Good point on the mixdown. I place a safe color limit over everything and render that which should do the job of a mixdown but in this case the same as source check box seemed to have overridden the render to dnx220 setting. I always put the safe color limit over the textless layers and then add separate safe color limits over graphic text elements. In this case that's what I believe caused the level shift given the graphic source was dnx 220 and the underlying safe color limit effect had rendered to XDCam 50Mbits. Video mixdown would have eliminated this issue on the QT ref export but then subsequent changes require a new video mix down, at least for the changed sections. I guess it's a choice of pick your poison and the bottom line is I need to be even more adamant about being given the time to QC all delivery files. That seems like a no brainer but in the heat of the battle things don't always go the way I would prefer.
--- In Avid-L2@yahoogroups.com, Bogdan Grigorescu <bogdan_grigorescu@...> wrote:
>
> 'Today's experience makes me even more nervous about assuming the file export is correct if I don't watch it down first.'
>
> or don't mix it down first...
>
> cheers,
> BG
> www.finale.tv
>
>
>
> ________________________________
> From: John Moore <bigfish@...>
> To: Avid L2 <Avid-L2@yahoogroups.com>
> Sent: Monday, September 2, 2013 2:35 PM
> Subject: [Avid-L2] Level shift in QT ref export?
>
>
>
> Â
> I'm working in a 1080i/59.94 Avid Project. The sources are a combination of DNX 220 and XDCam50Mbits. The XD cam material is from completed show masters that were exported to XDCamOp1A from avid. My understanding is the .mxf Op1a files were imported into avid, as opposed to ama linked and transcoded or consolidated. The fact that they are XDCam media makes me think they were consolidated through ama not imported but it is possible that they were imported to XDCam media.
>
> The issue that came up is when I finished the show I made a QT ref export and at the point were a matte key AE lower 3rd occurs there is a level shift in the QT Ref movie. Upon investigating I found that the safe color limit effect had over everything but text had rendered to XDCam 50Mbits not DNX 220. I found my render setting set to DNX220 but the same as source box was checked. Given the AE lower 3rd graphic is DNX 220 I guess it rendered to DNX 220. I cleared out all the renders of the safe color limit and all the text renders and unchecked the same as source box in media creations Renders. Now the level shift at the matte key is gone.
>
> My understanding of QT references is that they require everything to be in the same codec so originally when I made the QT ref at the matte key point I would think there was a difference in codecs going from the safe color limit at XDCam 50Mbits to the matte key section that I figure was at DNX 220. Can those two codecs co exist in a QT ref? Or is Avid smart enough to rerender the matte key to XDCam 50Mbits to make everything match? I'm thinking it was some render codec difference that was causing the level shift in the QT ref export. Anybody got any other theories or suggestions?
>
> This is frustrating because there was no level shift in the Avid timeline inside Avid. The problem only occurred on the QT ref export, a workflow I use all the time, so this makes me very cautious of file QT ref exports. I usually try to watch down my delivery files linked ama before sending them off but because everybody just thinks files just work I don't always get the time to do it. Today's experience makes me even more nervous about assuming the file export is correct if I don't watch it down first.
>
> Â
> John Moore
> Barking Trout Productions
> Studio City, CA
> bigfish@...
>
> [Non-text portions of this message have been removed]
>
>
>
>
> [Non-text portions of this message have been removed]
>
| Reply via web post | Reply to sender | Reply to group | Start a New Topic | Messages in this topic (3) |
No comments:
Post a Comment