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TSAC: Low Bitrate Audio Compression

bellard.org

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Re: TSAC: Low Bitrate Audio Compression

#21

Post by mythhabit »

gardaani wrote: post #17

An Nvidia GPU is necessary for fast operation. Compression is getting so heavy that soon it isn't possible to perform it on normal hardware. AV1 already proved that, the future audio/video codecs will be even heavier. Decompression is also getting heavier. Poor mobile devices. I'm starting to appreciate well written algorithms which don't require massive computing power. JPEG XL is a good example. It has the same com…

If I'm understanding the specs correctly, it is basically a LLM, but for audio. So it requires some serious power to encode it, because it is using the latest AI hype to achieve the result.

Re: TSAC: Low Bitrate Audio Compression

#22

Post by adamzochowski »

jjcm wrote: post #13

Always love a good bellard ship. This is definitely better than some of the others out there. I threw together some comparisons here at 7kb/s for mp3/opus/aac: https://non.io/TSAC-Comparisons Happy to add other comparisons if others want any. Overall, it's FAR better at these lower bit rates, but that doesn't mean it's necessarily good. One issue I see off the bat is that volume is fairly inconsistent in the output f…

Since Ballard's codec is "AI" based, can you add google's lyrav2 ( https://github.com/google/lyra ) and Facebook's/meta EnCodec ( https://github.com/facebookresearch/encodec ).

Also I don't seem to be able to access your page, so there might be error.

Finally, when doing opus comparison it's good now to denote if it is using Lace or NoLace decoder post processing filters that became available in opus 1.5 (note, this feature need to be enabled at compile time, and defying decode a new API call needs to be made to force higher complexity decoder) . See https://opus-codec.org/demo/opus-1.5/

Re: TSAC: Low Bitrate Audio Compression

#23

Post by steeve »

XMPPwocky wrote: post #6

if you patch out the CRC check in the binary with echo -ne "\x90\x90" | dd if=/dev/stdin of=tsac bs=1 seek=23914 conv=notrunc you can corrupt the compressed files with very interesting results: https://meow.social/@mimir/112238998609778334 the fast mode (you don't have to patch the binary for this one, it seems to not do the CRC check?) and the normal (non-fast) mode sound different, but both quite interesting

I can clearly hear Cotton Eye Joe in the second sample!

Re: TSAC: Low Bitrate Audio Compression

#25

Post by kazinator »

This doesn't have much of a use case.

- Can't use it in telephony (obvious application for low bitrates); phone handsets and headsets don't have the power to do it in real time.

- Very small files of good quality would be useful in tiny embedded systems that have low flash space: but what systems of that type have the processing power for decoding? Very low storage more or less goes hand in hand with weak processing.

The quality is astonishing for the bit rate, though.

Re: TSAC: Low Bitrate Audio Compression

#26

Post by apt-get »

thrdbndndn wrote: post #19

New advancement of media compression seems always focusing on low bitrate, be it audio, video or image. Which is totally fair given their applications, but I always wonder how much improvement they bring in high bitrate scenario. For example, are there codecs that have much better (perceptible) quality than Apple AAC 256kbps (or achieving similar quality at, say, 160kbps?) How much better are AV1 at 10Mbps compared t…

> are there codecs that have much better (perceptible) quality than Apple AAC 256kbps (or achieving similar quality at, say, 160kbps?)

Opus achieves ABX transparency at around 128kbps (as in, the threshold where the vast majority of users taking a fidelity test are unable to tell the difference between the opus-encoded and lossless version).

https://abx.digitalfeed.net/opus.html

Re: TSAC: Low Bitrate Audio Compression

#27

Post by thrdbndndn »

apt-get wrote: post #26
thrdbndndn wrote: post #19

New advancement of media compression seems always focusing on low bitrate, be it audio, video or image. Which is totally fair given their applications, but I always wonder how much improvement they bring in high bitrate scenario. For example, are there codecs that have much better (perceptible) quality than Apple AAC 256kbps (or achieving similar quality at, say, 160kbps?) How much better are AV1 at 10Mbps compared t…

> are there codecs that have much better (perceptible) quality than Apple AAC 256kbps (or achieving similar quality at, say, 160kbps?) Opus achieves ABX transparency at around 128kbps (as in, the threshold where the vast majority of users taking a fidelity test are unable to tell the difference between the opus-encoded and lossless version). https://abx.digitalfeed.net/opus.html

Thank you! The note there:

> NOTE:Opus doesn't support 44.1kHz sample rates, so encodes to 48kHz sample rate. As this causes browser playback issues, it has been resampled back to 44.1kHz. This may affect the sound quality, so this test should be taken with caution.

Is very surprising to me, in two ways.

Firstly I knew 44100 is a relic due to historical reasons, but it's still a quite widely used sample rate in audio world. I have no idea Opus does not support it.

Secondly, it seems to imply browser can't playback 48kHz audio properly. I didn't dig the details, but this sounds weird. Just like 44100, 48k is a very common sample rate, I can't imagine browser would have trouble with it (or any arbitrary sample rate, to be honest).

Re: TSAC: Low Bitrate Audio Compression

#28

Post by shvedsky »

kazinator wrote: post #25

This doesn't have much of a use case. - Can't use it in telephony (obvious application for low bitrates); phone handsets and headsets don't have the power to do it in real time. - Very small files of good quality would be useful in tiny embedded systems that have low flash space: but what systems of that type have the processing power for decoding? Very low storage more or less goes hand in hand with weak processing.…

don't be such a debbie downer! celebrate it, and we'll find a use for that some day

Re: TSAC: Low Bitrate Audio Compression

#29

Post by atoav »

kazinator wrote: post #25

This doesn't have much of a use case. - Can't use it in telephony (obvious application for low bitrates); phone handsets and headsets don't have the power to do it in real time. - Very small files of good quality would be useful in tiny embedded systems that have low flash space: but what systems of that type have the processing power for decoding? Very low storage more or less goes hand in hand with weak processing.…

Something like this might be useful to put into hardware, e.g. with custom silicon or FPGAs. Maybe then the processing power won't be a big issue?

Edit: Ok I just saw the thing is over 200 MB, might not be feasible for a while.

Re: TSAC: Low Bitrate Audio Compression

#30

Post by Lorin »

I attempted some ML-as-'compression' experiments ~2 years ago, ended up hitting a wall. Check out samples/pitch here: https://lorinhalpert.com/ipoc/ala/

If someone has audio encoding, playback, and/or DSPs experience email me to be invited to our our Discord server so we can take another crack at it! :)

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