2 * filter_resize.c -- resizing 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_resize.h"
23 #include <framework/mlt_frame.h>
32 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
36 // Get the properties from the frame
37 mlt_properties properties = mlt_frame_properties( this );
39 // Pop the top of stack now
40 mlt_filter filter = mlt_frame_pop_service( this );
42 // Assign requested width/height from our subordinate
44 int oheight = *height;
47 char *rescale = mlt_properties_get( properties, "rescale.interp" );
48 if ( rescale != NULL && !strcmp( rescale, "none" ) )
49 return mlt_frame_get_image( this, image, format, width, height, writable );
51 if ( mlt_properties_get( properties, "distort" ) == NULL )
53 // Normalise the input and out display aspect
54 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
55 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
56 double input_ar = mlt_frame_get_aspect_ratio( this );
57 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
59 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
60 int scaled_width = normalised_width;
61 int scaled_height = output_ar / input_ar * normalised_height;
63 // Now ensure that our images fit in the normalised frame
64 if ( scaled_height > normalised_height )
66 scaled_width = input_ar / output_ar * normalised_width;
67 scaled_height = normalised_height;
70 // Now calculate the actual image size that we want
71 owidth = scaled_width * owidth / normalised_width;
72 oheight = scaled_height * oheight / normalised_height;
74 // Tell frame we have conformed the aspect to the consumer
75 mlt_frame_set_aspect_ratio( this, output_ar );
78 // Now pass on the calculations down the line
79 mlt_properties_set_int( properties, "resize_width", *width );
80 mlt_properties_set_int( properties, "resize_height", *height );
83 error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
85 // We only know how to process yuv422 at the moment
86 if ( error == 0 && *format == mlt_image_yuv422 )
88 // Get the requested scale operation
89 char *op = mlt_properties_get( mlt_filter_properties( filter ), "scale" );
91 // Correct field order if needed
92 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
94 // Get the input image, width and height
96 uint8_t *image = mlt_properties_get_data( properties, "image", &size );
98 // Keep the original image around to be destroyed on frame close
99 mlt_properties_rename( properties, "image", "original_image" );
101 // Offset the image pointer by one line
105 // Set the new image pointer with no destructor
106 mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
108 // Set the normalised field order
109 mlt_properties_set_int( properties, "top_field_first", 0 );
112 if ( !strcmp( op, "affine" ) )
114 *image = mlt_frame_rescale_yuv422( this, *width, *height );
116 else if ( strcmp( op, "none" ) != 0 )
118 *image = mlt_frame_resize_yuv422( this, *width, *height );
130 /** Filter processing.
133 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
135 // Push this on to the service stack
136 mlt_frame_push_service( frame, this );
138 // Push the get_image method on to the stack
139 mlt_frame_push_get_image( frame, filter_get_image );
144 /** Constructor for the filter.
147 mlt_filter filter_resize_init( char *arg )
149 mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
150 if ( mlt_filter_init( this, this ) == 0 )
152 this->process = filter_process;
153 mlt_properties_set( mlt_filter_properties( this ), "scale", arg == NULL ? "off" : arg );