2 * filter_obscure.c -- obscure 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_obscure.h"
23 #include <framework/mlt_frame.h>
24 #include <framework/mlt_deque.h>
44 /** Parse a value from a geometry string.
47 static float parse_value( char **ptr, int normalisation, char delim, float defaults )
49 float value = defaults;
51 if ( *ptr != NULL && **ptr != '\0' )
54 value = strtod( *ptr, &end );
58 value = ( value / 100.0 ) * normalisation;
59 while ( *end == delim || *end == '%' )
68 /** Parse a geometry property string.
71 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property, int nw, int nh )
73 // Assign normalised width and height
77 // Assign from defaults if available
78 if ( defaults != NULL )
80 geometry->x = defaults->x;
81 geometry->y = defaults->y;
82 geometry->w = defaults->w;
83 geometry->h = defaults->h;
84 geometry->mask_w = defaults->mask_w;
85 geometry->mask_h = defaults->mask_h;
89 geometry->mask_w = 20;
90 geometry->mask_h = 20;
93 // Parse the geomtry string
94 if ( property != NULL )
97 geometry->x = parse_value( &ptr, nw, ',', geometry->x );
98 geometry->y = parse_value( &ptr, nh, ':', geometry->y );
99 geometry->w = parse_value( &ptr, nw, 'x', geometry->w );
100 geometry->h = parse_value( &ptr, nh, ':', geometry->h );
101 geometry->mask_w = parse_value( &ptr, nw, 'x', geometry->mask_w );
102 geometry->mask_h = parse_value( &ptr, nh, ' ', geometry->mask_h );
106 /** A Timism but not as clean ;-).
109 static float lerp( float value, float lower, float upper )
113 else if ( value > upper )
118 /** Calculate real geometry.
121 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position, int ow, int oh )
123 // Calculate this frames geometry
124 output->x = lerp( ( in->x + ( out->x - in->x ) * position ) / ( float )out->nw * ow, 0, ow );
125 output->y = lerp( ( in->y + ( out->y - in->y ) * position ) / ( float )out->nh * oh, 0, oh );
126 output->w = lerp( ( in->w + ( out->w - in->w ) * position ) / ( float )out->nw * ow, 0, ow - output->x );
127 output->h = lerp( ( in->h + ( out->h - in->h ) * position ) / ( float )out->nh * oh, 0, oh - output->y );
128 output->mask_w = in->mask_w + ( out->mask_w - in->mask_w ) * position;
129 output->mask_h = in->mask_h + ( out->mask_h - in->mask_h ) * position;
132 /** Calculate the position for this frame.
135 static float position_calculate( mlt_filter this, mlt_frame frame )
137 // Get the in and out position
138 mlt_position in = mlt_filter_get_in( this );
139 mlt_position out = mlt_filter_get_out( this );
141 // Get the position of the frame
142 mlt_position position = mlt_frame_get_position( frame );
145 return ( float )( position - in ) / ( float )( out - in + 1 );
148 /** The averaging function...
151 void obscure_average( uint8_t *start, int width, int height, int stride )
155 register int Y = ( *start + *( start + 2 ) ) / 2;
156 register int U = *( start + 1 );
157 register int V = *( start + 3 );
160 for ( y = 0; y < height; y ++ )
162 p = start + y * stride;
163 for ( x = 0; x < width / 2; x ++ )
165 Y = ( Y + *p ++ ) / 2;
166 U = ( U + *p ++ ) / 2;
167 Y = ( Y + *p ++ ) / 2;
168 V = ( V + *p ++ ) / 2;
172 for ( y = 0; y < height; y ++ )
174 p = start + y * stride;
176 for ( x = 0; x < width / 2; x ++ )
187 /** The obscurer rendering function...
190 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
192 int area_x = result.x;
193 int area_y = result.y;
194 int area_w = result.w;
195 int area_h = result.h;
197 int mw = result.mask_w;
198 int mh = result.mask_h;
204 uint8_t *p = image + area_y * width * 2 + area_x * 2;
206 for ( w = 0; w < area_w; w += mw )
208 for ( h = 0; h < area_h; h += mh )
210 aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
211 ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
212 if ( aw > 1 && ah > 1 )
213 obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2 );
221 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
223 // Get the frame properties
224 mlt_properties frame_properties = mlt_frame_properties( frame );
226 // Fetch the obscure stack for this frame
227 mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
229 // Pop the top of stack now
230 mlt_filter this = mlt_deque_pop_back( deque );
232 // Get the image from the frame
233 if ( mlt_frame_get_image( frame, image, format, width, height, 1 ) == 0 )
237 // Get the filter properties
238 mlt_properties properties = mlt_filter_properties( this );
240 // Obtain the normalised width and height from the frame
241 int normalised_width = mlt_properties_get_int( frame_properties, "normalised_width" );
242 int normalised_height = mlt_properties_get_int( frame_properties, "normalised_height" );
244 // Structures for geometry
245 struct geometry_s result;
246 struct geometry_s start;
247 struct geometry_s end;
249 // Calculate the position
250 float position = position_calculate( this, frame );
252 // Now parse the geometries
253 geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
254 geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
256 // Do the calculation
257 geometry_calculate( &result, &start, &end, position, *width, *height );
259 // Now actually render it
260 obscure_render( *image, *width, *height, result );
267 /** Filter processing.
270 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
272 // Get the frame properties
273 mlt_properties frame_properties = mlt_frame_properties( frame );
275 // Fetch the obscure stack for this frame
276 mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
278 // Create stack if necessary
282 deque = mlt_deque_init( );
284 // Assign to the frame
285 mlt_properties_set_data( frame_properties, "filter_obscure", deque, 0, ( mlt_destructor )mlt_deque_close, NULL );
288 // Push this on to the obscure stack
289 mlt_deque_push_back( deque, this );
291 // Push the get image call
292 mlt_frame_push_get_image( frame, filter_get_image );
297 /** Constructor for the filter.
300 mlt_filter filter_obscure_init( void *arg )
302 mlt_filter this = mlt_filter_new( );
305 mlt_properties properties = mlt_filter_properties( this );
306 this->process = filter_process;
307 mlt_properties_set( properties, "start", arg != NULL ? arg : "0%,0%:100%x100%" );
308 mlt_properties_set( properties, "end", "" );