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Opus 1.5 released: Opus gets a machine learning upgrade

opus-codec.org

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Re: Opus 1.5 released: Opus gets a machine learning upgrade

#61

Earlier quoted context omitted.

Imagine you release a codec which optimizes for cis white male voice, every other kind of voice has perceptibly lower fidelity (at low bitrates). That would not go well...

[flagged]

^- https://knowyourmeme.com/memes/conservatives-have-one-joke

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#62

Earlier quoted context omitted.

Why is the ethics question important? It is a new feature for an audio codec, not a new material to teach in your kids curriculum.

Imagine you release a codec which optimizes for cis white male voice, every other kind of voice has perceptibly lower fidelity (at low bitrates). That would not go well...

Meanwhile G.711 makes all dudes sound like disgruntled middle aged union workers

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#63

Earlier quoted context omitted.

Imagine you release a codec which optimizes for cis white male voice, every other kind of voice has perceptibly lower fidelity (at low bitrates). That would not go well...

[flagged]

https://en.wikipedia.org/wiki/Gay_male_speech?wprov=sfla1

HTH.

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#64
post #50

Earlier quoted context omitted.

To borrow from Joscha Bach: if you like the output, it's called creativity. If you don't, it's called a hallucination.

That sounds funny, but is it true? Certainly there's a bias that goes towards what you're quoting, but would you otherwise genuinely call the computer creative ? Is that a positive aspect of a speech codec or of an information source? Creative is when you ask a neural net to create a poem, or something else from "scratch" (meant to be unique). Hallucination is when you didn't ask it to make its answer up but to recit…

That's almost the same. You could say it's being creative by not following directions.

Creativity isn't well-defined. If you generate things at random, they are all unique. If you then filter them to remove all the bad output, the result could be just as "creative" as anything someone could write. (In principle. In practice, it's not that easy.)

And that's how evolution works. Many organisms have very "creative" designs. Filtering at scale, over a long enough period of time, is very powerful.

Generative models are sort of like that in that they often use a random number generator as input, and they could generate thousands of possible outputs. So it's not clear why this couldn't be just as creative as anything else, in principle.

The filtering step is often not that good, though. Sometimes it's done manually, and we call that cherry-picking.

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#65
post #41
post #5

Earlier quoted context omitted.

Isn't packet loss concealment (PLC) a form of hallucination? Not saying it's bad, just that it's still Making Shit Up™ in a statistically-credible way.

Well, there's different ways to make things up. We decided against using a pure generative model to avoid making up phoneme or words. Instead, we predict the expected acoustic features (using a regression loss), which means that model is able to continue a vowel. If unsure it'll just pick the "middle point", which won't be something recognizable as a new word. That's in line with how traditional PLCs work. It just so…

Any demos of this to listen to? It sounds potentially really good.

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#66
post #27

I wonder: did they address common ML ethics questions? Specifically: Are the ML algorithms better/worse on male than on female speech? How about different languages or dialects? Are they specifically tuned for speech at all, or do they also work well for music or birdsong? That said, the examples are impressive and I can't wait for this level of understandability to become standard in my calls.

Why is the ethics question important? It is a new feature for an audio codec, not a new material to teach in your kids curriculum.

This is a great question! Here's a related failure case that I think illustrates the issue.

In my country, public restroom facilities replaced all the buttons and levers on faucets, towel dispensers, etc. with sensors that detect your hand under the faucet. Black people tell me they aren't able to easily use these restrooms. I was surprised when I heard this, but if you google this, it's apparently a thing.

Why does this happen? After all, the companies that made these products aren't obviously biased against black people (outwardly, anyway). So this sort of mistake must be easy to fall into, even for smart teams in good companies.

The answer ultimately boils down to ignorance. When we make hand detector sensors for faucets, we typically calibrate them with white people in mind. Of course different skin tones have different albedo and different reflectance properties, so sensors are less likely to fire. Some black folks have a workaround where they hold a (white) napkin in their hand to get the faucet to work.

How do we prevent this particular case from happening in the products we build? One approach is to ensure that the development teams for skin sensors have a wide variety of skin types. If the product development team had a black guy for example, he could say "hey, this doesn't work with my skin, we need to tune the threshold." Another approach is to ensure that different skin types are reflected in the data used to fit the skin statistical models we use. Today's push for "ethics in ML" is borne out of this second path as a direct desire to avoid these sorts of problems.

I like this handwashing example because it's immediately apparent to everyone. You don't have to "prioritize DEI programs" to understand the importance of making sure your skin detector works for all skin types. But, teams that already prioritize accessibility, user diversity, etc. are less likely to fall into these traps when conducting their ordinary business.

For this audio codec, I could imagine that voices outside the "standard English dialect" (e.g. thick accents, different voices) might take more bytes to encode the same signal. That would raise bandwidth requirements, worsen latency, and increase data costs for these users. If the codec is designed for a standard American audience, that's less of an issue, but codecs work best when they fit reasonably well for all kinds of human physiology.

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#68

Earlier quoted context omitted.

Not that strange when you consider what “opus” means- product of work, with the connotation of being large and artistically important. It’s Latin, so it’s friendly phonemes to speakers of Romance languages and very scientific-and-important-sounding to English speaking ears. Basically the most generic name you can give your fine “work” in the western world.

Thanks for the definition. I like the word! I just haven't come across it in a long time, and seeing it twice on HN frontpage is bizarre!

It's funny, I was expecting the article to be about the Opus music font and was trying to figure out how ML could be involved.

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#69
What if there was a profiler or setting that helps to reencode existing lossy formats without introducing too many more artifacts? An sizeable collection runs into the issue, if the don't have (easily accessible) lossless masters.

I'd be very interested if I could move a variety of mp3s, aacs and vorbis to Opus if I knew additional quality loss was minimal.

Re: Opus 1.5 released: Opus gets a machine learning upgrade

#70

Why the hell opus still not in Bluetooth? Well i know - sweet sweet license fees (aKKtually, there IS opus codec, supported by pixel phones - google made it for VR/AR stuff. No one uses it, there are about ~1 headphone with opus support )

Opus isn’t patent free, and what’s worse it’s not particularly clear who owns what. The biggest patent pool is currently OpusPool but it’s not the only one. https://www.opuspool.com/

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