help required for capturing DSL box

[kumkum2]

Hi,

I'm curently trying to capture so TV records from a DSL box (french freebox).
But I've got some interferences, and not a good result.

Here's my conf:
- athlon 1,.3ghz, 512 Ram, windows XP
- tested softwares : dscaler, virtual vcr, iuvcr, ktv, virtualdub
-capturing with huffyuv, and no compression on the audio
-the software are set to capture PAL 60Hz

the acquisition card is an old MIRO PCTV PCI, connected with SVIDEO cable.
The audio is taken by a jack to the line-in of the sound card

My problem do not concern audio (not yet :)), but the video.
With all the softwares I 've got the same problem: some sort of interferences (lines) around the characters, escpecially when they move (for the moment I'm doing tests with cartoons)

I was first thinking to interferences coming from the SVIDEO cable, so I bought a very expensive gold one : nothing changed...

On another hand I have noticed that the problem was almost inexistant when I was capturing with smaller pitch (320 or 340 lines for example).

But I would rather capture with 720 lines (there is also one on the soft - don't remember which one- who looks to be abble to capture in 756 lines...)

Does anybody recognize the type of interference ? (see the images)

Is it something that deal with interlacing ? I do not think, because it would be regular in the video and on all the picture ...?

Could that come from a lack of power ?
if yes, what is not enough powerful : the computer or the acquisition card ?

Could that come from the huffyuv codec (that would take too much processor time...) ?

Could a recent usb acquisition module perform much better on that case ?

Thanks a lot for your help!!

kumkum

[Ghitulescu]

In my experience, these are voltage peaks - their source can be anything from a hairdryer on the same powerline to a motorcycle on the street, passing through a defective DSL box.
That you won't see then in 320i is due to interpolation.

Either solution require more money and lost time than the mere buy of the DVDs, which BTW would also give you a better quality than you can ever achieve using the analog capture. I "tape" (I have a DVB-S2 PVR) myself only the live events, that are extremely improbable to ever appear on DVD/BD or any succesor.

[kumkum2]

thanks for your advice on dvd buy, but it was not really the point...

regarding the voltage peaks, it's a interresting idea. but what is strange is that it really seems to appear when there are "moving characters"...
What is strange also, is that I do not have that kind of interferences when capturing from VHS tape.
I will try to unplug the most of electrical devices in the area to see if it change something.

any other idea ?

thanks again

[GrofLuigi]

Insuficient PCI bandwith.

This was a known problem with computers of that time (I encountered it on VIA motherboards).

Try increasing PCI latency (general - for all devices in BIOS, if there is such an option, or for the MIRO device - PowerStrip can do it, or try to find another program; PCI Latency Tool aka PCI Latency Config was one such fine tool, getting increasingly difficult to locate these days).

IF (motherboard=VIA) THEN try this (http://www.georgebreese.com/net/software/#PCI). :)

Usually the video card grabs all the bandwith. Try to take some away from it. IF (videocard=NVIDIA) then try PciLatencyTimerControl registry tweak.

Sometimes physically moving the card into another PCI slot can help. Sometimes nothing can. :scared:

GL

[kumkum2]

Very interrestin suggestions!

my video card is Nvidia (on the motherboard)
the motherboard is asus a7n8xe deluxe.

I will try your suggestion, but until now, I have never tried to tweak that kind of parameters
I think there are such ones in the bios

In relation with the other suggestion, I have also decided to buy some normal power plug for my box (it is currently using PLT power plug, and that could bring some interferences...)

thanks

[GrofLuigi]

Nforce2 chipset. Disregard everything about VIA.

Pci Latency Tool might help you. It's here (http://downloads.guru3d.com/download.php?det=951).

And a kind of a longshot - the CPU speed seems a little low for that generation. Are you sure there isn't some misconfiguration in the BIOS? (On the other hand, everything could be normal, just a rare setup or my hunch is wrong).

GL

[kumkum2]

And a kind of a longshot - the CPU speed seems a little low for that generation. Are you sure there isn't some misconfiguration in the BIOS? GL

well, I'm not sure, I've never touched the bios, and never tried to overclock the CPU...
What should I look for as misconfiguration ? (I'm not on my computer right now, I can only test it this evening)

[GrofLuigi]

well, I'm not sure, I've never touched the bios, and never tried to overclock the CPU...
What should I look for as misconfiguration ? (I'm not on my computer right now, I can only test it this evening)

OK, don't touch it if you're not sure. You could fry it.

GL

[kumkum2]

fantastic answers!!! that was it!
I made first tries by playing with these parameters and it change a lot!
First I've used the PCI tool to check or the current latency settings (after a piece of reading on the net...)
I had 3 latency different of 0:
- Pinacle Miro : 64
- Geforce mx440 : 248
- nvidia nforce2 AGP to PCI : 32

So I decided to change the settings "Pci latency" in the bios: from 32 to 248.
Back in windows, it showed the change in "nVidia nforce2 agp to pci" (updated to 248)

I made some capture tries with Dscaler: almost not anymore interference!!!
but , strangely, I did not managed to capture in 720*576 with other software (virtualVCR or virtualdub).
With Dscaler, I'm using a kind of specific driver for the Miro PCTV (that is to say not the WDM drivers of windows).

I would rather capture with virtualdub or virtualVCR, as I'm sure that there are not deinterlacing filter applied (I don't know if it is possible with dscaler to capture without deinterlacing).

So apparently the WDM drivers was not responding anymore for the big resolutions (ok for the small ones :320...)
It's a first try.
I will maybe try to do the reverse thing : set back to 32 in the bios, and trying to decrease to 64 AGP 440mx with the PCI latency tool) to see if it works better.
What do you think of these results? any advices ?

thank you so much again!!

[GrofLuigi]

Good job. There is a change because you modified their relative latencies to each other. :)

I would go for:

- Pinacle Miro : 128-248
- Geforce mx440 : 64-192 (don't reduce it too much or you'll have framedrops on playback)
- nvidia nforce2 AGP to PCI : 32 (it doesn't matter OR it helps mx440 :))

I don't think DScaler deinterlaces during capture (although it's a deinterlacer :p)

GL