How to find capture window of my MSI VIVO card?

[kevinm]

I am trying to find out the capture window for my MSI VIVO card, this is so that I can work out how I should resize my video, as per the following guide :

http://www.doom9.org/index.html?/capture/par.html


(this discussion originally started out in the AviSynth Usage forum but has moved from being a resizing question to a capture question, so in effect this is not cross posting, it is that the original tread has split into two different discussions.)


My capture card is a MSI MX440-VTD8X (MSI p/n ms-8888)

I have found some references on the web suggesting that this MSI card uses a Philips SAA-7114H capture device, but the guides referenced from Doom9 only give capture windows for two other SAA 7xxx devices, unfortunately not the one I am using.

I will open up the case of my computer and try to confirm what my VIVO card uses. Maybe then I can look at the Philips datasheet and figure it out, although I think the 7114 have scalars and other driver programmable modes so I am not sure if I also need to factor in the effects of the (WDM) driver.

I read one article explaining how to use a DVD and test video to determine capture window but I don't have a PAL DVD player to input to my capture card. I suppose I could just ask the manufacturer of my card (MSI) but I don't hold out much hope of getting a reply, especially as this card is now obsolete.

If anyone has any advice or knows the capture window of the MSI card I am using I would be very grateful if you could let me know,

thanks,

Kevin

[matrix]

I suppose you have an ntsc dvd, if you don't have a pal one.
Since you only need to determine the horizontal area, your device captures at, use whatever dvd you have.
The horizontal size is the same for both systems, but you need to find out how many of those 720 pixels, is captured by your card, in order to capture with the best possibile aspect ratio.

[kevinm]

Thanks Matrix,

yes, I only have an NTSC standalone DVD player. I can trick the player to play a PAL disk BUT it will still only output a NTSC signal to my capture card.

If you think I can still use my NTSC player to determine the PAL capture window then I will give it a shot,

Kevin

[matrix]

Yes, I think you can use your player to determine your capture area. Whether PAL or NTSC, the card always captures the same number of pixels.
From the guide:
The raw captured height is always 480 lines for NTSC and 576 for PAL. The width of the capture window has to be determined.
This makes calculating your source PAR easy. Once you have determined the aspect ratio of the capture window of your specific device, you can write it down and you never have to do this again. Calculating PAR simply becomes multiplying this aspect ratio with the vertical size you set and dividing by the horizontal size:
But since you do your test with an NTSC device, I think you should use the NTSC sample provided in that guide.
After you determine the aspect ratio of your capture window, if you capture from a PAL source, you set the vertical size to 576. The horizontal will be the one you determined.
At least this is my understanding of the whole thing.

[mg262]

@Kevinm

One thing I didn't get round to saying in the original thread... I think the settings you originally used would have resulted in aspect errors of ~10-20%... where as even if you don't get the aspect ratio for your card quite right, the error should be ~2-3% as all the capture windows are pretty close to each other. (I haven't really played with the stuff myself, but someone will jump on me pretty fast if that's wrong!) So even if you mismeasure slightly (or use value for a similar card), it's not the end of the world.

[kevinm]

mg262,
yes, looking at what I see on my TV, 20% error would explain the slightly strange picture.
I will ignore the capture window for now, and recalculate the resizing taking the capture window numbers for the SAA-7113 based card that is referenced through the guide. I think I will probably have to end up adding black borders on the left and right side, rather than the more usual black borders on the top and bottom.
Anyway, I will give it a try and see what it looks like.

I am tempted to try filming a piece of grid paper and just seeing what it looks like when I play the resulting DVD on my TV. I know it would not be terribly accurate, many factors would affect the result but I am curious to see what would happen,

Kevin

[kevinm]

Matrix,
thanks for your suggestion. First I will try resizing based on some numbers from a 7113 based card. After that I will try the method to determine the actual capture window of my card. I will use the NTSC sample,

BTW, I checked and my card uses a SAA-7114H codec device,

Kevin

[matrix]

You might have to add borders on each side, but that is not a problem, because part of the picture is hidden by overscan.
I capture at 688x480, and add 16 pixels on each side when encoding.

[Arachnotron]

After you determine the aspect ratio of your capture window, if you capture from a PAL source, you set the vertical size to 576. The horizontal will be the one you determined.Sometimes, a driver uses different capture windows in PAL and NTSC mode. So if you want to test what it does in PAL you need a pal signal.

The 7113 mentioned in the guide had a capture window that was the equivalent of 720 DVD pixels wide, since it did not have a scaler. Your SAA7114 does, so I would guess it is more likely to have a capture window of 704 pixels for both PAL and NTSC, just like most SAA713x chip based cards do. (mind, that all depends on the driver, not the chip).

I would suggest trying the NTSC test DVD in NTSC mode. If you find a NTSC capture window that is 704 DVD pixels / 52.14 µs wide, I think you can safely assume the driver falls in line with the other SAA713x drivers and the PAL window will be the same.

[kevinm]

Arachnotron,
thanks, your assumption sounds reasonable, I will give it a try with my NTSC "test signal",

Kevin