2 * filter_brightness.c -- gamma filter
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 #include "filter_brightness.h"
23 #include <framework/mlt_frame.h>
32 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
34 mlt_frame_get_image( this, image, format, width, height, 1 );
36 uint8_t *q = *image + *width * *height * 2;
38 // Get the brightness level
39 double level = mlt_properties_get_double( mlt_frame_properties( this ), "brightness.level" );
43 float x = (float) *p * level;
44 *p = x < 16 ? 16 : x > 235 ? 235 : x;
51 /** Filter processing.
54 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
56 double level = fabs( mlt_properties_get_double( mlt_filter_properties( this ), "start" ) );
58 // If there is an end adjust gain to the range
59 if ( mlt_properties_get( mlt_filter_properties( this ), "end" ) != NULL )
61 // Determine the time position of this frame in the transition duration
62 mlt_position in = mlt_filter_get_in( this );
63 mlt_position out = mlt_filter_get_out( this );
64 mlt_position time = mlt_frame_get_position( frame );
65 double position = ( double )( time - in ) / ( double )( out - in + 1 );
66 double end = fabs( mlt_properties_get_double( mlt_filter_properties( this ), "end" ) );
67 level += ( end - level ) * position;
69 mlt_frame_push_get_image( frame, filter_get_image );
70 mlt_properties_set_double( mlt_frame_properties( frame ), "brightness.level", level );
74 /** Constructor for the filter.
77 mlt_filter filter_brightness_init( char *arg )
79 mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
82 mlt_filter_init( this, NULL );
83 this->process = filter_process;
85 mlt_properties_set_double( mlt_filter_properties( this ), "start", atof( arg ) );