Running this command:
ffmpeg -i xr.mp4 -tune ya zu.mp4
reveals the possible tune values for x264 and in turn FFmpeg:
[libx264 @ 0000000002167100] Possible tunes: film animation grain stillimage psnr ssim fastdecode zerolatency
However I could not find a reference explaining what these values actually do.
Best Answer
This is what the modes do:
film
– intended for high-bitrate/high-quality movie content. Lower deblocking is used here.animation
– intended for cartoons, etc., where deblocking is boosted to compensate for larger, flat areas. More reference frames are used.grain
– this should be used for material that is already grainy. Here, the grain won't be filtered out as much.stillimage
– like the name says, it optimizes for still image encoding by lowering the deblocking filter.psnr
andssim
– these are debugging modes to optimize for good PSNR and SSIM values only. Better metrics don't necessarily mean better quality though.fastdecode
– disables CABAC and the in-loop deblocking filter to allow for faster decoding on devices with lower computational power.zerolatency
– optimization for fast encoding and low latency streamingYou can see the detailed options applied with each tune with
x264 --fullhelp
: