How are people configuring for interlaced displays? (1 Viewer)

[Lars E.]

I have a very good CRT TV which I have connected to my ATI X800 S-video output. I believe I have actually made the X800 send a proper interlaced signal to the TV as elements of single pixel height are flashing.

When I watch TV through MP it looks as if there have been some deinterlacing somewhere, even though I have tried to turn it off everywhere I can find.

As my analog antenna provides me with interlaced TV and my CRT is interlaced as well I would like to avoid deinterlacing. I would believe there's quite a few people out there in the same situation as me, how have you configured your solution?

Best Regards,
Lars E.

 

[CHli]

Which TV MPEG2 codec are you using ?

 

[Lars E.]

I am using MPV.
(Sorry I'm not posting my complete configuration, but my HTPC isn't booting at the moment...need some safe mode work)

Let me add that I am not sure exactly what happens. What I am seeing through MP is not the typical deinterlacing artifacts. Neither is it very bad as deinterlacing artifacts usually are, but fast-moving objects like footballs and snooker balls seems to be somewhat fuzzy/dull - at least more than when viewed directly from the antenna (I did a side-by-side comparison).

I also played with the deinterlace option inside MP and was able to produce real bad deinterlacing artifacts.

I tried setting encode quality to high in case the encoder was involved. but that didn't help either. Hm, maybe it is possible to fiddle with the capture card encoder as well.

 

[elorentz]

What kind of TV tuner do you use ?

 

[Lars E.]

Tuner is a Hauppage 500.
CPU is an AMD X2 3800+, 2GB RAM.

 

[elorentz]

I think that the signal get's deinterlaced by the PVR card, I might be mistaken though.

 

[Lars E.]

HTPC finally running again. Strange problem happened where I first couldn't change channels, then all channels were noise only. After reboot MP kept locking up the PC. Reinstalled MP, now it works - but lost TV channels, that is, the channel names were still there but noise only. Reentered frequency of each channel and it worked.

I do not think the signal is deinterlaced by the PVR card - or at least hope not.

I found that I could set card quality to high in the setup. This improved quality, but I still have excessive motion blur compared to my direct antenna connection. Still missing some sharpness as well. The picture is actually darker as well, but that could be some gamma adjustments in the ATI driver.

Now I found the Hauppage tweak tool and noticed there are settings available for temporal filters, sharpness etc., but at the moment I need to power-cycle myself so on to that tomorrow.

 

[mPod]

The movie gets deinterlaced by the MPEG codec you use and produces 50 frames per second. The output of your gfx card interlaces it again to 2x25 frames. At the end you have exactly the signal on your TV as it is in the MPEG. This sounds a bit weird at first, but this is how it works when you wanna output interlaced material with the TV output of your gfx card.

This is my setup:

nVidia 6600GT
PureVideo codec
MP configuration.exe/Television/Deinterlacing mode: NONE
MP configuration.exe/Decoder Filters/NVIDIA/De-Interlace Control:
AUTOMATIC
MP configuration.exe/Decoder Filters/NVIDIA/De-Interlace Control: VMR DEFAULT

These settings let the card do all deinterlacing in combination with the PureVideo codec being used and take advantage of full hardware acceleration when deinterlacing. This gives you the perfect image for tickers or fast camera movements.

This is just an example, as I could read you're on ATI. But maybe this helps you as a guide, you can set up other codecs to behave the same... (WinDVD, PowerDVD, should also work somehow with MPV)

Enjoy

 

[Lars E.]

OK, if I understand you correctly it is the MPEG decoder (not the encoder) that deinterlaces.
What sort of deinterlacing should that be? Bob? Weave?
If it is Weave I don't understand how the gfx card knows which field to pull from which frame. Doesn't it need to know that?

I will also hook up an oscilloscope to my S-video to check if it is actually 50Hz. If it is 60Hz that could give some strange motion artifacts. Maybe this is the time to buy a PC-based oscilloscope .

The Hauppage tweak tool didn't help me. There were settings for both sharpness and temporal filtering, but it didn't seem to do anything.

Thanks.

 

[mPod]

BOB, if you can't let your gfx card decide (see my example config above).