[alsa-devel] What's the deal with elements?

Clemens Ladisch clemens at ladisch.de
Thu Nov 24 14:37:56 CET 2011

Borg Onion wrote:
> the "enum _snd_ctl_elem_iface" definition hints at these element lists
> containing PCM devices.

iface=PCM means that the control is associated with some PCM device
(identified by device/subdevice).

> Lastly, my calls to snd_ctl_elem_list_get_index() always return 0.
> Shouldn't they be returning the index passed in?

A control is identified either by the numid, a non-zero unique number,
or by the interface/device/subdevice/name/index fields.  The index field
is used when there are multiple controls that would otherwise have the
same ID.


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