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_filter.h>
  35
  36 #define BLUESCREEN_HELP N_( \
  37     "This effect, also known as \"greenscreen\" or \"chroma key\" blends " \
  38     "the \"blue parts\" of the foreground image of the mosaic on the " \
  39     "background (like weather forecasts). You can choose the \"key\" " \
  40     "color for blending (blue by default)." )
  41
  42 #define BLUESCREENU_TEXT N_("Bluescreen U value")
  43 #define BLUESCREENU_LONGTEXT N_( \
  44         "\"U\" value for the bluescreen key color " \
  45         "(in YUV values). From 0 to 255. Defaults to 120 for blue." )
  46 #define BLUESCREENV_TEXT N_("Bluescreen V value")
  47 #define BLUESCREENV_LONGTEXT N_( \
  48         "\"V\" value for the bluescreen key color " \
  49         "(in YUV values). From 0 to 255. Defaults to 90 for blue." )
  50 #define BLUESCREENUTOL_TEXT N_("Bluescreen U tolerance")
  51 #define BLUESCREENUTOL_LONGTEXT N_( \
  52         "Tolerance of the bluescreen blender " \
  53         "on color variations for the U plane. A value between 10 and 20 " \
  54         "seems sensible." )
  55 #define BLUESCREENVTOL_TEXT N_("Bluescreen V tolerance")
  56 #define BLUESCREENVTOL_LONGTEXT N_( \
  57         "Tolerance of the bluescreen blender " \
  58         "on color variations for the V plane. A value between 10 and 20 " \
  59         "seems sensible." )
  60
  61 #define CFG_PREFIX "bluescreen-"
  62
  63 /*****************************************************************************
  64  * Local prototypes
  65  *****************************************************************************/
  66 static int  Create      ( vlc_object_t * );
  67 static void Destroy     ( vlc_object_t * );
  68
  69 static picture_t *Filter( filter_t *, picture_t * );
  70 static int BluescreenCallback( vlc_object_t *, char const *,
  71                                vlc_value_t, vlc_value_t, void * );
  72
  73 /*****************************************************************************
  74  * Module descriptor
  75  *****************************************************************************/
  76 vlc_module_begin ()
  77     set_description( N_("Bluescreen video filter") )
  78     set_shortname( N_("Bluescreen" ))
  79     set_help( BLUESCREEN_HELP )
  80     set_category( CAT_VIDEO )
  81     set_subcategory( SUBCAT_VIDEO_VFILTER )
  82     set_capability( "video filter2", 0 )
  83     add_shortcut( "bluescreen" )
  84     set_callbacks( Create, Destroy )
  85
  86     add_integer_with_range( CFG_PREFIX "u", 120, 0, 255, NULL,
  87                             BLUESCREENU_TEXT, BLUESCREENU_LONGTEXT, false )
  88     add_integer_with_range( CFG_PREFIX "v", 90, 0, 255, NULL,
  89                             BLUESCREENV_TEXT, BLUESCREENV_LONGTEXT, false )
  90     add_integer_with_range( CFG_PREFIX "ut", 17, 0, 255, NULL,
  91                             BLUESCREENUTOL_TEXT, BLUESCREENUTOL_LONGTEXT,
  92                             false )
  93     add_integer_with_range( CFG_PREFIX "vt", 17, 0, 255, NULL,
  94                             BLUESCREENVTOL_TEXT, BLUESCREENVTOL_LONGTEXT,
  95                             false )
  96 vlc_module_end ()
  97
  98 static const char *const ppsz_filter_options[] = {
  99     "u", "v", "ut", "vt", NULL
 100 };
 101
 102 struct filter_sys_t
 103 {
 104     vlc_mutex_t lock;
 105     int i_u, i_v, i_ut, i_vt;
