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 #include <stdlib.h>                                      /* malloc(), free() */
  28 #include <string.h>
  29
  30 #include <vlc/vlc.h>
  31 #include <vlc_vout.h>
  32
  33 #include "vlc_filter.h"
  34
  35 #include <math.h>                                                  /* exp() */
  36
  37 /*****************************************************************************
  38  * Local prototypes
  39  *****************************************************************************/
  40 static int  Create    ( vlc_object_t * );
  41 static void Destroy   ( vlc_object_t * );
  42
  43 static picture_t *Filter( filter_t *, picture_t * );
  44
  45 #define SIGMA_TEXT N_("Gaussian's std deviation")
  46 #define SIGMA_LONGTEXT N_( \
  47     "Gaussian's standard deviation. The bluring will take " \
  48     "into account pixels up to 3*sigma away in any direction.")
  49
  50 #define FILTER_PREFIX "gaussianblur-"
  51
  52 /*****************************************************************************
  53  * Module descriptor
  54  *****************************************************************************/
  55 vlc_module_begin();
  56     set_description( _("Gaussian blur video filter") );
  57     set_shortname( _( "Gaussian Blur" ));
  58     set_capability( "video filter2", 0 );
  59     set_category( CAT_VIDEO );
  60     set_subcategory( SUBCAT_VIDEO_VFILTER );
  61
  62     add_float( FILTER_PREFIX "sigma", 2., NULL, SIGMA_TEXT, SIGMA_LONGTEXT,
  63                VLC_FALSE );
  64
  65     set_callbacks( Create, Destroy );
  66 vlc_module_end();
  67
  68 static const char *ppsz_filter_options[] = {
  69     "sigma", NULL
  70 };
  71
  72 struct filter_sys_t
  73 {
  74     double f_sigma;
  75     int *pi_distribution;
  76     int i_dim;
  77     int *pi_buffer;
  78 };
  79
  80 static void gaussianblur_InitDistribution( filter_sys_t *p_sys )
  81 {
  82     double f_sigma = p_sys->f_sigma;
  83     int i_dim = (int)(3.*f_sigma);
  84     int *pi_distribution = (int*)malloc( (2*i_dim+1) * sizeof( int ) );
  85     int x;
  86     for( x = -i_dim; x <= i_dim; x++ )
  87         pi_distribution[i_dim+x] =
  88             (int)( sqrt( exp(-(x*x)/(f_sigma*f_sigma))
  89                    / (2.*M_PI*f_sigma*f_sigma) )* (double)(1<<16) );
  90     p_sys->i_dim = i_dim;
  91     p_sys->pi_distribution = pi_distribution;
  92 }
  93
  94 static int Create( vlc_object_t *p_this )
  95 {
  96     filter_t *p_filter = (filter_t *)p_this;
  97
  98     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
  99     if( p_filter->p_sys == NULL )
 100     {
 101         msg_Err( p_filter, "out of memory" );
 102         return VLC_ENOMEM;
 103     }
 104
 105     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 106                        p_filter->p_cfg );
 107
 108     p_filter->pf_video_filter = Filter;
 109
 110     p_filter->p_sys->f_sigma =
 111         var_CreateGetFloat( p_filter, FILTER_PREFIX "sigma" );
 112     if( p_filter->p_sys->f_sigma <= 0. )
 113     {
 114         msg_Err( p_filter, "sigma must be positive" );
 115         return VLC_EGENERIC;
 116     }
 117     gaussianblur_InitDistribution( p_filter->p_sys );
 118     msg_Dbg( p_filter, "gaussian distribution is %d pixels wide",
 119              p_filter->p_sys->i_dim*2+1 );
 120     p_filter->p_sys->pi_buffer = NULL;
 121
 122     return VLC_SUCCESS;
 123 }
 124
 125 static void Destroy( vlc_object_t *p_this )
 126 {
 127     filter_t *p_filter = (filter_t *)p_this;
 128     free( p_filter->p_sys->pi_distribution );
 129     free( p_filter->p_sys );
 130 }
 131
 132 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 133 {
 134     picture_t *p_outpic;
 135     filter_sys_t *p_sys = p_filter->p_sys;
 136     int i_plane;
 137     int *pi_buffer;
 138     const int *pi_distribution = p_sys->pi_distribution;
 139
 140     if( !p_pic ) return NULL;
 141
 142     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 143     if( !p_outpic )
 144     {
 145         msg_Warn( p_filter, "can't get output picture" );
 146         if( p_pic->pf_release )
 147             p_pic->pf_release( p_pic );
 148         return NULL;
 149     }
 150
 151     p_sys->pi_buffer = (int*)realloc( p_sys->pi_buffer,
 152                                       p_pic->p[Y_PLANE].i_visible_lines
 153                                       * p_pic->p[Y_PLANE].i_pitch
 154                                       * sizeof( int ) );
 155     pi_buffer = p_sys->pi_buffer;
 156
 157     for( i_plane = 0 ; i_plane < p_pic->i_planes ; i_plane++ )
 158     {
 159
 160         uint8_t *p_in = p_pic->p[i_plane].p_pixels;
 161         uint8_t *p_out = p_outpic->p[i_plane].p_pixels;
 162
 163         const int i_visible_lines = p_pic->p[i_plane].i_visible_lines;
 164         const int i_visible_pitch = p_pic->p[i_plane].i_visible_pitch;
 165         const int i_pitch = p_pic->p[i_plane].i_pitch;
 166
 167         const int i_dim = p_sys->i_dim;
 168
 169         int i_line, i_col;
 170         const int factor = i_plane ? 1 : 0;
 171
 172         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 173         {
 174             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 175             {
 176                 int value = 0;
 177                 int scale = 0;
 178                 int x;
 179                 const int c = i_line*i_pitch+i_col;
 180                 for( x = __MAX( -i_dim, -i_col );
 181                      x <= __MIN( i_dim, i_visible_pitch - i_col + 1 );
 182                      x++ )
 183                 {
 184                     const int weight = pi_distribution[x+i_dim];
 185                     scale += weight;
 186                     value += weight * p_in[c+(x>>factor)];
 187                 }
 188                 pi_buffer[c] = value/scale;
 189             }
 190         }
 191         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 192         {
 193             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 194             {
 195                 int value = 0;
 196                 int scale = 0;
 197                 int y;
 198                 const int c = i_line*i_pitch+i_col;
 199                 for( y = __MAX( -i_dim, -i_line );
 200                      y <= __MIN( i_dim, i_visible_lines - i_line - 1 );
 201                      y++ )
 202                 {
 203                     const int weight = pi_distribution[y+i_dim];
 204                     scale += weight;
 205                     value += weight * pi_buffer[c+(y>>factor)*i_pitch];
 206                 }
 207                 p_out[c] = value/scale;
 208             }
 209         }
 210     }
 211
 212     p_outpic->date = p_pic->date;
 213     p_outpic->b_force = p_pic->b_force;
 214     p_outpic->i_nb_fields = p_pic->i_nb_fields;
 215     p_outpic->b_progressive = p_pic->b_progressive;
 216     p_outpic->b_top_field_first = p_pic->b_top_field_first;
 217
 218     if( p_pic->pf_release )
 219         p_pic->pf_release( p_pic );
 220
 221     return p_outpic;
 222 }