git.sesse.net Git - mlt/blob - src/modules/core/filter_channelcopy.c

   1 /*
   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>
   5  *
   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.
  10  *
  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.
  15  *
  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
  19  */
  20
  21 #include <framework/mlt_filter.h>
  22 #include <framework/mlt_frame.h>
  23 #include <framework/mlt_log.h>
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28
  29 /** Get the audio.
  30 */
  31
  32 static int filter_get_audio( mlt_frame frame, void **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
  33 {
  34         // Get the properties of the a frame
  35         mlt_properties properties = MLT_FRAME_PROPERTIES( frame );
  36
  37         // Get the filter service
  38         mlt_filter filter = mlt_frame_pop_audio( frame );
  39
  40         int from = mlt_properties_get_int( properties, "channelcopy.from" );
  41         int to = mlt_properties_get_int( properties, "channelcopy.to" );
  42         int swap = mlt_properties_get_int( properties, "channelcopy.swap" );
  43
  44         // Get the producer's audio
  45         mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
  46
  47         // Copy channels as necessary
  48         if ( from != to)
  49         switch ( *format )
  50         {
  51                 case mlt_audio_s16:
  52                 {
  53                         int16_t *f = (int16_t*) *buffer + from;
  54                         int16_t *t = (int16_t*) *buffer + to;
  55                         int16_t x;
  56                         int i;
  57
  58                         if ( swap )
  59                                 for ( i = 0; i < *samples; i++, f += *channels, t += *channels )
  60                                 {
  61                                         x = *t;
  62                                         *t = *f;
  63                                         *f = x;
  64                                 }
  65                         else
  66                                 for ( i = 0; i < *samples; i++, f += *channels, t += *channels )
  67                                         *t = *f;
  68                         break;
  69                 }
  70                 case mlt_audio_s32:
  71                 {
  72                         int32_t *f = (int32_t*) *buffer + from * *samples;
  73                         int32_t *t = (int32_t*) *buffer + to * *samples;
  74
  75                         if ( swap )
  76                         {
  77                                 int32_t *x = malloc( *samples * sizeof(int32_t) );
  78                                 memcpy( x, t, *samples * sizeof(int32_t) );
  79                                 memcpy( t, f, *samples * sizeof(int32_t) );
  80                                 memcpy( f, x, *samples * sizeof(int32_t) );
  81                                 free( x );
  82                         }
  83                         else
  84                         {
  85                                 memcpy( t, f, *samples * sizeof(int32_t) );
  86                         }
  87                         break;
  88                 }
  89                 case mlt_audio_float:
  90                 {
  91                         float *f = (float*) *buffer + from * *samples;
  92                         float *t = (float*) *buffer + to * *samples;
  93
  94                         if ( swap )
  95                         {
  96                                 float *x = malloc( *samples * sizeof(float) );
  97                                 memcpy( x, t, *samples * sizeof(float) );
  98                                 memcpy( t, f, *samples * sizeof(float) );
  99                                 memcpy( f, x, *samples * sizeof(float) );
 100                                 free( x );
 101                         }
 102                         else
 103                         {
 104                                 memcpy( t, f, *samples * sizeof(float) );
 105                         }
 106                         break;
 107                 }
 108                 default:
 109                         mlt_log_error( MLT_FILTER_SERVICE( filter ), "Invalid audio format\n" );
 110                         break;
 111         }
 112
 113         return 0;
 114 }
 115
 116 /** Filter processing.
 117 */
 118
 119 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 120 {
 121         mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 122         mlt_properties frame_props = MLT_FRAME_PROPERTIES( frame );
 123
 124         // Propogate the parameters
 125         mlt_properties_set_int( frame_props, "channelcopy.to", mlt_properties_get_int( properties, "to" ) );
 126         mlt_properties_set_int( frame_props, "channelcopy.from", mlt_properties_get_int( properties, "from" ) );
 127         mlt_properties_set_int( frame_props, "channelcopy.swap", mlt_properties_get_int( properties, "swap" ) );
 128
 129         // Override the get_audio method
 130         mlt_frame_push_audio( frame, this );
 131         mlt_frame_push_audio( frame, filter_get_audio );
 132
 133         return frame;
 134 }
 135
 136 /** Constructor for the filter.
 137 */
 138
 139 mlt_filter filter_channelcopy_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 140 {
 141         mlt_filter this = mlt_filter_new( );
 142         if ( this != NULL )
 143         {
 144                 this->process = filter_process;
 145                 if ( arg != NULL )
 146                         mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "to", atoi( arg ) );
 147                 else
 148                         mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "to", 1 );
 149                 if ( strcmp(id, "channelswap") == 0 )
 150                         mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "swap", 1 );
 151         }
 152         return this;
 153 }