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

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

#171
This is subjective, but there is loss of real speech information here. I don't hear the accents of these speech samples daily. I can easily follow the uncompressed versions. But the heavily compressed versions delete cues and I could not initially understand them.

This is an effect even with regular telephony these days. A smartphone, carefully held a little way from your ear because you don't trust it to mask touch events when used as a phone, and using 16kbps audio, is not as understandable as an old fashioned hardline phone. Ironically, higher fidelity audio via app (e.g. Whatsapp phone calls) scores better, despite the occasional glitches.

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

#172

Earlier quoted context omitted.

Not OP, and I haven't done it myself yet, but it makes a lot of sense. It's basically free image hosting if you can get the file cached by Cloudflare. Imgur these days is slow and riddled by ads. A page show will sometimes load many times the image size in Javascript, stylesheets and images. It also doesn't allow the user to just view the raw image, going as far as redirecting requests to the raw image to a web page…

Are these imgur problems a USA thing? Because I literally never had any of the behavior described. Direct image links always go to the image, there is no JS or HTML or anything.

Yep same here. Maybe the issue is about non-direct links, but it could be that imgur changes what it responds with depending on the request. If the url ends with .jpg it can still serve an HTML page.

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

#173
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…

Arguing is definitely affected by latency but it is at least possible to reduce latency, e.g. by getting fibre internet or using ethernet.

A more annoying "feature" of many VoIP systems is that they mute the other person while you're talking. You literally can't interrupt people because they won't hear you.

I presume this is done in order to reduce feedback, but it still sucks.

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

#174
post #48
post #8

Nothing about licensing or patents. I assume the worst (read: unusable for small businesses)? 10+ years ago I worked in a small voip shop, where we had very high quality (low jitter), but low bandwidth connection. I researched many codecs of the time (2010-ish). We liked speex, because it can be used "without strings attached". Also, I can choose the quality depending on the bandwidth. Although for low bandwidth g729…

These days the correct comparison would be to Opus, which is similarly unencumbered and performs fantastically at low bitrates (and has a speech specific mode for even lower bitrates, because it's a hybrid of two codecs). It's also extremely low latency, so there's now no reason to accept trade-offs. (For the same bitrate as alaw/ulaw, you can get high quality full band music with Opus.) These days it's more or less…

They did compare to Opus.

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

#175
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…

Definitely a real effect, but Lyra is still clearly an improvement and I assume their MOS testing accounts for that.

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

#176

http://www.rowetel.com/wordpress/?page_id=452 Take a look at this too. Also runnable on low power devices. And there was some work of using AI to enhance the codec2 encoded bits too.

Yeah, with Codec 2 setting the gold standard, I don't find this very impressive. I find this more intelligible at one-third of the Lyra bitrate: http://www.rowetel.com/downloads/codec2/hts2a_1300.wav Codec 2 does a better job of isolating the parts of sound which are most necessary to intelligible speech, without necessarily caring too much about preserving the original qualities of the speaker's voice or environment…

It's definitely impressive but your ears are broken if you think that is more intelligible.

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

#177

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?

I think the old Iridium satellite constellation only went as high 3 kbps. It was heavily depended on by the US military. I'm sure there's still a need for this.

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

#178

When Google's announcement [1] was posted a few days ago, I listened to their samples and heard an odd effect in the "chocolate bread" sample (the video chat example) [1], which is not mirrored in this article. On that sample, I felt [2] that the Lyra version exaggerates the pronunciation of the phrase 'with chocolate' in a way that meaningfully differs from the speaker's original. It weakens the voiced 'th' to nothi…

"When a man looks for something beyond his reach ..." The word "looks" sounds completely wrong for me with Lyra. To the point of completely not understanding what this word is supposed to be (first example with your [1] link).

Similarly, for me, the word "miracle" in the the noisy environment becomes like "vericle" with Lyra, where in Opus it is clearer. (Speex does fairly badly, but in a way that's a clear failure overall rather than making it sound like something else.)

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

#180
Funny thing: voice codecs below 2.4kbps are export controlled by ITAR, right along side military technology and nuclear devices. David Rowe, who made the codec2 open source voice codec, had to get confirmation from his govt that they would not enforce it on his project: https://www.mail-archive.com/freetel-codec2@lists.sourceforg...

I'm not sure exactly why - someone mentioned that it might be because deep submarines have very little bandwidth and need to use them, but I don't have a reference.

Nevertheless, wouldn't be surprised if google didn't want the hassle.

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