Only do channelcopy/swap if there is valid work.

diff --git a/src/modules/core/filter_channelcopy.c b/src/modules/core/filter_channelcopy.c
index 02730495057e9b5f22125846748bd3910bb953b7..cbfb709b6005b2bf111d7719ce95aa3734cfec92 100644 (file)
--- a/src/modules/core/filter_channelcopy.c
+++ b/src/modules/core/filter_channelcopy.c
@@ -45,6 +45,7 @@ static int filter_get_audio( mlt_frame frame, void **buffer, mlt_audio_format *f
        mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
 
        // Copy channels as necessary
+       if ( from != to)
        switch ( *format )
        {
                case mlt_audio_s16: