modules/video_filter/bluescreen.c

   1 /*****************************************************************************
   2  * bluescreen.c : Bluescreen (weather channel like) video filter for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2005-2007 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Antoine Cellerier <dionoea at videolan tod org>
   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
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_vout.h>
  35
  36 #include "vlc_filter.h"
  37
  38 #define BLUESCREEN_HELP N_( \
  39     "This effect, also known as \"greenscreen\" or \"chroma key\" blends " \
  40     "the \"blue parts\" of the foreground image of the mosaic on the " \
  41     "background (like weather forcasts). You can choose the \"key\" " \
  42     "color for blending (blyyue by default)." )
  43
  44 #define BLUESCREENU_TEXT N_("Bluescreen U value")
  45 #define BLUESCREENU_LONGTEXT N_( \
  46         "\"U\" value for the bluescreen key color " \
  47         "(in YUV values). From 0 to 255. Defaults to 120 for blue." )
  48 #define BLUESCREENV_TEXT N_("Bluescreen V value")
  49 #define BLUESCREENV_LONGTEXT N_( \
  50         "\"V\" value for the bluescreen key color " \
  51         "(in YUV values). From 0 to 255. Defaults to 90 for blue." )
  52 #define BLUESCREENUTOL_TEXT N_("Bluescreen U tolerance")
  53 #define BLUESCREENUTOL_LONGTEXT N_( \
  54         "Tolerance of the bluescreen blender " \
  55         "on color variations for the U plane. A value between 10 and 20 " \
  56         "seems sensible." )
  57 #define BLUESCREENVTOL_TEXT N_("Bluescreen V tolerance")
  58 #define BLUESCREENVTOL_LONGTEXT N_( \
  59         "Tolerance of the bluescreen blender " \
  60         "on color variations for the V plane. A value between 10 and 20 " \
  61         "seems sensible." )
  62
  63 #define CFG_PREFIX "bluescreen-"
  64
  65 /*****************************************************************************
  66  * Local prototypes
  67  *****************************************************************************/
  68 static int  Create      ( vlc_object_t * );
  69 static void Destroy     ( vlc_object_t * );
  70
  71 static picture_t *Filter( filter_t *, picture_t * );
  72 static int BluescreenCallback( vlc_object_t *, char const *,
  73                                vlc_value_t, vlc_value_t, void * );
  74
  75 /*****************************************************************************
  76  * Module descriptor
  77  *****************************************************************************/
  78 vlc_module_begin();
  79     set_description( N_("Bluescreen video filter") );
  80     set_shortname( N_("Bluescreen" ));
  81     set_help( BLUESCREEN_HELP );
  82     set_category( CAT_VIDEO );
  83     set_subcategory( SUBCAT_VIDEO_VFILTER );
  84     set_capability( "video filter2", 0 );
  85     add_shortcut( "bluescreen" );
  86     set_callbacks( Create, Destroy );
  87
  88     add_integer_with_range( CFG_PREFIX "u", 120, 0, 255, NULL,
  89                             BLUESCREENU_TEXT, BLUESCREENU_LONGTEXT, false );
  90     add_integer_with_range( CFG_PREFIX "v", 90, 0, 255, NULL,
  91                             BLUESCREENV_TEXT, BLUESCREENV_LONGTEXT, false );
  92     add_integer_with_range( CFG_PREFIX "ut", 17, 0, 255, NULL,
  93                             BLUESCREENUTOL_TEXT, BLUESCREENUTOL_LONGTEXT,
