upsampling is possible, how about bit depth increase?

[soongsc]

I was wondering, since upsample conversion from say 44.1K to 48K or 96K is possible, is there any reason that bit depth cannot change from 16 to 24? There seems only information on upsample conversion methods, but no bit depth conversion methods. Since both are in fact changing the sample points of a contiguous music signal, I was wondering why would it not be possible to do both.

[Spoon]

Re: upsampling is possible, how about bit depth increase?

No audio quality is gained by upsampling or changing bit depth.

[soongsc]

Re: upsampling is possible, how about bit depth increase?

So why do people develop various algorithms to upsample? Why was HDCD developed? Surely it depends on algorithm used.

[Spoon]

Re: upsampling is possible, how about bit depth increase?

HDCD is a form of encoded compression, in that the extra 4 bits are decoded from the signal.

[soongsc]

Re: upsampling is possible, how about bit depth increase?

True, but if we look through the various processing that music go through, there are so many different ways to process them. XRCD ... and a whole bunch of others. Some do actually sound better even when played back in the normal CD format.