logoalt Hacker News

iso1631yesterday at 3:57 PM2 repliesview on HN

We use JXS when latency is critical. Most h24/265 decodes will have a 10 frame glass-glass delay, JXS drops that to 3 or 4, at a cost of bandwidth (our UHD jxs streams are 1.5gbit rather than 200mbit for hevc)


Replies

Dylan16807today at 12:18 AM

That's pretty depressing to read. x264 was handling the encoding side with sub-frame latency 15 years ago, and sub-frame decoding is significantly easier. "with –tune zerolatency, single-frame VBV, and intra refresh, x264 can achieve end-to-end latency (not including transport) of under 10 milliseconds for an 800×600 video stream"

But for some reason you can't make use of that and have to burn bandwidth instead.

jamesfmilneyesterday at 6:07 PM

Yeah, we've been deploying JPEG-XS for high bitrate streaming for a while.

A lot of our customers are moving their grading systems into data centres and streaming the images over IP back to their grading suites.

I've got it down to less than 1 frame for encode-transport-decode, but you've still got to copy the image to an SDI card and wait for that to clock out.