* Re: disable v4l2-ctl logging --log-status in /var/log/messages
@ 2009-03-12 9:28 Hans Verkuil
2009-03-12 9:49 ` Gregor Fuis
0 siblings, 1 reply; 6+ messages in thread
From: Hans Verkuil @ 2009-03-12 9:28 UTC (permalink / raw)
To: Gregor Fuis; +Cc: linux-media
> Hello,
>
> Is it possible to disable v4l2-ctl aplication logging into
> /var/log/messages.
> I am using it to control and monitor my PVR 150 cards and every time I
> run v4l2-ctl -d /dev/video0 --log-status all output is logged into
> /var/log/messages and some other linux log files.
All --log-status does is to tell the driver to show it's status in the
kernel log for debugging purposes. It cannot and should not be relied upon
for monitoring/controlling a driver.
What do you need it for anyway?
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: disable v4l2-ctl logging --log-status in /var/log/messages
2009-03-12 9:28 disable v4l2-ctl logging --log-status in /var/log/messages Hans Verkuil
@ 2009-03-12 9:49 ` Gregor Fuis
2009-03-12 23:34 ` Andy Walls
0 siblings, 1 reply; 6+ messages in thread
From: Gregor Fuis @ 2009-03-12 9:49 UTC (permalink / raw)
To: Hans Verkuil; +Cc: linux-media
On Thu, Mar 12, 2009 at 10:28 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>
>> Hello,
>>
>> Is it possible to disable v4l2-ctl aplication logging into
>> /var/log/messages.
>> I am using it to control and monitor my PVR 150 cards and every time I
>> run v4l2-ctl -d /dev/video0 --log-status all output is logged into
>> /var/log/messages and some other linux log files.
>
> All --log-status does is to tell the driver to show it's status in the
> kernel log for debugging purposes. It cannot and should not be relied upon
> for monitoring/controlling a driver.
>
> What do you need it for anyway?
I am just monitoring if signal is present on tuner, and what signal
format is detected.
These two lines:
cx25840 1-0044: Video signal: not present
cx25840 1-0044: Detected format: PAL-Nc
I run this every minute and it is really annoying to have all this in
my system logs.
Is it possible to modify v4l2-ctl source to disable system logging?
Regards,
Gregor
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: disable v4l2-ctl logging --log-status in /var/log/messages
2009-03-12 9:49 ` Gregor Fuis
@ 2009-03-12 23:34 ` Andy Walls
2009-03-12 23:39 ` Hans Verkuil
0 siblings, 1 reply; 6+ messages in thread
From: Andy Walls @ 2009-03-12 23:34 UTC (permalink / raw)
To: Gregor Fuis; +Cc: Hans Verkuil, linux-media
On Thu, 2009-03-12 at 10:49 +0100, Gregor Fuis wrote:
> On Thu, Mar 12, 2009 at 10:28 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> >
> >> Hello,
> >>
> >> Is it possible to disable v4l2-ctl aplication logging into
> >> /var/log/messages.
> >> I am using it to control and monitor my PVR 150 cards and every time I
> >> run v4l2-ctl -d /dev/video0 --log-status all output is logged into
> >> /var/log/messages and some other linux log files.
> >
> > All --log-status does is to tell the driver to show it's status in the
> > kernel log for debugging purposes. It cannot and should not be relied upon
> > for monitoring/controlling a driver.
> >
> > What do you need it for anyway?
>
> I am just monitoring if signal is present on tuner, and what signal
> format is detected.
> These two lines:
> cx25840 1-0044: Video signal: not present
> cx25840 1-0044: Detected format: PAL-Nc
> I run this every minute and it is really annoying to have all this in
> my system logs.
> Is it possible to modify v4l2-ctl source to disable system logging?
$ v4l2-ctl -d /dev/video0 -T
which calls the VIDIOC_G_TUNER ioctl(), can be used to tell you if a
signal is present:
Tuner:
Name : cx18 TV Tuner
Capabilities : 62.5 kHz multi-standard stereo lang1 lang2
Frequency range : 44.0 MHz - 958.0 MHz
Signal strength/AFC : 0%/-187500
Current audio mode : lang1
Available subchannels: mono
Signal strength will be 0% or 100% - both the cx18 driver and the
cx25840 driver behave the same in this regard.
AFAICT, other than --log-status (the VIDIOC_LOG_STATUS ioctl()) which
always writes to the system logs, there is no way for a non-root user to
read out the Video standard detected by the CX25843 hardware. That
would require a change to the driver(s) and maybe an API change (I'm not
sure).
