+/*
+ * filter_channelcopy.c -- copy one audio channel to another
+ * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
+ * Author: Dan Dennedy <dan@dennedy.org>
+ *
+ * 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_channelcopy.h"
+
+#include <framework/mlt_frame.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#define __USE_ISOC99 1
+#include <math.h>
+
+/** Get the audio.
+*/
+
+static int filter_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
+{
+ // Get the properties of the a frame
+ mlt_properties properties = mlt_frame_properties( frame );
+ int i, j;
+ int from = mlt_properties_get_int( properties, "channelcopy.from" );
+ int to = mlt_properties_get_int( properties, "channelcopy.to" );
+
+ // Restore the original get_audio
+ frame->get_audio = mlt_properties_get_data( properties, "channelcopy.get_audio", NULL );
+
+ // Get the producer's audio
+ mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
+
+ // Duplicate channels as necessary
+ {
+ int size = *channels * *samples * 2;
+ int16_t *new_buffer = mlt_pool_alloc( size );
+
+ mlt_properties_set_data( properties, "audio", new_buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
+
+ // Duplicate the existing channels
+ for ( i = 0; i < *samples; i++ )
+ {
+ for ( j = 0; j < *channels; j++ )
+ {
+ new_buffer[ ( i * *channels ) + j ] = (*buffer)[ ( i * *channels ) + ( j == to ? from : j ) ];
+ }
+ }
+ *buffer = new_buffer;
+ }
+ return 0;
+}
+
+/** Filter processing.
+*/
+
+static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
+{
+ mlt_properties properties = mlt_filter_properties( this );
+ mlt_properties frame_props = mlt_frame_properties( frame );
+
+ // Propogate the parameters
+ mlt_properties_set_int( frame_props, "channelcopy.to", mlt_properties_get_int( properties, "to" ) );
+ mlt_properties_set_int( frame_props, "channelcopy.from", mlt_properties_get_int( properties, "from" ) );
+
+ // Backup the original get_audio (it's still needed)
+ mlt_properties_set_data( frame_props, "channelcopy.get_audio", frame->get_audio, 0, NULL, NULL );
+
+ // Override the get_audio method
+ frame->get_audio = filter_get_audio;
+
+ return frame;
+}
+
+/** Constructor for the filter.
+*/
+
+mlt_filter filter_channelcopy_init( char *arg )
+{
+ mlt_filter this = mlt_filter_new( );
+ if ( this != NULL )
+ {
+ this->process = filter_process;
+ if ( arg != NULL )
+ mlt_properties_set_int( mlt_filter_properties( this ), "to", atoi( arg ) );
+ else
+ mlt_properties_set_int( mlt_filter_properties( this ), "to", 1 );
+ }
+ return this;
+}
projects / mlt / commitdiff