ao_coreaudio: support native mono output

We can be pretty sure that AudioUnit will remix for us.

Before this commit, we usually upmixed to stereo, because the
stereo and multichannel layouts were the only whitelisted ones.

1 files changed, 2 insertions, 0 deletions

diff --git a/audio/out/ao_coreaudio_chmap.c b/audio/out/ao_coreaudio_chmap.c
index 8da0c4c6f0..b1572dabd1 100644
--- a/audio/out/ao_coreaudio_chmap.c
+++ b/audio/out/ao_coreaudio_chmap.c
@@ -241,6 +241,8 @@ bool ca_init_chmap(struct ao *ao, AudioDeviceID device)
     struct mp_chmap_sel chmap_sel = {.tmp = ta_ctx};
     struct mp_chmap chmap = {0};
 
+    mp_chmap_sel_add_map(&chmap_sel, &(struct mp_chmap)MP_CHMAP_INIT_MONO);
+
     AudioChannelLayout *ml = ca_query_layout(ao, device, ta_ctx);
     if (ml && ca_layout_to_mp_chmap(ao, ml, &chmap))
         mp_chmap_sel_add_map(&chmap_sel, &chmap);