git.sesse.net Git - vlc/blob - 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 <assert.h>
  33
  34 #include <vlc_common.h>
  35 #include <vlc_plugin.h>
  36 #include <vlc_memory.h>
  37
  38 #include <vlc_filter.h>
  39 #include "filter_picture.h"
  40
  41 #include <math.h>                                          /* exp(), sqrt() */
  42
  43 /*****************************************************************************
  44  * Module descriptor
  45  *****************************************************************************/
  46 static int  Create    ( vlc_object_t * );
  47 static void Destroy   ( vlc_object_t * );
  48
  49 #define SIGMA_TEXT N_("Gaussian's std deviation")
  50 #define SIGMA_LONGTEXT N_( \
  51     "Gaussian's standard deviation. The bluring will take " \
  52     "into account pixels up to 3*sigma away in any direction.")
  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_capability( "video filter2", 0 )
  60     set_category( CAT_VIDEO )
  61     set_subcategory( SUBCAT_VIDEO_VFILTER )
  62
  63     add_float( FILTER_PREFIX "sigma", 2., NULL, SIGMA_TEXT, SIGMA_LONGTEXT,
  64                false )
  65
  66     set_callbacks( Create, Destroy )
  67 vlc_module_end ()
  68
  69 /*****************************************************************************
  70  * Local prototypes
  71  *****************************************************************************/
  72 static picture_t *Filter( filter_t *, picture_t * );
  73
  74 static const char *const ppsz_filter_options[] = {
  75     "sigma", NULL
  76 };
  77
  78 /* Comment this to use floats instead of integers (faster for bigger sigma
  79  * values)
  80  * For sigma = 2 ints are faster
  81  * For sigma = 4 floats are faster
  82  */
  83 #define DONT_USE_FLOATS
  84
  85 #ifdef DONT_USE_FLOATS
  86 #   define type_t int
  87 #else
  88 #   define type_t float
  89 #endif
  90
  91 struct filter_sys_t
  92 {
  93     double f_sigma;
  94     int i_dim;
  95
  96     type_t *pt_distribution;
  97     type_t *pt_buffer;
  98     type_t *pt_scale;
  99 };
 100
 101 static void gaussianblur_InitDistribution( filter_sys_t *p_sys )
 102 {
 103     double f_sigma = p_sys->f_sigma;
 104     int i_dim = (int)(3.*f_sigma);
 105     type_t *pt_distribution = malloc( (2*i_dim+1) * sizeof( type_t ) );
 106     int x;
 107
 108     assert( pt_distribution );
 109
 110     for( x = -i_dim; x <= i_dim; x++ )
 111     {
 112         const float f_distribution = sqrt( exp(-(x*x)/(f_sigma*f_sigma) ) / (2.*M_PI*f_sigma*f_sigma) );
 113 #ifdef DONT_USE_FLOATS
 114         const float f_factor = 1 << 8;
 115 #else
 116         const float f_factor = 1;
 117 #endif
 118
 119         pt_distribution[i_dim+x] = (type_t)( f_distribution * f_factor );
 120         //printf("%f\n",(float)pt_distribution[i_dim+x]);
 121     }
 122     p_sys->i_dim = i_dim;
 123     p_sys->pt_distribution = pt_distribution;
 124 }
 125
 126 static int Create( vlc_object_t *p_this )
 127 {
 128     filter_t *p_filter = (filter_t *)p_this;
 129
 130     if(   p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420
 131        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J420
 132        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_YV12
 133
 134        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_I422
 135        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J422
 136       )
 137     {
 138         /* We only want planar YUV 4:2:0 or 4:2:2 */
 139         msg_Err( p_filter, "Unsupported input chroma (%4s)",
 140                  (char*)&(p_filter->fmt_in.video.i_chroma) );
 141         return VLC_EGENERIC;
 142     }
 143
 144     if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
 145     {
 146         msg_Err( p_filter, "Input and output chromas don't match" );
 147         return VLC_EGENERIC;
 148     }
 149
 150     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 151     if( p_filter->p_sys == NULL )
 152         return VLC_ENOMEM;
 153
 154     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 155                        p_filter->p_cfg );
 156
 157     p_filter->pf_video_filter = Filter;
 158
 159     p_filter->p_sys->f_sigma =
 160         var_CreateGetFloat( p_filter, FILTER_PREFIX "sigma" );
 161     if( p_filter->p_sys->f_sigma <= 0. )
 162     {
 163         msg_Err( p_filter, "sigma must be positive" );
 164         return VLC_EGENERIC;
 165     }
 166     gaussianblur_InitDistribution( p_filter->p_sys );
 167     msg_Dbg( p_filter, "gaussian distribution is %d pixels wide",
 168              p_filter->p_sys->i_dim*2+1 );
 169
 170     p_filter->p_sys->pt_buffer = NULL;
 171     p_filter->p_sys->pt_scale = NULL;
 172
 173     return VLC_SUCCESS;
 174 }
 175
 176 static void Destroy( vlc_object_t *p_this )
 177 {
 178     filter_t *p_filter = (filter_t *)p_this;
