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Thor – A Project to Hammer Out a Royalty Free Video Codec

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Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#71

Post by billconan »

derf_ wrote: post #28
halosghost wrote: post #11

Actually, I'm still rooting for Daala (from Xiph.org, the same folks that did so well with Opus). It's still a long ways away from being finished, but their work is awesome and I've been following it for a while now! Either way, having another effort competing to make a great format is not a problem. Here's hoping it goes well!

Hello, I'm the Daala tech lead. One of the things that made Opus a success was the contributions of others. We certainly don't have a monopoly on good ideas. We'll take pieces of Daala and stick them in Thor and pieces of Thor and stick them in Daala, and figure out what works best. Some of that experimentation has already begun: https://github.com/cisco/thor/pull/8 https://review.xiph.org/874/ https://www.ietf.org/p…

I hope you could have a comprehensive write-up about how codec works.

your article, such as this http://people.xiph.org/~xiphmont/demo/daala/demo1.shtml is the best codec introduction I could find online, but still I couldn't follow, say, the deblocking part.

there doesn't seem to be a book covering this area.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#72

Post by loumf »

stephengillie wrote: post #69
tokenizerrr wrote: post #36

Earlier quoted context omitted.

Not just re-invent, since if you happen to invent something by yourself the same way as it happens to have been patented then you're still in trouble.

Or (I'm assuming, IANAL) you could pursue a court battle, and attempt to prove that your independent invention means it's too obvious to be patentable.

I think you mean "too obvious" (can't be too novel)

I think it would be a big mistake to admit that yours is the same, because if this doesn't carry you've effectively said you are infringing.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#73

Post by happyscrappy »

smithkl42 wrote: post #21
jngreenlee wrote: post #2

"We also hired patent lawyers and consultants familiar with this technology area. We created a new codec development process which would allow us to work through the long list of patents in this space, and continually evolve our codec to work around or avoid those patents. Our efforts are far from complete, but we felt it was time to open this up to the world." This burden is becoming far too great, when this is the…

Amen. As Thomas Jefferson (correctly) described patents, they're a part of positive law, not natural law. In other words, their only justification is pragmatic, not moral. You can't "own" an idea the way that you can own a couch or a car. We allow for (temporary) patent protection because it's supposed to encourage innovation and help our economy. If it doesn't - and it's clearly reached the point where it hinders ra…

Tesla(edit:SpaceX) is not bothering to file patents because it is just a blueprint for countries like China who quickly build knockoffs on someone else's R+D dime.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#74

Post by TD-Linux »

mappu wrote: post #64
TD-Linux wrote: post #25

Earlier quoted context omitted.

It is currently quite a bit slower, but the goal is to make a codec fast enough for real time communication use. VP9 is still about 9x slower than x264, but yields the same quality at half the bitrate. You can set VP9 to run a lot faster, but you'll lose some of the bitrate advantages. Still, VP9 is practical for a lot of applications, such as Youtube.

VP9 producing the same quality as x264 at half the bitrate is hard to believe. Do you have a citation? Which `--preset` for x264 are you basing this on?

It's based on --best for VP9 1.4.0 and placebo for x264. Generally improvement tends to be from 30-50%, based on the quality target and content (the lower the bitrate, the greater the improvement). I have objective metrics which test this at http://arewecompressedyet.com/.

If you're more of a visual person, you can take a look at some images here, compressed to 60KB: https://people.xiph.org/~tdaede/pcs2015_vp9_vs_x264/0.25/

Certainly libvpx still has a lot of optimization and tuning work left to do. But there's only so much x264 can do with a 15 year old bitstream format.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#75

Post by TD-Linux »

DarkLinkXXXX wrote: post #70
Sir_Cmpwn wrote: post #65

Earlier quoted context omitted.

I can anecdotally agree with him. I ran a service that did a lot of media encoding and VP9 is very, very slow to encode.

Could that be due to lack of hardware support?

No, generally encoding is done in software. It's just because VP9 is a much more complex format with many more different coding possibilities to search. It also hasn't been around as long as x264 to be hyper-optimized.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#76

Post by bqe »

jerf wrote: post #60
TD-Linux wrote: post #19

Earlier quoted context omitted.

VP9 is a good choice if you want a royalty free video codec right now. NETVC is shooting for the next generation. In addition, the goal is to get the video codec standardized at the IETF. NETVC participation is open to anyone though, so it is possible more players will show up.

