Deinterlacing PAL miniDV

[IceBone]

My miniDV cam records into interlaced PAL and i was just wondering if there's a better way or if not better, a faster way to deinterlacing the video than tomsmocomp(-1,5,1). Now i get stuff like this every few frames:

http://icebone.dyndns.org/deinterlaced.png

Cheers!

[Adub]

You say it is every few frames, are you sure it is not telecined? I know that is weird on a dv camcorder, but if it only happens on every few frames, then it might be telecined.

Can you find any recognizable pattern? Like 3 good frames and then 2 "bad" ones?

[Mug Funky]

more details plz :)

if you're using a recent panasonic DV camera, it's possible you're getting 4 progressive to 1 interlaced frame pattern (2:2:3:3 pattern, rather than 3:2 to be specific).

if this is the case you can safely just drop every 4th frame and keep the framerate at 24fps.

to do this, use this line:

selectevery(5,x), where "x" gets changed until you see no interlaced frames (ie, load the script with it 5,0 and then try 5,1, 5,2, 5,3, etc until there's no more interlaced frames).

to be safe, post a short unprocessed sample of about 100 frames so we can take a closer look and cut the guesswork

[IceBone]

nah, every frame is interlaced, but after deinterlace, i get that weird corruption.

i'll post a sample in the morning.

edit: my gf's new cam also records into interlaced pal (every frame) and after tomsmocomp (-1,5,1) the picture is smooth in every frame.

[communist]

Have you tried with TomsMoComp(0,5,1)? Just to make sure its really deinterlacing with BottomFirst.

[IceBone]

I'll give it a try, but first here's a 100 frame clip as requested. I transcoded it into Qt 2.0 XviD with interlacing.

http://icebone.dyndns.org/interlace_help.avi

would that be good enough or do you need completely unaltered?

EDIT: that clip doesn't really show the error, one moment...

EDIT #2: ok, replaced it with the same clip that the initial screenshot was taken from. The contrast between the lcd screen's edge and the black makes it pop out.

[2Bdecided]

Those artefacts are in the source (or maybe the DV decoder?). Even mcbob struggles.

The reason they're not on every field isn't clear to me, but it's something to do with what you're filming (a PC monitor, which will have its own native refresh rate) and how you're filming it: in the dark (high contrast) with a DV camcorder (4:2:0 colour space) with a fake (not FHA) widescreen effect applied (bad resampling?) while waving the camcorder about!

See which of those factors you have to remove to get a clip without this extreme problem, and you'll have your answer.

Or maybe it's something else.

Cheers,
David.

[IceBone]

Probably all of those combined, however tomsmocomp (0,5,1) handled it better. And the widescreen is just added black bars top and bottom (option on the cam). :)

[scharfis_brain]

it seems like the camera's internal digital image stabilisation messes up with the image.

try to disable it.

[IceBone]

I checked that, but the difference is less noticable, if at all, maybe i'm just imagining things, than switching tomsmocomp to BottomFirst.

thank you all! you've been a big help!