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 library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library 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 GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <framework/mlt_filter.h>
22 #include <framework/mlt_frame.h>
26 #define __USE_ISOC99 1
32 static int filter_get_audio( mlt_frame frame
, int16_t **buffer
, mlt_audio_format
*format
, int *frequency
, int *channels
, int *samples
)
34 // Get the properties of the a frame
35 mlt_properties properties
= MLT_FRAME_PROPERTIES( frame
);
37 int from
= mlt_properties_get_int( properties
, "channelcopy.from" );
38 int to
= mlt_properties_get_int( properties
, "channelcopy.to" );
40 // Get the producer's audio
41 mlt_frame_get_audio( frame
, buffer
, format
, frequency
, channels
, samples
);
43 // Duplicate channels as necessary
45 int size
= *channels
* *samples
* 2;
46 int16_t *new_buffer
= mlt_pool_alloc( size
);
48 mlt_properties_set_data( properties
, "audio", new_buffer
, size
, ( mlt_destructor
)mlt_pool_release
, NULL
);
50 // Duplicate the existing channels
51 for ( i
= 0; i
< *samples
; i
++ )
53 for ( j
= 0; j
< *channels
; j
++ )
55 new_buffer
[ ( i
* *channels
) + j
] = (*buffer
)[ ( i
* *channels
) + ( j
== to ? from
: j
) ];
63 /** Filter processing.
66 static mlt_frame
filter_process( mlt_filter
this, mlt_frame frame
)
68 mlt_properties properties
= MLT_FILTER_PROPERTIES( this );
69 mlt_properties frame_props
= MLT_FRAME_PROPERTIES( frame
);
71 // Propogate the parameters
72 mlt_properties_set_int( frame_props
, "channelcopy.to", mlt_properties_get_int( properties
, "to" ) );
73 mlt_properties_set_int( frame_props
, "channelcopy.from", mlt_properties_get_int( properties
, "from" ) );
75 // Override the get_audio method
76 mlt_frame_push_audio( frame
, filter_get_audio
);
81 /** Constructor for the filter.
84 mlt_filter
filter_channelcopy_init( mlt_profile profile
, mlt_service_type type
, const char *id
, char *arg
)
86 mlt_filter
this = mlt_filter_new( );
89 this->process
= filter_process
;
91 mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "to", atoi( arg
) );
93 mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "to", 1 );