filter_crop.c: add cropping filter (kdenlive-509)
[melted] / src / modules / core / filter_crop.c
1 /*
2 * filter_crop.c -- cropping filter
3 * Copyright (C) 2009 Ushodaya Enterprises Limited
4 * Author: Dan Dennedy <dan@dennedy.org>
5 *
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.
10 *
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.
15 *
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
19 */
20
21 #include <framework/mlt_filter.h>
22 #include <framework/mlt_frame.h>
23 #include <framework/mlt_log.h>
24
25 #include <stdio.h>
26 #include <string.h>
27 #include <stdlib.h>
28 #include <math.h>
29
30 static void crop( uint8_t *src, uint8_t *dest, int bpp, int width, int height, int left, int right, int top, int bottom )
31 {
32 int stride = ( width - left - right ) * bpp + 1;
33 int y = height - top - bottom + 1;
34 uint8_t *s = &src[ ( ( top * width ) + left ) * bpp ];
35
36 while ( --y )
37 {
38 int x = stride;
39 while ( --x )
40 *dest ++ = *s ++;
41 s += ( right + left ) * bpp;
42 }
43 }
44
45 /** Do it :-).
46 */
47
48 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
49 {
50 int error = 0;
51
52 // Get the properties from the frame
53 mlt_properties properties = MLT_FRAME_PROPERTIES( this );
54
55 // Correct Width/height if necessary
56 if ( *width == 0 || *height == 0 )
57 {
58 *width = mlt_properties_get_int( properties, "normalised_width" );
59 *height = mlt_properties_get_int( properties, "normalised_height" );
60 }
61
62 // Now get the image
63 error = mlt_frame_get_image( this, image, format, width, height, writable );
64
65 int left = mlt_properties_get_int( properties, "crop.left" );
66 int right = mlt_properties_get_int( properties, "crop.right" );
67 int top = mlt_properties_get_int( properties, "crop.top" );
68 int bottom = mlt_properties_get_int( properties, "crop.bottom" );
69 int owidth = *width - left - right;
70 int oheight = *height - top - bottom;
71
72 // We only know how to process yuv422 at the moment
73 if ( ( owidth != *width || oheight != *height ) &&
74 error == 0 && *format == mlt_image_yuv422 && *image != NULL && owidth > 0 && oheight > 0 )
75 {
76 // Provides a manual override for misreported field order
77 if ( mlt_properties_get( properties, "meta.top_field_first" ) )
78 {
79 mlt_properties_set_int( properties, "top_field_first", mlt_properties_get_int( properties, "meta.top_field_first" ) );
80 mlt_properties_set_int( properties, "meta.top_field_first", 0 );
81 }
82
83 if ( top % 2 )
84 mlt_properties_set_int( properties, "top_field_first", !mlt_properties_get_int( properties, "top_field_first" ) );
85
86 // Create the output image
87 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
88 if ( output )
89 {
90 // Call the generic resize
91 crop( *image, output, 2, *width, *height, left, right, top, bottom );
92
93 // Now update the frame
94 *image = output;
95 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
96 mlt_properties_set_int( properties, "width", owidth );
97 mlt_properties_set_int( properties, "height", oheight );
98 }
99
100 // We should resize the alpha too
101 uint8_t *alpha = mlt_frame_get_alpha_mask( this );
102 if ( alpha != NULL )
103 {
104 uint8_t *newalpha = mlt_pool_alloc( owidth * oheight );
105 if ( newalpha )
106 {
107 crop( alpha, newalpha, 1, *width, *height, left, right, top, bottom );
108 mlt_properties_set_data( properties, "alpha", newalpha, owidth * oheight, ( mlt_destructor )mlt_pool_release, NULL );
109 this->get_alpha_mask = NULL;
110 }
111 }
112 *width = owidth;
113 *height = oheight;
114 }
115
116 return error;
117 }
118
119 /** Filter processing.
120 */
121
122 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
123 {
124 if ( mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "active" ) )
125 {
126 // Push the get_image method on to the stack
127 mlt_frame_push_get_image( frame, filter_get_image );
128 }
129 else
130 {
131 mlt_properties filter_props = MLT_FILTER_PROPERTIES( this );
132 mlt_properties frame_props = MLT_FRAME_PROPERTIES( frame );
133 int left = mlt_properties_get_int( filter_props, "left" );
134 int right = mlt_properties_get_int( filter_props, "right" );
135 int top = mlt_properties_get_int( filter_props, "top" );
136 int bottom = mlt_properties_get_int( filter_props, "bottom" );
137 int width = mlt_properties_get_int( frame_props, "real_width" );
138 int height = mlt_properties_get_int( frame_props, "real_height" );
139
140 mlt_properties_set_int( frame_props, "crop.left", left );
141 mlt_properties_set_int( frame_props, "crop.right", right );
142 mlt_properties_set_int( frame_props, "crop.top", top );
143 mlt_properties_set_int( frame_props, "crop.bottom", bottom );
144 mlt_properties_set_int( frame_props, "real_width", width - left - right );
145 mlt_properties_set_int( frame_props, "real_height", height - top - bottom );
146 }
147 return frame;
148 }
149
150 /** Constructor for the filter.
151 */
152
153 mlt_filter filter_crop_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
154 {
155 mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
156 if ( mlt_filter_init( this, this ) == 0 )
157 {
158 this->process = filter_process;
159 if ( arg )
160 mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "active", atoi( arg ) );
161 }
162 return this;
163 }