Re: V4L2 spec behavior for G_TUNER and T_STANDBY

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Hans,

Thanks for the feedback.

On Sat, Jan 1, 2011 at 4:18 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
>> This basically means that a video tuner will bail out, which sounds
>> good because the rest of the function supposedly assumes a radio
>> device.  However, as a result the has_signal() call (which returns
>> signal strength) will never be executed for video tuners.  You
>> wouldn't notice this if a video decoder subdev is responsible for
>> showing signal strength, but if you're expecting the tuner to provide
>> the info, the call will never happen.
>
> I am not aware of any tuner that does that. I think that for video this
> is always done by a video decoder. That said, it isn't pretty, but a lot
> of this is legacy code and I wouldn't want to change it.

The Xceive tuners have their analog demodulator onboard, so they make
available a 0-100% signal strength.

> After digging some more I think that check_mode is a poor function. There are
> two things that check_mode does: checking if the tuner support radio and/or tv
> mode (that's fine), and if it is in standby: not so fine. That should be a
> separate function since filling in frequency ranges can be done regardless of
> the standby state.

Yeah, I didn't realize myself that is what check_mode was doing until
I had this problem.

I'll see if I can cook up a patch which returns the appropriate data
even when in standby, while trying to minimize the risk of introducing
a regression.

Thanks,

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux