I've become almost entranced with the concept of comparing things to the size of a Floppy Disk. I'm actually planning to get a tattoo of one on my right forearm. I've been working on a large business management platform for the last couple of years and noticed that after investing $500k (salaries/etc) and building a huge amount of functionality, the frontend and backend codebases are still under 1.5mb. Pretty amazing.
Codec2: A Whole Podcast on a Floppy Disk
31–40 of 137 posts
Re: Codec2: A Whole Podcast on a Floppy Disk
#32Everything spoken in a whole life could fit on a 128GB pendrive (assuming 5% talk time). Astounding.
Re: Codec2: A Whole Podcast on a Floppy Disk
#33Having 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 off the speech synthesis and just read it, which is much more convenient than listening to a linear sound file.
Re: Codec2: A Whole Podcast on a Floppy Disk
#34That 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!
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…
>Actually if you're lucky and make a phone call with HDVoice, or whatever they're calling it, the quality is excellent
Can confirm. I spend a lot of time in fringe reception areas, but every now and then I get a good, strong signal and the HD Voice kicks in between my iPhone and my wife's and it sounds like she's standing right next to me. It really is something to experience, especially if the previous phone call was over regular tech.
Back when AT&T was running the "You get what you pay for" ads to combat SPRINT and MCI, it had a service you could sign up for that would give your landline phone calls amazing quality.
Sadly, a majority of people would rather pay less for crap than more for quality; even back then.
Re: Codec2: A Whole Podcast on a Floppy Disk
#35Having 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…
That codec sounds great, if it exists.
If you have such a codec, it would be worth testing the word error rate on a long sample of audio. e.g. take a few hours of call centre recordings, pass them through each of {your codec, codec2}, and then have a human transcribe each of:
- the original recording
- the audio output from your proposed codec (which presumably does STT followed by TTS)
- the audio output from CODEC2 at 2048
Based on the current state of open source single-language STT models, I would imagine that CODEC2 would be much closer to the original. And if the input audio contains two or more languages, I cannot imagine the output of your codec will be useful at all.
Re: Codec2: A Whole Podcast on a Floppy Disk
#36"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…
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Re: Codec2: A Whole Podcast on a Floppy Disk
#37Earlier quoted context omitted.
As far as I know, enough podcast apps require MP3 (and not even VBR!) that you have to use MP3, and you can't have multiple s, so how would you do this? A separate RSS feed for Opus, linked only on the website and not submitted to aggregators?
> As far as I know, enough podcast apps require MP3 (and not even VBR!) that you have to use MP3… Nope! Podcast episodes can be encoded using AAC (which is as ubiquitous as MP3) without issue. That won't realistically possible with Opus until Opus hardware decoding has available in mobile devices for 5-10 years.
Or more like never unless you get Apple to front it...
Re: Codec2: A Whole Podcast on a Floppy Disk
#38Earlier quoted context omitted.
As far as I know, enough podcast apps require MP3 (and not even VBR!) that you have to use MP3, and you can't have multiple s, so how would you do this? A separate RSS feed for Opus, linked only on the website and not submitted to aggregators?
> As far as I know, enough podcast apps require MP3 (and not even VBR!) that you have to use MP3… Nope! Podcast episodes can be encoded using AAC (which is as ubiquitous as MP3) without issue. That won't realistically possible with Opus until Opus hardware decoding has available in mobile devices for 5-10 years.
I highly doubt there are any devices that are capable of accessing the modern web, with all its JavaScript bloat, yet cannot decode a simple audio codec. Even when Apple was installing AAC hardware decoders, they were already almost obsolete by modern embedded CPU development (especially the rise of medium-power ARM SoCs). I highly doubt any devices released in the past 5 years have any sort of fixed-function audio decoder. Maybe an encoder, possibly some general-purpose DSPs, but not a format-specific decoder.
Re: Codec2: A Whole Podcast on a Floppy Disk
#39Earlier quoted context omitted.
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.
> t's the lossy jbig2 compression in Xerox copiers: http://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_....
My understanding of this fault was that it was a bug in their implementation of JBIG2, not the actual compression? Linked article seems to support this.
Re: Codec2: A Whole Podcast on a Floppy Disk
#40Codec2 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
Is Speex also in that category?