microstutter test of non-matching recording / game frame rate
View video at 60 fps + 0.5x speed. Watch the ground texture. Both sides are recorded at 60 fps
Left: game is running at 90 fps
Right: game is running at 60 fps (matching the recording frame rate)
Right is smoother.
Explanation:
When the recording or streaming frame rate doesn't match the game's frame rate, microstutter can occur in the video or stream.
In this example on the left, because the recording is 60 fps but the game is running at 90 fps, a pattern occurs where only 2 out of every 3 frames are recorded. In the video, this appears as judder / microstutter. E.g., a pattern of 110110110. Every 0 will look like a frame skip.
The effect is more noticeable the lower the video frame rate. For example, a 30 fps video recording of a game running at 45 fps (since each frame lasts twice as long compared to at 60 fps, it's easier for eyes to notice the pattern). For a 60 fps video, it's hard to notice unless slowed down
When the game and the recording are both at a constant 60 fps, such as on the right, the recording and game's frame rate are 1-to-1, and there is no microstutter in the video.
If the game runs at exactly 120 fps (or an exact multiple of the recording frame rate), this shouldn't occur either, because you'll get 1 frame recorded for every 1 frame dropped. E.g., 101010. Each frame would just get 'doubled' evenly, and thus would not be perceived as stutter.
