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