[alsa-devel] [PATCH v2 2/3] route: Select slave chmap based on ttable information

[Raymond Yau]

2014-02-28 15:57 GMT+08:00 David Henningsson <
david.henningsson at canonical.com>:

> It means we need to initialize this order:
>
>  1) Read the ttable to figure out which channels are present
>  2) Open slave pcm and find a matching chmap
>  3) Determine size of ttable (this can now depend on the chmap)
>  4) Read ttable coefficients
>  5) At prepare time, select the matching chmap
>

Do this patch assume the slave.pcm of the route plugin must have a channel
map ?

are there any side effect when some of sound cards using route but does not
have channel map ?



e.g. ice1712,

	playback.pcm {
		type hooks
		slave.pcm {
			type route
			ttable.0.8 1
			ttable.1.9 1
			slave.pcm {
				type hw
				card $CARD
			}
			slave.format S32_LE
			slave.channels 10
		}


rme9652, ....

slave.pcm {
		type route
		slave {
			pcm {
				type hw
				card $CARD
			}
			channels 26
		}
		ttable.0.24 1
		ttable.1.25 1