noise.c 6 KB
Newer Older
Antoine Cellerier's avatar
Antoine Cellerier committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
/*****************************************************************************
 * noise.c : "add noise to image" video filter
 *****************************************************************************
 * Copyright (C) 2000-2006 the VideoLAN team
 * $Id$
 *
 * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/

28 29 30 31
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

32
#include <vlc_common.h>
33
#include <vlc_plugin.h>
Antoine Cellerier's avatar
Antoine Cellerier committed
34

Rémi Duraffort's avatar
Rémi Duraffort committed
35
#include <vlc_filter.h>
36
#include "filter_picture.h"
Antoine Cellerier's avatar
Antoine Cellerier committed
37 38 39 40 41 42 43 44 45 46 47 48 49 50

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Create    ( vlc_object_t * );
static void Destroy   ( vlc_object_t * );

static picture_t *Filter( filter_t *, picture_t * );

#define FILTER_PREFIX "noise-"

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
51 52 53 54 55 56
vlc_module_begin ()
    set_description( N_("Noise video filter") )
    set_shortname( N_( "Noise" ))
    set_capability( "video filter2", 0 )
    set_category( CAT_VIDEO )
    set_subcategory( SUBCAT_VIDEO_VFILTER )
Antoine Cellerier's avatar
Antoine Cellerier committed
57

58 59 60
    add_shortcut( "noise" )
    set_callbacks( Create, Destroy )
vlc_module_end ()
Antoine Cellerier's avatar
Antoine Cellerier committed
61 62

/*****************************************************************************
63
 * filter_sys_t: Distort video output method descriptor
Antoine Cellerier's avatar
Antoine Cellerier committed
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
 *****************************************************************************
 * This structure is part of the video output thread descriptor.
 * It describes the Distort specific properties of an output thread.
 *****************************************************************************/
struct filter_sys_t
{
    mtime_t last_date;
};

/*****************************************************************************
 * Create: allocates Distort video thread output method
 *****************************************************************************
 * This function allocates and initializes a Distort vout method.
 *****************************************************************************/
static int Create( vlc_object_t *p_this )
{
    filter_t *p_filter = (filter_t *)p_this;

    /* Allocate structure */
    p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
    if( p_filter->p_sys == NULL )
        return VLC_ENOMEM;

    p_filter->pf_video_filter = Filter;

    p_filter->p_sys->last_date = 0;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Destroy: destroy Distort video thread output method
 *****************************************************************************
 * Terminate an output method created by DistortCreateOutputMethod
 *****************************************************************************/
static void Destroy( vlc_object_t *p_this )
{
    filter_t *p_filter = (filter_t *)p_this;
    free( p_filter->p_sys );
}

/*****************************************************************************
 * Render: displays previously rendered output
 *****************************************************************************
 * This function send the currently rendered image to Distort image, waits
 * until it is displayed and switch the two rendering buffers, preparing next
 * frame.
 *****************************************************************************/
static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
{
    picture_t *p_outpic;
    filter_sys_t *p_sys = p_filter->p_sys;
    int i_index;
    mtime_t new_date = mdate();

    if( !p_pic ) return NULL;

Laurent Aimar's avatar
Laurent Aimar committed
121
    p_outpic = filter_NewPicture( p_filter );
Antoine Cellerier's avatar
Antoine Cellerier committed
122 123 124
    if( !p_outpic )
    {
        msg_Warn( p_filter, "can't get output picture" );
125
        picture_Release( p_pic );
Antoine Cellerier's avatar
Antoine Cellerier committed
126 127 128 129 130 131 132
        return NULL;
    }

    p_sys->last_date = new_date;

    for( i_index = 0 ; i_index < p_pic->i_planes ; i_index++ )
    {
133 134
        uint8_t *p_in = p_pic->p[i_index].p_pixels;
        uint8_t *p_out = p_outpic->p[i_index].p_pixels;
Antoine Cellerier's avatar
Antoine Cellerier committed
135

136 137 138
        const int i_num_lines = p_pic->p[i_index].i_visible_lines;
        const int i_num_cols = p_pic->p[i_index].i_visible_pitch;
        const int i_pitch = p_pic->p[i_index].i_pitch;
Antoine Cellerier's avatar
Antoine Cellerier committed
139

140
        int i_line, i_col;
Antoine Cellerier's avatar
Antoine Cellerier committed
141 142 143 144 145 146

        for( i_line = 0 ; i_line < i_num_lines ; i_line++ )
        {
            if( rand()%8 )
            {
                /* line isn't noisy */
147 148
                vlc_memcpy( p_out+i_line*i_pitch, p_in+i_line*i_pitch,
                            i_num_cols );
Antoine Cellerier's avatar
Antoine Cellerier committed
149 150 151 152 153 154 155 156 157
            }
            else
            {
                /* this line is noisy */
                int noise_level = rand()%8+2;
                for( i_col = 0; i_col < i_num_cols ; i_col++ )
                {
                    if( rand()%noise_level )
                    {
158 159
                        p_out[i_line*i_pitch+i_col] =
                            p_in[i_line*i_pitch+i_col];
Antoine Cellerier's avatar
Antoine Cellerier committed
160 161 162
                    }
                    else
                    {
163
                        p_out[i_line*i_pitch+i_col] = (rand()%3)*0x7f;
Antoine Cellerier's avatar
Antoine Cellerier committed
164 165 166 167 168 169
                    }
                }
            }
        }
    }

170
    return CopyInfoAndRelease( p_outpic, p_pic );
Antoine Cellerier's avatar
Antoine Cellerier committed
171
}