Regards,
Andy
>
> Regards,
> Gregor
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: disable v4l2-ctl logging --log-status in /var/log/messages
2009-03-12 23:34 ` Andy Walls
@ 2009-03-12 23:39 ` Hans Verkuil
0 siblings, 0 replies; 6+ messages in thread
From: Hans Verkuil @ 2009-03-12 23:39 UTC (permalink / raw)
To: Andy Walls; +Cc: Gregor Fuis, linux-media
On Friday 13 March 2009 00:34:43 Andy Walls wrote:
> On Thu, 2009-03-12 at 10:49 +0100, Gregor Fuis wrote:
> > On Thu, Mar 12, 2009 at 10:28 AM, Hans Verkuil <hverkuil@xs4all.nl>
wrote:
> > >> Hello,
> > >>
> > >> Is it possible to disable v4l2-ctl aplication logging into
> > >> /var/log/messages.
> > >> I am using it to control and monitor my PVR 150 cards and every time
> > >> I run v4l2-ctl -d /dev/video0 --log-status all output is logged into
> > >> /var/log/messages and some other linux log files.
> > >
> > > All --log-status does is to tell the driver to show it's status in
> > > the kernel log for debugging purposes. It cannot and should not be
> > > relied upon for monitoring/controlling a driver.
> > >
> > > What do you need it for anyway?
> >
> > I am just monitoring if signal is present on tuner, and what signal
> > format is detected.
> > These two lines:
> > cx25840 1-0044: Video signal: not present
> > cx25840 1-0044: Detected format: PAL-Nc
> > I run this every minute and it is really annoying to have all this in
> > my system logs.
> > Is it possible to modify v4l2-ctl source to disable system logging?
>
> $ v4l2-ctl -d /dev/video0 -T
>
> which calls the VIDIOC_G_TUNER ioctl(), can be used to tell you if a
> signal is present:
>
> Tuner:
> Name : cx18 TV Tuner
> Capabilities : 62.5 kHz multi-standard stereo lang1 lang2
> Frequency range : 44.0 MHz - 958.0 MHz
> Signal strength/AFC : 0%/-187500
> Current audio mode : lang1
> Available subchannels: mono
>
> Signal strength will be 0% or 100% - both the cx18 driver and the
> cx25840 driver behave the same in this regard.
>
> AFAICT, other than --log-status (the VIDIOC_LOG_STATUS ioctl()) which
> always writes to the system logs, there is no way for a non-root user to
> read out the Video standard detected by the CX25843 hardware. That
> would require a change to the driver(s) and maybe an API change (I'm not
> sure).
There is a VIDIOC_QUERYSTD ioctl. However, neither ivtv nor cx25840 supports
that. I've always thought that that would be a useful addition, but never
got around to implementing it. You are the first one for whom such an ioctl
would actually be useful, Gregor :-)
It should be fairly easy to add this, but I really don't have the time for
this I'm afraid.
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG
^ permalink raw reply [flat|nested] 6+ messages in thread
* disable v4l2-ctl logging --log-status in /var/log/messages
@ 2009-03-12 9:24 Gregor Fuis
0 siblings, 0 replies; 6+ messages in thread
From: Gregor Fuis @ 2009-03-12 9:24 UTC (permalink / raw)
To: linux-media
Hello,
Is it possible to disable v4l2-ctl aplication logging into /var/log/messages.
I am using it to control and monitor my PVR 150 cards and every time I
run v4l2-ctl -d /dev/video0 --log-status all output is logged into
/var/log/messages and some other linux log files.
Best Regards,
Gregor
^ permalink raw reply [flat|nested] 6+ messages in thread
* disable v4l2-ctl logging --log-status in /var/log/messages
@ 2009-03-12 9:14 Gregor Fuis
0 siblings, 0 replies; 6+ messages in thread
From: Gregor Fuis @ 2009-03-12 9:14 UTC (permalink / raw)
To: linux-media, video4linux-list
Hello,
Is it possible to disable v4l2-ctl application logging into
/var/log/messages.
I am using it to control and monitor my PVR 150 cards and every time I run
v4l2-ctl -d /dev/video0 --log-status all output is logged into
/var/log/messages and some other linux log files.
Best Regards,
Gregor
--
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Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/video4linux-list
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-03-12 23:38 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2009-03-12 9:28 disable v4l2-ctl logging --log-status in /var/log/messages Hans Verkuil
2009-03-12 9:49 ` Gregor Fuis
2009-03-12 23:34 ` Andy Walls
2009-03-12 23:39 ` Hans Verkuil
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2009-03-12 9:24 Gregor Fuis
2009-03-12 9:14 Gregor Fuis
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