 106     uint8_t *p_at;
 107 };
 108
 109 static int Create( vlc_object_t *p_this )
 110 {
 111     filter_t *p_filter = (filter_t *)p_this;
 112     filter_sys_t *p_sys;
 113
 114     if( p_filter->fmt_in.video.i_chroma != VLC_CODEC_YUVA )
 115     {
 116         msg_Err( p_filter,
 117                  "Unsupported input chroma \"%4.4s\". "
 118                  "Bluescreen can only use \"YUVA\".",
 119                  (char*)&p_filter->fmt_in.video.i_chroma );
 120         return VLC_EGENERIC;
 121     }
 122
 123     /* Allocate structure */
 124     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 125     if( p_filter->p_sys == NULL )
 126         return VLC_ENOMEM;
 127     p_sys = p_filter->p_sys;
 128
 129     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 130                        p_filter->p_cfg );
 131
 132     int val;
 133     vlc_mutex_init( &p_sys->lock );
 134 #define GET_VAR( name, min, max )                                           \
 135     val = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX #name );        \
 136     p_sys->i_##name = __MIN( max, __MAX( min, val ) );                      \
 137     var_AddCallback( p_filter, CFG_PREFIX #name, BluescreenCallback, p_sys );
 138
 139     GET_VAR( u, 0x00, 0xff );
 140     GET_VAR( v, 0x00, 0xff );
 141     GET_VAR( ut, 0x00, 0xff );
 142     GET_VAR( vt, 0x00, 0xff );
 143     p_sys->p_at = NULL;
 144 #undef GET_VAR
 145
 146     p_filter->pf_video_filter = Filter;
 147
 148     return VLC_SUCCESS;
 149 }
 150
 151 static void Destroy( vlc_object_t *p_this )
 152 {
 153     filter_t *p_filter = (filter_t *)p_this;
 154     filter_sys_t *p_sys = p_filter->p_sys;
 155
 156     var_DelCallback( p_filter, CFG_PREFIX "u", BluescreenCallback, p_sys );
 157     var_DelCallback( p_filter, CFG_PREFIX "v", BluescreenCallback, p_sys );
 158     var_DelCallback( p_filter, CFG_PREFIX "ut", BluescreenCallback, p_sys );
 159     var_DelCallback( p_filter, CFG_PREFIX "vt", BluescreenCallback, p_sys );
 160
 161     free( p_sys->p_at );
 162     vlc_mutex_destroy( &p_sys->lock );
 163     free( p_sys );
 164 }
 165
 166 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 167 {
 168     filter_sys_t *p_sys = p_filter->p_sys;
 169
 170     int i,j;
 171     int i_lines = p_pic->p[ A_PLANE ].i_lines;
 172     int i_pitch = p_pic->p[ A_PLANE ].i_pitch;
 173     uint8_t *p_a = p_pic->p[ A_PLANE ].p_pixels;
 174     uint8_t *p_at;
 175     uint8_t *p_u = p_pic->p[ U_PLANE ].p_pixels;
 176     uint8_t *p_v = p_pic->p[ V_PLANE ].p_pixels;
 177     uint8_t umin, umax, vmin, vmax;
 178
 179     if( p_pic->format.i_chroma != VLC_CODEC_YUVA )
 180     {
 181         msg_Err( p_filter,
 182                  "Unsupported input chroma \"%4.4s\". "
 183                  "Bluescreen can only use \"YUVA\".",
 184                  (char*)&p_pic->format.i_chroma );
 185         return NULL;
 186     }
 187
 188     p_sys->p_at = xrealloc( p_sys->p_at,
 189                             i_lines * i_pitch * sizeof( uint8_t ) );
 190     p_at = p_sys->p_at;
 191
 192     vlc_mutex_lock( &p_sys->lock );
 193     umin = p_sys->i_u - p_sys->i_ut >= 0x00 ? p_sys->i_u - p_sys->i_ut : 0x00;
 194     umax = p_sys->i_u + p_sys->i_ut <= 0xff ? p_sys->i_u + p_sys->i_ut : 0xff;
 195     vmin = p_sys->i_v - p_sys->i_vt >= 0x00 ? p_sys->i_v - p_sys->i_vt : 0x00;
 196     vmax = p_sys->i_v + p_sys->i_vt <= 0xff ? p_sys->i_v + p_sys->i_vt : 0xff;
