modules/video_filter/gaussianblur.c

   1 /*****************************************************************************
   2  * gaussianblur.c : gaussian blur video filter
   3  *****************************************************************************
   4  * Copyright (C) 2000-2007 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Antoine Cellerier <dionoea -at- videolan -dot- 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_memory.h>
  35
  36 #include <vlc_filter.h>
  37 #include "filter_picture.h"
  38
  39 #include <math.h>                                          /* exp(), sqrt() */
  40
  41 /*****************************************************************************
  42  * Module descriptor
  43  *****************************************************************************/
  44 static int  Create    ( vlc_object_t * );
  45 static void Destroy   ( vlc_object_t * );
  46
  47 #define SIGMA_TEXT N_("Gaussian's std deviation")
  48 #define SIGMA_LONGTEXT N_( \
  49     "Gaussian's standard deviation. The bluring will take " \
  50     "into account pixels up to 3*sigma away in any direction.")
  51
  52 #define GAUSSIAN_HELP N_("Add a blurring effect")
  53
  54 #define FILTER_PREFIX "gaussianblur-"
  55
  56 vlc_module_begin ()
  57     set_description( N_("Gaussian blur video filter") )
  58     set_shortname( N_( "Gaussian Blur" ))
  59     set_help(GAUSSIAN_HELP)
  60     set_capability( "video filter2", 0 )
  61     set_category( CAT_VIDEO )
  62     set_subcategory( SUBCAT_VIDEO_VFILTER )
  63
  64     add_float( FILTER_PREFIX "sigma", 2., SIGMA_TEXT, SIGMA_LONGTEXT,
  65                false )
  66
  67     set_callbacks( Create, Destroy )
  68 vlc_module_end ()
  69
  70 /*****************************************************************************
  71  * Local prototypes
  72  *****************************************************************************/
  73 static picture_t *Filter( filter_t *, picture_t * );
  74
  75 static const char *const ppsz_filter_options[] = {
  76     "sigma", NULL
  77 };
  78
  79 /* Comment this to use floats instead of integers (faster for bigger sigma
  80  * values)
  81  * For sigma = 2 ints are faster
  82  * For sigma = 4 floats are faster
  83  */
  84 #define DONT_USE_FLOATS
  85
  86 #ifdef DONT_USE_FLOATS
  87 #   define type_t int
  88 #else
  89 #   define type_t float
  90 #endif
  91
  92 struct filter_sys_t
  93 {
  94     double f_sigma;
  95     int i_dim;
  96
  97     type_t *pt_distribution;
  98     type_t *pt_buffer;
  99     type_t *pt_scale;
 100 };
 101
 102 static void gaussianblur_InitDistribution( filter_sys_t *p_sys )
 103 {
 104     double f_sigma = p_sys->f_sigma;
 105     int i_dim = (int)(3.*f_sigma);
 106     type_t *pt_distribution = xmalloc( (2*i_dim+1) * sizeof( type_t ) );
 107     int x;
 108
 109     for( x = -i_dim; x <= i_dim; x++ )
 110     {
 111         const float f_distribution = sqrt( exp(-(x*x)/(f_sigma*f_sigma) ) / (2.*M_PI*f_sigma*f_sigma) );
 112 #ifdef DONT_USE_FLOATS
 113         const float f_factor = 1 << 8;
 114 #else
 115         const float f_factor = 1;
 116 #endif
 117
 118         pt_distribution[i_dim+x] = (type_t)( f_distribution * f_factor );
 119         //printf("%f\n",(float)pt_distribution[i_dim+x]);
 120     }
 121     p_sys->i_dim = i_dim;
 122     p_sys->pt_distribution = pt_distribution;
 123 }
 124
 125 static int Create( vlc_object_t *p_this )
 126 {
 127     filter_t *p_filter = (filter_t *)p_this;
 128
 129     if(   p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420
 130        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J420
 131        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_YV12
 132
 133        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_I422
 134        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J422
 135       )
 136     {
 137         /* We only want planar YUV 4:2:0 or 4:2:2 */
 138         msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 139                  (char*)&(p_filter->fmt_in.video.i_chroma) );
 140         return VLC_EGENERIC;
 141     }
 142
 143     if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
 144     {
 145         msg_Err( p_filter, "Input and output chromas don't match" );
 146         return VLC_EGENERIC;
 147     }
 148
 149     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 150     if( p_filter->p_sys == NULL )
 151         return VLC_ENOMEM;
 152
 153     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 154                        p_filter->p_cfg );
 155
 156     p_filter->pf_video_filter = Filter;
 157
 158     p_filter->p_sys->f_sigma =
 159         var_CreateGetFloat( p_filter, FILTER_PREFIX "sigma" );
 160     if( p_filter->p_sys->f_sigma <= 0. )
 161     {
 162         msg_Err( p_filter, "sigma must be positive" );
 163         return VLC_EGENERIC;
 164     }
 165     gaussianblur_InitDistribution( p_filter->p_sys );
 166     msg_Dbg( p_filter, "gaussian distribution is %d pixels wide",
 167              p_filter->p_sys->i_dim*2+1 );
 168
 169     p_filter->p_sys->pt_buffer = NULL;
