2 * /brief Crop Detection filter
4 * /author Zachary Drew, Copyright 2005
6 * inspired by mplayer's cropdetect filter
8 * Note: The goemetry generated is zero-indexed and is inclusive of the end values
11 * -filter crop_detect debug=1 // Visualize crop
12 * -filter crop_detect frequency=25 // Detect the crop once a second
13 * -filter crop_detect frequency=0 // Never detect unless the producer changes
14 * -filter crop_detect thresh=100 // Changes the threshold (default = 25)
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software Foundation,
28 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
32 #define DEFAULT_THRESH 20
34 #include <framework/mlt.h>
40 #include "arrow_code.h"
42 #define ABS(a) ((a) >= 0 ? (a) : (-(a)))
44 // Image stack(able) method
45 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
48 // Get the filter object and properties
49 mlt_filter filter = mlt_frame_pop_service( this );
50 mlt_properties properties = MLT_FILTER_PROPERTIES( filter );
53 int error = mlt_frame_get_image( this, image, format, width, height, 1 );
56 mlt_properties_debug( MLT_FRAME_PROPERTIES(this), "error after mlt_frame_get_image()", stderr );
60 // Parameter that describes how often to check for the crop
61 int frequency = mlt_properties_get_int( properties, "frequency");
63 // Producers may start with blank footage, by default we will skip, oh, 5 frames unless overridden
64 int skip = mlt_properties_get_int( properties, "skip");
67 mlt_geometry_item bounds = mlt_properties_get_data( properties, "bounds", NULL );
69 // Initialize if needed
70 if( bounds == NULL ) {
71 bounds = calloc( 1, sizeof( struct mlt_geometry_item_s ) );
74 mlt_properties_set_data( properties, "bounds", bounds, sizeof( struct mlt_geometry_item_s ), free, NULL );
77 // For periodic detection (with offset of 'skip')
78 if( frequency == 0 || (int)(mlt_frame_get_position(this)+skip) % frequency != 0)
81 mlt_properties_set_data( MLT_FRAME_PROPERTIES(this), "bounds", bounds, sizeof( struct mlt_geometry_item_s ), NULL, NULL );
87 // There is no way to detect a crop for sure, so make up an arbitrary one
88 int thresh = mlt_properties_get_int( properties, "thresh" );
93 case mlt_image_yuv422:
98 fprintf(stderr, "image format not supported by filter_crop_detect\n");
102 int x, y, average_brightness, deviation; // Scratch variables
106 for( y = 0; y < *height/2; y++ ) {
108 average_brightness = 0;
110 q = *image + y*ystride;
111 for( x = 0; x < *width; x++ )
112 average_brightness += q[x*xstride];
114 average_brightness /= *width;
116 for( x = 0; x < *width; x++ )
117 deviation += abs(average_brightness - q[x*xstride]);
119 if( deviation*10 >= thresh * *width )
124 for( y = *height - 1; y >= *height/2; y-- ) {
126 average_brightness = 0;
128 q = *image + y*ystride;
129 for( x = 0; x < *width; x++ )
130 average_brightness += q[x*xstride];
132 average_brightness /= *width;
134 for( x = 0; x < *width; x++ )
135 deviation += abs(average_brightness - q[x*xstride]);
137 if( deviation*10 >= thresh * *width)
142 for( x = 0; x < *width/2; x++ ) {
144 average_brightness = 0;
146 q = *image + x*xstride;
147 for( y = 0; y < *height; y++ )
148 average_brightness += q[y*ystride];
150 average_brightness /= *height;
152 for( y = 0; y < *height; y++ )
153 deviation += abs(average_brightness - q[y*ystride]);
155 if( deviation*10 >= thresh * *width )
160 for( x = *width - 1; x >= *width/2; x-- ) {
162 average_brightness = 0;
164 q = *image + x*xstride;
165 for( y = 0; y < *height; y++ )
166 average_brightness += q[y*ystride];
168 average_brightness /= *height;
170 for( y = 0; y < *height; y++ )
171 deviation += abs(average_brightness - q[y*ystride]);
173 if( deviation*10 >= thresh * *width )
177 /* Debug: Draw arrows to show crop */
178 if( mlt_properties_get_int( properties, "debug") == 1 )
180 init_arrows( format, *width, *height );
182 draw_arrow(*image, bounds->x, *height/2, bounds->x+50, *height/2, 100);
183 draw_arrow(*image, *width/2, bounds->y, *width/2, bounds->y+50, 100);
184 draw_arrow(*image, bounds->w, *height/2, bounds->w-50, *height/2, 100);
185 draw_arrow(*image, *width/2, bounds->h, *width/2, bounds->h-50, 100);
186 draw_arrow(*image, bounds->x, bounds->y, bounds->x+40, bounds->y+30, 100);
187 draw_arrow(*image, bounds->x, bounds->h, bounds->x+40, bounds->h-30, 100);
188 draw_arrow(*image, bounds->w, bounds->y, bounds->w-40, bounds->y+30, 100);
189 draw_arrow(*image, bounds->w, bounds->h, bounds->w-40, bounds->h-30, 100);
192 // Convert to width and correct indexing
193 bounds->w -= bounds->x - 1;
194 bounds->h -= bounds->y - 1;
196 if( mlt_properties_get_int( properties, "debug") == 1 )
197 fprintf(stderr, "Top:%f Left:%f Width:%f Height:%f\n", bounds->y, bounds->x, bounds->w, bounds->h);
199 /* inject into frame */
200 mlt_properties_set_data( MLT_FRAME_PROPERTIES(this), "bounds", bounds, sizeof( struct mlt_geometry_item_s ), NULL, NULL );
207 /** Filter processing.
210 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
213 // Put the filter object somewhere we can find it
214 mlt_frame_push_service( frame, this);
216 // Push the frame filter
217 mlt_frame_push_get_image( frame, filter_get_image );
222 /** Constructor for the filter.
224 mlt_filter filter_crop_detect_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
226 mlt_filter this = mlt_filter_new( );
229 this->process = filter_process;
232 mlt_properties_set_int( MLT_FILTER_PROPERTIES(this), "frequency", 1);
233 mlt_properties_set_int( MLT_FILTER_PROPERTIES(this), "thresh", 5);
234 mlt_properties_set_int( MLT_FILTER_PROPERTIES(this), "clip", 5);
235 mlt_properties_set_int( MLT_FILTER_PROPERTIES(this), "former_producer_id", -1);
242 /** This source code will self destruct in 5...4...3...