Mono audio filter is a channel_mixer and not a convertor.

bdfdc200 · Jean-Paul Saman · 29b5f303 · bdfdc200 · bdfdc200 · bdfdc200
Commit bdfdc200 authored Sep 25, 2006 by Jean-Paul Saman
--- a/modules/audio_filter/channel_mixer/Modules.am
+++ b/modules/audio_filter/channel_mixer/Modules.am
@@ -2,3 +2,4 @@ SOURCES_trivial_channel_mixer = trivial.c
 SOURCES_simple_channel_mixer = simple.c
 SOURCES_headphone_channel_mixer = headphone.c
 SOURCES_dolby_surround_decoder = dolby.c
+SOURCES_mono = mono.c
--- a/modules/audio_filter/converter/mono.c
+++ b/modules/audio_filter/converter/mono.c
--- a/modules/audio_filter/converter/Modules.am
+++ b/modules/audio_filter/converter/Modules.am
@@ -15,4 +15,3 @@ SOURCES_s8tofloat32 = s8tofloat32.c
 SOURCES_u8tofixed32 = u8tofixed32.c
 SOURCES_u8tofloat32 = u8tofloat32.c
 SOURCES_mpgatofixed32 = mpgatofixed32.c
-SOURCES_mono = mono.c