[pvrusb2] Two PVR USB2 unit initially tune PAL as black and white

[Tom Warren]

On 4 May 2011 13:17, Tom Warren <psycadillac at gmail.com> wrote:
>
> Greetings,
>
> I have two WinTV PVR USB boxes I'm using with the pvrusb2 driver which feed into tvheadend playing PAL cable channels. The set up works but I always get the first tuned channel in black & white and have to tune to one (or more) different channels and then go back to the original channel get colour. Occasionally a channel will later go black and white again and I must apply the same fix. Both boxes are the 'new' hardware version.
>
> Could this be a driver problem, hardware problem, or fine-tuning problem??
>
> I saw a post from 2006 that describes a similar issue but using NTSC:
>
> http://www.isely.net/pipermail/pvrusb2/2006-January/000384.html
>
> I'm running Ubuntu server 10.10 64-bit with the driver from linux-s2api-tbs6980-1_20101024 (commercial mod for the Tenow International dual satellite card) in which I made a small modification to set:
>
> .pixelformat    = V4L2_PIX_FMT_MPEG,
>
> ...in the pvrusb2-v4l2.c file in order for tvheadend to recognise it as a valid source.
>
> Since both boxes behave the same way, I suspect this is an issue with the driver. What can I do to debug the issue further?
>
>
> Thanks,
>
> Tom
> --
>

I have tried "pre-tuning" several channels with a script using v4lctl
before launching tvheadend, but this does not solve the problem. I've
compared the settings while B&W vs colour but can't find any
differences. What could be causing this?