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lingua-libre / SignIt

🌻 Lingua Libre SignIt web-browser extension translates selected word in French Sign Language via an elegant pop up so you learn sign language while reading online.
https://addons.mozilla.org/en-US/firefox/addon/lingua-libre-signit/
MIT License
11 stars 13 forks source link

Improve videos encoding quality and size #54

Open edouard-lopez opened 4 months ago

edouard-lopez commented 4 months ago

Not sure that the right place to put it, feel free to copy/paste.

Comparison

Videos uploaded by Lingua Libre are approximately 5-10 times larger than the one I extracted and encoded from Laura Jauvert video (for the same duration and with a lower resolution).

Source Example Duration Resolution Size (Kb)
Lingua Libre LL-Q33302 (fsl)-Taliba31-comédien.webm 2.0 s 640 × 480 622 KB
LSF-data Adolescent.webm 2.0 s 1,280 × 720 123 KB

Increase Quality

When I worked on the project I played a bit with FFMPEG options to get video as light and sharp as possible, i.e. with minimal blur on movement and small size as I targeted mobile usage.

My encoding script used the libvpx-vp9 codec and a bunch of other option for mobile (640x480) and desktop (1280x720).

Hope this could help

hugolpz commented 3 months ago

We are recording with vp9 too so this is a bit weird : 

mimeType = 'video/webm;codecs="vp9,opus"';
edouard-lopez commented 3 months ago

With what options? Default are not great, but the VP9 doc is really well done