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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

#141

Post by mfkp »

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 would like having to do the extra work to translate this in my head on every conversation.

It's more apparent in the video example from the Google post, I won't spoil it but there's a word that starts with B that sounds very funny in the Lyra version (listen to that one first): https://ai.googleblog.com/2021/02/lyra-new-very-low-bitrate-...

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

#142

Post by ChuckMcM »

bscphil wrote: post #113
ChuckMcM wrote: post #111

Earlier quoted context omitted.

So nearly 6dB louder. That is quite a bit.

Yes. Assuming this was done by the Lyra encoder directly, and not the person who wrote the blog post pushing the slider, you have to wonder how it would respond to an input with a peak around -3 dB. Would it clip? Is it performing some kind of normalization? Who knows! It's also interesting that the Lyra clip is ever so slightly longer than the other two. The Opus clip has exactly the same number of samples as the re…

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 this seed creates." kind of thing.

Another way to look at it would be to think about text to speech. That takes words, as characters, and applies a model for how the speech is spoken, and generates audio. You could think of that as really low bit rate audio but the result doesn't "sound" like the person who wrote the text, it sounds like the model. If instead, you did speech to text and captured the person's timbre and allophones as a model, sent the model and then sent the text, you would get what they said, and it would sound like them.

It is a pretty neat trick if they are doing it that way since it seems reasonably obvious for speech that if you could do it this way then the combination of model deltas and phonemes would be a VERY dense encoding.

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

#143

Post by Semaphor »

jeroenhd wrote: post #101
domoritz wrote: post #95

Earlier quoted context omitted.

Off topic but how do you put images on ipfs and what’s the advantage over e.g. Imgur?

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.

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

#144

Post by jhoechtl »

bscphil wrote: post #79

I've just taken a minute to confirm what my ears told me in Audacity. Please have a look at this screenshot: https://cloudflare-ipfs.com/ipfs/Qma41RMzieQ6ZGdGem9rLxnxEL1... The Lyra version is clearly much louder. This is a serious problem and it borders on being reasonable to call it "cheating". It's well known in the audio biz that if you ask people to compare two experiences, and one of them is a bit louder than t…

I wouldn't call this cheating though. Audio compression makes use of the mental way we perceive sound. If a sound artefact is perceived to sound more clear when it is louder compared to another one with the same compression bitrate yet less volume I would say this falls into the category psychoaccoustic compression

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

#145

Post by nayuki »

cnorthwood wrote: post #96
andai wrote: post #91

Earlier quoted context omitted.

I thought the delay would be because VoIP uses packet-based communications rather than a direct connection.

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.

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

#146

Post by rcthompson »

jhoechtl wrote: post #144
bscphil wrote: post #79

I've just taken a minute to confirm what my ears told me in Audacity. Please have a look at this screenshot: https://cloudflare-ipfs.com/ipfs/Qma41RMzieQ6ZGdGem9rLxnxEL1... The Lyra version is clearly much louder. This is a serious problem and it borders on being reasonable to call it "cheating". It's well known in the audio biz that if you ask people to compare two experiences, and one of them is a bit louder than t…

I wouldn't call this cheating though. Audio compression makes use of the mental way we perceive sound. If a sound artefact is perceived to sound more clear when it is louder compared to another one with the same compression bitrate yet less volume I would say this falls into the category psychoaccoustic compression

If simply turning up the volume made it easier to understand the speech, then not turning up the volume on the other codecs would make for an unfair comparison.

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

#147

Post by dguaraglia »

hackmiester wrote: post #89
reaperducer wrote: post #45

Earlier quoted context omitted.

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…

VoIP is definitely not the issue here. Codecs can be, and are, fast. I have no idea what cellular providers are doing to mangle the voice path so bad, but it certainly isn’t inherent to VoIP.

I have no idea what they are doing but it sucks. I have in many occasions found that making a call using WhatsApp works much better - both in quality and latency - than making a phone call. Phone lines are so atrociously bad, they've put me off from doing a voice call unless it's absolutely necessary.

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

#148

Post by SilverRed »

manigandham wrote: post #134
superkuh wrote: post #109

Earlier quoted context omitted.

If you upload and then link to an image on Imgur and the person clicking the link has not run Imgur's javascript yet within $timeperiod, the image will not display. Instead you'll be given javascript to run. Cloudflare as a gateway is distasteful and this won't last long, but for now at least when you click an ipfs image over cloudflare you get an image and not javascript code.

Why is CF distasteful?

Not OP but I assume because it kind of defets the purpose of IPFS. IPFS is all about links that refer to content and not location, a cloudflare link is now back to a location and when the cf mirror goes down, the link will be broken.

But its also the only way normal users can see the content.

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

#149

Post by cycomanic »

ChuckMcM wrote: post #142
bscphil wrote: post #113

Earlier quoted context omitted.

Yes. Assuming this was done by the Lyra encoder directly, and not the person who wrote the blog post pushing the slider, you have to wonder how it would respond to an input with a peak around -3 dB. Would it clip? Is it performing some kind of normalization? Who knows! It's also interesting that the Lyra clip is ever so slightly longer than the other two. The Opus clip has exactly the same number of samples as the re…

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.

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

#150

Post by yholio »

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 would go the exact opposite route for this exact reason: something like 24Kbit ADPCM or 16Kbit G728 can provide an absolutely decent quality with only a 5 ms delay. This kind of bandwidth is now available in the vast majority of VoIP scenarios, an 100ms 3Kbps codec is only relevant for the extreme niches.
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