2 * filter_channelcopy.c -- copy one audio channel to another
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Dan Dennedy <dan@dennedy.org>
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_channelcopy.h"
23 #include <framework/mlt_frame.h>
27 #define __USE_ISOC99 1
33 static int filter_get_audio( mlt_frame frame
, int16_t **buffer
, mlt_audio_format
*format
, int *frequency
, int *channels
, int *samples
)
35 // Get the properties of the a frame
36 mlt_properties properties
= MLT_FRAME_PROPERTIES( frame
);
38 int from
= mlt_properties_get_int( properties
, "channelcopy.from" );
39 int to
= mlt_properties_get_int( properties
, "channelcopy.to" );
41 // Get the producer's audio
42 mlt_frame_get_audio( frame
, buffer
, format
, frequency
, channels
, samples
);
44 // Duplicate channels as necessary
46 int size
= *channels
* *samples
* 2;
47 int16_t *new_buffer
= mlt_pool_alloc( size
);
49 mlt_properties_set_data( properties
, "audio", new_buffer
, size
, ( mlt_destructor
)mlt_pool_release
, NULL
);
51 // Duplicate the existing channels
52 for ( i
= 0; i
< *samples
; i
++ )
54 for ( j
= 0; j
< *channels
; j
++ )
56 new_buffer
[ ( i
* *channels
) + j
] = (*buffer
)[ ( i
* *channels
) + ( j
== to ? from
: j
) ];
64 /** Filter processing.
67 static mlt_frame
filter_process( mlt_filter
this, mlt_frame frame
)
69 mlt_properties properties
= MLT_FILTER_PROPERTIES( this );
70 mlt_properties frame_props
= MLT_FRAME_PROPERTIES( frame
);
72 // Propogate the parameters
73 mlt_properties_set_int( frame_props
, "channelcopy.to", mlt_properties_get_int( properties
, "to" ) );
74 mlt_properties_set_int( frame_props
, "channelcopy.from", mlt_properties_get_int( properties
, "from" ) );
76 // Override the get_audio method
77 mlt_frame_push_audio( frame
, filter_get_audio
);
82 /** Constructor for the filter.
85 mlt_filter
filter_channelcopy_init( char *arg
)
87 mlt_filter
this = mlt_filter_new( );
90 this->process
= filter_process
;
92 mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "to", atoi( arg
) );
94 mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "to", 1 );