reuse rendered frames?

[amiga78]

I was under the impression that DCP-o-matic reused rendered frames when a I wanted to make a second DCP from the same project, but twice now it has rerendered all frame from scratch on the OSX version 1,730.

What I do is that I from a 25FPS MOV source first render a 25FPS DCP that takes 12 hours and I then change the frame-rate to 24FPS for compatibility with old DCP players and expect DCP-o-matic to make a DCP from the already rendered frames in 40 minutes, but it rerenders all frames again. I vaguely remember that this was not the case on the PC version I used last time.

[amiga78]

OK, I just tried this on a short clip, and the PC version will also rerender all frames, so I was mistaken here.

Is it possible to make DCP-o-matic reuse the rendered frames when I'm just changing from 25FPS to 24FPS? No new frames should be needed as the audio is just stretched to fit the slightly longer 24FPS version.

[Carsten]

You are right in that it should not need to do it, but due to an 'image encoding parameter' changed, it may still recreate the frames. Maybe Carl can find a straight way to fix this, but it could be difficult because the rendering process is not capable to create new video/audio time references without an explicit indication and process for 'only video timing reference changed'. However, 'Trimming' would have the same basic issue, but goes without recreating J2C...

- Carsten

[carl]

Hi folks,

This is a little complicated as a change from 25 to 24fps should not re-encode frames, but a change from, say, 25 to 50fps will at the very least have to duplicate frames in the output (so it can't just use the same video MXF). There should be a way around that, though: I'll look into it. I've put it onto the bug tracker: http://carlh.net/mantis/view.php?id=419.

[amiga78]

Awesome =)