Hacker News Reader

Comment by jjice | Hacker News Reader

My 2014 Thinkpad X1 Carbon (gen 3) doesn't have hardware transcoding as far as I can tell made Zoom and Discord impossible to use for class, especially because there was no way (that I knew of) to disable all video except the presenter. Even playing a YouTube video on it makes it ramp up.

View on HN

I'm not sure which CPU you have specifically but the lowest-end model of the X1 Carbon Gen3 has an i5-5200U [1] that lists Intel Quick Sync Video support.

From the wiki page for Quick Sync [2]:

> Intel Quick Sync Video is Intel's brand for its dedicated video encoding and decoding hardware core. Quick Sync was introduced with the Sandy Bridge CPU microarchitecture on 9 January 2011 and has been found on the die of Intel CPUs ever since.

I can't confirm but I'd guess your performance issues lie elsewhere than in the h264 decoding specifically.

[1] - https://ark.intel.com/content/www/us/en/ark/products/85212/i...

[2] - https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video

If you check out the generation-codec table in that wikipedia article [1], under Broadwell (I believe that's the 5200U's generation name), it says there is support for AVC (which I believe is H264, I'm not a codec wiz), so that's a really good point. I'm not sure why I've consistently had issues with this on my machine then. I wonder if this is something with a configuration on Linux then?

Thanks for pointing that out. I've looked at this table before and payed attention to HEVC, not AVC, so I believe that's where my mistake came from.

[1] https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video#Hardwar...

AVC is H.264, yes.

Accelerated video decode is often disabled by default on Linux versions of browsers and can be quite dependent on versions of drivers/mesa/X-vs-Wayland/etc.

YouTube by default prefers newer, bitrate saving codecs over old ones if it thinks your CPU can handle software decoding them. On my 2017 Dell XPS 1080p and lower resolutions on YouTube play in software decoded AV1, only 1440p and higher play in hardware decoded VP9, so playing 4K video on YouTube is less taxing for my CPU than playing a 1080p video....

You can use h264ify extension to fix it.

The problem is Zoom and Discord are doing multiple streams. But it really shouldn't be a problem.

H.264, even on the high profile is not CPU intensive on a 2014 machine. Unless you are watching 1080P with 5-10Mbps, which is not the norm for internet video.

Reply on news.ycombinator.com