XDCAM HD downconversion to SD

[Eugene Kosarovich]

Any recommendations on which deinterlace setting to use, blend or interpolate, when using XDCAM HD footage (1440X1080i) and producing widescreen DV output?

I've read the general advice in the Vegas in-line help that blend is better for "higher resolution and slower movement" and interpolate is better for "lower resolution and faster movement". The "lower resolution" being because it throws away a field. But for going from 1080 to 480, I assume one would have to throw away a field anyway.

So my question is, since my projects are never just slow movement or fast movement, but typically always a combination of both, what would be the best deinterlace mode to set and leave for XDCAM HD to SD downconversion?

Thanks.

[Douglas Spotted Eagle]

did you shoot progressive or interlaced in the XDCAM?
And...widescreen SD can remain interlaced if you'd prefer.
That said, you've got the idea exactly right, except that you don't need to worry about resolution; your source is high resolution so it will downconvert very nicely in most cases, and will deinterlace very nicely from HD to SD.

[Eugene Kosarovich]

I shot the XDCAM HD as interlaced.

My downconverted widescreen SD is interlaced as well.

But I thought I still need to specifiy a deinterlace method for Vegas, since in the resizing to half the normal vertical resolution, going from 1080 to 480, it's going to deinterlace when doing this scaling. Isn't it?

I tried the three different choices of none, blend, and interpolate in my SD widescreen project with the XDCAM HD footage, setting preview to best and doing a render to RAM so I could play in full quality via firewire to my NTSC monitor.

I found that the blend and interpolate both looked good and "fluid" in downconverted interlaced. I found that the none option didn't look smooth, like it had become progressive, which wasn't my intent. It just didn't look naturally fluid like the original interlaced HD did. (No offense to people that love the progressive look, I just didn't want it in this case.)

That's why I assumed I need to pick blend or interpolate for this type of project.

Though like you point out, going from HD to SD, maybe it doesn't really matter which of the two I choose.

But aren't I correct that I do need to choose one of those and not "none" to keep the motion and cadence like the original footage?

Thanks.

BTW, great meeting you at NAB at your seminar on the new hybrids! :)