• Adobe Premiere Pro

  unsynchronizes on render

  Posted by Chris Wood on January 30, 2008 at 5:50 pm

  Hello all. Let me preface this by saying I’m a newbie both to Premiere and this forum, but this issue either constitutes a legitimate bug or likely has a more advanced fix…

  So I have two video clips of a racing event from two different cameras. One is a fairly low-buck digital camera that I use to record low-res video simply and show it as picture-in-picture for a supplemental interior or exterior view of the car.

  Currently the two clips are in a Premiere Pro project and when played as a preview, they are both perfectly synchronized. I can see workers on the racetrack pass by at the same time in each view through the entire ~6min segment of the total clip that I want to render.

  Unfortunately when rendered, these views start in-sync and get progressively more out-of-sync as time goes on.

  Of note:

  Both cameras record to SD cards and I did not need to “capture” anything from tape. The claimed frame rate of the main clip is 30fps, while the secondary one claims to be at 20fps. I suspect the second clip may have been recorded at some frame rate that is slightly higher or lower than it is reported as in Premiere. These are both low-cost cameras, but in this application and for my purposes they are adequate.

  What could cause the two clips to go out-of-sync on rendering?

  Is there some way of time-stretching or time-scaling clips with two markers as sync points?

  Thanks,
  -Chris

  Chris Wood replied 18 years, 7 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Jon Barrie

  January 30, 2008 at 11:56 pm

  First thing you want to do is confirm the frame rates of your footage…
  you can check that with Quicktime Player or another stand alone player you know how to check properties for frame rate.
  The 20fps thing is probably causing issues.
  If you find it has a different frame rate than that, interpret the footage (right click in project panel) and change the frame rate to the actual frame rate. It will affect your clips edits, length and speed.
  I’d render out the 20fps one on it’s own to a 30fps clip from a 30fps project. Reimport it and check the sync of it against your main clip.
  Frame rate is definitely causing you problems.
  – Jon

  How many editors does it take to change a light bulb?
• 

  Chris Wood

  January 31, 2008 at 6:40 am

  Thanks, Jon! That gives me somewhere to start looking. This is what I’ve found:

  The 20fps video appears to be exactly 20fps as per Win Media Player (not a QT encoding). The other file is reported as 28.95fps by Quicktime Player when Premiere claims it to be 30fps. Interpreting it as 28.95fps makes it out of sync in the preview.

  Rendering the first clip as 30fps in a new project looks to be a pain, but I’ll do it if that will work. Won’t recompressing it be unnecessarily lossy? I guess that’s secondary to getting this in-sync right now.

Reply to this Discussion! Login or Sign Up