'Checking existing image data'

Anything and everything to do with DCP-o-matic.
Carsten
Posts: 2807
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

'Checking existing image data'

Post by Carsten »

I was just going to create a second audio version after a successful encoding within the existing project.

This is a full length feature - the checking is taking ages. I also notice that a copy of the existing video file turns up in the video folder.

Why, at this stage, is this check necessary? I remember that in older versions, creating a new DCP with some audio changes (e.g. gain change) went by very quickly. Now it seems that the time saved in video encoding is spent for content check.

Carl - can you explain again the reason why this check is necessary?

I rarely notice it for shorts or slides, but for full length features, it's a real pain...

- Carsten
carl
Site Admin
Posts: 2550
Joined: Thu Nov 14, 2013 2:53 pm

Re: 'Checking existing image data'

Post by carl »

I think the scenario is:
  • You make a project and create a DCP.
  • This DCP's video MXF is a hard-link to a file in the video/ folder.
  • You modify the sound in your project and make a new DCP.
  • This re-writes some IDs in the MXF within video/ which in turn corrupts the original DCP you made.
To "fix" this we copy the video MXF, which is the long step you are seeing.

I'm not sure of the correct fix for this just at the moment. Maybe in this case we should just re-use the video MXF with exactly the same IDs.
Carsten
Posts: 2807
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: 'Checking existing image data'

Post by Carsten »

Yup, when it finished, I saw it took longer than the initial conversion - because of the added time to copy the large video MXF. Now doing a third version, and wish I had already started the second as a VF...

You modify the sound in your project and make a new DCP.
This re-writes some IDs in the MXF within video/ which in turn corrupts the original DCP you made.
Hmm, why do changes to the audio cause changes in the video MXF?

- Carsten
carl
Site Admin
Posts: 2550
Joined: Thu Nov 14, 2013 2:53 pm

Re: 'Checking existing image data'

Post by carl »

I think it's because it never checks to see if the video could be re-used as-is. It finds the last existing frame in any video asset that already exists (which might be incomplete). But AFAICS it should just re-use the video asset if it finds it complete...