Blackmagic Forum

Hi

I'm completely new to Resolve, and inexperienced in software of this calibre. I discovered Resolve while looking for something to stabilize Go Pro footage. After I played with it a bit and realised how perfect it would be for me to do everything I needed to compile projects I went through this crash course:

As I went through this I pulled Go Pro footage of my own in and made several clips, played with all manner of things, including transitions between clips. I had no trouble at all with play back, no stalling or stuttering it is all perfect.

Then I went to start another project and dragged a few clips in, added a transition and the playback is terrible. It suffers from lag as a result of transitions badly. When I look at the original project I did I notice that the CPU is about 20-30% playing a clip then jumps to about 40-50% during a transition. With the second project the CPU usage jumps to 80-90% at a transition during playback.

I'm using clips straight off the Go Pro camera and I'm using the same clips in the two projects. I've tried looking all over the place for why this is happening, tried numerous caching and just can't find the reason this is happening.

Can you help please?

Thanks

GoPro footage is traditionally H.264, and you'd be better off using a non-Long-GOP format like DNxHD or ProRes, which is a lot easier for most computers to play back.

Is smart caching enabled in one of the two projects? Does one timeline have a blue line(s) above the ruler and the other one does not? The presence of the blue line would indicate the timeline is playing back cached (rendered) media in place of computationally expensive effects.

Thanks a lot Marc/Igor both these comments helped me out.

The videos are in H.264 and it tipped me off to set Project Settings > General Options > Cache frames in to DNxHR HQ.

Setting up "smart caching" lead me to finding this video:



I didn't realise that I had to just sit back and wait for the cache bar to turn blue, and the time of the video thumbnail. Once I did that I can play it back no problems.

This software is amazing.

If your GoPro footage is HD size drop down your cache format setting to DNxHD. HR is for "high resolution" i.e. 4k.

Phil Hoffman wrote:I didn't realise that I had to just sit back and wait for the cache bar to turn blue, and the time of the video thumbnail. Once I did that I can play it back no problems.

Yes, the SmartCache will basically temporarily transcode everything to whatever format you select. Me personally, I'd rather control what format it's going to and where the files are being stored, but I'd agree that if it was a quick GoPro job and not a big deal, then using the Cache would be OK. I always say, "hey, if it works, it works."

Igor Riđanović wrote:If your GoPro footage is HD size drop down your cache format setting to DNxHD. HR is for "high resolution" i.e. 4k.

DNxHD can't be used as a caching codec in Resolve (not in the latest versions any way), and frankly there's no need. DNxHR is basically the same but not locked to a few fixed resolutions.