←back to thread

Web Browser Engineering (2021)

(browser.engineering)
679 points MrVandemar | 1 comments | 15 Oct 24 09:42 UTC | HN request time: 0s | source
Show context
mannyv ◴[15 Oct 24 13:50 UTC] No.41848587[source]▶
One great thing about this book is the 'stuff I didn't do' part.

Layout is really hard. Just tables by themselves are hard, even without any css around them. CSS makes layout impossibly difficult. I challenge anyone to keep the whole CSS spec and its associated behaviors in their head.

At this point css + html + javascript have become a dynamic PDL, and probably is one of the most complex pieces of software today.

As an aside, video decoding is offloaded onto hardware, so it's not as battery intensive as it used to be.

replies(11): >>41848643 #>>41848664 #>>41848729 #>>41848784 #>>41848785 #>>41849444 #>>41849487 #>>41849657 #>>41851786 #>>41852399 #>>41854447 #
pstrateman ◴[15 Oct 24 13:56 UTC] No.41848643[source]▶
> As an aside, video decoding is offloaded onto hardware, so it's not as battery intensive as it used to be.

This is technically but not usefully true with most videos on the web today.

The video decode itself is accelerated, but each frame passes through JavaScript to be composited.

The only time video is fully hardware decoded is when it's a simple video element to a static video file.

replies(4): >>41848766 #>>41848790 #>>41848852 #>>41849217 #
1. pjc50 ◴[15 Oct 24 14:50 UTC] No.41849217[source]▶
> The video decode itself is accelerated, but each frame passes through JavaScript to be composited

I don't think that's true, and it's even less true once DRM video is involved - it becomes very difficult to get other software on the machine to even see the video, at least on Windows. You can very occasionally see bugs where the hardware accelerated playback ends up in a different place to where the browser thinks the video should have been put, too.

What does happen is the video data gets reassembled in Javascript (e.g. Video.js) because the native player doesn't support HLS. Not quite the same thing. It's just reformatting MPEG-TS to the similar but not identical MP4. Oddly, the browser in my LG TV does play HLS video natively, and I think Safari does?