Entries by tag: xiph

xiphmont

Introduction to Daala part 4: Chroma from Luma

Another new demo, another new technique specific to Daala: frequency domain prediction of the chroma planes from the luma plane!

Predicting the chroma planes from the luma plane isn't a brand-new idea. Still, we're both the only codec to actually be deploying it, and we're doing it entirely in the frequency domain (which is novel).

Read on!

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xiphmont

Introducing Daala, part 3: Time/Frequency Resolution Switching

I've just posted part 3 in my demo series introducing the Daala video codec. This one is kind of a long one, mainly because I think it's one of the only really detailed presentations of a technique Jean-Marc Valin of Xiph invented and first introduced in the Opus audio codec: 'TF' aka Time/Frequency resolution switching.

Even better... while I was documenting TF for posterity, I spotted a possible improvement. So, I've tossed in documentation of a brand new technique as well!

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xiphmont

Introducing Daala part 2: Frequency Domain Intra Prediction

Now up, part two of the introduction I'm writing for Xiph's upcoming video codec Daala. The fact that we're using lapped transforms means we've had to apply a little cleverness to intra prediction, and so we've opted to do it in the frequency domain...

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xiphmont

A new demo page for the Opus 1.1 beta release

I've made another demo page, this one in celebration of the Opus 1.1 beta release today...

"Opus marches onward toward its manifest destiny with today's beta of the upcoming 1.1 release. This will be the first major update to libopus since standardization as RFC 6716 in 2012, and includes improvements to performance, encoding quality, and the library APIs. Here's a few of the upgrades that Opus users and implementors will care about the most."

Cheers!

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xiphmont

Next-Next Generation Video: Introducing Daala

Xiph.Org has been working on Daala, a new video codec for some time now, though Opus work had overshadowed it until just recently. With Opus finalized and much of the mop-up work well in hand, Daala development has taken center stage.

I've started work on 'demo' pages for Daala, just like I've done demos of other Xiph development projects. Daala aims to be rather different from other video codecs (and it's the first from-scratch design attempt in a while), so the first few demo pages are going to be mostly concerned with what's new and different in Daala.

I've finished the first 'demo' page (about Daala's lapped transforms), so if you're interested in video coding technology, go have a look!

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xiphmont

Wait, dude, what?

Oh. Oh my. After a decade of the MPEG LA saying they were coming to destroy the FOSS codec movement, with none other than the late Steve Jobs himself chiming in, today the Licensing Authority announced what we already knew.

They got nothing. There will be no Theora patent pool. There will be no VP8 patent pool. There will be no VPnext patent pool.

We knew that of course, we always did. It's just that I never, in a million years, expected them to put it in writing and walk away. The wording suggests Google paid some money to grease this along, and the agreement wording is interesting [and instructive] but make no mistake: Google won. Full stop.

This is not an unconditional win for FOSS, of course, the LA narrowed the scope of the agreement as much as they could in return for agreeing to stop being a pissy, anti-competetive brat. But this is still huge. We can work with this.

For at least the immediate future, I shall have to think some uncharacteristically nice things about the MPEG LA.*

And now... Discuss!

*Apologies to Rep. Barney Frank


xiphmont

It's Out! It's Finally Out!

We did it. We finally finished Xiph's second big video: Episode 2: Digital Show & Tell

"The second video from Xiph.Org explores multiple facets of digital audio signals and how they really behave in the real world. Sampling, quantization, dither, band-limiting, and vintage bench equipment all in one video!" Go see it!

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xiphmont

Why 24-bit/192kHz music downloads make no sense

(by Monty and the Xiph.Org community)

Articles last month revealed that musician Neil Young and Apple's Steve Jobs discussed offering digital music downloads of 'uncompromised studio quality'. Much of the press and user commentary was particularly enthusiastic about the prospect of uncompressed 24 bit 192kHz downloads. 24/192 featured prominently in my own conversations with Mr. Young's group several months ago.

Unfortunately, there is no point to distributing music in 24-bit/192kHz format. Its playback fidelity is slightly inferior to 16/44.1 or 16/48, and it takes up 6 times the space.

If you just said 'Whaa?', you may want to read the whole article.

It's fairly long... but hearing, perception and fidelity are complicated topics. Shysters and charlatans exploit that nuance (and misunderstanding) to bilk unsuspecting consumers of their money, all the while convincing them they're paying for 'quality'.

Anyway, happy reading and comments welcome!


xiphmont

XiphQT components, MAC OS X and 64 bit iTunes

Camilla forwarded a necessary tip for installing the XiphQT components on a 64 bit Mac OS X so that it works with iTunes. This is a reasonably well known tip, but it wasn't in our FAQ or installation instructions (well it is now as of about ten minutes ago) so I'm passing it along now too...

I upgraded to Lion, and my ogg files stopped being able to play in iTunes (silently). Here's how to make it go:
  1. "show in finder" your iTunes binary (either navigate to the Applications folder, or right/control click on it in the dock, and choose "show in finder")
  2. right/control click on iTunes in the finder, and select "Get Info"
  3. Under General, check the box marked "Open in 32-bit mode"

You should put the above on something linked from: http://www.xiph.org/quicktime/download.html I paraphrased it from roaringapps.com.

If XiphQT can be rebuilt in 64 bit mode, and that shipped that way to Lion users, that would also be a good solution.

That last comment is actually a bit of an embarrassment for us at the moment; neither the XiphQT builds nor code have been updated since 2009 or so, despite multiple releases, fundamental improvements and new features in the Xiph codecs since. There are actually more recent beta builds of updated Mac OS X and Win32 XiphQT components than never got bumped to the official XiphQT download page, but even these builds are from mid 2009.

We don't have any high-powered Mac OS hackers in the core Xiph group at the moment. I have some relatively insignificant amount of experience coding for Mac OS X and Quicktime, but I've been hoping for a volunteer with more chops. Any takers?

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xiphmont

Ghost Update: Demo 4

Turns out I missed blogging about the latest Ghost update... back in November...

Ghost Demo4 is up on the demo list showing the sinusoidal extractor doing some very early sinusoidal tracking frame to frame, and a very early example of the analysis performing real sinusoidal/non-sinusoidal audio splitting. Pictures and interactive listening, oh my!

It looks like I'll be putting a month or two into transOgg before getting back to Ghost work (and demo 5). The work that went into demo4 raised a number of questions I'm not sure how to approach answering yet, so I'm going to let that percolate for a bit.

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