search

ekisu / mpv-webm

Simple WebM maker for mpv, with no external dependencies.
MIT License
556 stars 33 forks source link

Using twopass with libvpx (VP8) degrades quality #75

Open FilthyLiquid opened 4 years ago

FilthyLiquid commented 4 years ago

mpv version and platform

Windows 10 (1903) mpv 0.30.0-284

Description

Using identical settings, newer versions perform worse than older versions. Here are 2 screenshots that used identical settings within the script. 2b-19-12-19_07 40 05 000 1g-19-12-19_07 39 57 000

It only lasts for a few frames but it is pretty jarring. Top is the most recent version, bottom is an older version (2bf01eba96d0d1215496a59748f0b6bdfb921e8e).

ekisu commented 4 years ago

Logs of both runs, please.

FilthyLiquid commented 4 years ago

log.txt

here you go, both are in the file

ghost commented 4 years ago

I have the same issue

These are my settings https://pastebin.com/D8gjX3pQ

ghost commented 4 years ago

The new webm script is broken for sure. None of the settings are working as intended. For now, the old webm script is better.

Top = new script Bottom = old script

1 2

ekisu commented 4 years ago

Sorry for the (very) late reply, had some IRL shit going on.

This seems to be a problem with how libvpx handles twopass. Older versions of the script always did onepass, even if twopass was enabled. This was fixed, however it seems libvpx has some issues regarding video quality on twopass (see #6 discussion for more details).

If you want to restore the old behavior, simply disable twopass. I'll leave this open because twopass is indeed broken, and if someone finds some magical flags or something to make libvpx behave correctly I'll be very glad.

soredake commented 4 years ago

In my case with 2pass it looks like this: image