Sliders "Sticky"

neumannu47

New member
I've been using VRD since Pentium 4 days, but I haven't used it much in the last couple of years, although I have kept the installed version up to date. Today, when I started it, I was advised to update to the latest version, which I did. When I loaded an MP4 file and tried to edit it, the sliders are "sticky", is the the only way I know how to explain it. They have always been very smooth and easy to use. The problem seems like an underpowered computer, but I'm using an i7-3770 with Windows 7 and 4GB of RAM and an NVIDIA GT610 graphics card. Am I doing something wrong?
 

neumannu47

New member
Are you referring to the slider jumping to the next I-frame?
I don't know what an I-frame is, but when I try to move the slider, it may move, it may not. When it does move, it's not smooth or fluid. And yes, since the video jumps around unpredictably, it seems that it is jumping frames. I wish I could provide a better explanation. Again, it seems like a dramatically underpowered computer, but that's obviously not the case.
 

jmc

Active member
"Sticky movement" sounds like what happens with me
when the file needs a "Quick Steam Fix"

jmc
 

phd

Super Moderator
Click on the menu: View>Display On Screen Information to display IBP info.
 

Danr

Administrator
Staff member
Let's learn a bit more about the file. Open the file, click on Tools>Show Program Info. Using the copy button on that page, paste the results here.
 

Dan203

Senior Developer
Staff member
Do me a favor too... Got to Tools->Options->Navigation and set the Shifted state to "Next I frame". Then go into your video, hold shift and click the right arrow on your keyboard. This should jump to an I or IDR frame. Take note of the timecode. Now do it again and compare the timecodes. What's the difference?

I've seen some files with as much as 30 seconds between I frames. If that's the case here then it would explain the issue. Compressed video like this can only be decoded starting at an I frame. To make scrubbing smooth we decode an entire GOP at a time (all frames between I frames) and store them in a buffer. However if the space between I frames is too long then there isn't enough space in the buffer to hold all the frames and you end up getting jerky motion like this because we have to back up all the way to the previous I frame to decode the frame you landed on.
 
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