View Full Version : Deinterlacing Questions?


Mark Ortiz
January 18th, 2007, 04:41 PM
Hi,
I'm a little new to the world of HDV, am looking for a good prosumer camera to buy, and would like to know if anybody has any experience with the Sony Professional HVR-A1U CMOS? Is it a good buy for the money?

I would eventually like to be able to use After FX to combine some computer animation w/the video that I shoot, however I am concerned that the HVR's interlaced picture might make this difficult to do.

As I said I am a little new to the world of HDV, and am by no means an authority on deinterlacing. One website I checked out seemed to imply that it can be done using a combination of VirtualDub, Divix, AviSynth, and ZoomPlayer. Has anybody out there used this method, and if so did it 1) produce decent results, and 2) was it fairly user friendly?

I don't want to spend a lot of money on an HD camera if I can't add any animation to what I shoot.

Thanks,
--Mark

Graham Hickling
January 18th, 2007, 09:10 PM
It is certainly possible to get a good result deinterlacing the A1's 1080i footage - and Virtualdub in combination with a smartdeinterlacer plugin is one of the most straightforward ways to achieve that. The A1 also has a pseudo-progressive Cineframe mode that might work for you but isnt all that great.

So ........ I wouldn't really factor that into your choice of camera unless you need a LOT of deinterlaced footage - think more about camera size, handling, lowlight capability, manual control etc etc.

If you MAINLY want progressive footage, then perhaps look at one of the JVC, Sony or Canon models that do offer true progreessive. Indeed, you could get a JVC HD1u on Ebay for less than half the price of an A1, and it has a nice 30P progressive image, though this camera is bulkier and has some limitations relative to the A1.

Mikko Lopponen
January 19th, 2007, 06:35 AM
Adding animations and tracking footage with the a1 maybe a bit more difficult because it has a rolling shutter. i.e, upper part of the picture is later than the lower. This will cause headaches after deinterlacing and definitely makes tracking harder.

Also remember that mpeg artifacts maybe more distracting when working on a frame by frame basis. If you're doing simple stuff then the a1 will satisfy your needs. The hc1 satisfies mine, although I'm looking at the canon xh a1 and drooling.

Wes Vasher
January 19th, 2007, 09:21 AM
Magic Bullet and Deartifactor from Red Giant work wonders on HDV footage. The processing time is pretty long but for VFX shots they can't be beat.

Mauritius Seeger
January 23rd, 2007, 10:02 PM
one thing to consider: you should be able convert interlaced HD (60i) to progressive SD (60p!) virtually without loosing much quality when compared with SD video recorded directly in progressive. with twice the frame rate to boot.

this is because each HD field - although only half the resolution of an HD frame - is still 1080 /2 = 540 lines, which is not much less than the DV standard 576 lines in a progressive SD frame. so an HD field should convert nicely to an SD frame. for 30p you just chuck half the frames away. or you can leave them and play back at half the speed, i.e. smooth slow motion.

in short, what i am saying is you can use your HD camera as a quasi-progressive SD camera with overcranking. assuming you can make do with SD.