the image and subtitle quality get bad once the video plays

[Otsuka Electronics]

I have put high-resolution image & subtitle provided by Premier Rush.

It looks fine when the video is paused, it gets worse once played though.

Is there any way to solve this problem? Or is it a temporary error which disappears when exported?

I'm working on it with the desktop.

[Steve Grisetti]

When you play your timeline, you are seeing a preview of your video. Not the final video. Depending on the specs of the device you're editing on, the specs of your video and the number of effects you've added, this quality can appear greatly reduced in order to allow for smooth playback.

Try outputting your video or a sample of your video. Most likely its final output will look just fine.