Real-time screen recording for a bug report tool (like Loom). H.264 for instant playback, ultrafast preset because encoding happens live while the user records, 480p and CRF 28 to keep CPU usage under 10% on a laptop.
| Video Codec | H.264 |
| CRF | 28 |
| Resolution | 480p |
| Audio | AAC |
| Container | MP4 |
| Preset | ultrafast |
ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset ultrafast -vf scale=-2:480 -c:a aac -b:a 64k output.mp4The ultrafast preset disables most H.264 compression features: no B-frames, no CABAC (uses CAVLC), simplified motion estimation. File sizes are ~2-3x larger than medium, but encoding uses ~10x less CPU — critical for live capture.
A new FFmpeg encoding puzzle every day. Six tries, in the browser or from your terminal.