I have installed KnoppMyth and I would like to set the video paramerters
(contrast, brightness, and saturation) so they presist.

I have a prv-350 card. It looks better if I tune the video parameters. I can do this
as follows:

/usr/local/bin/test_ioctl -y brightness=170
/usr/local/bin/test_ioctl -y contrast=90
/usr/local/bin/test_ioctl -y saturation=60

After doing the above:

$ test_ioctl -Y
ioctl: VIDIOC_QUERYCTRL
Brightness = 170
Contrast = 90
Saturation = 60
Hue = 0
Volume = 58950
Mute = 0

After chaning a channel

$ test_ioctl -Y
ioctl: VIDIOC_QUERYCTRL
Brightness = 127
Contrast = 63
Saturation = 63
Hue = 0
Volume = 58950
Mute = 0

These seem to be the default parameter settings.

Can this be made persistant? Where would be a good place to set this sot that
iit would be the bootup default?

Thanks in advance....
Sorry if this is a novice question but I could not find the answer

These are set on a per channel basis for recording (which includes watching live TV). You can change them using the channel editor or from the web interface, but If you have a lot of channels that's going to be something of a project.

On MythWeb the following message appears:

Please be warned that by altering this table without knowing what you are doing, you could seriously disrupt mythtv functionality.

What sort of serious disruption can result?

Thanks,
Mike G.

You could hose you frequency list...

I still don't understand.

Can the frequency list be repaired?

I guess my question is if I play around with the values and at some point use an invalid value that hoses my frequency list, what is the consequence no TV, no TV for that channel, the system turns into a brick.

Also if I do use incorrect values and record a know set of working values, will I be able to go back and backout the incorrect values?

I am trying to understand serious distruption. What does that mean?

Thanks,
Mike G.

Sorry, it was a quick off the cuff answer. There are two ways of looking at this:

1) It's "only" configuration data, you can always reset it:

2) You might "never" be able to get it back to the way it was.

There is some truth to both views. In addition, given pathalogical settings, you might even be able to do something bad to the hardware.

Happily, the layout of the data is pretty sane, rather than mucking with the frequencies directly there are seperate fine tuning adjustments. This helps to seperate out things you fiddle with from things you should leave alone. You can probably even use mythbackup and mythrestore to make it safer by saving your current set up and putting it back if you botch something.

For what you want to do, which is just to adjust the picture parameters for every channel, I'd say it's pretty safe. They all start out with essentially the same set of values. Write down one set for reference, and then have at it. Don't get sloppy about which field you're editting on the form and everything should be fine.

PS - I'd do one or two channels first, and test them before doing the whole list...

PPS - Actually, on my own system I would probably make the change directly in the MySQL db, but I DO NOT recommend that. Unless you're really comfortabl;e with that kind of low level hacking it's much too easy to seriously hose your system that way (as in "wipe the disk and reinstall" to recover). If you have to ask how, it's probably not for you.

ok thanks for the information.

I have a couple more questions.

1. freqid what are the range of valid values? What is an acceptable increment to use to tune the frequency?

2. brightness, contrase, colur and hue have a default value of 32768. Is the range for these values 0 - 32768 or 0 65536? also what is an acceptable increment to test values.

Thanks,
Mike G.

Don't mess with the frequncy unless you have to. I have two channels which had a distorted signal (vertical bars of yellow) because my cable companies equipment is out of spec. and a finetune value of 25 was plenty. However, unless you're seeing "out of tune" noise in the picture, leave it be.

Never having messed with the brightness, colour, contrast or hue controls here I have no idea how much you should tweak them. You will have to experiment. Given such big numbers I'd guess that 100 might make a reasonable step size.