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00027 #include <stdlib.h>
00028 #include <string.h>
00029
00030 #include <vlc/vlc.h>
00031 #include "audio_output.h"
00032 #include "aout_internal.h"
00033
00034
00035
00036
00037 static int Create ( vlc_object_t * );
00038
00039 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
00040 aout_buffer_t * );
00041
00042
00043
00044
00045 vlc_module_begin();
00046 set_description( _("audio filter for trivial channel mixing") );
00047 set_capability( "audio filter", 1 );
00048 set_category( CAT_AUDIO );
00049 set_subcategory( SUBCAT_AUDIO_MISC );
00050 set_callbacks( Create, NULL );
00051 vlc_module_end();
00052
00053
00054
00055
00056 static int Create( vlc_object_t *p_this )
00057 {
00058 aout_filter_t * p_filter = (aout_filter_t *)p_this;
00059
00060 if ( (p_filter->input.i_physical_channels
00061 == p_filter->output.i_physical_channels
00062 && p_filter->input.i_original_channels
00063 == p_filter->output.i_original_channels)
00064 || p_filter->input.i_format != p_filter->output.i_format
00065 || p_filter->input.i_rate != p_filter->output.i_rate
00066 || (p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
00067 && p_filter->input.i_format != VLC_FOURCC('f','i','3','2')) )
00068 {
00069 return -1;
00070 }
00071
00072 p_filter->pf_do_work = DoWork;
00073 if ( aout_FormatNbChannels( &p_filter->input )
00074 > aout_FormatNbChannels( &p_filter->output ) )
00075 {
00076
00077 p_filter->b_in_place = 1;
00078 }
00079 else
00080 {
00081
00082 p_filter->b_in_place = 0;
00083 }
00084
00085 return 0;
00086 }
00087
00088
00089
00090
00091 static void SparseCopy( int32_t * p_dest, const int32_t * p_src, size_t i_len,
00092 int i_output_stride, int i_input_stride )
00093 {
00094 int i;
00095 for ( i = i_len; i--; )
00096 {
00097 int j;
00098 for ( j = 0; j < i_output_stride; j++ )
00099 {
00100 p_dest[j] = p_src[j % i_input_stride];
00101 }
00102 p_src += i_input_stride;
00103 p_dest += i_output_stride;
00104 }
00105 }
00106
00107
00108
00109
00110 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
00111 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
00112 {
00113 int i_input_nb = aout_FormatNbChannels( &p_filter->input );
00114 int i_output_nb = aout_FormatNbChannels( &p_filter->output );
00115 int32_t * p_dest = (int32_t *)p_out_buf->p_buffer;
00116 int32_t * p_src = (int32_t *)p_in_buf->p_buffer;
00117
00118 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
00119 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * i_output_nb / i_input_nb;
00120
00121 if ( (p_filter->output.i_original_channels & AOUT_CHAN_PHYSMASK)
00122 != (p_filter->input.i_original_channels & AOUT_CHAN_PHYSMASK)
00123 && (p_filter->input.i_original_channels & AOUT_CHAN_PHYSMASK)
00124 == (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT) )
00125 {
00126 int i;
00127
00128 if ( !(p_filter->output.i_original_channels & AOUT_CHAN_LEFT) )
00129 {
00130 p_src++;
00131 }
00132 if ( p_filter->output.i_physical_channels == AOUT_CHAN_CENTER )
00133 {
00134
00135 for ( i = p_in_buf->i_nb_samples; i--; )
00136 {
00137 *p_dest = *p_src;
00138 p_dest++;
00139 p_src += 2;
00140 }
00141 }
00142 else
00143 {
00144
00145 for ( i = p_in_buf->i_nb_samples; i--; )
00146 {
00147 *p_dest = *p_src;
00148 p_dest++;
00149 *p_dest = *p_src;
00150 p_dest++;
00151 p_src += 2;
00152 }
00153 }
00154 }
00155 else if ( p_filter->output.i_original_channels
00156 & AOUT_CHAN_REVERSESTEREO )
00157 {
00158
00159 int i;
00160 for ( i = p_in_buf->i_nb_samples; i--; )
00161 {
00162 *p_dest = p_src[1];
00163 p_dest++;
00164 *p_dest = p_src[0];
00165 p_dest++;
00166 p_src += 2;
00167 }
00168 }
00169 else
00170 {
00171 SparseCopy( p_dest, p_src, p_in_buf->i_nb_samples, i_output_nb,
00172 i_input_nb );
00173 }
00174 }
00175