Can't wait to try that in ffmpeg!
Google open-sources the Lyra audio codec
91–100 of 145 posts
Re: Google open-sources the Lyra audio codec
#92[deleted]
Re: Google open-sources the Lyra audio codec
#93This seems kind of unnecessary, compared to Opus at ~10 kbps. If you're sending IPv6+UDP in 40 ms chunks, that's 9.6 kbps just from the packet headers (25 Hz * 40+8 bytes).
When the voice payload is smaller than the packet headers, you're well into diminishing returns territory.
Re: Google open-sources the Lyra audio codec
#94If I remember correctly the original landline audio was 64kpbs, 8000 Hz. So Lyra is 1/20 of this. And probably still sounds better.
Original landline audio was/is analog
Re: Google open-sources the Lyra audio codec
#95One thing I'm slightly worried about "machine learning" in compression rather than conventional everything-is-sines mathematical approaches is the possibility of odd nonlinear errors. Remember the photocopier that worked by OCR and would occasionally mis-transcribe numbers? I don't mind compressing a phoneme to as much as I would mind it compressing it to a clearly audible different phoneme.
Are you aware that the same exact uncompressed recording sounds different depending on context? This is known as the McGurk effect.
Very worth your two minutes if you're not yet familiar with the effect: https://www.youtube.com/watch?v=2k8fHR9jKVM
Re: Google open-sources the Lyra audio codec
#96Doesn't seem that better compared to Codec2 which is already fully Open Source (LGPL), even taking into account that Codec2's examples originals are already of much worse quality than the ones on Lyra's website. I'd be curious to hear both working on the same set of audio samples. https://www.rowetel.com/?page_id=452
Agreed; codec2 doesn't alter speech as aggressively, require proprietary components, or have as strong a connection to Google.
Re: Google open-sources the Lyra audio codec
#97Earlier quoted context omitted.
>These speech attributes, also called features, are extracted in chunks of 40ms, then compressed and sent over the network. So while Encoding doesn't take 40ms, the latency + encoding will indeed be 40ms+. 150ms is the End to End Latency, which is basically everything from Encoding + Network + Decoding. We cant beat the speed of light on our fibre network. We can certainly do something with Encoding and Decoding. And…
> We cant beat the speed of light on our fibre network. Speed of light in what? We can absolutely be faster than fibre optics, which are quite slow relatively speaking (2/3rds that of light in a vacuum).
Internet latency is much higher than it could be, even using fiber: https://arxiv.org/abs/1811.10737
And adding an HFT-style microwave backbone could reduce Internet latency even more: https://arxiv.org/abs/1809.10897
Re: Google open-sources the Lyra audio codec
#98If I remember correctly the original landline audio was 64kpbs, 8000 Hz. So Lyra is 1/20 of this. And probably still sounds better.
PCMU/PCMA (G.711μ and G.711a) are not original landline quality audio, but rather what Bell Systems felt they could get away with passing off as a toll quality call in 1972.
Lyra will likely sound better, but the reproduction accuracy is apt to be quite a bit poorer as many others have commented. G.711 was created to require nearly no processing (its nearly raw PCM data from a sound card after all) while operating at reasonable bitrates, Lyra looks much more computationally intensive and will likely only run on smartphones in the next few years.
Edit: Is Lyra a significant improvement over modern Opus at 8Kbps? You can buy a Grandstream HT802 analog telephone adapter for ~$30 and its DSP can decode Opus today, whereas Lyra will require orders of magnitude more power to decode while providing much worse reproduction accuracy.
Re: Google open-sources the Lyra audio codec
#99Re: Google open-sources the Lyra audio codec
#100Earlier quoted context omitted.
whiskey hotel yankee delta oscar india hotel alpha victor echo tango oscar sierra papa echo alpha kilo tango hotel echo lima alpha november golf uniform alpha golf echo oscar foxtrot tango hotel echo mike alpha charlie hotel india november echo ? tango hotel alpha tango india sierra india november sierra alpha november echo!
Humans adapt a whole hell of a lot easier than machines. Sure, it would be nice to have clean high bandwidth, low latency voice channels to everywhere so you could drop pins and expect the other side to hear it. Unfortunately, high bandwidth never really happened, and some places never ran land lines to everyone's home, and nobody wants to pay the high price of circuit switched voice when packet switched voice mostly…
But is Lyra a significant improvement over modern Opus at 8Kbps? You can buy a Grandstream HT802 for ~$30 and its DSP can decode Opus today, whereas Lyra will require orders of magnitude more power to decode while providing much worse reproduction accuracy.