After attaching a video to a score, CPU usage is high

It’s okay when not playing, but the CPU usage suddenly becomes very high when playing. Also, when switching from the video window to the score window, the video window would turn black. I use WIN10.

I am not surprised.

What format is your video file in, @Dongww? Is it very high resolution (e.g. 4K or higher)?

mp4, 2560x1440, 30fps.

I tried a video with a resolution of 1920X1080, the result is the same. CPU usage is close to 30%.
My CPU is Intel(R) Core™ i7-7700K.

This is the case only if the video window is opened.

I guess this is par for the course, and the expected behaviour.

Can’t optimize anymore? Such high CPU usage is rare in other software, and it is unsettling when working long hours.

30% CPU usage isn’t high, and it will do your computer no harm at all.