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
)
35 int error
= mlt_frame_get_image( this, image
, format
, width
, height
, 1 );
37 // Only process if we have no error and a valid colour space
38 if ( error
== 0 && *format
== mlt_image_yuv422
)
40 // Get the brightness level
41 double level
= mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "brightness" );
43 // Only process if level is something other than 1
47 uint8_t *q
= *image
+ *width
* *height
* 2;
49 int32_t m
= level
* ( 1 << 16 );
54 *p
= x
< 16 ?
16 : x
> 235 ?
235 : x
;
63 /** Filter processing.
66 static mlt_frame
filter_process( mlt_filter
this, mlt_frame frame
)
68 // Get the starting brightness level
69 double level
= fabs( mlt_properties_get_double( MLT_FILTER_PROPERTIES( this ), "start" ) );
71 // If there is an end adjust gain to the range
72 if ( mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "end" ) != NULL
)
74 // Determine the time position of this frame in the transition duration
75 mlt_position in
= mlt_filter_get_in( this );
76 mlt_position out
= mlt_filter_get_out( this );
77 mlt_position time
= mlt_frame_get_position( frame
);
78 double position
= ( double )( time
- in
) / ( double )( out
- in
+ 1 );
79 double end
= fabs( mlt_properties_get_double( MLT_FILTER_PROPERTIES( this ), "end" ) );
80 level
+= ( end
- level
) * position
;
83 // Push the frame filter
84 mlt_properties_set_double( MLT_FRAME_PROPERTIES( frame
), "brightness", level
);
85 mlt_frame_push_get_image( frame
, filter_get_image
);
90 /** Constructor for the filter.
93 mlt_filter
filter_brightness_init( char *arg
)
95 mlt_filter
this = mlt_filter_new( );
98 this->process
= filter_process
;
99 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "start", arg
== NULL ?
"1" : arg
);