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Codec2: A Whole Podcast on a Floppy Disk

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Re: Codec2: A Whole Podcast on a Floppy Disk

#91

Post by merinowool »

gwern wrote: post #66
MrRadar wrote: post #21

Codec2 is also fully open source and patent-free, in contrast to virtually every other ultra-low-bitrate voice codec (which are proprietary and have expensive patent licensing attached). He has a Patreon if you want to support him in the ongoing development of Codec2 and his SDR modems to enable use of it in amateur radio: https://www.patreon.com/drowe67

Codec2 might be patent-free, but Codec2 with a WaveNet decoder isn't because WaveNet (convolutional neural networks for generating audio sequence data) is patented: https://patents.justia.com/patent/20180075343

When it was patented? When I was working with AI about 15 years ago I was experimenting with conv nn to generate audio. I wouldn't have expected for this to be patented as this is so friggin obvious thing to do. It is like patenting 2+2=4 once you discover numbers.

Re: Codec2: A Whole Podcast on a Floppy Disk

#92

Post by peterbmarks »

mrob wrote: post #33
corruptio wrote: post #9

Having grown accustom to MP3 artifacts, it's strange to hear artifacts that are natural, but just aren't quite right. More specifically, in the male voice sample: "sold about seventy-seven", I received it as "sold about se th enty-seven".

If we're abandoning accurate reproduction of sound and just making up anything that sounds plausible, there's already a far more efficient codec: plain text. Assuming 150wpm and an average 2 bytes per word (with lossless compression), we get about 5bps, which makes 2400bps look much less impressive. Add some markup for prosody and it will still be much lower. This codec also has the great advantage that you can turn…

Speech to text is certainly getting better but it makes mistakes. If the transcribed text was sent over the link and then a text to speech spoke at the other end you'd lose one of the great things about codec2 - the voice that comes out is recognisable as it sounds a bit like the person.

A few of us have a contact on Sunday mornings here in Eastern Australia and it's amazing how the ear gets used to the sound and it quickly becomes quite listenable and easy to understand.

Re: Codec2: A Whole Podcast on a Floppy Disk

#93

Post by terramex »

mockery wrote: post #2

None of the audio samples play for me (In neither Chrome nor Edge... Other sites play just fine.) Makes it very hard to evaluate claims of codec quality, which seems like the primary purpose of the blog post. :(

I confirm, doesn't work for me too. Neither in Safari 56 nor Chrome 67 (macOS 10.13).

Re: Codec2: A Whole Podcast on a Floppy Disk

#94

Post by poizan42 »

gsich wrote: post #73
namibj wrote: post #65

Earlier quoted context omitted.

I remember differently, but I don't want to pull up the source right now. I did check some of the sources, but was not able to find the one I remember which had statistics on it. The xerox FAQ to it does lead me to consider that I might be confusing this with some other incident though, as they claim that Scanning is the only thing that is affected.

https://media.ccc.de/v/31c3_-_6558_-_de_-_saal_g_-_201412282... I'd believe him more then any other source.

He did his presentation in english at FrOSCon 2015, can be seen here: https://www.youtube.com/watch?time_continue=95&v=c0O6UXrOZJo

Re: Codec2: A Whole Podcast on a Floppy Disk

#95

Post by dredmorbius »

Ambroos wrote: post #12

That is very impressive! I wonder if a WaveNet decoder could be built for phone calls, as those still sound awful. If it's possible to do this only on the decoder side you don't have to wait for your network to start supporting HD voice or VoLTE to get better quality audio!

Chaining codecs arbitrarily tends to create really bad artifacting. Current cell and VOIP systems already utilise multiple compression algos.

Re: Codec2: A Whole Podcast on a Floppy Disk

#96

Post by dredmorbius »

I read, and listemn, to this, and am impressed.

Then I think of the possible negative applications.

a noation of 100m people, talking an hour per day on phone or other audio channel, could be stored on 100m * 365 * 1.5 MB of storage annually: 54 PB.

In raw storage, that's less than $2 million. Far below national actor budgets.

Re: Codec2: A Whole Podcast on a Floppy Disk

#97

Post by toadworrier »

corruptio wrote: post #9

Having grown accustom to MP3 artifacts, it's strange to hear artifacts that are natural, but just aren't quite right. More specifically, in the male voice sample: "sold about seventy-seven", I received it as "sold about se th enty-seven".

One of the very few things I know about audio codecs is that they at least implicitly embody a "psychoaccoustic model". The "psycho" is crucial because the human mind is the standard that tells us what we can afford to throw away.

So a codec that agressively throws away data but still gets good results must somehow enbody sophisticated facts about what human minds really care about. Hence "artifacts that are natural".

Re: Codec2: A Whole Podcast on a Floppy Disk

#98

Post by bcaa7f3a8bbc »

The article failed to mention the original reason why Codec2 is invented.

In digital amateur radio communication, currently the most widely-used codec is AMBE. But AMBE is a proprietary codec, covered by patents, unhackable - the counter-thesis of amateur radio. Codec2 was born to bring freedom to digital amateur radio communication, and technically even better than AMBE.

Re: Codec2: A Whole Podcast on a Floppy Disk

#99

Post by IshKebab »

gsich wrote: post #61
IshKebab wrote: post #20

Earlier quoted context omitted.

Actually if you're lucky and make a phone call with HDVoice, or whatever they're calling it, the quality is excellent. It makes a huge difference. Unfortunately the place where you really want good quality is call centres - it's often hard to hear people and half of the reason is the shitty POTS quality - and call centres will probably get HDVoice in about 40-50 years. Maybe. Edit: nm should have read all of your com…

What do you mean with "HDVoice"? On landline connections this usually means G722. G711u/a is definitly not "HD".

I don't know what technology it is specifically, but it's a brand name they used for actual high quality calls. Think, 128 kB/s MP3, rather than the standard cups-and-string quality.

It only seems to work on mobile.

Re: Codec2: A Whole Podcast on a Floppy Disk

#100

Post by ahoka »

merinowool wrote: post #91
gwern wrote: post #66

Earlier quoted context omitted.

Codec2 might be patent-free, but Codec2 with a WaveNet decoder isn't because WaveNet (convolutional neural networks for generating audio sequence data) is patented: https://patents.justia.com/patent/20180075343

When it was patented? When I was working with AI about 15 years ago I was experimenting with conv nn to generate audio. I wouldn't have expected for this to be patented as this is so friggin obvious thing to do. It is like patenting 2+2=4 once you discover numbers.

> It is like patenting 2+2=4 once you discover numbers.

Welcome to software patents.

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