Hi Laurent and Mauro,

On Mon, Jun 11, 2012 at 10:30 AM, Mauro Carvalho Chehab
<mche...@redhat.com> wrote:
> Em 07-06-2012 15:26, Ezequiel Garcia escreveu:
>> Hi all,
>>
>> (I hope this is a genuine question, and I'm not avoiding my own homework 
>> here.)
>>
>> I'm trying to support the audio part of the stk1160 usb bridge
>> (similar to em28xx).
>> Currently, the snd-usb-audio module is being loaded when I physically
>> plug my device,
>> but I can't seem to capture any sound with vlc.
>
> Laurent already explained why snd-usb-audio is loaded.
>>
>> I still have to research and work a lot to understand the connection
>> between my device
>> and alsa, and altough I could write a working module similar to
>> em28xx-alsa.ko, I still
>> can't figure out why do I need to write one in the first place.
>
> On em28xx, some devices use UAC (USB Audio Class), while others use a 
> proprietary
> vendor class protocol. The em28xx-alsa module is used only for the devices 
> with a
> vendor class.
>>
>> Why is this module suffficient for gspca microphone devices (gspca, to name 
>> one)
>> and why is a new alsa driver needed for em28xx (or stk1160)?
>
> On em28xx, even the ones that use UAC require some configuration, for audio 
> to work.
>
> some setup is required to configure the audio input associated with a video 
> input,
> and to enable clock for the audio sampler. Such setup is made when a video 
> input is
> selected. You likely need something similar for stk1160.
>

It is *much* clear now, thanks to both.

Ezequiel.
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