2 * filter_brightness.c -- gamma filter
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library 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 GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <framework/mlt_filter.h>
22 #include <framework/mlt_frame.h>
28 #define CLAMP( x, min, max ) (x) < (min) ? (min) : (x) > (max) ? (max) : (x)
33 static int filter_get_image( mlt_frame
this, uint8_t **image
, mlt_image_format
*format
, int *width
, int *height
, int writable
)
36 int error
= mlt_frame_get_image( this, image
, format
, width
, height
, 1 );
38 // Only process if we have no error and a valid colour space
39 if ( error
== 0 && *format
== mlt_image_yuv422
)
41 // Get the brightness level
42 double level
= mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "brightness" );
44 // Only process if level is something other than 1
47 int i
= *width
* *height
+ 1;
49 int32_t m
= level
* ( 1 << 16 );
50 int32_t n
= 128 * ( ( 1 << 16 ) - m
);
54 p
[0] = CLAMP( (p
[0] * m
) >> 16, 16, 235 );
55 p
[1] = CLAMP( (p
[1] * m
+ n
) >> 16, 16, 240 );
64 /** Filter processing.
67 static mlt_frame
filter_process( mlt_filter
this, mlt_frame frame
)
69 // Get the starting brightness level
70 double level
= fabs( mlt_properties_get_double( MLT_FILTER_PROPERTIES( this ), "start" ) );
72 // If there is an end adjust gain to the range
73 if ( mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "end" ) != NULL
)
75 // Determine the time position of this frame in the transition duration
76 mlt_position in
= mlt_filter_get_in( this );
77 mlt_position out
= mlt_filter_get_out( this );
78 mlt_position time
= mlt_frame_get_position( frame
);
79 double position
= ( double )( time
- in
) / ( double )( out
- in
+ 1 );
80 double end
= fabs( mlt_properties_get_double( MLT_FILTER_PROPERTIES( this ), "end" ) );
81 level
+= ( end
- level
) * position
;
84 // Push the frame filter
85 mlt_properties_set_double( MLT_FRAME_PROPERTIES( frame
), "brightness", level
);
86 mlt_frame_push_get_image( frame
, filter_get_image
);
91 /** Constructor for the filter.
94 mlt_filter
filter_brightness_init( mlt_profile profile
, mlt_service_type type
, const char *id
, char *arg
)
96 mlt_filter
this = mlt_filter_new( );
99 this->process
= filter_process
;
100 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "start", arg
== NULL ?
"1" : arg
);