  94                             false );
  95     add_integer_with_range( CFG_PREFIX "vt", 17, 0, 255, NULL,
  96                             BLUESCREENVTOL_TEXT, BLUESCREENVTOL_LONGTEXT,
  97                             false );
  98 vlc_module_end();
  99
 100 static const char *const ppsz_filter_options[] = {
 101     "u", "v", "ut", "vt", NULL
 102 };
 103
 104 struct filter_sys_t
 105 {
 106     int i_u, i_v, i_ut, i_vt;
 107     uint8_t *p_at;
 108 };
 109
 110 static int Create( vlc_object_t *p_this )
 111 {
 112     filter_t *p_filter = (filter_t *)p_this;
 113     filter_sys_t *p_sys;
 114
 115     if( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') )
 116     {
 117         msg_Err( p_filter,
 118                  "Unsupported input chroma \"%4s\". "
 119                  "Bluescreen can only use \"YUVA\".",
 120                  (char*)&p_filter->fmt_in.video.i_chroma );
 121         return VLC_EGENERIC;
 122     }
 123
 124     /* Allocate structure */
 125     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 126     if( p_filter->p_sys == NULL )
 127     {
 128         msg_Err( p_filter, "out of memory" );
 129         return VLC_ENOMEM;
 130     }
 131     p_sys = p_filter->p_sys;
 132
 133     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 134                        p_filter->p_cfg );
 135
 136 #define GET_VAR( name, min, max )                                           \
 137     p_sys->i_##name = __MIN( max, __MAX( min,                               \
 138         var_CreateGetIntegerCommand( p_filter, CFG_PREFIX #name ) ) );      \
 139     var_AddCallback( p_filter, CFG_PREFIX #name, BluescreenCallback, p_sys );
 140
 141     GET_VAR( u, 0x00, 0xff );
 142     GET_VAR( v, 0x00, 0xff );
 143     GET_VAR( ut, 0x00, 0xff );
 144     GET_VAR( vt, 0x00, 0xff );
 145     p_sys->p_at = NULL;
 146
 147     p_filter->pf_video_filter = Filter;
 148
 149     return VLC_SUCCESS;
 150 }
 151
 152 static void Destroy( vlc_object_t *p_this )
 153 {
 154     filter_t *p_filter = (filter_t *)p_this;
 155
 156     free( p_filter->p_sys->p_at );
 157     free( p_filter->p_sys );
 158 }
 159
 160 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 161 {
 162     filter_sys_t *p_sys = p_filter->p_sys;
 163
 164     int i,j;
 165     int i_lines = p_pic->p[ A_PLANE ].i_lines;
 166     int i_pitch = p_pic->p[ A_PLANE ].i_pitch;
 167     uint8_t *p_a = p_pic->p[ A_PLANE ].p_pixels;
 168     uint8_t *p_at;
 169     uint8_t *p_u = p_pic->p[ U_PLANE ].p_pixels;
 170     uint8_t *p_v = p_pic->p[ V_PLANE ].p_pixels;
 171     uint8_t umin, umax, vmin, vmax;
 172
 173     if( p_pic->format.i_chroma != VLC_FOURCC('Y','U','V','A') )
 174     {
 175         msg_Err( p_filter,
 176                  "Unsupported input chroma \"%4s\". "
 177                  "Bluescreen can only use \"YUVA\".",
 178                  (char*)&p_pic->format.i_chroma );
 179         return NULL;
 180     }
 181
 182     p_sys->p_at = realloc( p_sys->p_at, i_lines * i_pitch * sizeof( uint8_t ) );
 183     p_at = p_sys->p_at;
 184
 185     umin = p_sys->i_u - p_sys->i_ut >= 0x00 ? p_sys->i_u - p_sys->i_ut : 0x00;
 186     umax = p_sys->i_u + p_sys->i_ut <= 0xff ? p_sys->i_u + p_sys->i_ut : 0xff;
 187     vmin = p_sys->i_v - p_sys->i_vt >= 0x00 ? p_sys->i_v - p_sys->i_vt : 0x00;
 188     vmax = p_sys->i_v + p_sys->i_vt <= 0xff ? p_sys->i_v + p_sys->i_vt : 0xff;
