2 * transition_composite.c -- compose one image over another using alpha channel
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Dan Dennedy <dan@dennedy.org>
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 "transition_composite.h"
22 #include <framework/mlt_frame.h>
39 /** Parse a geometry property string.
42 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property )
44 // Assign from defaults if available
45 if ( defaults != NULL )
47 geometry->x = defaults->x;
48 geometry->y = defaults->y;
49 geometry->w = defaults->w;
50 geometry->h = defaults->h;
51 geometry->mix = defaults->mix;
58 // Parse the geomtry string
59 if ( property != NULL )
60 sscanf( property, "%f,%f:%fx%f:%f", &geometry->x, &geometry->y, &geometry->w, &geometry->h, &geometry->mix );
63 /** Calculate real geometry.
66 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position )
68 // Calculate this frames geometry
69 output->x = in->x + ( out->x - in->x ) * position;
70 output->y = in->y + ( out->y - in->y ) * position;
71 output->w = in->w + ( out->w - in->w ) * position;
72 output->h = in->h + ( out->h - in->h ) * position;
73 output->mix = in->mix + ( out->mix - in->mix ) * position;
76 /** Calculate the position for this frame.
79 static float position_calculate( mlt_transition this, mlt_frame frame )
81 // Get the in and out position
82 mlt_position in = mlt_transition_get_in( this );
83 mlt_position out = mlt_transition_get_out( this );
85 // Get the position of the frame
86 mlt_position position = mlt_frame_get_position( frame );
89 return ( float )( position - in ) / ( float )( out - in + 1 );
92 /** Composite function.
95 static int composite_yuv( uint8_t *p_dest, mlt_image_format format_dest, int width_dest, int height_dest, mlt_frame that, struct geometry_s geometry )
102 int x_src = 0, y_src = 0;
104 mlt_image_format format_src = format_dest;
105 int x = ( int )( ( float )width_dest * geometry.x / 100 );
106 int y = ( int )( ( float )height_dest * geometry.y / 100 );
107 float weight = geometry.mix / 100;
108 int width_src = ( int )( ( float )width_dest * geometry.w / 100 );
109 int height_src = ( int )( ( float )height_dest * geometry.h / 100 );
111 mlt_properties b_props = mlt_frame_properties( that );
112 mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
113 mlt_properties properties = mlt_transition_properties( this );
115 if ( mlt_properties_get( properties, "distort" ) == NULL &&
116 mlt_properties_get( mlt_frame_properties( that ), "real_width" ) != NULL )
118 int width_b = mlt_properties_get_int( mlt_frame_properties( that ), "real_width" );
119 int height_b = mlt_properties_get_int( mlt_frame_properties( that ), "real_height" );
121 if ( width_b < width_src )
123 if ( height_b < height_src )
124 height_src = height_b;
125 mlt_properties_set( mlt_frame_properties( that ), "rescale.interp", "none" );
127 else if ( mlt_properties_get( mlt_frame_properties( that ), "real_width" ) != NULL )
129 mlt_properties_set( mlt_frame_properties( that ), "rescale.interp", "none" );
134 if ( width_src <= 0 || height_src <= 0 )
137 // optimization point - no work to do
138 if ( ( x < 0 && -x >= width_src ) || ( y < 0 && -y >= height_src ) )
141 format_src = mlt_image_yuv422;
142 format_dest = mlt_image_yuv422;
144 mlt_frame_get_image( that, &p_src, &format_src, &width_src, &height_src, 1 /* writable */ );
146 stride_src = width_src * 2;
147 stride_dest = width_dest * 2;
149 // crop overlay off the left edge of frame
157 // crop overlay beyond right edge of frame
158 else if ( x + width_src > width_dest )
159 width_src = width_dest - x;
161 // crop overlay off the top edge of the frame
167 // crop overlay below bottom edge of frame
168 else if ( y + height_src > height_dest )
169 height_src = height_dest - y;
171 // offset pointer into overlay buffer based on cropping
172 p_src += x_src * 2 + y_src * stride_src;
174 // offset pointer into frame buffer based upon positive, even coordinates only!
175 p_dest += ( x < 0 ? 0 : x ) * 2 + ( y < 0 ? 0 : y ) * stride_dest;
177 // Get the alpha channel of the overlay
178 uint8_t *p_alpha = mlt_frame_get_alpha_mask( that );
180 // offset pointer into alpha channel based upon cropping
182 p_alpha += x_src + y_src * stride_src / 2;
187 uint8_t *z = p_alpha;
194 // now do the compositing only to cropped extents
195 for ( i = 0; i < height_src; i++ )
202 for ( j = 0; j < width_src; j ++ )
206 a = ( z == NULL ) ? 255 : *z ++;
207 value = ( weight * ( float ) a / 255.0 );
208 *o ++ = (uint8_t)( Y * value + *q++ * ( 1 - value ) );
209 *o ++ = (uint8_t)( UV * value + *q++ * ( 1 - value ) );
213 p_dest += stride_dest;
215 p_alpha += stride_src / 2;
225 static int transition_get_image( mlt_frame a_frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
227 // Get the b frame from the stack
228 mlt_frame b_frame = mlt_frame_pop_frame( a_frame );
230 // Get the image from the a frame
231 mlt_frame_get_image( a_frame, image, format, width, height, 1 );
233 if ( b_frame != NULL )
235 // Get the properties of the b frame
236 mlt_properties b_props = mlt_frame_properties( b_frame );
238 // Get the transition from the b frame
239 mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
241 // Get the properties from the transition
242 mlt_properties properties = mlt_transition_properties( this );
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, a_frame );
252 // Now parse the geometries
253 geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ) );
254 geometry_parse( &end, &start, mlt_properties_get( properties, "end" ) );
256 // Do the calculation
257 geometry_calculate( &result, &start, &end, position );
259 // Composite the b_frame on the a_frame
260 composite_yuv( *image, *format, *width, *height, b_frame, result );
266 /** Composition transition processing.
269 static mlt_frame composite_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
271 // Propogate the transition properties to the b frame
272 mlt_properties b_props = mlt_frame_properties( b_frame );
273 mlt_properties_set_data( b_props, "transition_composite", this, 0, NULL, NULL );
274 mlt_frame_push_get_image( a_frame, transition_get_image );
275 mlt_frame_push_frame( a_frame, b_frame );
279 /** Constructor for the filter.
282 mlt_transition transition_composite_init( char *arg )
284 mlt_transition this = calloc( sizeof( struct mlt_transition_s ), 1 );
285 if ( this != NULL && mlt_transition_init( this, NULL ) == 0 )
287 this->process = composite_process;
288 mlt_properties_set( mlt_transition_properties( this ), "start", arg != NULL ? arg : "85,5:10x10" );
289 mlt_properties_set( mlt_transition_properties( this ), "end", "" );