"NETVC is shooting for the next generation." What makes a codec "next generation"? I assume, broadly, it involves trading off more yet more computation for a tighter encode? (As nearly an embarassingly-parallel problem, video coding continues to get faster with more silicon even if serial performance is stagnant.) What kind of gains can we expect from the "next generation"? All honest questions, BTW. Links welcome, t…

Next generation is indeed a vague term, but I would use HEVC as a good example of a next generation codec.

For another codec to be next gen, it should have the same or better compression than HEVC: about half as many bits to encode the same video than H.264 required.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#77

Post by theandrewbailey »

russtrotter wrote: post #58

Wasn't Ogg Theora created under just the same principles? I'm not smart enough in all things codec to know how it stacks up technically, but best I can tell, it's unencumbered. https://en.wikipedia.org/wiki/Theora

Theora simply can't do what H264 can.

example: http://www.streaminglearningcenter.com/articles/ogg-vs-h264-...

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#78

Post by astrange »

jerf wrote: post #60
TD-Linux wrote: post #19

Earlier quoted context omitted.

VP9 is a good choice if you want a royalty free video codec right now. NETVC is shooting for the next generation. In addition, the goal is to get the video codec standardized at the IETF. NETVC participation is open to anyone though, so it is possible more players will show up.

"NETVC is shooting for the next generation." What makes a codec "next generation"? I assume, broadly, it involves trading off more yet more computation for a tighter encode? (As nearly an embarassingly-parallel problem, video coding continues to get faster with more silicon even if serial performance is stagnant.) What kind of gains can we expect from the "next generation"? All honest questions, BTW. Links welcome, t…

Video encoding is not embarrassingly parallel; no kind of compression ever can be, because if any bit doesn't depend on the previous bit you've wasted it. It is pretty suited to ASICs.

Codecs are only efficient up to a certain image size, and then stop working because all the details are too large-scale for them. HEVC works much better than H.264 on 4K. Besides that, there's higher bit depth pixels, 3D, that kind of stuff.

Also there's usually so many mistakes and compromises in any standard that you can always find something to fix in the next one.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#79

Post by lawl »

jerf wrote: post #60
TD-Linux wrote: post #19

Earlier quoted context omitted.

VP9 is a good choice if you want a royalty free video codec right now. NETVC is shooting for the next generation. In addition, the goal is to get the video codec standardized at the IETF. NETVC participation is open to anyone though, so it is possible more players will show up.

"NETVC is shooting for the next generation." What makes a codec "next generation"? I assume, broadly, it involves trading off more yet more computation for a tighter encode? (As nearly an embarassingly-parallel problem, video coding continues to get faster with more silicon even if serial performance is stagnant.) What kind of gains can we expect from the "next generation"? All honest questions, BTW. Links welcome, t…

From https://xiph.org/~xiphmont/demo/daala/demo1.shtml

> Our performance target is roughly a generation beyond current 'next-generation' codecs like VP9 and HEVC, making Daala a next-next-generation effort.

and

> The next-generation VP9 and HEVC codecs are the latest incremental refinements of a basic codec design that dates back 25 years to h.261. This conservative, linear development strategy evolving a proven design has yielded reliable improvement with relatively low risk, but the law of diminishing returns is setting in. Recent performance increases are coming at exponentially increasing computational cost.

> Daala tries for a larger leap forward— by first leaping sideways— to a new codec design and numerous novel coding techniques. In addition to the technical freedom of starting fresh, this new design consciously avoids most of the patent thicket surrounding mainstream block-DCT-based codecs. At its very core, for example, Daala is based on lapped transforms, not the traditional DCT.

Re: Thor – A Project to Hammer Out a Royalty Free Video Codec

#80

Post by TD-Linux »

mappu wrote: post #66
bitmapbrother wrote: post #54

Earlier quoted context omitted.

VP9 being 9x slower than x264 is hard to believe. Do you have a citation?

"VP9 encoding (using libvpx) is horrendously slow – like, 50x slower than VP8/x264 encoding. This means that encoding a 3-minute 1080p clip takes several days on a high-end machine. ... libvpx multithreading [encoding] performance is deplorable. It gains virtually nothing."[1] 1. https://blogs.gnome.org/rbultje/2014/02/22/the-worlds-fastes... n.b. x264 comparisons were taken with `--preset veryslow` which understates…

This is old. libvpx 1.4.0 is a lot faster now and has multithreading. On my i7-4900MQ laptop, I get about 3fps encoding 1080p content. Still very slow, but 24 minutes for a 3 minute clip, not days.
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