1 /*****************************************************************************
2 * noise.c : "add noise to image" video filter
3 *****************************************************************************
4 * Copyright (C) 2000-2006 the VideoLAN team
7 * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
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.
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.
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 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
32 #include <vlc_common.h>
33 #include <vlc_plugin.h>
35 #include <vlc_filter.h>
36 #include "filter_picture.h"
38 /*****************************************************************************
40 *****************************************************************************/
41 static int Create ( vlc_object_t * );
42 static void Destroy ( vlc_object_t * );
44 static picture_t *Filter( filter_t *, picture_t * );
46 #define FILTER_PREFIX "noise-"
48 /*****************************************************************************
50 *****************************************************************************/
52 set_description( N_("Noise video filter") )
53 set_shortname( N_( "Noise" ))
54 set_capability( "video filter2", 0 )
55 set_category( CAT_VIDEO )
56 set_subcategory( SUBCAT_VIDEO_VFILTER )
58 add_shortcut( "noise" )
59 set_callbacks( Create, Destroy )
62 /*****************************************************************************
63 * filter_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 *****************************************************************************/
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 )
80 filter_t *p_filter = (filter_t *)p_this;
82 /* Allocate structure */
83 p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
84 if( p_filter->p_sys == NULL )
87 p_filter->pf_video_filter = Filter;
89 p_filter->p_sys->last_date = 0;
94 /*****************************************************************************
95 * Destroy: destroy Distort video thread output method
96 *****************************************************************************
97 * Terminate an output method created by DistortCreateOutputMethod
98 *****************************************************************************/
99 static void Destroy( vlc_object_t *p_this )
101 filter_t *p_filter = (filter_t *)p_this;
102 free( p_filter->p_sys );
105 /*****************************************************************************
106 * Render: displays previously rendered output
107 *****************************************************************************
108 * This function send the currently rendered image to Distort image, waits
109 * until it is displayed and switch the two rendering buffers, preparing next
111 *****************************************************************************/
112 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
115 filter_sys_t *p_sys = p_filter->p_sys;
117 mtime_t new_date = mdate();
119 if( !p_pic ) return NULL;
121 p_outpic = filter_NewPicture( p_filter );
124 msg_Warn( p_filter, "can't get output picture" );
125 picture_Release( p_pic );
129 p_sys->last_date = new_date;
131 for( i_index = 0 ; i_index < p_pic->i_planes ; i_index++ )
133 uint8_t *p_in = p_pic->p[i_index].p_pixels;
134 uint8_t *p_out = p_outpic->p[i_index].p_pixels;
136 const int i_num_lines = p_pic->p[i_index].i_visible_lines;
137 const int i_num_cols = p_pic->p[i_index].i_visible_pitch;
138 const int i_pitch = p_pic->p[i_index].i_pitch;
142 for( i_line = 0 ; i_line < i_num_lines ; i_line++ )
146 /* line isn't noisy */
147 vlc_memcpy( p_out+i_line*i_pitch, p_in+i_line*i_pitch,
152 /* this line is noisy */
153 int noise_level = rand()%8+2;
154 for( i_col = 0; i_col < i_num_cols ; i_col++ )
156 if( rand()%noise_level )
158 p_out[i_line*i_pitch+i_col] =
159 p_in[i_line*i_pitch+i_col];
163 p_out[i_line*i_pitch+i_col] = (rand()%3)*0x7f;
170 return CopyInfoAndRelease( p_outpic, p_pic );