[alsa-devel] how to enumerate useful ALSA devices?

[Raymond Yau]

2012/1/6, Anssi Hannula <anssi.hannula at iki.fi>:
> On 06.01.2012 01:06, Raymond Yau wrote:
>> 2012/1/5, Anssi Hannula <anssi.hannula at iki.fi>:
>>> On 04.01.2012 22:47, Anssi Hannula wrote:
>>>> On 04.01.2012 21:49, Andrew Eikum wrote:
>>>
>>>>> So I'm really stuck here. Where am I supposed to get a list of devices
>>>>> that I can present to the user, including their Bluetooth devices and
>>>>> virtual devices from asound.conf?
>>>>
>>>> I guess the preferred one is 'snd_device_name_hint()', but I don't
>>>> really know if the caller is supposed to then handle surroundXX stuff
>>>> themself.
>>>
>>> Reading your last reply made me realize that I forgot that when
>>> pulseaudio is not configured, there is also the "default:CARD=foo"
>>> device listed (which you noticed), so I guess one could just ignore
>>> entries beginning with "front:" or "surround(40|41|50|51|71):", since
>>> one can just use "default" instead of them.
>>>
>>
>> No , this won't work for emu10k1 and ca0106
>>
>> snd-emu10k1 require "front", "surround40","surround51" and
>> "surround71"  which use "multi" plugin of "front" , "rear" , "clfe" or
>> "side" devices
>>
>> you can play stereo stream to "rear" device
>
> Ah, thanks for the correction.
>
>

The use of "surround51" is not limited to emu10k1, some ac97 codec
which support smart51 or Universal Jacks need to switch "channel mode"
to 6ch when the motherboards have 3 audio jacks

https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5548