[mythtv-users] Video noise or distortion across very top edge of image

Johnny Walker johnnyjboss at gmail.com
Fri Nov 20 17:09:13 UTC 2009

Oh that's great news about the HDMI not being a pain. My frontend is
actually an ASUS M3N78-EM motherboard so that's great.

I'm also familiar with nvidia-settings I've just never messed with overscan.

I'll try this when I get home.

I'm also seeing the following in the dmesg on the backend:

[  128.035461] hdpvr 1-4:1.0: untested firmware version 0xf, the
driver might not work
[  128.333099] hdpvr 1-4:1.0: device now attached to /dev/video0

I assumed I had the latest firmware since my HD-PVR purchase was 1
week ago. Message threads seem to indicate that this message appears
if your firmware is too recent. Does anyone know what version 0xf
equates to and if I need to find a Windows machine to upgrade the
firmware on my HD-PVR with? The only windows machine in my house my
partner's laptop running Vista. Is Vista even a supported OS for the
firmware update or do I need to temporarily load XP on a spare

On Fri, Nov 20, 2009 at 10:58 AM, Travis Tabbal <travis at tabbal.net> wrote:
> On Fri, Nov 20, 2009 at 9:49 AM, Johnny Walker <johnnyjboss at gmail.com>
> wrote:
>> I've got the HD-PVR running on Component capture of a Motorola DCX3200
>> on a dedicated backend.
>> I've got a dedicated frontend using VDPAU and 0.22 compiled from source.
>> Channel 222 is CNN Headline News (love my Robin Meade). I am seeing
>> some sort of video noise or distortion across what seems to be the
>> very top pixel of my playback image. This happens in LiveTV and also
>> on Recording.
>> This morning I used the Shutdown-Menu on the Motorola DCX3200 to tell
>> the STB that my TV only handles 1080i and 720p which finally got me a
>> full screen image on my Samsung LCD Television. Now that Samsung is
>> connected to frontend using the VGA dsub. The max resolution on this
>> Tv is 1368x768 so I wasn't going to mess with the HDMI out on my
>> frontend's motherboard.
>> The motherboard is an ASUS with an onboard nVidia as follows from lspci:
>> 02:00.0 VGA compatible controller: nVidia Corporation C77 [GeForce
>> 8300] (rev a2)
>> VDPAU seems to be working ok out of the box - the distro is MythBuntu
>> 9.10.
>> I tried adjusting the Vertical offset in the Setup-->Playback menu. I
>> moved it from 0 through 10 (trying each incrementally) and I wasn't
>> able to notice any difference. It does seem that each time I invoke
>> the LiveTv mode I may get a more or less dramatic experience of this
>> noise.
>> Does anyone know what this is and how to go about resolving it?
> Sounds like the Closed Caption data. You don't normally see it because of
> overscan. Try the newest NVidia drivers and see if you can get it to
> overscan the TV output just a little to get that row of pixels out of the
> visible area of the screen. When using VDPAU, you can't use the scaling and
> such built into Myth from what I've read on the list, so you need to use the
> drivers to do it. Both of my systems overscan way to much by default, so I
> use the "Overscan Compensation" in the Nvidia X setup utility to set it so
> that I just just a little overscan, so I don't see that line but I can see
> all of the image.
> You might have more luck getting overscanning on HDMI as the VGA output
> might not support it (it's not generally done on computer monitors). Modern
> video cards like the 8300 work pretty much out of the box with HDMI. I
> didn't do any setup to get it working on my machine other than making sure
> the NVidia driver was installed. Even BIOS/POST show up over HDMI now.  One
> of my frontends uses an Asus M3N78 with the onboard 8300 chip. Works great
> with HDMI. I'm not using HDMI audio, so I can't speak to that. That TV is
> just using the TV speakers, so I used analog stereo out for it.
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