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Good 1bit-ADPCM codecs?

Hello,

it is a bit embarassing to ask this in a hifi forum, but:

What are the best 1-bit ADPCM codecs available for download?

I know, they all are noisy but I developed my own and want to compare the quality of mine with others, because it still sounds pretty "clear" using only one bit per sample^^.

I'm not sure if it worth to release it.

These 1-bit ADPCMs are hard to find in google :-(.
I found only one at GitHub but it did sound much worse at same quality.

Thank you very much.


Re: Good 1bit-ADPCM codecs?

Reply #1
I'm not sure I would call this a hifi forum. It is a digital audio/audio codecs forum.

Re: Good 1bit-ADPCM codecs?

Reply #2
Then I'm right here, because I'm developing one :-D.

I read "Audio Technology Enthusiast's Ressource", and I thought, this is more a HiFI forum. :))


Re: Good 1bit-ADPCM codecs?

Reply #3
Are there really any popular ones? I think most of them are proprietary video game codecs. I think 1-bit makes sense only in DSD.

Re: Good 1bit-ADPCM codecs?

Reply #4
I've said, it is not HiFi quality.
But in most cases, it performs similar to IMA and MS ADPCM if used in 2-bit mode.

It is old, but yesterday, I improved it a bit (just for fun).

But it can't keep on the same level as modern frequency transformation based codecs. It would loose in compare to Opus and Vorbis.

I originally made it many years ago to transform audio to pictures. These pictures were intended to be print on paper so you can save audio on paper^^. This was somewhere in the time of Windows 98. These papers worked similar to QR codes and you can scan them to get the audio files back. That technique needed heavy compression to get the paper sheets scannable. That isn't useful anymore since hard drives became bigger and bigger so I butchered this ancient project yesterday (but resqued this codec from it).

Today, it might be still useful for microprocessors, where resources are limited, because only integer addition and subtraction is needed to decode it. IMA and MS need more processing power to decode. ;D

I find the technique behind ADPCM codecs interesting so I made my own.  :D

It seems, no one ever wants to use any kind of ADPCM anymore, so I keep it for myself.

Re: Good 1bit-ADPCM codecs?

Reply #5
ADPCM is vaguely interesting. It may be worth sharing, if only for passing interest and nostalgia value.

Re: Good 1bit-ADPCM codecs?

Reply #6
OK so now things make more sense. So you want to make something like a QR code that each dot actually represents a bit of an ADPCM file. That would be extremely hard since there is pretty like zero room for improving 1bit. On the other hand, if you used a lossy/speech codec with extremely good resilience in errors or dropped packages you might achieve the same or better results. It also kinda matches with the idea I had a long time now of somehow modulating a lossy audio stream into a normal cassette tape, more like a DIY DCC tape that uses regular tapes. The key is the modulation method/technic that I haven't found yet, though I bet there is one out there.

Re: Good 1bit-ADPCM codecs?

Reply #7
You misunderstood it. ;)

The codec and the project, which uses it, already exists for years.

The question was: Does the quality of the codec worth to keep it (That is, what I need other similar codecs for)?

Now it isn't there anymore because it became useless and I scraped it, but kept the codec from it.  :D

But yes, the pixels represented the ADPCM samples.

Re: Good 1bit-ADPCM codecs?

Reply #8
Appendix, because I cannot edit my posts  :(

Here is a sample:

https://www.dropbox.com/s/1gpj3iakv6aqh0x/adpcm.zip?dl=0

The package contains a few seconds of the left channel from this song (https://modarchive.org/index.php?request=view_by_moduleid&query=59502) encoded (and decoded back) using the 1-bit ADPCM.

Annotations:
- Left channel only, because the source file is not mono compatible.
- I converted it to WAV using Audacity before doing the conversion. It is resampled to 48000Hz because there is no support for the original 44100Hz. It is in fact an 1.08-bit encoding.

Re: Good 1bit-ADPCM codecs?

Reply #9
That dropbox link seems to be dead; gives a link not found error. I would be interested in seeing how this sounds, ADPCM is interesting to me.

 

 
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