Rendering: Difference in font size with Roboto Medium in VSFilter and libass

[raziel711]

Screenshots

MPC-HC (internal subtitle renderer):

mpv:

Description of the issue

With subtitles with Roboto Medium as a font for the main dialogue, the font size consistently looks larger when played with VSFilter than with a libass renderer like mpv.

Font:
font.zip

libass version

mpv v0.38.0-91-g69d70148 from https://github.com/zhongfly/mpv-winbuild

Is it a regression?

No

ASS Sample

Subtitle file:
subtitle.zip

Sample video:

sample.zip

The issue in the screenshot comparison is with the Main style in the script:
Style: Main,Roboto Medium,26,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,1.3,0,2,20,20,23,1

Special Fonts

I uploaded or linked to the required font

System Information

OS: Windows 10 Pro 22H2 19045.4355
CPU: Intel(R) Core(TM) i9-10885H

Log

log.txt

Additional info

No response

[astiob]

I can’t reproduce your MPC-HC screenshot in my MPC-HC 2.2.1 (nor 2.1.5). It looks the same as the mpv screenshot. I’ve tried the internal VSFilter, the internal libass, and XySubFilter.

[clsid2]

Perhaps settings were changed to render relative to window. That increases font size if black bars are present in window.

[raziel711]

I think I figured out what the problem was. I had a different version of Roboto Medium installed as a system font and MPC-HC was using that instead of the version of the font embedded in the mkv. After updating Roboto to match the version embedded in the mkv on my system, MPC-HC now looks the same as mpv.