jerkiness in zoom shots with keyframes upon export

[bartonlew]

I have created zoom shots using keyframes that appear smoothly in my timeline, but upon export, there is jerkiness in some (not all) of them.  I am using the first preset in the list - Match Source - High Bitrate.  Is there an obvious or common reason for this?  Many thanks.  In case it's helpful, my OS is Windows 10.  

[Steve Griffiths · Accepted solution]

Hard to know what might be going wrong without seeing what you are seeing. Any chance you could upload and link a short clip showing the issue?

However - preview render one of the problem 'zooms' in your timeline? Does it still look OK or does it now look the same as when you export.

Your selected export preset should be fine and should not have any affect on the zooms, so that's unlikely the issue.

Only other thing I can think of - does the footage that exhibits jerkiness when scaled/zoomed match the frame rate of your timeline?

Or is it VFR (variable frame rate) footage?

[bartonlew]

thank you, Steve.  I've attached the clip as well as a link to it on Dropbox.  In answer to your 1st question, the footage looks fine in the timeline inside Premiere - no jerkiness at all.  

As to your 2nd question, I'm afraid I don't know enough to answer it - can you explain how I compare the frame rates and determining whether it's VFR footage?  Thank you.  

https://www.dropbox.com/s/9zx0zhy4g8084uc/mailbox_medley.mp4?dl=0

[bartonlew]

Well I just viewed the video by clicking on the attachmet I uploaded here, and there is no jerkiness.  I then opened the file on my computer and played it with Movies & TV and Windows Media Player and it played smoothly in both.  My assumption is that the jerkiness was due to an unstable internet connection perhaps.  Thanks for your help.  

[Ann Bens]

Try using the Transform effect instead of Motion.

[bartonlew]

Thank you, Ann.  I am setting keyframes to each jpg, which I can see falls under the Motion heading in the Effect Controls panel.  Can you explain how I make the switch to Transform that you refer to?  Thank you.

[Ann Bens]