoryPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
 199 {
 200     const int i_color = p_data[0]&0x0f;
 201 #if 0
 202     const int i_repeat= p_data[1]&0x0f;
 203 #endif
 204     /* if i_repeat > 0 we could ignore it if we have a reliable stream */
 205     ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, i_color );
 206     return 0;
 207 }
 208 static int DecodeBorderPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
 209 {
 210     const int i_color = p_data[0]&0x0f;
 211
 212     /* */
 213     ScreenFill( p_cdg,   0,   0,
 214                 CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
 215     ScreenFill( p_cdg,   0, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT,
 216                 CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
 217     ScreenFill( p_cdg,   0, CDG_SCREEN_BORDER_HEIGHT,
 218                 CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
 219     ScreenFill( p_cdg,   CDG_SCREEN_WIDTH-CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_BORDER_HEIGHT,
 220                 CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
 221     return 0;
 222 }
 223
 224 static int DecodeLoadColorTable( decoder_sys_t *p_cdg, const uint8_t *p_data, int i_base )
 225 {
 226     int n;
 227     for( n = 0; n < 8; n++ )
 228     {
 229         const int c = ((p_data[2*n+0] << 8) | p_data[2*n+1]);
 230         const int r = (c >> 10)&0x0f;
 231         const int g = ((c >> 6)&0x0c) | ((c >> 4)&0x03);
 232         const int b = c &0x0f;
 233
 234         p_cdg->color[i_base+n][0] = r << 4;
 235         p_cdg->color[i_base+n][1] = g << 4;
 236         p_cdg->color[i_base+n][2] = b << 4;
 237     }
 238     return 0;
 239 }
 240 static int DecodeTileBlock( decoder_sys_t *p_cdg, const uint8_t *p_data, int doXor )
 241 {
 242     int p_color[2];
 243     int sx, sy;
 244     int x, y;
 245
 246     p_color[0] = p_data[0] & 0x0f;
 247     p_color[1] = p_data[1] & 0x0f;
 248
 249     sy = (p_data[2] & 0x1f)*12;
 250     sx = (p_data[3] & 0x3f)*6;
 251
 252     for( y = 0; y < 12; y++ )
 253     {
 254         for( x = 0; x < 6; x++ )
 255         {
 256             const int idx = ( p_data[4+y] >> (5-x) ) & 0x01;
 257             uint8_t *p = &p_cdg->p_screen[(sy+y)*CDG_SCREEN_PITCH+(sx+x)];
 258             if( doXor )
 259                 *p ^= p_color[idx];
 260             else
 261                 *p = p_color[idx];
 262         }
 263     }
 264     return 0;
 265 }
 266
 267 static int DecodeScroll( decoder_sys_t *p_cdg, const uint8_t *p_data, int b_copy )
 268 {
 269     uint8_t copy[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
 270
 271     uint8_t color = p_data[0]&0x0f;
 272     int i_shifth;
 273     int i_shiftv;
 274     int x, y;
 275
 276     /* */
 277     p_cdg->i_offseth = p_data[1]&0x7;
 278     if( p_cdg->i_offseth >= CDG_SCREEN_BORDER_WIDTH )
 279         p_cdg->i_offseth = CDG_SCREEN_BORDER_WIDTH-1;
 280
 281     p_cdg->i_offsetv = p_data[2]&0xf;
 282     if( p_cdg->i_offsetv >= CDG_SCREEN_BORDER_HEIGHT )
 283         p_cdg->i_offsetv = CDG_SCREEN_BORDER_HEIGHT-1;
 284
 285     /* */
 286     switch( (p_data[1] >> 4)&0x3 )
 287     {
 288     case 0x01: i_shifth =  6; break;
 289     case 0x02: i_shifth = -6; break;
 290     default:
 291         i_shifth = 0;
 292         break;
 293     }
 294     switch( (p_data[2] >> 4)&0x3 )
 295     {
 296     case 0x01: i_shiftv = 12; break;
 297     case 0x02: i_shiftv =-12; break;
 298     default:
 299         i_shiftv = 0;
 300         break;
 301     }
 302
 303     if( i_shifth == 0 && i_shiftv == 0 )
 304         return 0;
 305
 306     /* Make a copy of the screen */
 307     memcpy( copy, p_cdg->screen, sizeof(p_cdg->screen) );
 308
 309     /* Fill the uncovered part XXX way too much */
