git.sesse.net Git - vlc/blob - modules/video_filter/noise.c

   1 /*****************************************************************************
   2  * noise.c : "add noise to image" video filter
   3  *****************************************************************************
   4  * Copyright (C) 2000-2006 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 <string.h>
  28
  29 #include <vlc/vlc.h>
  30 #include <vlc_vout.h>
  31
  32 #include "vlc_filter.h"
  33
  34 /*****************************************************************************
  35  * Local prototypes
  36  *****************************************************************************/
  37 static int  Create    ( vlc_object_t * );
  38 static void Destroy   ( vlc_object_t * );
  39
  40 static picture_t *Filter( filter_t *, picture_t * );
  41
  42 #define FILTER_PREFIX "noise-"
  43
  44 /*****************************************************************************
  45  * Module descriptor
  46  *****************************************************************************/
  47 vlc_module_begin();
  48     set_description( _("Noise video filter") );
  49     set_shortname( _( "Noise" ));
  50     set_capability( "video filter2", 0 );
  51     set_category( CAT_VIDEO );
  52     set_subcategory( SUBCAT_VIDEO_VFILTER );
  53
  54     add_shortcut( "noise" );
  55     set_callbacks( Create, Destroy );
  56 vlc_module_end();
  57
  58 static const char *ppsz_filter_options[] = {
  59     NULL
  60 };
  61
  62 /*****************************************************************************
  63  * vout_sys_t: Distort video output method descriptor
  64  *****************************************************************************
  65  * This structure is part of the video output thread descriptor.
  66  * It describes the Distort specific properties of an output thread.
  67  *****************************************************************************/
  68 struct filter_sys_t
  69 {
  70     mtime_t last_date;
  71 };
  72
  73 /*****************************************************************************
  74  * Create: allocates Distort video thread output method
  75  *****************************************************************************
  76  * This function allocates and initializes a Distort vout method.
  77  *****************************************************************************/
  78 static int Create( vlc_object_t *p_this )
  79 {
  80     filter_t *p_filter = (filter_t *)p_this;
  81
  82     /* Allocate structure */
  83     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
  84     if( p_filter->p_sys == NULL )
  85     {
  86         msg_Err( p_filter, "out of memory" );
  87         return VLC_ENOMEM;
  88     }
  89
  90     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
  91                        p_filter->p_cfg );
  92
  93     p_filter->pf_video_filter = Filter;
  94
  95     p_filter->p_sys->last_date = 0;
  96
  97     return VLC_SUCCESS;
  98 }
  99
 100 /*****************************************************************************
 101  * Destroy: destroy Distort video thread output method
 102  *****************************************************************************
 103  * Terminate an output method created by DistortCreateOutputMethod
 104  *****************************************************************************/
 105 static void Destroy( vlc_object_t *p_this )
 106 {
 107     filter_t *p_filter = (filter_t *)p_this;
 108     free( p_filter->p_sys );
 109 }
 110
 111 /*****************************************************************************
 112  * Render: displays previously rendered output
 113  *****************************************************************************
 114  * This function send the currently rendered image to Distort image, waits
 115  * until it is displayed and switch the two rendering buffers, preparing next
 116  * frame.
 117  *****************************************************************************/
 118 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 119 {
 120     picture_t *p_outpic;
 121     filter_sys_t *p_sys = p_filter->p_sys;
 122     int i_index;
 123     mtime_t new_date = mdate();
 124
 125     if( !p_pic ) return NULL;
 126
 127     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 128     if( !p_outpic )
 129     {
 130         msg_Warn( p_filter, "can't get output picture" );
 131         if( p_pic->pf_release )
 132             p_pic->pf_release( p_pic );
 133         return NULL;
 134     }
 135
 136     p_sys->last_date = new_date;
 137
 138     for( i_index = 0 ; i_index < p_pic->i_planes ; i_index++ )
 139     {
 140         uint8_t *p_in = p_pic->p[i_index].p_pixels;
 141         uint8_t *p_out = p_outpic->p[i_index].p_pixels;
 142
 143         const int i_num_lines = p_pic->p[i_index].i_visible_lines;
 144         const int i_num_cols = p_pic->p[i_index].i_visible_pitch;
 145         const int i_pitch = p_pic->p[i_index].i_pitch;
 146
 147         int i_line, i_col;
 148
 149         for( i_line = 0 ; i_line < i_num_lines ; i_line++ )
 150         {
 151             if( rand()%8 )
 152             {
 153                 /* line isn't noisy */
 154                 p_filter->p_libvlc->pf_memcpy( p_out+i_line*i_pitch,
 155                                                p_in+i_line*i_pitch,
 156                                                i_num_cols );
 157             }
 158             else
 159             {
 160                 /* this line is noisy */
 161                 int noise_level = rand()%8+2;
 162                 for( i_col = 0; i_col < i_num_cols ; i_col++ )
 163                 {
 164                     if( rand()%noise_level )
 165                     {
 166                         p_out[i_line*i_pitch+i_col] =
 167                             p_in[i_line*i_pitch+i_col];
 168                     }
 169                     else
 170                     {
 171                         p_out[i_line*i_pitch+i_col] = (rand()%3)*0x7f;
 172                     }
 173                 }
 174             }
 175         }
 176     }
 177
 178     p_outpic->date = p_pic->date;
 179     p_outpic->b_force = p_pic->b_force;
 180     p_outpic->i_nb_fields = p_pic->i_nb_fields;
 181     p_outpic->b_progressive = p_pic->b_progressive;
 182     p_outpic->b_top_field_first = p_pic->b_top_field_first;
 183
 184     if( p_pic->pf_release )
 185         p_pic->pf_release( p_pic );
 186
 187     return p_outpic;
 188 }