explanation:
- vf=setpts=PTS/1 ensures that each frame is shown at its correct time according to the video’s original timing. It does not affect the overall playback speed dictated by the frame rate setting. ( i use 20 fps to avoid getting drowsy )
- vf=setpts=PTS/1 is set to prevent issues like audio-video desynchronization or to ensure smooth playback, especially with variable frame rate (VFR) videos.