You cannot create the timelapse with OBS directly. You need a postprocessing step to actually speed up the video. If you record with 1/2 = 0.5 fps, OBS actually writes only 1 frame every 2 seconds, resulting in very compact files. However, the fps is recorded with the video file, so the media player knows that it should show every frame for 2 seconds, so the display time of the video is exactly the recording time.
If you want to speed this up to 24 fps, you need to apply a postprocessing step that speeds the video up by a factor of 48, so 0.5 fps becomes 24 fps. You can use ffmpeg for this, see this post of mine and the follwing post:
I want to record an hour of video with OBS. Afterwards I want to compress that hour into 10 seconds via for example Adobe Premiere. However, the whole process takes too much time and Premiere can only compress it to lets say around 1 minute, and it takes a long time to compress it, and the...
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