Use CPU optimized memcpy if available.

modules/audio_filter/channel_mixer/mono.c

@@ -373,7 +373,7 @@ static int OpenFilter( vlc_object_t *p_this )
         (p_filter->fmt_out.i_codec != AOUT_FMT_S16_NE) )
     {
         msg_Err( p_this, "filter discarded (invalid format)" );
-        return -1;
+        return VLC_EGENERIC;
     }
 
     if( (p_filter->fmt_in.audio.i_format != p_filter->fmt_out.audio.i_format) &&
@@ -583,9 +583,9 @@ static void stereo2mono_downmix( aout_instance_t * p_aout, aout_filter_t * p_fil
         i_overflow_size = p_sys->i_overflow_buffer_size;
 
         if ( i_out_size > i_overflow_size )
-            memcpy( p_out, p_overflow, i_overflow_size );
+            p_filter->p_vlc->pf_memcpy( p_out, p_overflow, i_overflow_size );
         else
-            memcpy( p_out, p_overflow, i_out_size );
+            p_filter->p_vlc->pf_memcpy( p_out, p_overflow, i_out_size );
 
         p_slide = p_sys->p_overflow_buffer;
         while( p_slide < p_overflow + i_overflow_size )
@@ -594,9 +594,10 @@ static void stereo2mono_downmix( aout_instance_t * p_aout, aout_filter_t * p_fil
             {
                 memset( p_slide, 0, i_out_size );
                 if( p_slide + 2 * i_out_size < p_overflow + i_overflow_size )
-                    memcpy( p_slide, p_slide + i_out_size, i_out_size );
+                    p_filter->p_vlc->pf_memcpy( p_slide, p_slide + i_out_size,
+                                                i_out_size );
                 else
-                    memcpy( p_slide, p_slide + i_out_size,
+                    p_filter->p_vlc->pf_memcpy( p_slide, p_slide + i_out_size,
                             p_overflow + i_overflow_size - ( p_slide + i_out_size ) );
             }
             else