What are the factors that affects a video's quality?

I am new to this website and this is my first question, really appreciate if someone can provide some advice about my current problem.

I've been testing some videos on my computer to see at what video quality will the video start to jitter. I've tried using multiple ways to create the video, from creating an animation video off adobe aftereffects to downloading existing videos.

As I tested the videos on my computer, I realise even videos with the same bitrate, resolution and FPS, the smoothness still differs from video to video. I ensured the videos are all smooth on a more powerful computer prior to the testing.

Does anyone know what are the other factors that might affect the quality of the video which is causing the difference?

Your advice is really much appreciated, thanks!

1 Answer

The codec being used (both for compression and decompression) and the complexity (amount of change) can cause substantial variances, as can the method of encoding. Particularly with systems with lots of changes, the computer may need to do more work to calculate them out.