Microsoft also just announced a 6kbps advanced audio codec:
https://techcommunity.microsoft.com/t5/microsoft-teams-blog/...
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
#32This is blogspam that doesn't add meaningfully to the original[1].
[1]: https://ai.googleblog.com/2021/02/lyra-new-very-low-bitrate-...
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#33Earlier quoted context omitted.
Isn‘t VoIP at such low data rates already dominated by the overhead of UDP, IP and whatever lower layer? Multiplexing it with a low-bandwidth video stream would be possible, though. I was thinking this could be most relevant for something like digital wireless transmissions.
To say the least, yeah. At 3kbps and 20ms framing, it's only 7.5 bytes of payload per frame. RTP, UDP, IP, and Ethernet overhead are what - 60-ish bytes?
You might have PPPoE on top of that with another 8 bytes.
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#34We are getting to the point where compression is so good, you aren’t actually hearing the other person. Wild
you'll never know if you're speaking to the Blight.
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#35Important to remember that this type of codec can be used as a backup for higher-bandwidth codecs. You don’t necessarily need to hear it’s artifacts all the time. The higher level codec also only needs to encode the differences between the prediction and groundtruth. The same thinking applies to video especially of faces. Neural nets are a huge leap forward for this type of data compression and will likely be used pretty much everywhere in the future with great success.
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#36I found the Lyra codecs in both examples easily the most difficult to comprehend, even compared against the scratchy Speex. Am I the only one? It is a little odd to me to see the praise here and on the previous discussion. To be fair, I am convinced I have APD (and, to be fair again, I have never got it checked out). E: Just realized there is a third example. Perhaps it is not as strong a statement due to Opus' doubl…
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Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#37http://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…
I had to listen to your wav sample 4 times before understanding what it was saying... To me, that isn't intelligible... Perhaps with practice one could learn to understand it, but that isn't really what I want from my audio codec.
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#38Nothing 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…
I wouldn't be as pessimistic—they invented VP9 and were important to AV1, and continue to promote both and use them everywhere.
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#39What 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 to fidelity are nice-to-have, but I would like some real-time in my real-time communications, please.
Re: Lyra audio codec enables high-quality voice calls at 3 kbps bitrate
#40http://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…
Completely unrelated but damn so they need to update the illustration at the top of that page. It's hideous.