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: A Whole Podcast on a Floppy Disk
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Re: Codec2: A Whole Podcast on a Floppy Disk
#22Having 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".
Yes, and "certificates" sounds like "certiticates".
Reminds me of a story about a copying machine that had a image compression algorithm for scans which changed some numbers on the scanned page to make the compressed image smaller. (Can't remember where I read about that, must have been a couple years ago on HN)
Re: Codec2: A Whole Podcast on a Floppy Disk
#23None 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. :(
Fine by me on Firefox/Linux.
Re: Codec2: A Whole Podcast on a Floppy Disk
#24Having 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".
Yes, and "certificates" sounds like "certiticates". Reminds me of a story about a copying machine that had a image compression algorithm for scans which changed some numbers on the scanned page to make the compressed image smaller. (Can't remember where I read about that, must have been a couple years ago on HN)
It's the lossy jbig2 compression in Xerox copiers: http://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_...
And yes, I think this is a relevant comparison. As the entropy model becomes more sophisticated, errors are more likely to be plausible texts with different meaning, and less likely to be degraded in ways that human processing can intuitively detect and compensate for.
Re: Codec2: A Whole Podcast on a Floppy Disk
#25Having 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".
Yes, and "certificates" sounds like "certiticates". Reminds me of a story about a copying machine that had a image compression algorithm for scans which changed some numbers on the scanned page to make the compressed image smaller. (Can't remember where I read about that, must have been a couple years ago on HN)
Xerox copier flaw changes numbers in scanned docs: https://www.theregister.co.uk/2013/08/06/xerox_copier_flaw_m...
Re: Codec2: A Whole Podcast on a Floppy Disk
#26On a related note, I wish more (any!) podcasts were distributed in opus.
All the +2k podcasts hosted on Podigee (a podcast hosting company mainly known in German-speaking countries) are distributed in opus. But it is, and probably will always be, a rather niche distribution format. AAC had its moment, but MP3 is alive and kicking. Even Apple acknowledges its importance by adding support for chapter markers in iOS12.
> AAC had its moment…
That moment is 15 years in with no signs of losing steam[1]. AAC effectively replaced MP3 for most online audio use cases, with podcasting as a notable exception[2]. And of course, AAC is the audio format for all basically all online video distribution.
[1] Apple kicked off the transition in 2003 with the introduction of AAC-based digital music sales.
[2] Because podcasting is a decentralized medium, and the vast majority of podcasters don't know much (if anything) about media encoding.
Re: Codec2: A Whole Podcast on a Floppy Disk
#27"The man behind it, David Rowe, is an electronic engineer currently living in South Australia. He started the project in September 2009, with the main aim of improving low-cost radio communication for people living in remote areas of the world. With this in mind, he set out to develop a codec that would significantly reduce file sizes and the bandwidth required when streaming." What do you know, it's sort of like Pie…
I've been reading David Rowe's blog [0] since 2008, there are some other really interesting projects and products on it. One of my favorites back then was his home build electric car.
Re: Codec2: A Whole Podcast on a Floppy Disk
#28Aside from the seriously impressive WaveNet based results, I think the article doesn't do the codec itself enough justice.
I mean, low-bitrate speech codecs have been around for some time (hey, vocoders are the oldest kind of audio codecs in history!), and I grew skeptical when they started to compare with mp3 and opus.
But looking at this page Codec2 really holds its own when compared to AMBE and especially MELP, two of the most prominent ultra low-bandwidth speech codecs used today: https://www.rowetel.com/?p=5520
Re: Codec2: A Whole Podcast on a Floppy Disk
#29But this guy a beer. What a feat!
Re: Codec2: A Whole Podcast on a Floppy Disk
#30The WaveNet demos are indeed impressive. But I wonder if the WaveNet decoder needed to be trained for those specific voices.