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>
36 #include "vlc_filter.h"
37 #include "filter_picture.h"
39 /*****************************************************************************
41 *****************************************************************************/
42 static int Create ( vlc_object_t * );
43 static void Destroy ( vlc_object_t * );
45 static picture_t *Filter( filter_t *, picture_t * );
47 #define FILTER_PREFIX "noise-"
49 /*****************************************************************************
51 *****************************************************************************/
53 set_description( N_("Noise video filter") );
54 set_shortname( N_( "Noise" ));
55 set_capability( "video filter2", 0 );
56 set_category( CAT_VIDEO );
57 set_subcategory( SUBCAT_VIDEO_VFILTER );
59 add_shortcut( "noise" );
60 set_callbacks( Create, Destroy );
63 /*****************************************************************************
64 * vout_sys_t: Distort video output method descriptor
65 *****************************************************************************
66 * This structure is part of the video output thread descriptor.
67 * It describes the Distort specific properties of an output thread.
68 *****************************************************************************/
74 /*****************************************************************************
75 * Create: allocates Distort video thread output method
76 *****************************************************************************
77 * This function allocates and initializes a Distort vout method.
78 *****************************************************************************/
79 static int Create( vlc_object_t *p_this )
81 filter_t *p_filter = (filter_t *)p_this;
83 /* Allocate structure */
84 p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
85 if( p_filter->p_sys == NULL )
88 p_filter->pf_video_filter = Filter;
90 p_filter->p_sys->last_date = 0;
95 /*****************************************************************************
96 * Destroy: destroy Distort video thread output method
97 *****************************************************************************
98 * Terminate an output method created by DistortCreateOutputMethod
99 *****************************************************************************/
100 static void Destroy( vlc_object_t *p_this )
102 filter_t *p_filter = (filter_t *)p_this;
103 free( p_filter->p_sys );
106 /*****************************************************************************
107 * Render: displays previously rendered output
108 *****************************************************************************
109 * This function send the currently rendered image to Distort image, waits
110 * until it is displayed and switch the two rendering buffers, preparing next
112 *****************************************************************************/
113 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
116 filter_sys_t *p_sys = p_filter->p_sys;
118 mtime_t new_date = mdate();
120 if( !p_pic ) return NULL;
122 p_outpic = filter_NewPicture( p_filter );
125 msg_Warn( p_filter, "can't get output picture" );
126 picture_Release( p_pic );
130 p_sys->last_date = new_date;
132 for( i_index = 0 ; i_index < p_pic->i_planes ; i_index++ )
134 uint8_t *p_in = p_pic->p[i_index].p_pixels;
135 uint8_t *p_out = p_outpic->p[i_index].p_pixels;
137 const int i_num_lines = p_pic->p[i_index].i_visible_lines;
138 const int i_num_cols = p_pic->p[i_index].i_visible_pitch;
139 const int i_pitch = p_pic->p[i_index].i_pitch;
143 for( i_line = 0 ; i_line < i_num_lines ; i_line++ )
147 /* line isn't noisy */
148 vlc_memcpy( p_out+i_line*i_pitch, p_in+i_line*i_pitch,
153 /* this line is noisy */
154 int noise_level = rand()%8+2;
155 for( i_col = 0; i_col < i_num_cols ; i_col++ )
157 if( rand()%noise_level )
159 p_out[i_line*i_pitch+i_col] =
160 p_in[i_line*i_pitch+i_col];
164 p_out[i_line*i_pitch+i_col] = (rand()%3)*0x7f;
171 return CopyInfoAndRelease( p_outpic, p_pic );