ffmpeg

Video and audio processing with format conversion, resizing, compression, and Remotion asset preparation. FFmpeg is the essential tool for video/audio processing. This skill covers common operations for Remotion video projects. Why these flags: Note: Re-encoding is recommended for trimming. Stream copy ( -c copy ) can silently drop video if the seek point doesn't align with a keyframe. When to use FFmpeg vs Remotion playbackRate : Remotion limitation: playbackRate must be constant. Dynamic interpolation like playbackRate={interpolate(frame, [0, 100], [1, 5])} won't work correctly because Remotion evaluates frames independently. Calculate speed factor: Extreme speed (>2x audio): Chain atempo filters (each limited to 0.5-2.0 range): Add scale filter: -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" Use: -movflags faststart -pix_fmt yuv420p -c:v libx264 Use filter_complex with atempo: -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" Increase CRF (23→28) or reduce resolution After Remotion renders your video (typically to out/video.mp4 ), use FFmpeg to optimize for each distribution platform.