/***************************************************************************** * 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 *****************************************************************************/#ifdef HAVE_CONFIG_H# include "config.h"#endif#include <vlc_common.h>#include <vlc_plugin.h>#include <vlc_vout.h>#include "vlc_filter.h"#include "filter_picture.h"/***************************************************************************** * 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 *****************************************************************************/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 );    add_shortcut( "noise" );    set_callbacks( Create, Destroy );vlc_module_end();/***************************************************************************** * vout_sys_t: Distort video output method descriptor ***************************************************************************** * 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;    p_outpic = filter_NewPicture( p_filter );    if( !p_outpic )    {        msg_Warn( p_filter, "can't get output picture" );        picture_Release( p_pic );        return NULL;    }    p_sys->last_date = new_date;    for( i_index = 0 ; i_index < p_pic->i_planes ; i_index++ )    {        uint8_t *p_in = p_pic->p[i_index].p_pixels;        uint8_t *p_out = p_outpic->p[i_index].p_pixels;        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;        int i_line, i_col;        for( i_line = 0 ; i_line < i_num_lines ; i_line++ )        {            if( rand()%8 )            {                /* line isn't noisy */                vlc_memcpy( p_out+i_line*i_pitch, p_in+i_line*i_pitch,                            i_num_cols );            }            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 )                    {                        p_out[i_line*i_pitch+i_col] =                            p_in[i_line*i_pitch+i_col];                    }                    else                    {                        p_out[i_line*i_pitch+i_col] = (rand()%3)*0x7f;                    }                }            }        }    }    return CopyInfoAndRelease( p_outpic, p_pic );}