2 * filter_charcoal.c -- charcoal 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_charcoal.h"
23 #include <framework/mlt_frame.h>
29 static inline int get_Y( uint8_t *pixels
, int width
, int height
, int x
, int y
)
31 if ( x
< 0 || x
>= width
|| y
< 0 || y
>= height
)
37 uint8_t *pixel
= pixels
+ y
* ( width
<< 1 ) + ( x
<< 1 );
42 static inline int sqrti( int n
)
70 static int filter_get_image( mlt_frame
this, uint8_t **image
, mlt_image_format
*format
, int *width
, int *height
, int writable
)
73 mlt_filter filter
= mlt_frame_pop_service( this );
76 int error
= mlt_frame_get_image( this, image
, format
, width
, height
, 1 );
78 // Only process if we have no error and a valid colour space
79 if ( error
== 0 && *format
== mlt_image_yuv422
)
81 // Get the charcoal scatter value
82 int x_scatter
= mlt_properties_get_double( MLT_FILTER_PROPERTIES( filter
), "x_scatter" );
83 int y_scatter
= mlt_properties_get_double( MLT_FILTER_PROPERTIES( filter
), "y_scatter" );
84 float scale
= mlt_properties_get_double( MLT_FILTER_PROPERTIES( filter
), "scale" );
85 float mix
= mlt_properties_get_double( MLT_FILTER_PROPERTIES( filter
), "mix" );
86 int invert
= mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter
), "invert" );
88 // We'll process pixel by pixel
92 // We need to create a new frame as this effect modifies the input
93 uint8_t *temp
= mlt_pool_alloc( *width
* *height
* 2 );
97 // Calculations are carried out on a 3x3 matrix
100 // Used to carry out the matrix calculations
107 for ( y
= 0; y
< *height
; y
++ )
109 // Loop for each pixel
110 for ( x
= 0; x
< *width
; x
++ )
112 // Populate the matrix
113 matrix
[ 0 ][ 0 ] = get_Y( *image
, *width
, *height
, x
- x_scatter
, y
- y_scatter
);
114 matrix
[ 0 ][ 1 ] = get_Y( *image
, *width
, *height
, x
, y
- y_scatter
);
115 matrix
[ 0 ][ 2 ] = get_Y( *image
, *width
, *height
, x
+ x_scatter
, y
- y_scatter
);
116 matrix
[ 1 ][ 0 ] = get_Y( *image
, *width
, *height
, x
- x_scatter
, y
);
117 matrix
[ 1 ][ 2 ] = get_Y( *image
, *width
, *height
, x
+ x_scatter
, y
);
118 matrix
[ 2 ][ 0 ] = get_Y( *image
, *width
, *height
, x
- x_scatter
, y
+ y_scatter
);
119 matrix
[ 2 ][ 1 ] = get_Y( *image
, *width
, *height
, x
, y
+ y_scatter
);
120 matrix
[ 2 ][ 2 ] = get_Y( *image
, *width
, *height
, x
+ x_scatter
, y
+ y_scatter
);
123 sum1
= (matrix
[2][0] - matrix
[0][0]) + ( (matrix
[2][1] - matrix
[0][1]) << 1 ) + (matrix
[2][2] - matrix
[2][0]);
124 sum2
= (matrix
[0][2] - matrix
[0][0]) + ( (matrix
[1][2] - matrix
[1][0]) << 1 ) + (matrix
[2][2] - matrix
[2][0]);
125 sum
= scale
* sqrti( sum1
* sum1
+ sum2
* sum2
);
128 *p
++ = !invert ?
( sum
>= 16 && sum
<= 235 ?
251 - sum
: sum
< 16 ?
235 : 16 ) :
129 ( sum
>= 16 && sum
<= 235 ? sum
: sum
< 16 ?
16 : 235 );
131 val
= 128 + mix
* ( *q
++ - 128 );
132 val
= val
< 16 ?
16 : val
> 240 ?
240 : val
;
137 // Return the created image
140 // Store new and destroy old
141 mlt_properties_set_data( MLT_FRAME_PROPERTIES( this ), "image", *image
, *width
* *height
* 2, mlt_pool_release
, NULL
);
147 /** Filter processing.
150 static mlt_frame
filter_process( mlt_filter
this, mlt_frame frame
)
152 // Push the frame filter
153 mlt_frame_push_service( frame
, this );
154 mlt_frame_push_get_image( frame
, filter_get_image
);
159 /** Constructor for the filter.
162 mlt_filter
filter_charcoal_init( char *arg
)
164 mlt_filter
this = mlt_filter_new( );
167 this->process
= filter_process
;
168 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "x_scatter", "1" );
169 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "y_scatter", "1" );
170 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", "1.5" );
171 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "mix", "0" );