View Full Version : ProRes 422 and XDCam HD


Dan Brazda
May 30th, 2007, 08:32 AM
I'm still having trouble seeing the advantage to converting native XDCam HD 35 VBR to ProRes 422. I've heard you get SD file sizes with HD material when using ProRes but XDCam HD already does that. Is it a color space issue? Speed of rendering? I always thought it was a bad idea to transcode a native format to something else unless you had no choice.

Steve Connor
May 30th, 2007, 10:34 AM
The better colourspace will help with any rendered effects such as filters, CC and transitions etc.

Simple way is to do all the work in XDCam HD codec and when you are finished drop the finished sequence into a ProRes timeline and render.

If you are planning on mastering back to XDCam then I can't see where there would be an advantage to this route. However if you are outpuuting to HDCam or above then it will improve the quality.

Greg Boston
May 30th, 2007, 10:40 AM
Dan, the main promise of ProRes is to make UNCOMPRESSED HD come down to near standard DV data size without a loss in visual quality. Since XDCAM HD is already just above DV25 data rates, there is no significant advantage to using ProRes. If however, you were grabbing a live HDSDI feed from the camera head into an uncompressed capture, ProRes would be your friend.

-gb-

Bennis Hahn
May 30th, 2007, 10:50 AM
There is also the issue of an Intraframe codec vs. a Interframe codec

Steve Connor
May 30th, 2007, 10:55 AM
Ah yes the evil of Mpeg 2 Long GOP!

Greg Boston
May 30th, 2007, 11:14 AM
There is also the issue of an Intraframe codec vs. a Interframe codec

Help me out Bennis. I don't see the relevance of your statement in the context of this thread.


-gb-

Steve Connor
May 30th, 2007, 11:27 AM
I think it's another long GOP Mpeg2 is bad to edit with reference

Nate Weaver
May 30th, 2007, 11:41 AM
There's a setting in FCP6, that if you have a native HDV/XDCAM HD timeline, FCP can use ProRes as a render format. It's in Sequence Settings/Render Control.

This makes the old method of copy/pasting XDCAM HD native timelines into Uncompressed or other codec timelines unnecessary (or mostly unnecessary).

Steve Connor
May 30th, 2007, 11:45 AM
Cool, I'm getting my copy of 6 next week.

Dan Brazda
May 30th, 2007, 05:02 PM
Thanks for all the responses and for confirming where I was headed. We shoot on XDCam HD 35 VBR, edit natively and then master back to XDCam HD 35 VBR so in this workflow I see little advantage to ProRez. VERY COOL though for the HDCam and higher folks.

Dan Brazda
May 31st, 2007, 08:10 PM
Hate to beat a dead horse here, but just when I thought I had it all figured out I have to ask:

-If you are XDCam HD native all the way through post and then mastering back to XDCam HD- why would rendering in ProRez do you any good?

Greg Boston
May 31st, 2007, 09:33 PM
Hate to beat a dead horse here, but just when I thought I had it all figured out I have to ask:

-If you are XDCam HD native all the way through post and then mastering back to XDCam HD- why would rendering in ProRez do you any good?

Okay Dan, as much as I loathe animal cruelty, I'll bring out the whip one more time. In the scenario you mentioned, there is no benefit of ProRes 4:2:2 IMO.

-gb-

Dan Brazda
June 1st, 2007, 06:10 AM
Thanks for the additional swat at the beast Greg. I brought it up again because I keep seeing it mentioned on other "reputable" sites that one should use an XDCam HD timeline but render in ProRes for the scenario I described. This site has a higher percentage rate of correct advice in my experience so I'm going with that.

Andy Mees
June 7th, 2007, 09:29 PM
i beleive (though have not personally tested) that using ProRes422 as the render codec may provide a speed advantage. rather than conforming every render file as MPEG HD the renders are instead encoded as ProRes422.

as I said, I've not tested this, am merely offering it up as a suggestion.

Bennis Hahn
June 7th, 2007, 10:05 PM
There is also the issue of an Intraframe codec vs. a Interframe codec

One reason you may want to not stay with the XDcam format is because it is interframe which isn't as ideally suited to editing as intraframe (prores422). Depending of what you are doing, this could be a factor.

Greg Boston
June 7th, 2007, 10:40 PM
Thanks for the additional swat at the beast Greg. I brought it up again because I keep seeing it mentioned on other "reputable" sites that one should use an XDCam HD timeline but render in ProRes for the scenario I described. This site has a higher percentage rate of correct advice in my experience so I'm going with that.

Dan, I want to correct myself because I have been thinking in terms of one codec for the entire timeiine a la FCP5. But, with FCP6, you can apparently have your source material stay in the XDCAM HD codec, while using ProRes to handle graphics and transitions on the same timeline. That's a workflow being put forth by others to get the best of both worlds. As for what you would eventually master out to, that's your choice.

There has been two schools of thought on this for some time now. Either stay in your native mpeg2 codec end to end, or, take it immediately to an intraframe codec as Bennis suggests. However, with faster and faster systems, editing in an interframe codec isn't the nasty beast it used to be.


-gb-

Hornady Setiawan
June 18th, 2007, 08:23 PM
ProRes is Apple's take on Avid's DNxHD.

Just like Avid, the Apple software suite will perform better with less hiccups using ProRes than if using native XDCAM Mpeg.

In Avid i notice render bugs n less performance if using native XDCAM mpeg, compared to using Avid's own DNxHD.

Haven't compared in FCP Studio 2, but my guess the logic will be the same.
The apps will better-support its own codec than outsider's codec.

So the advantage will be performance wise and less-crash/bug wise.

:)