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Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

cnx-software.com

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Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#151

Post by ChuckMcM »

cycomanic wrote: post #149
ChuckMcM wrote: post #142

Earlier quoted context omitted.

Well the blog post states they use a generative model. If that means what I think that means, they are doing in audio what folks have done in images which is sketch where a rabbit should be and have the model generate a rabbit there. Great encoding because the notion of 'rabbit-ness' is in the model not the data. Again, assuming I understand correctly, that isn't a "trans coder" that is "here is a seed, generate what…

From that I would naively expect that the performance of the codec could be very language dependent. It would be interesting to see how well it does in other languages.

But that is the thing, what if it isn't a codec? What if it is simply a set of model parameters, a generative model, and a stream of fiducial bits which trigger the model? We have already seen some of this with generative models that let you generate voices that sound like speaker data used to train the model right? What if, instead of say "i-frames" (or what ever their equivalent would be in an audio codec) you sent "m-frames" which were tweaks to the generative model for the next few bits of data.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#152

Post by comex »

nayuki wrote: post #145
cnorthwood wrote: post #96

Earlier quoted context omitted.

Most landline networks are also digital now for exchange to exchange communications, so even those will be packet based

Not all packets are created equal. ATM (Asynchronous Transfer Mode) cells have a fixed 48-byte payload, but IP (Internet Protocol) packets have longer headers and variable-length payloads up to about 1500 bytes. ATM is designed for low latency audio transfer, whereas IP incentivizes using bigger packets to reduce overhead at the expense of more latency.

Historically, sure. But at a realistic modern internet speed of, say, 15 MB/s, 1500 bytes takes 0.1ms to transfer. Even at 1.5 MB/s it takes 1ms. Typical VoIP call latency apparently ranges from 20ms to 200ms, so packet size is not a major contributor.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#153

Post by tgv »

reaperducer wrote: post #45
rectang wrote: post #39

What I want to know is whether Lyra takes any longer to encode than the alternatives. Because as far as I can tell, nobody cares in the slightest about latency. Phone calls are getting to be like writing postcards to each other. Speak in a whole paragraph. Wait several seconds for the latency to clear. Then the other party responds with a whole paragraph, waits several seconds for the latency to clear... Improvements…

I had the pleasure of using a real landline just before the pandemic. Honest wire-to-wire connection between two ranches, so no silly VOIP steps between. It was fantastic. You don't appreciate how much latency is destroying our ability to communicate verbally until you go back to the old way. One example is arguing. It's no wonder people used to be able to argue with one another on a telephone. You could raise your v…

Another thing I clearly experienced in the beginning of the mobile phone era, when one still could compare those things, was dynamic range. When speaking via a good landline, you could hear the presence of the other, but on mobile, there was only speech or silence. Noise suppression saves bandwidth, but it is so aggressive that the nuances in the other's utterances (breathing, hesitations, etc.) simply disappear. For a simple transaction that's not a problem, but when your SO lives far away, miscommunication arises too easily.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#154

Post by kevin_thibedeau »

chrisseaton wrote: post #49
kevin_thibedeau wrote: post #46

Earlier quoted context omitted.

Just disable VoIP or disconnect from WiFi.

Isn't the actual phone network packet-switched and running over fibre optics now anyway? I don't think you can get a literally analog phone call anymore can you?

Telco networks have QoS guarantees that your ISP will never meet. Bypass the ISP and you won't have to deal with their latency.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#155

Post by jbluepolarbear »

I listened to the first 4 samples of the woman speaking and Lyra was the most clear and close to the loudness of the original, but it was also the most different. Lyra sounds like a computer voice of the women speaking the sentence back. I don’t know how to explain it better, I pick out the slight buildup/double “p” and it’s not present in the Lyra version. Almost like it’s removing human speech imperfections.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#156

Post by morsch »

rectang wrote: post #39

What I want to know is whether Lyra takes any longer to encode than the alternatives. Because as far as I can tell, nobody cares in the slightest about latency. Phone calls are getting to be like writing postcards to each other. Speak in a whole paragraph. Wait several seconds for the latency to clear. Then the other party responds with a whole paragraph, waits several seconds for the latency to clear... Improvements…

There is voip software that is designed to be low latency, eg Jamulus. It's not as easy to use as Jitsi and Zoom are, though.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#157

Post by perryizgr8 »

walrus01 wrote: post #31

Microsoft also just announced a 6kbps advanced audio codec: https://techcommunity.microsoft.com/t5/microsoft-teams-blog/...

And it sounds significantly better to me, which is expected since they use double the bitrate.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#159

Post by jbluepolarbear »

mfkp wrote: post #141

After reading vidarh's comment below ("The biggest challenge with evaluating all of these, is that once you've listened to a comprehensible version of one of these samples, they all sound more intelligible."), I recommend trying to listen to the Lyra version first, then listen to the original next. It actually does sound very strange when you don't have the true audio parsed in your head already. I'm not sure if I wo…

I did as you said and watched the Lyra version first. I couldn’t understand her and the tone wasn’t matching her lips and mouth. It sounds like someone with a speech impediment is dubbing someone who is not. I wonder how much miscommunication is caused by poor compression and latency.

Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate

#160

Post by vortico »

Why in the world do we need 3 kbps audio for voice? It's so hard to hear people speaking over mobile phones. Why don't we use 32-64 kbps 48 kHz for all voice communication? GSM CSD offers 9-14 kbps down/up, 3G offers 384 kbps, and EDGE offers 473 kbps. Why limit to 3 kbps?
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