VMAF is Hackable: What Now?

Just a quick note to let you know about some recent findings relating to the Netflix VMAF metric. By way of background, VMAF launched in June 2016 as the metric that powered Netflix’s per-title encoding engine, replacing PSNR. The fact that Netflix created and used VMAF gave the metric tremendous credibility and because Netflix open-sourced…

Using a Simple Wildcard Command in FFmpeg

Author’s note: This is a very simple automation technique for FFmpeg beginners. I’m sure there are much more efficient ways to script this project, but this represents my baby steps in FFmpeg automation. I recently started a consulting project that involved encoding multiple files to multiple CRF values to create rate-distortion curves and BD-Rate computations.…

Choosing an x264 Preset

All codecs and encoding tools have a configuration option that controls the quality/encoding time tradeoff. With x264 (and x265) the preset controls that tradeoff. When choosing a preset you should consider 3 criteria: Overall quality – the overall quality produced by that preset Low frame quality – the quality of the lowest frame produced by…