FORUMS: list search recent posts

Using QuickTime Reference files, proxy audio only (sometimes)

COW Forums : Square Box CatDV

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jack Lenk
Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 10, 2012 at 6:43:08 pm

Hi, I'm wondering if anyone's run into problems using QT Ref files? On the assumption that they are small and faster to export, we have been using them to post our rough cuts from FCP7 into CatDV. No problems viewing the HD files, but *sometimes* the proxy (made by Worker + Compressor 4) comes out containing audio only. Why?

Is it possible that we overwhelm the "reference" ability of QT with multi-cam and mixed-format sequences with color-correction and transitions applied, etc? Why would CatDV play the HD ref file fine but Compressor render a bum proxy?

We use CatDV as a platform for collaboration on editorial/content decisions, and I'm not sure what format is best for all those rough cut versions... Any ideas appreciated.

Thanks in advance,
Jack


Return to posts index

Rolf Howarth
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 10, 2012 at 8:22:33 pm

I don't recall seeing this issue. If you have a reference movie that fails I would do some tests on that to try and work down what's happening:

- verify you can import and play that file in CatDV
- try to export a movie from that in various formats (File > Export As Movie) and see if they play ok
- repeat the export from Compressor
- try importing, playing, and transcoding that reference file in other apps (eg. FCP7, QuickTime Player, etc.)



Return to posts index

Robb Harriss
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 11, 2012 at 1:09:44 am

I always export a master reference file that's self contained. Then I make a proxy from that (using CatDv) as am mp4 or motion jpeg. Non-self contained "reference files are playing back your timeline as best they can, in non-real time. If there are elements FC cannot find (say a drive is offline) then it burps. When you're asking another app to convert that "virtual master" it may be asking too much at times. Me, I like having the self contained master sitting around. Always seems that someone wants to see the cut when the project is offline, or I have to render it out as a different size or format. I used to have a lot of trouble with Soundtrack Pro loosing the video links when using a non-self contained reference file.

Non-linear: all the time and nothing but.


Return to posts index


Rolf Howarth
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 11, 2012 at 8:57:28 am

"Self-contained reference file" is a contradiction in terms. If you create a sequence by assembling parts of several movie files into one there are three ways you can export this as a movie using QuickTime:
  • A reference file, which might typically be only 4K in size and is a list of pointers that refer to your original media files. A reference movie therefore won't play if any of those source media files are moved go offline.
  • A self-contained or flattened movie, which has the same structure as a reference movie (same number of tracks etc.) but includes a copy in it of the media that it needs, without transcoding, so it doesn't depend on any other files.
  • A movie that has been transcoded to a new format. Again, this doesn't depend on any other files, and has the effect of burning in things like an overlayed watermark image or timecode display.




Return to posts index

bryson jones
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 11, 2012 at 3:41:22 pm

If you're doing sequences as a QT ref, I've seen tons of issues with these. Usually it's an effect or mixed format as you mentioned.

Media Composers seem to do a better job with ref exports in my experience but Media Composer users tend to work in more controlled formats as well which might explain some of that. (Don't start a flame war here, just sharing my experience!) ;)

I love refs for speed but I've not been able to make them reliable above the clip level. Anyone else have experience to share?

bryson

bryson "at" hidefcowboy.com

hidefcowboy.com


Return to posts index

Jack Lenk
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 11, 2012 at 7:08:36 pm

Thanks for your comments. This helps me understand that we should probably use ProRes(Proxy) to export rough cuts, or perhaps a native-format, self-contained sequence export (usually xdcam-ex in our case). I'll have to test which is faster/smaller.

I'd like to follow up with the question: would transferring sequences (w/ multi-cam, effects, mixed formats) via XML to CatDV be a viable option to consider? I'm tempted to think that puts a heavy burden on CatDV to reconstruct on-the-fly...

Thanks again,
Jack


Return to posts index


Rolf Howarth
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 12, 2012 at 8:27:47 pm

CatDV only has fairly limited sequence support (cuts only, limited audio handling, no effects or transitions). It's mainly designed to help with logging (eg. if you've cut a sequence and want to generate subclips from it) rather than rendering a complex sequence on the fly (though you can do that for simple cuts only sequences).



Return to posts index

John Heagy
Re: Using QuickTime Reference files, proxy audio only (sometimes)
on Jul 13, 2012 at 3:31:13 am

[Jack Lenk] "we have been using them to post our rough cuts from FCP7 into CatDV. No problems viewing the HD files, but *sometimes* the proxy (made by Worker + Compressor 4) comes out containing audio only. Why?"

It sounds like CatDV is not able to resolve the references video media in the FCP7 ref movie at the time the proxy is made. The reason you are getting the audio is because FCP7 doesn't reference the audio... it self contains it so it can't be orphaned like the video can. If an orphaned FCP7 ref file was sent to Worker to make proxy you would get only the audio.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]