 197     vlc_mutex_unlock( &p_sys->lock );
 198
 199     for( i = 0; i < i_lines*i_pitch; i++ )
 200     {
 201         if(    p_u[i] < umax && p_u[i] > umin
 202             && p_v[i] < vmax && p_v[i] > vmin )
 203         {
 204             p_at[i] = 0x00;
 205         }
 206         else
 207         {
 208             p_at[i] = 0xff;
 209         }
 210     }
 211     /* Gaussian convolution to make it look cleaner */
 212     vlc_memset( p_a, 0, 2 * i_pitch );
 213     for( i = 2; i < i_lines - 2; i++ )
 214     {
 215         p_a[i*i_pitch] = 0x00;
 216         p_a[i*i_pitch+1] = 0x00;
 217         for( j = 2; j < i_pitch - 2; j ++ )
 218         {
 219             p_a[i*i_pitch+j] = (uint8_t)((
 220               /* 2 rows up */
 221                 ( p_at[(i-2)*i_pitch+j-2]<<1 )
 222               + ( p_at[(i-2)*i_pitch+j-1]<<2 )
 223               + ( p_at[(i-2)*i_pitch+j]<<2 )
 224               + ( p_at[(i-2)*i_pitch+j+1]<<2 )
 225               + ( p_at[(i-2)*i_pitch+j+2]<<1 )
 226               /* 1 row up */
 227               + ( p_at[(i-1)*i_pitch+j-2]<<2 )
 228               + ( p_at[(i-1)*i_pitch+j-1]<<3 )
 229               + ( p_at[(i-1)*i_pitch+j]*12 )
 230               + ( p_at[(i-1)*i_pitch+j+1]<<3 )
 231               + ( p_at[(i-1)*i_pitch+j+2]<<2 )
 232               /* */
 233               + ( p_at[i*i_pitch+j-2]<<2 )
 234               + ( p_at[i*i_pitch+j-1]*12 )
 235               + ( p_at[i*i_pitch+j]<<4 )
 236               + ( p_at[i*i_pitch+j+1]*12 )
 237               + ( p_at[i*i_pitch+j+2]<<2 )
 238               /* 1 row down */
 239               + ( p_at[(i+1)*i_pitch+j-2]<<2 )
 240               + ( p_at[(i+1)*i_pitch+j-1]<<3 )
 241               + ( p_at[(i+1)*i_pitch+j]*12 )
 242               + ( p_at[(i+1)*i_pitch+j+1]<<3 )
 243               + ( p_at[(i+1)*i_pitch+j+2]<<2 )
 244               /* 2 rows down */
 245               + ( p_at[(i+2)*i_pitch+j-2]<<1 )
 246               + ( p_at[(i+2)*i_pitch+j-1]<<2 )
 247               + ( p_at[(i+2)*i_pitch+j]<<2 )
 248               + ( p_at[(i+2)*i_pitch+j+1]<<2 )
 249               + ( p_at[(i+2)*i_pitch+j+2]<<1 )
 250               )/152);
 251               if( p_a[i*i_pitch+j] < 0xbf ) p_a[i*i_pitch+j] = 0x00;
 252         }
 253     }
 254     return p_pic;
 255 }
 256
 257 /*****************************************************************************
 258 * Callback to update params on the fly
 259 *****************************************************************************/
 260 static int BluescreenCallback( vlc_object_t *p_this, char const *psz_var,
 261                                vlc_value_t oldval, vlc_value_t newval,
 262                                void *p_data )
 263 {
 264     VLC_UNUSED(p_this); VLC_UNUSED(oldval);
 265     filter_sys_t *p_sys = (filter_sys_t *) p_data;
 266
 267     vlc_mutex_lock( &p_sys->lock );
 268 #define VAR_IS( a ) !strcmp( psz_var, CFG_PREFIX a )
 269     if( VAR_IS( "u" ) )
 270         p_sys->i_u = __MAX( 0, __MIN( 255, newval.i_int ) );
 271     else if( VAR_IS( "v" ) )
 272         p_sys->i_v = __MAX( 0, __MIN( 255, newval.i_int ) );
 273     else if( VAR_IS( "ut" ) )
 274         p_sys->i_ut = __MAX( 0, __MIN( 255, newval.i_int ) );
 275     else if( VAR_IS( "vt" ) )
 276         p_sys->i_vt = __MAX( 0, __MIN( 255, newval.i_int ) );
 277     vlc_mutex_unlock( &p_sys->lock );
 278
 279     return VLC_SUCCESS;
 280 }