NetVC BoF and a roundup of things IETF

In case folks hadn't heard the good news from IETF92 in Dallas, hums from the NetVC BoF indicated consensus for forming a NetVC working group. It's now up to the IESG to formally approve or nack formation. Should the working group be formally approved, we'll obviously submit Daala as one of the inputs to the development and standardization process.

The articles above are a good summary if a bit overly Daala-centric. It's unlikely that the final codec will be 'Daala', much as the IETF work on Opus drew from our codec CELT, but also drew from other contributors, most notably the SILK codec from Skype. We hope and expect to see substantial input from other participants (such as Cisco and Google).

As a parting mention, any IETF followers or insiders who haven't yet seen ietfmemes are missing their recommended daily allowance of realtime insider process backchannel snark :-)


Daala Blog-Like Update: Bug or feature? [or, the law of Unintentionally Intentional Behaviors]

Codec development is often an exercise in tracking down examples of "that's funny... why is it doing that?" The usual hope is that unexpected behaviors spring from a simple bug, and finding bugs is like finding free performance. Fix the bug, and things usually work better.

Often, though, hunting down the 'bug' is a frustrating exercise in finding that the code is not misbehaving at all; it's functioning exactly as designed. Then the question becomes a thornier issue of determining if the design is broken, and if so, how to fix it. If it's fixable. And the fix is worth it.

[continue reading at Xiph.Org....]

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Relocated to Mountain View

For the next few months, I'm spending most of my time in Mountain View at the main Mozilla office in order to be closer to most of the rest of the Daala team. For now the plan is to be here through middle of June.

This isn't a permanent move, at least I'm not currently planning it to be. I intend to return to Somerville in the middle of June. But for now, I'm local to the other codec and FOSS hackers out in Silly Valley!


A Fabulous Daala Holiday Update

Before we get into the update itself, yes, the level of magenta in that banner image got away from me just a bit. Then it was just begging for inappropriate abuse of a font...


Hey everyone! I just posted a Daala update that mostly has to do with still image performance improvements (yes, still image in a video codec. Go read it to find out why!). The update includes metric plots showing our improvement on objective metrics over the past year and relative to other codecs. Since objective metrics are only of limited use, there's also side-by-side interactive image comparisons against jpeg, vp8, vp9, x264 and x265.

The update text (and demo code) was originally for a July update, as still image work was mostly in the beginning of the year. That update get held up and hadn't been released officially, though it had been discovered by and discussed at forums like doom9. I regenerated the metrics and image runs to use latest versions of all the codecs involved (only Daala and x265 improved) for this official better-late-than-never progress report!
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Daala Demo 6: Perceptual Vector Quantization (by J.M. Valin)

Jean-Marc has finished the sixth Daala demo page, this one about PVQ, the foundation of our encoding scheme in both Daala and Opus.

(I suppose this also means we've finally settled on what the acronym 'PVQ' stands for: Perceptual Vector Quantization. It's based on, and expanded from, an older technique called Pyramid Vector Quantization, and we'd kept using 'PVQ' for years even though our encoding space was actually spherical. I'd suggested we call it 'Pspherical Vector Quantization' with a silent P so that we could keep the acronym, and that name appears in some of my slide decks. Don't get confused, it's all the same thing!)

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Intra-Paint: A new Daala demo from Jean-Marc Valin

Intra paint is not a technique that's part of the original Daala plan and, as of right now, we're not currently using it in Daala. Jean-Marc envisioned it as a simpler, potentially more effective replacement for intra-prediction. That didn't quite work out-- but it has useful and visually pleasing qualities that, of all things, make it an interesting postprocessing filter, especially for deringing.

Several people have said 'that should be an Instagram filter!' I'm sure Facebook could shake a few million loose for us to make that happen ;-)

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ThinkPad hacking: LED backlight conversion

In case anyone was wondering what I was doing with all the LEDs recently, I've been converting classic Thinkpads with old, dying CCFL backlights to LED. It's a popular mod, and there are plenty of generic DIY backlight kits out there. Unfortunately, most of these kits don't work as-is, and there are no good instructions, walkthroughs, reviews or comparisons of various kits anyway.

I've just had a great deal of fun fixing that. Consider this a beta-test invitation :-)

Also... I touched the white tape. I touched it really quite a lot.

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Anyone know the manufacturer of this LED?

I've been working on a backlight retrofit project with some odd and fairly tight spectral output requirements. Specifically, I need a cool-white LED with a very low CIE Y value. Something around x=.3 y=.28 resulting in a purplish/pinkish tinge.

As luck would have it, one of the first engineering samples I ordered from <insert random Chinese Supplier here> as part of a larger kit nailed the requirement perfectly. What luck! I ordered an additional large lot of exactly the same part--- and was sent completely different LEDs the second time around. The combination of language barrier and reluctance to name their own suppliers has meant I've made no progress on tracking more of these suckers down. I have 50. I need about 2000.

Large photomicrographs under the cutCollapse )


And then there's this guy.

( You are about to view content that may only be appropriate for adults. )


Presentations, presentations, presentations and slide decks

The spring 'conference tour' season is finally coming to a close. I'm a bit surprised by the number of people who have asked for my slide decks. Well, slide deck actually, since of course I mostly reused the same slides across the talks this spring.

In any case, I 've posted the latest iteration (from my presentation at the just-finished Google VP9 Summit) for anyone who's interested:


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