+
+/*****************************************************************************
+ * aout_ChannelExtract:
+ *****************************************************************************/
+static inline void ExtractChannel( uint8_t *pi_dst, int i_dst_channels,
+ const uint8_t *pi_src, int i_src_channels,
+ int i_sample_count,
+ const int *pi_selection, int i_bytes )
+{
+ for( int i = 0; i < i_sample_count; i++ )
+ {
+ for( int j = 0; j < i_dst_channels; j++ )
+ memcpy( &pi_dst[j * i_bytes], &pi_src[pi_selection[j] * i_bytes], i_bytes );
+ pi_dst += i_dst_channels * i_bytes;
+ pi_src += i_src_channels * i_bytes;
+ }
+}
+
+void aout_ChannelExtract( void *p_dst, int i_dst_channels,
+ const void *p_src, int i_src_channels,
+ int i_sample_count, const int *pi_selection, int i_bits_per_sample )
+{
+ /* It does not work in place */
+ assert( p_dst != p_src );
+
+ /* Force the compiler to inline for the specific cases so it can optimize */
+ if( i_bits_per_sample == 8 )
+ ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 1 );
+ else if( i_bits_per_sample == 16 )
+ ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 2 );
+ else if( i_bits_per_sample == 24 )
+ ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 3 );
+ else if( i_bits_per_sample == 32 )
+ ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 4 );
+ else if( i_bits_per_sample == 64 )
+ ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 8 );
+}
+
+bool aout_CheckChannelExtraction( int *pi_selection,
+ uint32_t *pi_layout, int *pi_channels,
+ const uint32_t pi_order_dst[AOUT_CHAN_MAX],
+ const uint32_t *pi_order_src, int i_channels )
+{
+ const uint32_t pi_order_dual_mono[] = { AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT };
+ uint32_t i_layout = 0;
+ int i_out = 0;
+ int pi_index[AOUT_CHAN_MAX];
+
+ /* */
+ if( !pi_order_dst )
+ pi_order_dst = pi_vlc_chan_order_wg4;
+
+ /* Detect special dual mono case */
+ if( i_channels == 2 &&
+ pi_order_src[0] == AOUT_CHAN_CENTER && pi_order_src[1] == AOUT_CHAN_CENTER )
+ {
+ i_layout |= AOUT_CHAN_DUALMONO;
+ pi_order_src = pi_order_dual_mono;
+ }
+
+ /* */
+ for( int i = 0; i < i_channels; i++ )
+ {
+ /* Ignore unknown or duplicated channels or not present in output */
+ if( !pi_order_src[i] || (i_layout & pi_order_src[i]) )
+ continue;
+
+ for( int j = 0; j < AOUT_CHAN_MAX; j++ )
+ {
+ if( pi_order_dst[j] == pi_order_src[i] )
+ {
+ assert( i_out < AOUT_CHAN_MAX );
+ pi_index[i_out++] = i;
+ i_layout |= pi_order_src[i];
+ break;
+ }
+ }
+ }
+
+ /* */
+ for( int i = 0, j = 0; i < AOUT_CHAN_MAX; i++ )
+ {
+ for( int k = 0; k < i_out; k++ )
+ {
+ if( pi_order_dst[i] == pi_order_src[pi_index[k]] )
+ {
+ pi_selection[j++] = pi_index[k];
+ break;
+ }
+ }
+ }
+
+ *pi_layout = i_layout;
+ *pi_channels = i_out;
+
+ for( int i = 0; i < i_out; i++ )
+ {
+ if( pi_selection[i] != i )
+ return true;
+ }
+ return i_out == i_channels;
+}
+
+/*****************************************************************************
+ * aout_BufferAlloc:
+ *****************************************************************************/
+
+aout_buffer_t *aout_BufferAlloc(aout_alloc_t *allocation, mtime_t microseconds,
+ aout_buffer_t *old_buffer)
+{
+ if ( !allocation->b_alloc )
+ {
+ return old_buffer;
+ }
+
+ size_t i_alloc_size = (int)( (uint64_t)allocation->i_bytes_per_sec
+ * (microseconds) / 1000000 + 1 );
+
+ return block_Alloc( i_alloc_size );
+}
+
+
+/* This function will add or remove a a module from a string list (colon
+ * separated). It will return true if there is a modification
+ * In case p_aout is NULL, we will use configuration instead of variable */
+bool aout_ChangeFilterString( vlc_object_t *p_obj, aout_instance_t *p_aout,
+ const char *psz_variable,
+ const char *psz_name, bool b_add )
+{
+ char *psz_val;
+ char *psz_parser;
+
+ if( *psz_name == '\0' )
+ return false;
+
+ if( p_aout )
+ psz_val = var_GetString( p_aout, psz_variable );
+ else
+ {
+ psz_val = var_CreateGetString( p_obj->p_libvlc, psz_variable );
+ var_Destroy( p_obj->p_libvlc, psz_variable );
+ }
+
+ if( !psz_val )
+ psz_val = strdup( "" );
+
+ psz_parser = strstr( psz_val, psz_name );
+
+ if( ( b_add && psz_parser ) || ( !b_add && !psz_parser ) )
+ {
+ /* Nothing to do */
+ free( psz_val );
+ return false;
+ }
+
+ if( b_add )
+ {
+ char *psz_old = psz_val;
+ if( *psz_old )
+ {
+ if( asprintf( &psz_val, "%s:%s", psz_old, psz_name ) == -1 )
+ psz_val = NULL;
+ }
+ else
+ psz_val = strdup( psz_name );
+ free( psz_old );
+ }
+ else
+ {
+ const int i_name = strlen( psz_name );
+ const char *psz_next;
+
+ psz_next = &psz_parser[i_name];
+ if( *psz_next == ':' )
+ psz_next++;
+
+ memmove( psz_parser, psz_next, strlen(psz_next)+1 );
+ }
+
+ if( p_aout )
+ var_SetString( p_aout, psz_variable, psz_val );
+ else
+ config_PutPsz( p_obj, psz_variable, psz_val );
+ free( psz_val );
+ return true;
+}