1080 24p HDV, how to render.

farss wrote on 3/7/2007, 3:57 AM
How is this supposed to work in Vegas 7?
I'm starting from 25p, convert to 24p as recommended by stretching the clip. Looks perfect. Tried rendering to a number of mpeg HD templates and the results are tragic compared to the original on the T/L.

I'm getting interlace combing (yeah, really) and the macroblocking is woeful. Why do the default templates have the Quality slider set to 50%, I've put it back to 100%, is that a problem.

It looks almost like pulldown has been added and then the fields compressed as frames, that'd explain why things are falling apart.

Bob.

Comments

ForumAdmin wrote on 3/7/2007, 6:50 AM
1080 24p HDV render- you are printing the timeline to what device?

I ask this because if you are trying to go out to a V1 and then lay that off to HDCAM or similar, there's no way to get true 24p out of the V1, either via component or HDMI.

You can create a 24p file master at HDV-like bitrates for XDCAM HD- just use the HD 1080-24p template. Customize it to 35mb for best quality.

MH_Stevens wrote on 3/7/2007, 7:15 AM
Bob: I've always wondered why quality defaults to 50% too. Did you try converting to 24p in the render and not this clip streaching that I dodn't understand. ie Render the 25p timeline to a 24p template.
farss wrote on 3/7/2007, 11:16 AM
Initially I wasn't planning on any PTT, just wanted to get a rendered 24p clip. Then I was indeed planning to PTT on a M15 VCR.
I'd planned on adding pulldown to 60i.

I'll try your suggestion using XDCAM HD.

Thanks for the prompt reply.
farss wrote on 3/7/2007, 11:25 AM
Rendering the 25p to 24p means that you preserve the length and the audio but the vision is interpolated.

'Clip stretching' means you keep the exact same number of frames. The video runs around 4% slower, the clip is 4% longer. Any audio will be pitch shifted or you can decide to live with the pitch shift.
This 25p to 24p conversion is the inverse of what telecines do in PAL land. It's very easy to do in Vegas, manual covers it quite well although it took me a few minutes to grasp how it works.

You can really only do this say between 24fps and 25fps, going 25fps to 30fps you need to interpolate as a 20% speedup for most things is way too much.

Bob.
farss wrote on 3/7/2007, 5:07 PM
After a little fiddling around I've been able to convert 25PsF from the V1P to a 24p/60i m2t file.
You can download it from here.
Warning large file, 66MBs.

Dropping it back into a Vegas 24p HDV project with pulldown removal enabled it looks pretty good although I've yet to view it on a full 1080 monitor. Footage was shot with 360deg shutter so it looks pretty 'filmic'.
And no I haven't gone over to The Dark Side of 25fps, just that 24p is about the only thing that lets you preserve true progressive, so far, as of this writting, probably subject to change at NAB :)

Bob.