research.m1stereo.tv/gitweb/ - melted/blob - src/modules/core/filter_brightness.c

   1 /*
   2  * filter_brightness.c -- gamma filter
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   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.
  10  *
  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.
  15  *
  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.
  19  */
  20
  21 #include "filter_brightness.h"
  22
  23 #include <framework/mlt_frame.h>
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28
  29 /** Do it :-).
  30 */
  31
  32 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  33 {
  34         mlt_frame_get_image( this, image, format, width, height, 1 );
  35         uint8_t *p = *image;
  36         uint8_t *q = *image + *width * *height * 2;
  37
  38         // Get the brightness level
  39         double level = mlt_properties_get_double( mlt_frame_properties( this ), "brightness.level" );
  40
  41         while ( p != q )
  42         {
  43                 float x = (float) *p * level;
  44                 *p = x < 16 ? 16 : x > 235 ? 235 : x;
  45                 p += 2;
  46         }
  47
  48         return 0;
  49 }
  50
  51 /** Filter processing.
  52 */
  53
  54 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
  55 {
  56         double level = fabs( mlt_properties_get_double( mlt_filter_properties( this ), "start" ) );
  57
  58         // If there is an end adjust gain to the range
  59         if ( mlt_properties_get( mlt_filter_properties( this ), "end" ) != NULL )
  60         {
  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;
  68         }
  69         mlt_frame_push_get_image( frame, filter_get_image );
  70         mlt_properties_set_double( mlt_frame_properties( frame ), "brightness.level", level );
  71         return frame;
  72 }
  73
  74 /** Constructor for the filter.
  75 */
  76
  77 mlt_filter filter_brightness_init( char *arg )
  78 {
  79         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
  80         if ( this != NULL )
  81         {
  82                 mlt_filter_init( this, NULL );
  83                 this->process = filter_process;
  84                 if ( arg != NULL )
  85                         mlt_properties_set_double( mlt_filter_properties( this ), "start", atof( arg ) );
  86         }
  87         return this;
  88 }
  89