 189
 190     for( i = 0; i < i_lines*i_pitch; i++ )
 191     {
 192         if(    p_u[i] < umax && p_u[i] > umin
 193             && p_v[i] < vmax && p_v[i] > vmin )
 194         {
 195             p_at[i] = 0x00;
 196         }
 197         else
 198         {
 199             p_at[i] = 0xff;
 200         }
 201     }
 202     /* Gaussian convolution to make it look cleaner */
 203     vlc_memset( p_a, 0, 2 * i_pitch );
 204     for( i = 2; i < i_lines - 2; i++ )
 205     {
 206         p_a[i*i_pitch] = 0x00;
 207         p_a[i*i_pitch+1] = 0x00;
 208         for( j = 2; j < i_pitch - 2; j ++ )
 209         {
 210             p_a[i*i_pitch+j] = (uint8_t)((
 211               /* 2 rows up */
 212                 ( p_at[(i-2)*i_pitch+j-2]<<1 )
 213               + ( p_at[(i-2)*i_pitch+j-1]<<2 )
 214               + ( p_at[(i-2)*i_pitch+j]<<2 )
 215               + ( p_at[(i-2)*i_pitch+j+1]<<2 )
 216               + ( p_at[(i-2)*i_pitch+j+2]<<1 )
 217               /* 1 row up */
 218               + ( p_at[(i-1)*i_pitch+j-2]<<2 )
 219               + ( p_at[(i-1)*i_pitch+j-1]<<3 )
 220               + ( p_at[(i-1)*i_pitch+j]*12 )
 221               + ( p_at[(i-1)*i_pitch+j+1]<<3 )
 222               + ( p_at[(i-1)*i_pitch+j+2]<<2 )
 223               /* */
 224               + ( p_at[i*i_pitch+j-2]<<2 )
 225               + ( p_at[i*i_pitch+j-1]*12 )
 226               + ( p_at[i*i_pitch+j]<<4 )
 227               + ( p_at[i*i_pitch+j+1]*12 )
 228               + ( p_at[i*i_pitch+j+2]<<2 )
 229               /* 1 row down */
 230               + ( p_at[(i+1)*i_pitch+j-2]<<2 )
 231               + ( p_at[(i+1)*i_pitch+j-1]<<3 )
 232               + ( p_at[(i+1)*i_pitch+j]*12 )
 233               + ( p_at[(i+1)*i_pitch+j+1]<<3 )
 234               + ( p_at[(i+1)*i_pitch+j+2]<<2 )
 235               /* 2 rows down */
 236               + ( p_at[(i+2)*i_pitch+j-2]<<1 )
 237               + ( p_at[(i+2)*i_pitch+j-1]<<2 )
 238               + ( p_at[(i+2)*i_pitch+j]<<2 )
 239               + ( p_at[(i+2)*i_pitch+j+1]<<2 )
 240               + ( p_at[(i+2)*i_pitch+j+2]<<1 )
 241               )/152);
 242               if( p_a[i*i_pitch+j] < 0xbf ) p_a[i*i_pitch+j] = 0x00;
 243         }
 244     }
 245     return p_pic;
 246 }
 247
 248 /*****************************************************************************
 249 * Callback to update params on the fly
 250 *****************************************************************************/
 251 static int BluescreenCallback( vlc_object_t *p_this, char const *psz_var,
 252                                vlc_value_t oldval, vlc_value_t newval,
 253                                void *p_data )
 254 {
 255     VLC_UNUSED(p_this); VLC_UNUSED(oldval);
 256     filter_sys_t *p_sys = (filter_sys_t *) p_data;
 257
 258 #define VAR_IS( a ) !strcmp( psz_var, CFG_PREFIX a )
 259     if( VAR_IS( "u" ) )
 260     {
 261         p_sys->i_u = __MAX( 0, __MIN( 255, newval.i_int ) );
 262     }
 263     else if( VAR_IS( "v" ) )
 264     {
 265         p_sys->i_v = __MAX( 0, __MIN( 255, newval.i_int ) );
 266     }
 267     else if( VAR_IS( "ut" ) )
 268     {
 269         p_sys->i_ut = __MAX( 0, __MIN( 255, newval.i_int ) );
 270     }
 271     else if( VAR_IS( "vt" ) )
 272     {
 273         p_sys->i_vt = __MAX( 0, __MIN( 255, newval.i_int ) );
 274     }
 275
 276     return VLC_SUCCESS;
 277 }