3 ms·
av1an is essentially a "wrapper" around other encoders. I've played around with it lot in the past, but have never seen any real quality gains from using it (as
by querez 3y ago
av1an is essentially a "wrapper" around other encoders. I've played around with it lot in the past, but have never seen any real quality gains from using it (as measured by VMAF) instead of just using the encoder directly. Am I doing something wrong? What exactly does av1an buy me (except maybe for better independent threads?)
- brucethemoose2 3y agoFirst some background. Av1an works by splitting videos into scenes/chunks, which it then encodes in parallel. But this also allows it to change encoding settings for each scene. Specifically, it has a "VMAF target" mode that encodes a few frames from each scene as samples, measures their VMAF, and then boosts or reduces the encoding preset for that individual scene based on the result. It also has a "black boost" feature to allocate more bitrate to dark scenes, which encoders and various metrics tend to misrepresent. Also, the possibilities with the VapourSynth support are infinite. Some simple examples include denoising a noisy video on the GPU for better quality than the encoders' CPU denoising, or deblocking with custom parameters, or upscaling with some model in PyTorch. And that's just the start: https://vsdb.top/ https://vsdb.top/
- FreezyLemon 3y agoThere's a feature that allows you to try and target a specific VMAF score, but it doesn't work very well. What av1an does do for you is increase the speed by a lot, especially for aomenc and rav1e, which don't scale well with high thread counts. SVT-AV1 doesn't really have this problem. A faster encode might allow using a slower speed/preset setting, which would increase quality per bitrate a little bit. But I don't really consider av1an a tool that increases encode quality, to be honest.