Low-resolution captures...why?

[Pace]

I've been thinking about changing my Firewire card to something better than the generic Taiwanese one that came with my sisters Canon MV400i (see <a href="http://forums.murc.ws/showthread.php?s=&threadid=30359">What IEEE1394 (FireWire) card do you recommend?</a>).

However, a little birdy tells me that my low res capture problem isn't because of my ("crap") card, but probably the software side. A search provided me with the Doc's opinion that DX7 was a bit poor for this, so I ran to dxdiag to check...but alas, I'm already on DX8.1.

OHCI cards work just fine if you have a decent DV codec to use with them. The one provided with DirectX 7 and earlier was drekware. The one that comes with DirectX 8 is much better, so an update in that direction should be considered.

For those who don't know, I can only seem to capture at 360x288 from two DV/D8 cameras I've used, and I'd much rather be getting 720x576

Off to play around with my settings in Windows, been through Device Manager and DXDiag so far...

Thanks in advance,

Paul.

Edit: PS: I've downloaded the PICVideo Motion JPEG codec, but, alas(!), it appears that registration is no longer free.

[dZeus]

How do you know that the captured data is half res?

Many software DV codecs for playback, play back at half res, even if the source is full res. (and you can often set the playback res. in the codec properties).

[Pace]

Hail Frank the King!

Ok, never thought it'd be playback problem

Went into WMP6.4 playback and there was the option! It was the fact it reported the video as being 360x288 that put me off! However, the video doesn't seem quite "right". As in, there are lines on the output - is this a WMP codec problem, or capture problem?

[Dr Mordrid]

It's a combination of DirectShow and lousy coding on the part of Microsoft for MediaPlayer.

What happens is that the WMP default half size playback setting gets "stuck" in DirectShow's defaults and affects the MSPro preview function which also operates using DirectShow's DV filter. This can cause all manner of problems.

Setting WMP to full frame takes care of the problems in MSPro.

In WMP 7.x this can be found in the Tools/Options/Performance tab. You turn the Digital Video slider to LARGE. This fixes MSPro, but DV still plays half size in WMP. Go figure.

Another fix you can use at your own risk is to copy the following to a Notepad file saved as "fullDVsize.reg";

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\DirectShow\DV DecProperties]
"PropDisplay"=dword:000003e8

Running this sets the registry's DirectShow DV decoder settings to full screen display. Works a bit better than using the WMP settings as it acts directly on DS.

Dr. Mordrid

[dZeus]

Re: Hail Frank the King!

Originally posted by Pace
...
However, the video doesn't seem quite "right". As in, there are lines on the output - is this a WMP codec problem, or capture problem?

It's because of the nature of the video camera and how it records video. What you're seeing is 'interlaced' lines. It's a bit difficult to explain in not too many words, but it all comes down to the fact that TVs only display half of the lines (which are all of the same 'timeframe', called 'field' in right terminology) at a time, thus you won't see it when you output the video to a TV through DVD-MAX on a Matrox card (with 'field scaling' enabled in DVD-MAX properties).

Some DV cameras allow you to set 'progressive' mode, which will have the effect that you will have twice as many lines at each 'timeframe' that the camera records motion, but only half as many 'timeframes' a second that the camera actually records motion at all compared to 'interlaced' mode.

You shouldn't worry too much about interlaced output when previewing it on your computer monitor, as long as the target video you want to output your project in MSP (or whichever video editing tool you use) is MPEG2, since all Software DVD players have build-in de-interlace filters (because DVDs often also have interlaced MPEG2 streams). If you want to output to MPEG4, then you should apply a 'deinterlace' filter in MSP or the like, prior to converting the project, if you can't set your camera to 'progressive' mode (in that case the latter is adviced for this purpose).

You might even be able to view the DV 'deinterlaced' by using both the software DV codec for playback and a software de-interlace filter called 'DScaled' (search on google ). I don't know how to use this, but I've read that it's supposed to deinterlace the output of whatever video codec you want.

Btw. if you want to 'preview' the video with correct aspect ratio, since I assume that the software DV codec doesn't rescale the input, I advice you to use the Sasami2k player, and force Aspect ratio to 4:3. This is, because DV doesn't use a square pixel-format for representation of the video image. i.e. 480x576 (the stored image pixels in a PAL DV stream), are not 4:3, but 768x576 is (and sasami2k can rescale the software DV codec's output to this resolution if you force the 4:3 aspect format).

Have fun editing DV!