Encoding Discussion Megathread (ffmpeg, Handbrake, AV1, etc...)

[manu98]

Thanks for your answer. Unfortunately, removing the keyframe option does not help.
I did not use it originally, but it was one of many things I tried out.

Do you have any other suggestions?

Have you tried without scene change detection? There were a few things I tried when I was first experimenting with SVT-AV1 that sound really cool that jacked up my files. Super resolution was one of them, overlays was another suggested as something that could reduce filesize and increase clarity but in the end does nothing. I recall turning on scene change detection as well and turning it off after having issues, but I don't recall if it was because of performance issues or due to the same kind of seek problems that you're having. My understanding is that SCD tries to find the best spot to throw in keyframes, but I'm not sure what goes on behind the scenes and what actually changes. So...I have two suggestions to try. First would be try turning off SCD and see what happens. Second would be to go back to where your original command was (-ish) and try preset 4:

Code:

ffmpeg -i in.mkv -map 0 -c:v libsvtav1 -preset 4 -crf 30 -pix_fmt yuv420p10le -svtav1-params tune=0:scd=1 -movflags +faststart -c:a libopus -ac 6 -b:a 256k -c:s copy out.mkv

You could even add back in your keyframe call if you want (-g 240).

The reason I feel this is a valid suggestion is because I don't think most people are sure what the difference between the presets is. There isn't great (or any, that I've found) documentation on what preset "5" vs. "4" actually means when using SVT-AV1...we all assume it's "quality" and "encoding time" which, in general, is true, but why? What settings are changed when going from 6 > 5 > 4? I've settled pretty well into preset 4 when I'm not running things through my A380 since the time savings aren't that significant and the quality difference -- I've found -- can be quite striking, particularly when looking at 4K HDR, but even at 1080p. Any lower, it's probably not worth the extra clock cycles.

Thanks for your feedback. Using preset 4 results in the same behaviour, unfortunately.

Things are getting really strange now. I limited the length of the new video file, so I could test more options.
But when limiting the video time, it suddenly works!

Working:

Code:

ffmpeg -i in.mkv -to 0:2:0 -map 0 -c:v libsvtav1 -preset 5 -crf 30 -pix_fmt yuv420p10le -svtav1-params tune=0:scd=1 -movflags +faststart -c:a libopus -ac 6 -b:a 256k -c:s copy out.mkv

Not working:

Code:

ffmpeg -i in.mkv -map 0 -c:v libsvtav1 -preset 5 -crf 30 -pix_fmt yuv420p10le -svtav1-params tune=0:scd=1 -movflags +faststart -c:a libopus -ac 6 -b:a 256k -c:s copy out.mkv

I could send you both samples via DM, if you want to have a closer look?