[fluffything]

And that point is wrong, since there are some cloud providers using normal GPU cores for exactly this.

The codecs that NVEnc supports are just a few bunch, there is no real-time audio, no nothing.

All of this is implemented in CUDA, using normal CUDA implementations of audio and video codecs, and running on normal GPUs using normal GPU cores. In real time. Supporting thousands of audio and video channels concurrently.

Also, even for NVEnc and NVDec themselves, in some of the GPUs they do not use any specialized hardware and use normal GPU cores instead (e.g. see the older GM20x GPUs).

[vlovich123]

Are any of these transcoding libraries open source?

[fluffything]

None of the ones I know are. They are all proprietary.

I'm not sure they are for sale either (probably for the right price), since they sell these "as a service", which pays better. I also don't think these are on sale for "small" customers.

[fomine3]

Can you refer any encoder that only uses CUDA?

[fluffything]

From these products, most of them, since NVEnc doesn't really support many formats (AV1, VP9, Speex, ...).