Black border on top and left of Marvel MJPEG projects...

[Aryko]

I've also noticed that this effect changes from signal to signal. For example, while watching TV, I noticed that a commercial would be misaligned over to the right by about four lines, then it would pop back to normal for the show, then down a bit for another commercial... could it have something to do with differing formats between television production types?

I'm not sure if adding a way to control the input position to the next driver set would help much in that case, but if you were consistently down and right a few lines when capturing from your Hi-8 camcorder, then yeah, it would.

- Aryko

[Grigory]

If input alignment is possible in software, it is possible to create different profiles for different sources.

We cannot see a shift on normal TV monitor. Who cares what is outside the visible range?

BTW, is this downleft shift reproducible for all commecials? A good way to detect them and remove!

Side note:
I suppose that DV equipment from Sony uses the same chip in DV to analog coding.
Does it necessarily mean that all Sony DV camcorders will have same downleft shift on Marvel (Bt848, Canopus Raptor analog overlay channel, other devices)? Note, the shift is present on all analog-to-PC capture devices I have seen, and has same value and sign.

Grigory

[A_BIT]

It's true you don't see the border on normal TV, but for moving path it is a big problem. Maybe cropping is the solution for that. I would like to see a realtime crop during capture instead.

-Anthony

[Aryko]

Grigory,

I'll have to do some serious TV watching to see if it's reproducible for all commercials. Wouldn't that be a treat!

- Aryko

[Grigory]

Hi,

The borders are present on any movie I can capture with any device. Even "pure digital" firewire DV frames have two-three top black lines. So, the presence of black borders is a kind of invetitable thing.

They are a problem in production of any PC screen movie, and for any moving frame effect, I agree.

It becomes especially bad for making fixed size interlaced movies like MPEG2, if you want to play them on PC. Cropping without resizing keeps correct field order, but is not usable for correct playback. Cropping with resising to standard height may introduce flickering because for mixing two fields in a frame.

The only solution I know is to replace black borders with flickering top lines by regular border having the heigth in multiples of 16.

This ensures that the border itself will not introduce compression artefacts because of sharp vertical transition from black to bright at the top of frame.

Cumulative shift makes the life even more difficult. Unfortunately, there is no regular workaround.

Grigory

[Aryko]

Well, I think having video input position control in a new driver set would go a long way to helping avoid this problem at the outset.

What's the other option, to apply a static moving path to your captured clips to center them? Wouldn't there be a corresponding white border on the bottom and right sides?

- Aryko

[Grigory]

You can apply clip filter in Premiere to moving frames. Set the border color and make it transparent.
This does not introduce field order or incorrect movie frame size problem.


Grigory