Help on specifying 'chmap' in asound.conf

Dear all,

I am having a question regarding how to specify 'champ' for a plugin. I do not see any examples of this. I tried many ways to specify but failed.

As indicated by the link below, I can specify the MAP as a string array. Can someone provide one example on how exactly this [chmap MAP] can be specified?

" pcm.name { type cras [chmap MAP] # Provide channel maps; MAP is a string array } " https://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html

I can something like these, but none of these work for me.

chmap LFE chmap "LFE" chmap FR,FL,LFE champ "FR,FL,LFE"

Thanks!

Xinhui,