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H.264 is Magic

sidbala.com

191–200 of 230 posts

Re: H.264 is Magic

#191
post #168

Earlier quoted context omitted.

I would probably say I found a two headed coin. I also like how "HHHHHHHHHH" is shorter than "I tossed it 10 times, all heads"

The all-heads sequence is exactly as likely as any other sequence.

right, but you can also say there are many sequences that aren't all heads.

Re: H.264 is Magic

#192

Absolutely love this: 'Suppose you have some strange coin - you've tossed it 10 times, and every time it lands on heads. How would you describe this information to someone? You wouldn't say HHHHHHHHH. You would just say "10 tosses, all heads" - bam! You've just compressed some data! Easy. I saved you hours of mindfuck lectures.' This is a really great, simple way to explain what is otherwise a fairly complex concept…

I definitely wouldn't say "HHHHHHHHH," since I tossed it 10 times, not 9. Saying "10 tosses, all heads" reduces the chance of omitting a toss in data entry, which is all to the better.

You're making the assumption the other party knows English, rather than say the abstraction of 'coinflip' which in itself can be abstracted. Do they understand the concept of fairness - is it even odds or not? There's a reason that numbers are considered a more universal 'language' than other forms of communication.

Re: H.264 is Magic

#193
This is great as a high-level overview... except that it's way too high-level. These are all extremely well-known techniques. Is there any modern video compression scheme that doesn't employ them?

In other words, why is H.264 in particular magical?

Re: H.264 is Magic

#194
post #32

Earlier quoted context omitted.

This is really interesting and the imgur picture you linked (with your explanation) explains it really clearly! But when seeking, why wouldn't any local media playback seek backwards and reconstruct the full frame? It's not like the partial frame after seeking is useful - I'd rather wait 2 seconds while it scrambles (i mean "hurries up") to show me a proper seek, wouldn't everyone? What was your Internet search for f…

"datamoshing" is a term I've heard for people deliberately removing I-frames, so P-frames are applied to the wrong base image.

In a course I taught (2010) on music visualizations that's the term I used.

The example I used in the lecture where datamoshing came up was the music video for Charlift's "Evident Utensil"[1]; I always thought this was a neat example.

[1]: https://www.youtube.com/watch?v=mvqakws0CeU

Re: H.264 is Magic

#196
post #187

Earlier quoted context omitted.

FAIL. "10 tosses, all heads" is 20 characters while "HHHHHHHHHH" is 10 characters. You've conducted expansion rather than compression.

"10H" is the string you should be comparing it to (or something equivalent.)

If we're going there, H10 may be more efficient.... h10t5h1... Thinking the heads vs tails expression would be before the iteration as a better use case.

Re: H.264 is Magic

#197

"See how the compressed one does not show the holes in the speaker grills in the MacBook Pro? If you don't zoom in, you would even notice the difference. " Ehm, what?! The image on the right looks really bad and the missing holes was the first thing I noticed. No zooming needed. And that's exactly my problem with the majority of online video (iTunes store, Netflix, HBO etc). Even when it's called "HD", there are comp…

Yep, me too - more like, if I was blind, I wouldn't notice the difference. Which is why the bitrate is always the first thing I look at when sourcing video.

But given other settings with even h.264 vs. h.265 and the source content, that isn't always a valid metric either.

I mean for fast action scenes, I rarely notice the difference between 720p and 1080p at 10ft away... but different encoding and sources, not just size alone can make significant differences.

Re: H.264 is Magic

#198

Earlier quoted context omitted.

I stopped using VLC when I found mpv [0]. I really like it because it exposes everything from the CLI, so once you're familiarized with the flags you're interested in using, it's easy to play anything. For everyday usage it "just works" too, as expected of any video player. [0] https://mpv.io/

How does it compare to mplayer? My biggest complaint about mplayer is it still doesn't play VFR videos well.

I've tried it.

* Sane defaults (encodings and fonts, scaletempo for audio)

* instantaneous play of next and previous videos

* navigation in random playlist actually works

* Easy always on top key binding

* Most mplayer key bindings work

I'll definitely keep on trying it for a while.

Re: H.264 is Magic

#199

I recently experienced this as follows: https://www.sublimetext.com has an animation which is drawn via JavaScript. In essence, it loads a huge .png [1] that contains all the image parts that change during the animation, then uses to draw them. I wanted to recreate this for the home page of my file manager [2]. The best I could come up with was [3]. This PNG is 900KB in size. The H.264 .mp4 I now have on the home pag…

You could give FLIF [1] a try. With the help of Poly-FLIF [2] you can render it in the browser. Don't forget to try the lossy mode, it gives better compression with negligible loss in quality.

1: http://flif.info

2: https://github.com/UprootLabs/poly-flif/

Re: H.264 is Magic

#200
post #97
post #33

Earlier quoted context omitted.

H.265 gets you half the file size for ten times more in royalty fees, or saving 50% of bandwidth for 1000% more in royalty.

Do you have a reference for that? I was under the impression that the first 100,000 units are free, and then 20c per unit afterwards to a max of $25m. H264 drops to 10c per unit after 5m units, to a max of $6.5m. You need to be shipping 125 million units annually to hit the full $25m. Yes it's more, but it's not quite ten times. And notably if the chip maker pays the royalties, then the content creators don't need to…

It is actually more then 10x. The annual cap for H.264 royalty fees is 6.5M from MPEG-LA. For H.265 it is 25M from MPEG-LA, AND 50M from HEVC-Advance. That is a total of 75M. And like others have pointed out there are Technicolor patents fees not included.

So it depends how these royalty works in details. If only the chip manufacture are paying, Mediatek, Qualcomm, Samsung, Intel, AMD, Nvidia, Apple. That is at least 10 players paying maximum. And if you consider small players, the total contribution of Royalty fees to HEVC is 1 Billion / Year. ONE BILLION!! In the life time of a Video Codec that typically run at least a decade, these patents are 10 Billions.

Do you think that is a fair price, i think everyone should decide for their selves.

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