route and chmap

[Jonas Holmberg]

CC Takashi.

On Thu, Mar 26, 2020 at 02:41:11PM +0100, Jonas Holmberg wrote:
> Hi,
> I use the route plugin to copy mono to both FL and FR (front left and 
> front right stereo) of the slave during playback. When get_chmap() is 
> called in the route plugin it will call get_chmap() of the slave, 
> which returns 2 channels with FL and FR positions, and then route 
> itself returns 1 channel with FL position. But the application that 
> called snd_pcm_get_chmap() on the playback device expected to get 
> position MONO instead of FL since the number of channels is 1.
> 
> Is the application wrong in not accepting the chmap or should the 
> route plugin have changed position from FL to MONO? Is it possible to 
> add something to the config (asound.conf) to make FL become MONO in 
> the reply of get_chmap() or solve the problem in any other way?
> 
> BR
> /Jonas