 310     ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, color );
 311
 312     /* Copy back */
 313     for( y = 0; y < CDG_SCREEN_HEIGHT; y++ )
 314     {
 315         int dy = i_shiftv + y;
 316         for( x = 0; x < CDG_SCREEN_WIDTH; x++ )
 317         {
 318             int dx = i_shifth + x;
 319
 320             if( b_copy )
 321             {
 322                 dy = ( dy + CDG_SCREEN_HEIGHT ) % CDG_SCREEN_HEIGHT;
 323                 dy = ( dy + CDG_SCREEN_WIDTH  ) % CDG_SCREEN_WIDTH;
 324             }
 325             else
 326             {
 327                 if( dy < 0 || dy >= CDG_SCREEN_HEIGHT ||
 328                     dx < 0 || dx >= CDG_SCREEN_WIDTH )
 329                     continue;
 330             }
 331             p_cdg->screen[dy*CDG_SCREEN_PITCH+dx] = copy[y*CDG_SCREEN_PITCH+x];
 332         }
 333     }
 334     /* */
 335     //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 );
 336     return 0;
 337 }
 338
 339 static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer )
 340 {
 341     const int i_cmd = p_buffer[0] & 0x3f;
 342     const int i_instruction = p_buffer[1] & 0x3f;
 343     const uint8_t *p_data = &p_buffer[4];
 344
 345     if( i_buffer != CDG_PACKET_SIZE )
 346         return -1;
 347
 348     p_cdg->i_packet++;
 349
 350     /* Handle CDG command only */
 351     if( i_cmd != 0x09 )
 352         return 0;
 353
 354     switch( i_instruction )
 355     {
 356         case 1:
 357             DecodeMemoryPreset( p_cdg, p_data );
 358             break;
 359         case 2:
 360             DecodeBorderPreset( p_cdg, p_data );
 361             break;
 362         case 6:
 363             DecodeTileBlock( p_cdg, p_data, 0 );
 364             break;
 365         case 20:
 366             DecodeScroll( p_cdg, p_data, 0 );
 367             break;
 368         case 24:
 369             DecodeScroll( p_cdg, p_data, 1 );
 370             break;
 371         case 28:
 372             /* FIXME what to do about that one ? */
 373             //CdgDebug( CDG_LOG_WARNING, "DecodeDefineTransparentColor not implemented\n" );
 374             //DecodeDefineTransparentColor( p_cdg, p_data );
 375             break;
 376         case 30:
 377             DecodeLoadColorTable( p_cdg, p_data, 0 );
 378             break;
 379         case 31:
 380             DecodeLoadColorTable( p_cdg, p_data, 8 );
 381             break;
 382         case 38:
 383             DecodeTileBlock( p_cdg, p_data, 1 );
 384             break;
 385         default:
 386             break;
 387     }
 388     return 0;
 389 }
 390
 391 static void RenderPixel( picture_t *p_picture, int x, int y, uint32_t c )
 392 {
 393     const int i_plane = 0;
 394     const int i_pitch = p_picture->p[i_plane].i_pitch;
 395     uint32_t *s = (uint32_t*)&p_picture->p[i_plane].p_pixels[y*i_pitch + x*sizeof(uint32_t)];
 396     *s = c;
 397 }
 398 static uint32_t RenderRGB( int r, int g, int b )
 399 {
 400     return ( r << CDG_COLOR_R_SHIFT ) | ( g << CDG_COLOR_G_SHIFT ) | ( b << CDG_COLOR_B_SHIFT );
 401 }
 402
 403 static int Render( decoder_sys_t *p_cdg, picture_t *p_picture )
 404 {
 405     int x, y;
 406
 407     for( y = 0; y < CDG_DISPLAY_HEIGHT; y++ )
 408     {
 409         for( x = 0; x < CDG_DISPLAY_WIDTH; x++ )
 410         {
 411             const int sx = x + p_cdg->i_offseth + CDG_SCREEN_BORDER_WIDTH;
 412             const int sy = y + p_cdg->i_offsetv + CDG_SCREEN_BORDER_HEIGHT;
 413             uint8_t cidx = p_cdg->p_screen[sy*CDG_SCREEN_PITCH +sx];
 414             uint8_t r = p_cdg->color[cidx][0];
 415             uint8_t g = p_cdg->color[cidx][1];
 416             uint8_t b = p_cdg->color[cidx][2];
 417
 418             RenderPixel( p_picture, x, y, RenderRGB( r, g, b ) );
 419         }
 420     }
 421     return 0;
 422 }
 423