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98 lines
2.7 KiB
98 lines
2.7 KiB
/*
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* filter_mono.c -- Arbitrary alpha channel shaping
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* Copyright (C) 2005 Visual Media Fx Inc.
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* Author: Charles Yates <charles.yates@pandora.be>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include "filter_mono.h"
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#include <string.h>
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#include <framework/mlt_factory.h>
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#include <framework/mlt_frame.h>
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#include <framework/mlt_producer.h>
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#include <framework/mlt_geometry.h>
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/** Get the images and apply the luminance of the mask to the alpha of the frame.
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*/
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static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
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{
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int use_alpha = mlt_deque_pop_back_int( MLT_FRAME_IMAGE_STACK( this ) );
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int midpoint = mlt_deque_pop_back_int( MLT_FRAME_IMAGE_STACK( this ) );
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// Render the frame
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if ( mlt_frame_get_image( this, image, format, width, height, writable ) == 0 )
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{
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uint8_t *p = *image;
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int size = *width * *height;
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if ( !use_alpha )
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{
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while( size -- )
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{
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if ( *p >= midpoint )
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*p ++ = 16;
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else
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*p ++ = 235;
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*p ++ = 128;
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}
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}
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else
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{
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uint8_t *alpha = mlt_frame_get_alpha_mask( this );
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while( size -- )
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{
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if ( *alpha ++ < midpoint )
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*p ++ = 16;
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else
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*p ++ = 235;
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*p ++ = 128;
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}
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}
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}
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return 0;
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}
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/** Filter processing.
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*/
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static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
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{
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int midpoint = mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "midpoint" );
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int use_alpha = mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "use_alpha" );
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mlt_deque_push_back_int( MLT_FRAME_IMAGE_STACK( frame ), midpoint );
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mlt_deque_push_back_int( MLT_FRAME_IMAGE_STACK( frame ), use_alpha );
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mlt_frame_push_get_image( frame, filter_get_image );
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return frame;
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}
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/** Constructor for the filter.
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*/
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mlt_filter filter_mono_init( char *arg )
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{
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mlt_filter this = mlt_filter_new( );
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if ( this != NULL )
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{
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mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "midpoint", 128 );
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mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "use_alpha", 0 );
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this->process = filter_process;
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}
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return this;
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}
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