MobileRead Forums - View Single Post - Head's up for those that build Sigil from source

KevinH · 10-09-2026, 04:26 PM

FWIW, I can see the slowness of the QtWebEngine load of avif on my old intel Mac as well.

On a lark, I changed URLSchemeHandler to polyfill avif with jpeg at 95% and Preview now loads a bit faster than it did before.

Still not fast but there is something very very slow in the Chrome 140 decoding of avif files. Our own qt plugin does it faster.

I did not push this change because it should not be needed. Native loading of an avif file in QtWebEngine is just very slow. I wonder if anyone upstream at Qt has noticed this?

10-09-2026, 04:26 PM	#28
KevinH Sigil Developer Posts: 10,142 Karma: 7640000 Join Date: Nov 2009 Device: many	FWIW, I can see the slowness of the QtWebEngine load of avif on my old intel Mac as well. On a lark, I changed URLSchemeHandler to polyfill avif with jpeg at 95% and Preview now loads a bit faster than it did before. Still not fast but there is something very very slow in the Chrome 140 decoding of avif files. Our own qt plugin does it faster. I did not push this change because it should not be needed. Native loading of an avif file in QtWebEngine is just very slow. I wonder if anyone upstream at Qt has noticed this?