[dsrb]

But that's completely butchering the signal. The whole point of DAC-side interpolation is to round the waves off, thereby removing the post-Nyquist nonsense that results from square waves. Why would you deliberately circumvent this?!

11.025 kHz sounds muffled because it is. A properly output signal at this rate will only contain frequencies up to 5.5125 kHz, which will naturally sound muffled to us, being used to music with hats, cymbals, and whatnot to 16 kHz and a bit beyond. If you want to get around this, find a better sample, rather than mutilating the signal into an obscene square wave that it was never supposed to be.

Edit: fixing sampling rate figures to proper accuracy

This post has been edited by dsrb: 22 January 2012 - 09:09 AM

[Falk]

Sik, on 22 January 2012 - 08:14 AM, said:

Falk, on 21 January 2012 - 05:18 PM, said:

I don't know if you're trolling but... no. O_o

I'm not trolling. If anything, the sound hardware is x_x When playing 11KHz samples they interpolate like hell to make it sound "nicer", but the result is extreme muffling. The interpolation is much smaller for higher sample rates. Thereby, if you take a 11KHz waveform, repeat every sample four times and feed it to the sound hardware as 44KHz, it will sound much less muffled.

It doesn't make the original waveform sound better than it is, but rather it prevents it from sounding worse than it should.

That's the complete opposite way around. You're essentially thinking that interpolation is a problem and zero-order hold is the fix. In fact, it's the other way around. Zero-order hold and the resultant random inharmonics generated as a result is the problem, and interpolation is the fix. The rest was pretty much covered by dsrb.

Considering that zero-order hold is pretty much the easiest way to implement a DAC (and sounds bad) and interpolation methods have been refined over the years... decades really, to best rectify the problem I'm completely baffled as to how you could think the problem and solution are the other way around. The irony is you yourself said "You're trying to generate data that doesn't exist" because that's -exactly- what zero-order hold does. It generates frequencies above Nyquist, which should not exist.

edit: Might as well add that's why I'm baffled as to why this audio engine's 'interpolation' results in frequencies that weren't previously there, when interpolation is supposed to get rid of frequencies that shouldn't exist, but -this- dead horse has been beaten to a fine pulp by now and is more of semantics.

edit2: to make this post more useful:
http://en.wikipedia....ampling_theorem
http://en.wikipedia....Zero-order_hold

Not exactly the most layman of explanations but good enough.

This post has been edited by Falk: 22 January 2012 - 03:50 PM

[winterhell]

Can we say that the results of sample repetition (like Sik said) and interpolation are similar to that of nearest neighbor and bilinear in imaging ?

btw personal opinions:
I can rarely hear a difference between 192kbps and 320kbps mp3 and CD audio. But if its recorded 24bit/48KHz and done correctly it sounds better even if lossy.
For the synthesized sound of Sonic 2 if you can run it directly at the target frequency will be better instead of recording it and so on. Or you are talking only for the digital samples like the "Sega" chant ?

[Falk]

winterhell, on 23 January 2012 - 03:56 AM, said:

Can we say that the results of sample repetition (like Sik said) and interpolation are similar to that of nearest neighbor and bilinear in imaging ?

Quite right, although I'd add that it'd be more akin to a non-integer resize if you're going from 11,025 to e.g. 48kHz (which used to be quite common)

Sample repetition, or 'nearest-neighbour', would look something like this when not every pixel of an input represents the same number of pixels on an output:

This post has been edited by Falk: 23 January 2012 - 07:23 AM

[dsrb]

winterhell, on 23 January 2012 - 03:56 AM, said:

But if its recorded 24bit/48KHz and done correctly it sounds better even if lossy.

Assuming you're referring to 24 bit / 48 kHz vs. 16 bit / 44.1 kHz:

Congratulations on having superhuman hearing and/or terrible hardware. Please post ABX results.

[Falk]

Actually due to the way recording works, recording at 24 vs 16 (and keeping it that way throughout the whole production process) is a massive difference. After all is said and done and the music has been mixed and mastered then dithered to 16bit though, yeah, 24 and 16 is pretty hard to tell apart. :P

We're talking about professional studios, not people dicking around in FL with soundfonts. The dynamic range of something as unassuming as a wind or string instrument (or even voice) can go >30dB just due to many factors, and you want to catch all of it with as low a noise floor/quantization error as possible. 16bit is 96dB from floor to clip, and while it's possible and even mandatory at times in the past to squeeze the dynamics into an adequate recording (tape had far less headroom) there's so much else that can go wrong in the studio that you just don't want to worry about it. 24bit allows you to gainstage very very comfortably where you know you aren't going to clip yet are going to keep the noise floor really low.

On a semi-related note there's quite a bit of consternation at recording at 48kHz when you don't have to (I.e. your target media isn't film or DVD) since resampling from 48 to 44.1 introduces more problems than the original extra clarity is worth, but a lot of people record at 96kHz then resample to 44.1 OR 48, which f- things up a lot less.

This post has been edited by Falk: 25 January 2012 - 06:50 PM

[HeartAttack]

Some of you know sound theory on a pretty deep level. Cool?

[Falk]

You're making it sound like I'm fishing for validation. Let me reassure you that internet forums really aren't my cup of tea for a captive audience.

I just like to make sure people don't keep spreading misinformation. I just enjoy being a jackass.

[HeartAttack]

Well I didn't say that. Nor was I specifically referring to you.

So what's this talk about not fishing for validation? Nice

[Aerosol]

That's neither relevant nor appropriate.

[saxman]

Hamneggs, on 21 January 2012 - 06:35 PM, said:

So are you guys still having the DirectX issues?

I've held off answering this because I don't know to be quite honest. It's in LOst's hands right now. We are making progress on this, but I haven't personally dealt with this for about two weeks. I'm instead working on some new editing tools for the game.

[Hamneggs]

saxman, on 27 January 2012 - 04:45 PM, said:

I've held off answering this because I don't know to be quite honest. It's in LOst's hands right now. We are making progress on this, but I haven't personally dealt with this for about two weeks. I'm instead working on some new editing tools for the game.

Hmm, so from what I can gather, after LOst finishes the DirectX issues, the S2HD alpha will be *gasp* done? That's intense. Also, if you don't mind me asking, what became of Hill Top Zone?

[Cinossu]

Hamneggs, on 01 February 2012 - 09:51 AM, said:

Hmm, so from what I can gather, after LOst finishes the DirectX issues, the S2HD alpha will be *gasp* done? That's intense. Also, if you don't mind me asking, what became of Hill Top Zone?

It became a homeless alcoholic after failing in university. After several nights of binge drinking, it was caught trying to steal rings out of the Casino Night Zone. It's now behind bars, due for release in 2015.

Seriously, what do you think became of it? :P They're working on it, most likely still at the same time as Emerald Hill due to the somewhat matching tile sets, unless they've decided to branch it off differently this time.

[Canned Karma]

Yeah, that's pretty much spot on Hamneggs. One of the curses of doing game development in your spare time is how when life throws a curve at any of our team members, progress slows down until things are back on track for them again. We just haven't posted anything in the way of updates recently because there's really nothing more to report. I'm seriously hoping this is our last hurdle before we can get the demo into everyone's hands.

[Aerosol]

There seems to be an awful lot of refinement going on with the alpha. Assuming that there are no glaring bugs in the impending release, will the engine itself be complete, leaving only the artwork of the game to be done?