[mythtv-users] HD-PVR recordings oversaturated

Michael T. Dean mtdean at thirdcontact.com
Mon Aug 29 17:20:13 UTC 2011

On 08/29/2011 11:26 AM, Jerry Rubinow wrote:
>> On 29/08/2011 12:56 AM, Jerry Rubinow wrote:
>>> On Sat, Aug 27, 2011 at 12:28 AM, Jerry Rubinow wrote:
>>>>      On Fri, Aug 26, 2011 at 11:28 PM, Jerry Rubinow wrote:
>>>>> I just upgraded the firmware on my HD-PVR from version 0x12
>>>>> May 7, 2009 to the latest from the Hauppauge web site, 0x17
>>>>> July 27, 2011.  Now all recordings from the HD-PVR are way
>>>>> oversaturated.  Catting /dev/video0 and playing the file with
>>>>> vlc yields the same result.  According to v4l2-ctl -l, the
>>>>> settings are all at defaults.
>>>> I tried adjusting the brightness and contrast in the channel
>>>> change script, via:
>>>> /usr/bin/v4l2-ctl --device=/dev/video0 --set-ctrl=brightness=100
>>> It seems like Myth must be setting the hd-pvr to a default state after
>>> running the channel change script.
> That's an excellent kludge, thanks for the idea.  I'll try that out tonight
> and hopefully that'll last until I'm able to find older firmware or
> otherwise figure out why this started happening.
> Janne, Jarod, or anyone who's familiar with the driver, any ideas?  Is there
> a potential kernel incompatibility with the firmware?  I wanted to save
> doing a full system update as a last resort since things are otherwise
> pretty stable.

I'm definitely not "anyone who's familiar with the driver", but I will 
say that for other analog encoders (such as the IVTV devices), MythTV 
always sets the contrast, brightness, color (or colour, as the case may 
be), and hue according to the values you specified--which all start at 
default values.

You can change the default values by using G in Live TV playback to set 
the capture card picture controls.  Note that this will not work on a 
digital capture device (DVB/ATSC/QAM/Firewire/...) because those aren't 
actually recording the video, but just writing the provided recorded 
video stream.

Using G to set the capture card picture controls differs from using F to 
set the playback picture controls.  F is used in Live TV or recording 
playback to change the contrast, brightness, color, and hue at 
playback--and affects playback of all recordings and videos, regardless 
of channel and capture device.  Note, also, there's a per-channel 
picture control available, in which you can specify contrast, 
brightness, color, and hue for individual channels using the 
mythtv-setup or MythWeb channel editor.  You also don't want 
this--especially if you have, for example, an IVTV card recording from 
the same channel.

I don't know if this applied to HD-PVR, but before you go and set up a 
hack, try G--and then tell all the others who are using the hacks if it 
works properly for the HD-PVR.  :)


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