Saturday, January 17, 2015

Re: [Avid-L2] Speed Ramps of converted 23.98 clips in a 59.94i project don't match offline?

 

My usual recommendation is to maintain the original base frame rate to the entire offline and online process. Do not change frame rates. Mix it down and bring the mixdown version to delivery frame rate. This will result in a consist 2:3 pulldown. Or have Symphony do the conversion during baseband SDI output.

I think the problem is you transcoded to the target frame rate in the uprez process. I am unsure how you even relinked back to your sequence.

Dom Q. Silverio

On Sat, Jan 17, 2015 at 3:24 PM, John Moore bigfish@pacbell.net [Avid-L2] <Avid-L2@yahoogroups.com> wrote:


We are experiencing a very annoy problem where the speed ramped shots from the 30i offline don't line up when the 23.98 source clips are converted during uprez.

Here is the AE workflow that was explained to me:
The main offline project is an SD 30i project.  For the file based 23.98 media they bring that into a 1080p/23.976 HD project and they add a tape name, I'm told they can't add a tape name to these clips while in an SD project.  Once the tape name is added then they toggle the project format to 23.976o NTSC project.  The clips are then transcoded to 14:1, 10:1 or 10:1m.  I think they mostly go to 14:1.  These clips are broll and are not grouped.  The offline cuts in the 23.98 sd clips.  At uprezz the AE ama links to the 23.98 media and adds the tape name then they transcode while in the final delivery 59.94i 1080 project choosing to convert the clips.  This is what I get in my online sequence.  These converted clips aren't matching the offline speed ramp moves.  They are usually close to the shot but have to manipulated to match.  The best workaround they have come up with is to manually figure out the time code range needed and manually convert a clip containing all the necessary frames.  They save the motion effect to a bin then cut in the converted clip matching the first frame visually then dropping the saved motion effect onto the converted clip.  I'm told this has worked in the past but it doesn't seem to be working of late and they are having to manually go in an tinker with the speed ramps. 

I think the crux of the problem stems from the added tape name which tell Avid the source is tape based.  Now when the toggle back to the 23.076p NTSC project I'm speculating that the project only knows tape machines that were 29.97 from the traditional telecine work flows.  I'm thinking when they transcode to SD media Avid is confusing the source 24 frame time code with 30 frame code.  If I look at the motion effect editor window I can see for example that parking on an anchor point at the beginning of the effect shows a time code ending in :17 in motion effect window while in the timeline the clips time code reads ending in :24.  These is one of the reasons I thing there is a 24 frame vs 30 timecode misinterpretation that is shifting the shots.  I think this combined with motion effects that get trimmed so the original anchor point is well outside the actual frame range that is visible is also contributing to the mis synced pictures.

Anybody seen this before?  I haven't had time to really experiment with the material do to deadlines but I think I've got the issue surrounded.
 
John Moore
Barking Trout Productions
Studio City, CA
bigfish@pacbell.net



__._,_.___

Posted by: "Dom Q. Silverio" <domqsilverio@gmail.com>
Reply via web post Reply to sender Reply to group Start a New Topic Messages in this topic (2)

.

__,_._,___

No comments:

Post a Comment