 179
 180     free( p_filter->p_sys->pt_distribution );
 181     free( p_filter->p_sys->pt_buffer );
 182     free( p_filter->p_sys->pt_scale );
 183
 184     free( p_filter->p_sys );
 185 }
 186
 187 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 188 {
 189     picture_t *p_outpic;
 190     filter_sys_t *p_sys = p_filter->p_sys;
 191     int i_plane;
 192     const int i_dim = p_sys->i_dim;
 193     type_t *pt_buffer;
 194     type_t *pt_scale;
 195     const type_t *pt_distribution = p_sys->pt_distribution;
 196
 197     if( !p_pic ) return NULL;
 198
 199     p_outpic = filter_NewPicture( p_filter );
 200     if( !p_outpic )
 201     {
 202         picture_Release( p_pic );
 203         return NULL;
 204     }
 205     if( !p_sys->pt_buffer )
 206     {
 207         p_sys->pt_buffer = realloc_or_free( p_sys->pt_buffer,
 208                                p_pic->p[Y_PLANE].i_visible_lines *
 209                                p_pic->p[Y_PLANE].i_pitch * sizeof( type_t ) );
 210     }
 211
 212     pt_buffer = p_sys->pt_buffer;
 213     if( !p_sys->pt_scale )
 214     {
 215         const int i_visible_lines = p_pic->p[Y_PLANE].i_visible_lines;
 216         const int i_visible_pitch = p_pic->p[Y_PLANE].i_visible_pitch;
 217         const int i_pitch = p_pic->p[Y_PLANE].i_pitch;
 218         int i_col, i_line;
 219
 220         p_sys->pt_scale = malloc( i_visible_lines * i_pitch * sizeof( type_t ) );
 221         pt_scale = p_sys->pt_scale;
 222         assert( pt_scale );
 223
 224         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 225         {
 226             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 227             {
 228                 int x, y;
 229                 type_t t_value = 0;
 230
 231                 for( y = __MAX( -i_dim, -i_line );
 232                      y <= __MIN( i_dim, i_visible_lines - i_line - 1 );
 233                      y++ )
 234                 {
 235                     for( x = __MAX( -i_dim, -i_col );
 236                          x <= __MIN( i_dim, i_visible_pitch - i_col + 1 );
 237                          x++ )
 238                     {
 239                         t_value += pt_distribution[y+i_dim] *
 240                                    pt_distribution[x+i_dim];
 241                     }
 242                 }
 243                 pt_scale[i_line*i_pitch+i_col] = t_value;
 244             }
 245         }
 246     }
 247
 248     pt_scale = p_sys->pt_scale;
 249     for( i_plane = 0 ; i_plane < p_pic->i_planes ; i_plane++ )
 250     {
 251
 252         uint8_t *p_in = p_pic->p[i_plane].p_pixels;
 253         uint8_t *p_out = p_outpic->p[i_plane].p_pixels;
 254
 255         const int i_visible_lines = p_pic->p[i_plane].i_visible_lines;
 256         const int i_visible_pitch = p_pic->p[i_plane].i_visible_pitch;
 257         const int i_pitch = p_pic->p[i_plane].i_pitch;
 258
 259         int i_line, i_col;
 260         const int x_factor = p_pic->p[Y_PLANE].i_visible_pitch/i_visible_pitch-1;
 261         const int y_factor = p_pic->p[Y_PLANE].i_visible_lines/i_visible_lines-1;
 262
 263         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 264         {
 265             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 266             {
 267                 type_t t_value = 0;
 268                 int x;
 269                 const int c = i_line*i_pitch+i_col;
 270                 for( x = __MAX( -i_dim, -i_col*(x_factor+1) );
 271                      x <= __MIN( i_dim, (i_visible_pitch - i_col)*(x_factor+1) + 1 );
 272                      x++ )
 273                 {
 274                     t_value += pt_distribution[x+i_dim] *
 275                                p_in[c+(x>>x_factor)];
 276                 }
 277                 pt_buffer[c] = t_value;
 278             }
 279         }
 280         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 281         {
 282             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 283             {
 284                 type_t t_value = 0;
 285                 int y;
 286                 const int c = i_line*i_pitch+i_col;
 287                 for( y = __MAX( -i_dim, (-i_line)*(y_factor+1) );
 288                      y <= __MIN( i_dim, (i_visible_lines - i_line)*(y_factor+1) - 1 );
 289                      y++ )
 290                 {
 291                     t_value += pt_distribution[y+i_dim] *
 292                                pt_buffer[c+(y>>y_factor)*i_pitch];
 293                 }
 294
 295                 const type_t t_scale = pt_scale[(i_line<<y_factor)*(i_pitch<<x_factor)+(i_col<<x_factor)];
 296                 p_out[c] = (uint8_t)(t_value / t_scale); // FIXME wouldn't it be better to round instead of trunc ?
 297             }
 298         }
 299     }
 300
 301     return CopyInfoAndRelease( p_outpic, p_pic );
 302 }