xiphmont: (Default)

Opus 1.1 just hit release candidate; pending any last minute bug discoveries or showstoppers, this will become the final 1.1 release.

The release candidate includes two major improvements over the previous 1.1 beta.

We've further improved surround encoding quality and tuning of both surround and stereo at lower bitrates. As an example, full 48kHz 5.1 surround is now tested and tuned down to 45kpbs (it's nowhere near audiophile quality at that rate, but it is surprisingly good).

In addition, we also landed additional encode/decode optimizations for all CPU types, but especially ARM which now includes NEON encoding optimizations.

And of course, we hopefully cleared the 1.1-beta buglist :-)

xiphmont: (Default)

Greg Maxwell has just posted a nice second 'demo' page for Opus. It mostly covers the recent listening testing done by volunteers at Hydrogen Audio. Pretty colors and interactive listening/comaprison scripting!

For those of you new to Opus, it's the FOSS/RF codec we're working on within the IETF codec working group. Opus is a collaborative hybrid speech / high-fidelity audio codec built using primarily Xiph's CELT codec and the Skype SILK voice codec as inputs. That makes Opus similar in some ways to what MPEG is trying to achieve with USAC (Unified Speech and Audio Coding), though Opus is also ultra-low latency, so it looks like we're considerably ahead of MPEG here.

xiphmont: (Default)

A quick post to mention that I've just put a new demo page up introducing a new audio codec named CELT. It's Xiph's first next-generation audio codec now emerging from the development pipeline, intended for high fidelity use at ultra-low latency.

Follow the above link to a ton more about it. As usual, the demo's got plenty of... well... demo, in addition to eye candy and hard information.

Buried in that larger announcement (about a much larger project) is a mention in passing of Squishyball, a cute little app I wrote last month to do fast/easy/convenient comparison between groups of similar samples. It also performs more rigorous A/B, A/B/X and X/X/Y double-blind testing. We'd all been limping along with harder to use apps that caused us to avoid or put off careful listening tests as part of day-to-day codec development. Hopefully Squishyball fixes that.


xiphmont: (Default)


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