Timeline lag but only near the end of long videos

[Mitch Kehler]

Hey everyone,

So I'm having a weird issue in premiere.

I work with really long video files (anything from 2-6 hours) and when I put one of these clips into the timeline, it will work fine for the first part of the clip but by the end of the clip it will start to lag like crazy. I have gpu exceleration on so I'm not sure why this is happening. It's not high res video either, typically 720

again this only happens when the videos are over 1 hour. If I'm editing a video that's 1 hour long there will not be any lag. If the video is longer, it will start lagging at the 30- 60 min mark. 

thanks! 

[Steve Griffiths]

Are these files by any chance .mpg files?

I've had this issue with very long standard definition mpeg files from weird sources that grind Premiere Pro to a halt.

Possible solution is to convert these files for a more edit friendly format (Like Prores) before you edit.

[Mitch Kehler]

They're mp4 files but I could try converting them to a different format to see! 

[Steve Griffiths]

Give it a go - test transcode maybe just one long clip on your next edit. Unfortunately with the length of your clips and if you go to something like Prores they are going to be much larger files sizes + the time to transcode. You might get OK results with ProresLT for the Standard Defintions clips.

I would be very interested to hear how you go ... if it does work at least you'll know it's (likely) something to do with the encoding of the original files.