Capturing problems: speed fluctuates

[zenovdb]

So a while back I purchased an Avermedia Game Capture HD II to record the output of Resolume.
All seemed fine, nice smooth recording in decent quality, until today when I had a closer look:
The recording totally warps the speed of the input, see attached file as an example of a file which originally was 6.19 minutes and now 5.25! It's not a constant warp but it fluctuates, also warping the audio badly.

Does anybody have an idea how to fix this? Do I have to adjust something in Resolume? Or is it just the crappy Avermedia product? I have only been able to find very positive reviews so I hope it's just some user error on my account..

[Oaktown]

Looking at the difference in duration, it sound like your file was recorded at 25fps and is being played back at 29.97/30fps.

[zenovdb]

That was my first thought as well but it seems the speed fluctuations are not stable, sometimes it goes faster than other times. I have tried slowing it down to match the original but that's not possible.
I'm suspecting the fluctuations in framerate of the Resolume output is being forced into 30fps which gives this result?

[Oaktown]

What settings and codec are you using for your recording?

[zenovdb]

Well the Avermedia doesn't have that much settings, but this was with the highest quality (1080) in mp4.

[zenovdb]

anyone got an idea how to fix this?
in this article featured on Resolume.com they're talking about the use of an Avermedia device to record the output so I'm still hoping it's just an user error on my side...

[Zoltán]

is your system powerful enough to do the capture and encoding real-time?
if not that could cause dropped frames in the recording which could produce what you are experiencing.

[zenovdb]

thanks for the reply! but the Avermedia is an external recorder, exactly to avoid those problems

[Zoltán]

ok, and have you tried a lower resolution recording?
do you have an option to choose CBR vs VBR ?
what type of video are you capturing,
slow moving landscape would require less computing while a flashy fast moving swarm of birds with lots of detail wood need a lot.
so maybe you are reaching the encoding capabilities of the device.

[zenovdb]

I'm afraid it doesn't have CBR/VBR settings..
The footage is quite intense, lots of moire patterns and thin lines, see attachment, so that might be pushing the limits of the machine?