 170     p_filter->p_sys->pt_scale = NULL;
 171
 172     return VLC_SUCCESS;
 173 }
 174
 175 static void Destroy( vlc_object_t *p_this )
 176 {
 177     filter_t *p_filter = (filter_t *)p_this;
 178
 179     free( p_filter->p_sys->pt_distribution );
 180     free( p_filter->p_sys->pt_buffer );
 181     free( p_filter->p_sys->pt_scale );
 182
 183     free( p_filter->p_sys );
 184 }
 185
 186 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 187 {
 188     picture_t *p_outpic;
 189     filter_sys_t *p_sys = p_filter->p_sys;
 190     int i_plane;
 191     const int i_dim = p_sys->i_dim;
 192     type_t *pt_buffer;
 193     type_t *pt_scale;
 194     const type_t *pt_distribution = p_sys->pt_distribution;
 195
 196     if( !p_pic ) return NULL;
 197
 198     p_outpic = filter_NewPicture( p_filter );
 199     if( !p_outpic )
 200     {
 201         picture_Release( p_pic );
 202         return NULL;
 203     }
 204     if( !p_sys->pt_buffer )
 205     {
 206         p_sys->pt_buffer = realloc_or_free( p_sys->pt_buffer,
 207                                p_pic->p[Y_PLANE].i_visible_lines *
 208                                p_pic->p[Y_PLANE].i_pitch * sizeof( type_t ) );
 209     }
 210
 211     pt_buffer = p_sys->pt_buffer;
 212     if( !p_sys->pt_scale )
 213     {
 214         const int i_visible_lines = p_pic->p[Y_PLANE].i_visible_lines;
 215         const int i_visible_pitch = p_pic->p[Y_PLANE].i_visible_pitch;
 216         const int i_pitch = p_pic->p[Y_PLANE].i_pitch;
 217         int i_col, i_line;
 218
 219         p_sys->pt_scale = xmalloc( i_visible_lines * i_pitch * sizeof( type_t ) );
 220         pt_scale = p_sys->pt_scale;
 221
 222         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 223         {
 224             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 225             {
 226                 int x, y;
 227                 type_t t_value = 0;
 228
 229                 for( y = __MAX( -i_dim, -i_line );
 230                      y <= __MIN( i_dim, i_visible_lines - i_line - 1 );
 231                      y++ )
 232                 {
 233                     for( x = __MAX( -i_dim, -i_col );
 234                          x <= __MIN( i_dim, i_visible_pitch - i_col + 1 );
 235                          x++ )
 236                     {
 237                         t_value += pt_distribution[y+i_dim] *
 238                                    pt_distribution[x+i_dim];
 239                     }
 240                 }
 241                 pt_scale[i_line*i_pitch+i_col] = t_value;
 242             }
 243         }
 244     }
 245
 246     pt_scale = p_sys->pt_scale;
 247     for( i_plane = 0 ; i_plane < p_pic->i_planes ; i_plane++ )
 248     {
 249
 250         uint8_t *p_in = p_pic->p[i_plane].p_pixels;
 251         uint8_t *p_out = p_outpic->p[i_plane].p_pixels;
 252
 253         const int i_visible_lines = p_pic->p[i_plane].i_visible_lines;
 254         const int i_visible_pitch = p_pic->p[i_plane].i_visible_pitch;
 255         const int i_in_pitch = p_pic->p[i_plane].i_pitch;
 256
 257         int i_line, i_col;
 258         const int x_factor = p_pic->p[Y_PLANE].i_visible_pitch/i_visible_pitch-1;
 259         const int y_factor = p_pic->p[Y_PLANE].i_visible_lines/i_visible_lines-1;
 260
 261         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 262         {
 263             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 264             {
 265                 type_t t_value = 0;
 266                 int x;
 267                 const int c = i_line*i_in_pitch+i_col;
 268                 for( x = __MAX( -i_dim, -i_col*(x_factor+1) );
 269                      x <= __MIN( i_dim, (i_visible_pitch - i_col)*(x_factor+1) + 1 );
 270                      x++ )
 271                 {
 272                     t_value += pt_distribution[x+i_dim] *
 273                                p_in[c+(x>>x_factor)];
 274                 }
 275                 pt_buffer[c] = t_value;
 276             }
 277         }
 278         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 279         {
 280             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 281             {
 282                 type_t t_value = 0;
 283                 int y;
 284                 const int c = i_line*i_in_pitch+i_col;
 285                 for( y = __MAX( -i_dim, (-i_line)*(y_factor+1) );
 286                      y <= __MIN( i_dim, (i_visible_lines - i_line)*(y_factor+1) - 1 );
 287                      y++ )
 288                 {
 289                     t_value += pt_distribution[y+i_dim] *
 290                                pt_buffer[c+(y>>y_factor)*i_in_pitch];
 291                 }
 292
 293                 const type_t t_scale = pt_scale[(i_line<<y_factor)*(i_in_pitch<<x_factor)+(i_col<<x_factor)];
 294                 p_out[i_line * p_outpic->p[i_plane].i_pitch + i_col] = (uint8_t)(t_value / t_scale); // FIXME wouldn't it be better to round instead of trunc ?
 295             }
 296         }
 297     }
 298
 299     return CopyInfoAndRelease( p_outpic, p_pic );
 300 }