just stay with the defaults unless you know what you're changing. With the exception of lag-in-frames (kind of like a lookahead, but seems a little more effective?), and maybe 10-bit encoding, aomenc is pretty much like x264/x265. It's certainly much better than the H.264 FGS model that was available with HD-DVD players (although never used in any actual discs AFAIK). I quite like the AV1 FGS implementation, and is probably technology that will be reused in other contexts. Of course, the FGS being orthogonal, decoders which support it with AV1 could easily support FGS for HEVC and VVC too. And the FGS implementations aren't quite to the point where they can be used automatically, but that's orthogonal to codec bitstream itself, and I believe will be continuously improved. But that's really the only case where I've seen a reliable reduction in bitrate versus HEVC when compared at the same bitrate and encoding time. There's no doubt that, with a good Film Grain Synthesis implementation, AV1 can outperform HEVC for grainy content at lower bitrates. Maybe PSNR at fixed QP or something, but certainly not in subjective MOS testing of subjectively-tuned encodes. Although their assertion that VP9 is 40% better than H.264 and equivalent to HEVC is flat-out wrong for every scenario I've tested. To be fair, at least AOM doesn't argue otherwise and a multi-codec-world is the future which includes the patented (and more efficient) mpeg codecs like VVC.

Ffmpeg av1