How does a video codec work? • Hacker News Board

Re: How does a video codec work?

#51

Post by lightedman » Sun, Nov 24, 2019, 5:24 PM UTC

EvanAnderson wrote: post #44

lightedman wrote: post #41

Earlier quoted context omitted.

278GB is a bit off. The real number is higher than that, but not by too much more, but they definitely messed up on their math somewhere. 1280 horizontal pixels times 720 vertical pixels times 8 bits per pixel color channel times 3 color channels (RGB) times 30 FPS times 60 SPM (sec per min) times 60 MPH (min per hour) divided by 8 bits to convert bits to bytes and finally divided by 1,024 bytes per kilobyte gives 29…

You're mixing Si units and IEC units[1]. The article's measurement of 278 GB (sic) is really 278 GiB. 1280 horizontal resolution x 720 vertical resolution x 3 8-bit bytes per pixel x 30 frames per second x 3600 seconds per hour is 298,598,400,000 bytes per hour. 1GiB (1,024 bytes x 1,024 KiB x 1,024 MiB) is 1,073,741,824 bytes. Dividing that out gives ~278.09 GiB. [1] https://en.wikipedia.org/wiki/Binary_prefix

I'm responding directly to the GB claim. I'm very well-aware of binary prefix (in fact several of my other online names are those very words) and the general industry-wide mix-up that is used on the common consumer is to start with KiB and then just run that in plain units of 1,000 for MB and GB, which is what I went with.

Re: How does a video codec work?

#52

Post by danbmil99 » Sun, Nov 24, 2019, 7:51 PM UTC

CharlesW wrote: post #46

danbmil99 wrote: post #37

Earlier quoted context omitted.

sure, if by support you mean "embrace, extend, extinguish". Today, Apple is every bit as monopolistic and anti-competitive as Microsoft was during Peak Ballmer.

If that's the narrative you're focused on, you'll want to point to something else to support that. Apple not only uses standards-based compressed media formats exclusively, but the MPEG-4 file format is the QuickTime Movie file format (which Apple contributed to the standard).

I'm referring to their gamesmanship wrt AV1. Of course they supported Mpeg4, they were part of the patent cartel (MPEG-LA) with a get-out-of-jail antitrust exemption and cross-licensing to other bigco's such as MS and Sony.

One reason Google bought On2 and pushed VPx/webm/AV1 was because they didn't have video patents to use as trading chips in the cartel (On2 had several patents).

Full disclosure: I was co-founder of On2

Re: How does a video codec work?

#53

Post by CharlesW » Mon, Nov 25, 2019, 5:53 PM UTC

danbmil99 wrote: post #52

CharlesW wrote: post #46

Earlier quoted context omitted.

If that's the narrative you're focused on, you'll want to point to something else to support that. Apple not only uses standards-based compressed media formats exclusively, but the MPEG-4 file format is the QuickTime Movie file format (which Apple contributed to the standard).

I'm referring to their gamesmanship wrt AV1. Of course they supported Mpeg4, they were part of the patent cartel (MPEG-LA) with a get-out-of-jail antitrust exemption and cross-licensing to other bigco's such as MS and Sony. One reason Google bought On2 and pushed VPx/webm/AV1 was because they didn't have video patents to use as trading chips in the cartel (On2 had several patents). Full disclosure: I was co-founder o…

> I'm referring to their gamesmanship wrt AV1.

As I'm sure you know, Apple joined AOMedia to demonstrate their support of AV1, and they're actively looking for Media Video Engineers with experience in AV1 and other video standards[1].

If there's been anti-standards gamesmanship, I'm not aware of it and would appreciate it if you'd share what you know.

[1] https://jobs.apple.com/en-us/details/200109105/media-video-e...