Hi Hans,

> To my knowledge nobody has done much if any work on this. Usually the
> audio part is handled by alsa, but it is not clear if support is also
> needed from the V4L2 API.

Actually, the application needs to know when to ask the capture device to start 
capturing.

Let's say, the cable is already plugged in/or plugged out.

So, any events will be missed as the driver state machine starts during boot up 
and app is not started.

App starts later, registers for (V4L2_EVENT_SOURCE_CHANGE back ported to 3.10) 
and listens, but will not receive any as they are already generated.


So, the application is in a blind spot whether to start capture or not.

If we get the same interface as video it's good. I mean G_FMT with a union for 
audio as well.

Otherwise, I can go with a proprietary control/ioctl indicating whether audio 
is valid or not. 

ioctl seems to be an easy choice, because this subdev is not exposing any 
controls, so, registration with ctrl framework for a single one seems a bit of 
overload.


Regards,

Divneil                                           --
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to