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 int real_width = mlt_properties_get_int( properties, "real_width" );
57 int real_height = mlt_properties_get_int( properties, "real_height" );
58 if ( real_width == 0 )
59 real_width = mlt_properties_get_int( properties, "width" );
60 if ( real_height == 0 )
61 real_height = mlt_properties_get_int( properties, "height" );
62 double input_ar = mlt_frame_get_aspect_ratio( this ) * real_width / real_height;
63 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
65 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
66 int scaled_width = input_ar / output_ar * normalised_width + 0.5;
67 int scaled_height = normalised_height;
69 // Now ensure that our images fit in the output frame
70 if ( scaled_width > normalised_width )
72 scaled_width = normalised_width;
73 scaled_height = output_ar / input_ar * normalised_height + 0.5;
76 // Now calculate the actual image size that we want
77 owidth = scaled_width * owidth / normalised_width;
78 oheight = scaled_height * oheight / normalised_height;
80 // Tell frame we have conformed the aspect to the consumer
81 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
84 // Now pass on the calculations down the line
85 mlt_properties_set_int( properties, "resize_width", *width );
86 mlt_properties_set_int( properties, "resize_height", *height );
89 error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
91 // We only know how to process yuv422 at the moment
92 if ( error == 0 && *format == mlt_image_yuv422 )
94 // Get the requested scale operation
95 char *op = mlt_properties_get( mlt_filter_properties( filter ), "scale" );
97 // Correct field order if needed
98 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
100 // Get the input image, width and height
102 uint8_t *image = mlt_properties_get_data( properties, "image", &size );
104 // Keep the original image around to be destroyed on frame close
105 mlt_properties_rename( properties, "image", "original_image" );
107 // Duplicate the last line in the field to avoid artifact
108 memcpy( image + oheight * owidth * 2, image + oheight * owidth * 2 - owidth * 4, owidth * 2 );
110 // Offset the image pointer by one line
114 // Set the new image pointer with no destructor
115 mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
117 // Set the normalised field order
118 mlt_properties_set_int( properties, "top_field_first", 0 );
121 if ( !strcmp( op, "affine" ) )
123 *image = mlt_frame_rescale_yuv422( this, *width, *height );
125 else if ( strcmp( op, "none" ) != 0 )
127 *image = mlt_frame_resize_yuv422( this, *width, *height );
139 /** Filter processing.
142 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
144 // Push this on to the service stack
145 mlt_frame_push_service( frame, this );
147 // Push the get_image method on to the stack
148 mlt_frame_push_get_image( frame, filter_get_image );
153 /** Constructor for the filter.
156 mlt_filter filter_resize_init( char *arg )
158 mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
159 if ( mlt_filter_init( this, this ) == 0 )
161 this->process = filter_process;
162 mlt_properties_set( mlt_filter_properties( this ), "scale", arg == NULL ? "off" : arg );