FFmpeg Command Generator
Configure high-performance media tasks visually. Scale, compress, or convert video and audio with zero syntax errors.
Video Parameters
Understanding CRF
Constant Rate Factor (CRF) is the standard for x264/x265 encoding. The range is 0 to 51. Lower is better quality.
- 18-20: Visually lossless.
- 23: Default (Standard).
- 28: Noticeable quality drop, but very small file size.
Why use "Stream Copy"?
Setting the codec to Copy is like a file transfer. It doesn't re-calculate any pixels; it just moves the video data into a new container (e.g., MKV to MP4). It is nearly instantaneous and results in zero quality loss. Use this whenever you don't need to change the resolution or quality.
Professional Tip
When trimming, placing the -ss (start time) flag before the -i (input) flag tells FFmpeg to use "Fast Seek." This jumps to the timestamp without decoding the whole video first, saving massive amounts of CPU time on large files.