+ Added rudimentary chroma to alpha filter (optimised on green by default)

git-svn-id: https://mlt.svn.sourceforge.net/svnroot/mlt/trunk/mlt@812 d19143bc-622f-0410-bfdd-b5b2a6649095

diff --git a/src/modules/vmfx/Makefile b/src/modules/vmfx/Makefile
index 83e766515f9bca24f698d61e29334ebea46a2b95..98eb547462a539fc26355427c152cc4fc11a73ba 100644 (file)
--- a/src/modules/vmfx/Makefile
+++ b/src/modules/vmfx/Makefile
@@ -3,6 +3,7 @@ include ../../../config.mak
 TARGET = ../libmltvmfx$(LIBSUF)
 
 OBJS = factory.o \
+          filter_chroma.o \
           filter_shape.o \
           producer_pgm.o
 

diff --git a/src/modules/vmfx/configure b/src/modules/vmfx/configure
index f80432cadbbd96db0e1d4b126966d076cb38490f..37230f95697b316e8f546bc0c13bc630ddb01ef9 100755 (executable)
--- a/src/modules/vmfx/configure
+++ b/src/modules/vmfx/configure
@@ -8,6 +8,7 @@ pgm                             libmltvmfx$LIBSUF
 EOF
 
 cat << EOF >> ../filters.dat
+chroma                 libmltvmfx$LIBSUF
 shape                  libmltvmfx$LIBSUF
 EOF
 

diff --git a/src/modules/vmfx/factory.c b/src/modules/vmfx/factory.c
index b1b809b18e7168d4728458de389eddffbbbf7fe6..cd67d5ceba5d6ef836ca93e420bcc2faaeb35df0 100644 (file)
--- a/src/modules/vmfx/factory.c
+++ b/src/modules/vmfx/factory.c
@@ -20,6 +20,7 @@
 
 #include <string.h>
 
+#include "filter_chroma.h"
 #include "filter_shape.h"
 #include "producer_pgm.h"
 
@@ -32,6 +33,8 @@ void *mlt_create_producer( char *id, void *arg )
 
 void *mlt_create_filter( char *id, void *arg )
 {
+       if ( !strcmp( id, "chroma" ) )
+               return filter_chroma_init( arg );
        if ( !strcmp( id, "shape" ) )
                return filter_shape_init( arg );
        return NULL;

diff --git a/src/modules/vmfx/filter_chroma.c b/src/modules/vmfx/filter_chroma.c
new file mode 100644 (file)
index 0000000..565ac02
--- /dev/null
+++ b/src/modules/vmfx/filter_chroma.c
@@ -0,0 +1,96 @@
+/*
+ * filter_chroma.c -- Maps a chroma key to the alpha channel
+ * Copyright (C) 2005 Visual Media Fx Inc.
+ * Author: Charles Yates <charles.yates@pandora.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "filter_chroma.h"
+#include <stdlib.h>
+#include <framework/mlt_factory.h>
+#include <framework/mlt_frame.h>
+#include <framework/mlt_producer.h>
+#include <framework/mlt_geometry.h>
+
+static inline int in_range( uint8_t v, uint8_t c, int var )
+{
+       return ( v >= c - var ) && ( v <= c + var );
+}
+
+static inline uint8_t alpha_value( uint8_t a, uint8_t *p, uint8_t u, uint8_t v, int var )
+{
+       return ( in_range( *( p + 1 ), u, var ) && in_range( *( p + 3 ), v, var ) ) ? 0 : a;
+}
+
+/** Get the images and map the chroma to the alpha of the frame.
+*/
+
+static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
+{
+       mlt_filter this = mlt_frame_pop_service( frame );
+       char *key = mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "key" );
+       int variance = 255 * mlt_properties_get_double( MLT_FILTER_PROPERTIES( this ), "variance" ) + 0.5;
+       int32_t key_val = strtol( key, &key, 0 );
+       uint8_t b = key_val & 0xff;
+       uint8_t g = ( key_val >> 8 ) & 0xff;
+       uint8_t r = ( key_val >> 16 ) & 0xff;
+       uint8_t y, u, v;
+
+       RGB2YUV( r, g, b, y, u, v );
+
+       if ( mlt_frame_get_image( frame, image, format, width, height, writable ) == 0 )
+       {
+               uint8_t *alpha = mlt_frame_get_alpha_mask( frame );
+               uint8_t *p = *image;
+               int size = *width * *height;
+               int odd = 0;
+               while ( size -- )
+               {
+                       *alpha = alpha_value( *alpha, p, u, v, variance );
+                       if ( odd ) p += 4;
+                       odd = !odd;
+                       alpha ++;
+               }
+       }
+
+       return 0;
+}
+
+/** Filter processing.
+*/
+
+static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
+{
+       mlt_frame_push_service( frame, this );
+       mlt_frame_push_service( frame, filter_get_image );
+       return frame;
+}
+
+/** Constructor for the filter.
+*/
+
+mlt_filter filter_chroma_init( char *arg )
+{
+       mlt_filter this = mlt_filter_new( );
+       if ( this != NULL )
+       {
+               mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "key", arg == NULL ? "0x00ff00" : arg );
+               mlt_properties_set_double( MLT_FILTER_PROPERTIES( this ), "variance", 0.3 );
+               this->process = filter_process;
+       }
+       return this;
+}
+

diff --git a/src/modules/vmfx/filter_chroma.h b/src/modules/vmfx/filter_chroma.h
new file mode 100644 (file)
index 0000000..13c7a13
--- /dev/null
+++ b/src/modules/vmfx/filter_chroma.h
@@ -0,0 +1,28 @@
+/*
+ * filter_chroma.h -- Maps a chroma key to the alpha channel
+ * Copyright (C) 2005 Visual Media Fx Inc.
+ * Author: Charles Yates <charles.yates@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _FILTER_CHROMA_H_
+#define _FILTER_CHROMA_H_
+
+#include <framework/mlt_filter.h>
+
+extern mlt_filter filter_chroma_init( char *arg );
+
+#endif