Re: Bah! How do I change channels?
- Date: Fri, 26 Jun 2009 13:32:40 -0400
- From: Devin Heitmueller <dheitmueller@xxxxxxxxxxxxxx>
- Subject: Re: Bah! How do I change channels?
On Fri, Jun 26, 2009 at 1:28 PM, Robert
> Yes, it is run after mplayer initially tunes it. However, what is the
> difference between mplayer tuning and v4l-ctl tuning? They are both
> submitting the same IOCTLs to the driver to accomplish the same end
> result; or is mplayer probably submitting some additional IOCTLS to
> "wake" the device?
The issue is that the tuner gets powered down when the v4l device is
closed. So, when running mplayer first, and then v4l-ctl is being
used to tune, the file handle is held active by mplayer. But if you
run v4l-ctl first, the v4l-ctl opens the handle, tunes successfully,
and then closes the handle (which powers down the tuner). Then when
running mplayer (or whatever app), the handle gets reopened but the
tuner is not tuned to the target frequency that v4l-ctl set.
Devin J. Heitmueller - Kernel Labs
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