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Time Remapped Dolly Shot, Smooth in AE, but Jerky in Rendering

Apr 6, 2012 11:49 AM

Hi,

 

My workflow:  Canon h.264 original footage transcoded to ProRes 4444 in Compressor.  Imported to HD project in AE, footage time remapped to smooth out uneveness in dolly speed, with Frame Blending turned on.  AE 5.5 Mac OS 10.6

 

My question is that the ram preview  below is relatively smooth, but when I exported a PR4444 sequence to FCP, once in the timeline it's jerky and stutters. (Forgive the sloppy mask, it's now fixed).  The stutters and jerks also appear when playing the 4444 clip back in QT10, and Vimeo.

 

Any suggestions?  Pixel Motion needed?

 

http://vimeo.com/39895088

 

Jesse

 
Replies
  • Currently Being Moderated
    Apr 6, 2012 12:32 PM   in reply to JesseHarris

    Plays perfectly smooth for me. There's a bit of a travelling bump at 0:08:15. What sloppy mask? 

    A jerky playback in a timeline is always caused by the timeline requiring more processing than it can do in real time.

     
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    Apr 6, 2012 1:31 PM   in reply to JesseHarris

    > My question is that the ram preview  below is relatively smooth, but when I exported a PR4444 sequence to FCP, once in the timeline it's jerky and stutters. (Forgive the sloppy mask, it's now fixed).  The stutters and jerks also appear when playing the 4444 clip back in QT10, and Vimeo.<

     

    Depends on what your set up is in FCP. I'm going to assume you know what you're doing in FCP as far as how to set sequences properly and you know the limitations of your machine.

     

    > Yes I'm aware of the timeline issues, and had hoped that once exported/rendered out of fcp that it would go away.  The above link was a Vimeo compressed RAM preview out of AE And that plays smoothly!.  Not out of fcp however. <

     

    Well, exporting out of FCP is not really part of this equation. If you export to the codec you're using for your playback of the finished project, say, H.264 or MP4 or MPEG2, the clip will play perfectly within the capabilites of your machine and the player app you are using.

     

    > Would it help to see what it looks like out of fcp on Vimeo? <

     

    Nope. The vimeo clip will always play fine because, regardless of what it started out as, when you upload to vimeo it is transocded to the vimeo-friendly codec.

     

    > Do you think this is because of the heaviness of the 4444 clip?<

     

    Not liekly. Heavy, maybe, but ProRes is designed to be used without issues in FCP on Macs in Quicktime. One uses 4444 only if one needs the alpha. If you don't need the alpha, any of the 422s will work fine. I didn't see the mask you mentioned so I don't know why you're using 4444. It is not often that 4444 cannot be played in FCP unless the pixel dimensions are just too large or you've chosen a weird frame rate. In that case, the clip must be heavily processed before it can fit the timeline's settings.

     

    I find the time remapping and motion smoothing capabilites of Apple Motion's optical flow functions are completely adequate for all but the most extreme screwups encountered while shooting.

     

    Message was edited by: bogiesan

     
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    Apr 9, 2012 9:50 AM   in reply to JesseHarris

    Explore the optical flow options in Apple Motion, forget time remapping in FCP.

    I do not understand the referfence you have made to the two different clips not playing. If a clip uploaded to vimeo plays incorreclty, you muste determine fi the original file is not good, the upload was no good or out of spec, the vimeo-encode is not good, your connection is ot good or there's some other fluke involved. Only after you determine where the playba k issue lies can you then begin to explore any of th may cuases for the file to have failed.

     

    ProRes 4444 is fabulous but you need to spend some time in the Apple docos for the codec family.

     
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  • Currently Being Moderated
    Apr 9, 2012 11:59 AM   in reply to JesseHarris

    JesseHarris wrote:

    The RAM Preview of my time remapped AE comp... rendered out of AE and compressed in Compressor by a proven Vimeo setting (I use it all successfully all the time) plays fine in Vimeo.

     

    The same AE comp rendered at 4444, placed in FCP timeline then compressed by the same Vimeo setting is jerky and stutters when played back in Vimeo.

     

     

    It sounds like you saved your RAM Preview, and used the AE Render Queue for the ProRes 4444 version.  A common reason for a disparity like this is using Open GL to accelerate AE renders.  If that's true, turn it off and try the render again.

     

    Incidentally, unless you need ProRes 4444 for its alpha channel support, ProRes 422 will be just fine.

     
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    Apr 10, 2012 1:08 PM   in reply to JesseHarris

    JesseHarris wrote:

    is is the RAM Preview output from my AE comp, Time Remapping applied, (original footage h264 transcoded to 4444 ProRes in Compressor and worked on in AE comp)  This is the result I'm happy with!

     

     

    You can select the codec to use for RAM Previews; when you save the preview, it saves in that codec.  What are you using?  Think you can use it for rendering?

     
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    Apr 10, 2012 2:36 PM   in reply to JesseHarris

    You'll find the current defaults in the Output Module templates.  You'll have to look for it; I forget where it's located in AE 10.5.

     
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    Apr 11, 2012 8:36 AM   in reply to JesseHarris

    If you have ProRes 4444, I'd bet you also run Final Cut Pro 7.  FCP will re-render the Animation files... and the problem may manifest itself again, sorry to say.

     

    If it does, you'll have to go through your entire workflow to check FRAME RATES.  An extremely common problem comes if you shoot 24p and edit in a 29.97 timeline.

     

    Another common problem comes from assigning the wrong frame rate in AE.  You see, FCP LIES -- lies, I say! -- when it uses 23.98 to refer to the frame rate of 24p.  It's actually 23.976.  If you made the mistake of making a 23.98 AE comp, change the frame rate to 23.976 and the problem goes away.

     

    So to summarize frame rates:

     

    24p=23.976

    30=29.97

    60=59.94

     

    Not knowing the correct frame rates'll kill you every time.

     
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    Apr 11, 2012 2:28 PM   in reply to JesseHarris

    Here's my last suggestion, and after this I'm out of answers.

     

    Put the ProRes 4444 file you rendered in AE in FCP.  For both the imported clip from AE and edit timeline, check to make sure each is set to a field order (incorrectly called field dominance in FCP) of None.  You check & change the clip if necessary in the FCP Browser.  You check & change the edit timeline in the Sequence Settings.

     

    Incidentally, ProRes 4444 is ONLY necessary if you need transparency: it supports alpha channels.  For everything else, normal ProRes 422 is just fine.  You gain precisely ZERO additional image quality by transcoding to 4444 instead of 422.  You DO gain much larger file sizes, and if that's your goal, please continue the practice.

     

    To see any kind of image degradation whatsoever in 422, you would have to re-render a clip six times over.  I can think of no workflow where that would occur.

     
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    Apr 12, 2012 11:13 AM   in reply to JesseHarris

    ...I tried your suggestion:  my sequence already had a Field Dominance of None - I right-clicked in the Browser and changed the dominance from Upper to None.  Unfortunately it didn't seem to affect the clip.

     

    After you correct the field order, you need to put the clip back into the timeline.  The changes don't carry through automatically to the clip that's already in the timeline. 

     

    Field order issues with progressive ProRes footage rendered in AE are a known issue. 

    Apparently this was a Final Cut Pro thread from the very beginning, because it never was an After Effects thread.

     
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