1 /*
2 * filter_audiomap.c -- remap audio channels
3 * Copyright (C) 2015 Meltytech, LLC
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20 #include <framework/mlt_filter.h>
21 #include <framework/mlt_frame.h>
22 #include <framework/mlt_log.h>
23
24 #include <string.h>
25 #include <stdlib.h>
26
27 #define MAX_CHANNELS 32
28
filter_get_audio(mlt_frame frame,void ** buffer,mlt_audio_format * format,int * frequency,int * channels,int * samples)29 static int filter_get_audio( mlt_frame frame, void **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
30 {
31 char prop_name[32], *prop_val;
32 int i, j, l, m[MAX_CHANNELS];
33
34 mlt_filter filter = mlt_frame_pop_audio(frame);
35
36 // Get the producer's audio
37 int error = mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
38 if ( error ) return error;
39
40 mlt_properties properties = MLT_FILTER_PROPERTIES(filter);
41
42 /* find samples length */
43 int len = mlt_audio_format_size( *format, 1, 1 );
44
45 /* pcm samples buffer */
46 uint8_t *pcm = *buffer;
47
48 /* build matrix */
49 for ( i = 0; i < MAX_CHANNELS; i++ )
50 {
51 m[i] = i;
52
53 snprintf( prop_name, sizeof(prop_name), "%d", i );
54 if ( ( prop_val = mlt_properties_get( properties, prop_name ) ) )
55 {
56 j = atoi( prop_val );
57 if( j >= 0 && j < MAX_CHANNELS )
58 m[i] = j;
59 }
60 }
61
62 /* process samples */
63 for ( i = 0; i < *samples; i++ )
64 {
65 uint8_t tmp[MAX_CHANNELS * 4];
66
67 for ( j = 0; j < MAX_CHANNELS && j < *channels; j++ )
68 for(l = 0; l < len; l++)
69 tmp[j * len + l] = pcm[m[j] * len + l];
70
71 for ( j = 0; j < MAX_CHANNELS && j < *channels; j++ )
72 for ( l = 0; l < len; l++ )
73 pcm[j * len + l] = tmp[j * len + l];
74
75 pcm += len * (*channels);
76 }
77
78 return 0;
79 }
80
81 /** Filter processing.
82 */
83
filter_process(mlt_filter filter,mlt_frame frame)84 static mlt_frame filter_process( mlt_filter filter, mlt_frame frame )
85 {
86 mlt_frame_push_audio( frame, filter );
87 mlt_frame_push_audio( frame, filter_get_audio );
88 return frame;
89 }
90
91 /** Constructor for the filter.
92 */
93
filter_audiomap_init(mlt_profile profile,mlt_service_type type,const char * id,char * arg)94 mlt_filter filter_audiomap_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
95 {
96 mlt_filter filter = mlt_filter_new();
97 if ( filter )
98 filter->process = filter_process;
99 return filter;
100 }
101