[alsa-devel] TLV support for PCM (in driver)

Jaroslav Kysela perex at perex.cz
Wed Jan 16 15:23:37 CET 2008


	I am actually thinking to add TLV support to each PCM stream. The 
reason is to obtain various "static" information from the driver without 
even opening the PCM stream. The current API lack:

a) get channel info / name / position (e.g. Front Left Speaker)
   - not sure how to handle multichannel cards
   - I'm sure that this is something to be user configurable
b) get possible channels
c) get possible formats
d) various inter-PCM-device constraint description (e.g. if S/PDIF 
   PCM stream can be used with analog etc.)
e) eventually more information for device name hinting for userspace 
   (current problems for HDA, AC97, USB devices are that we have only one 
   .conf file per driver covering all hardware - we need to detect real 
   device capabilities and show only devices which can be really used)



Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.

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