BPM performance at 50Hz.

Post your questions here and we'll all try to help.
Post Reply
User avatar
manoeuvretv
Is taking Resolume on a second date
Posts: 33
Joined: Sun Feb 19, 2012 12:27
Location: Melbourne, Australia

BPM performance at 50Hz.

Post by manoeuvretv »

Has the Resolume team done much testing of playback at 50Hz with clips set to bpm. I had stopped using bpm features on anything but effects because of stuttery video playback at 50Hz but I had a show on the weekend that I had to use bpm for clips. What got me wondering is that my composition was only hitting 50fps but was smooth at 59/60Hz but stuttering at 50Hz. Obviously 30/60fps content at 60Hz is going to work better for bpm clips because it's easily divisible and dropping less frames but I was wondering if it's possible to improve the visual performance of bpm content at 50Hz. I'm just interested because you can playback 30/60fps content in a standard way at 50Hz without problem at any speed 1.5x, 2x etc.
Richard De Souza
MNVR
http://www.mnvr.tv

Joris
Doesn't Know Jack about VJ'ing or Software Development and Mostly Just Gets Coffee for Everyone
Posts: 5185
Joined: Fri May 22, 2009 11:38

Re: BPM performance at 50Hz.

Post by Joris »

I'm not sure if I understand the problem.

When using BPM Sync for playback, on each render cycle, Resolume will do a calculation on where the clip needs to be in its timeline, based on the current beat and measure, in combination with the amount of beats it's set to play back in. It will then set the playhead to that frame and display it. On the next render cycle it repeats this process and comes up with the next frame. Continue ad infinitum.

That calculation doesn't really change when outputting at different refresh rates. When rendering at 60Hz, the calculation is done at a maximum of 60 times a second. When rendering at 50Hz, the calculation is done at a maximum 50 times a second. That's really the only difference and should not affect perceived fluidity, since perceived fluidity is only affected by how close the playback rate is to the clips own, 'native' playback rate.

Perhaps you can describe steps or provide some example footage where we can clearly see the difference you are talking about?

User avatar
manoeuvretv
Is taking Resolume on a second date
Posts: 33
Joined: Sun Feb 19, 2012 12:27
Location: Melbourne, Australia

Re: BPM performance at 50Hz.

Post by manoeuvretv »

Thanks for explanation, I'll try to capture an example for you. I haven't isolated exactly what causes it yet but I've only noticed it while running at 50Hz, it's not like a stutter from disk access or low fps but a regular cycle pause that breaks smooth motion. I'll look into it more.
Richard De Souza
MNVR
http://www.mnvr.tv

User avatar
4eyes
Hasn't felt like this about software in a long time
Posts: 88
Joined: Tue Oct 02, 2012 03:50

Re: BPM performance at 50Hz.

Post by 4eyes »

What is your Audio Buffer set to Richard? Anytime I set it to a value greater than 1024, BPM clips have stuttery playback.

Cheers

Post Reply