Wavosaur

bolewin · Joined: 13 Jan 2008 Posts: 1 Location: Sweden

For starters: Thanks for a capable and robust program.

I am using a Zoom H2 for recording which is usually done at 48 kHz (since the circuitry in the H2 is supposedly optimised for that although recording is possible also on 41.1 and 96 kHz) using 24 bits since the increased resolution makes it less imperative to be that dangerously close to 0dB.

Now to my queries, could anyone be so kind to comment on whether it is advisable to FIRST downsample to 41.1 kHz and THEN reduce depth from 24 to 16 bits, or if the other way around would be preferable?

I would also very much appreciate comments on the alghoritms used in Wavosaur for these procedures. Under which circumstances would the arious alternatives be preferable?

Looking forward to comments from authors and community!

Rex · Site Admin Joined: 05 Oct 2006 Posts: 797

Hello, welcome to the forum.

I think you can resample and bit-depth convert no matter the order.

I have to ask the main dev about the algorithms, there's a checkbox in Wavosaur resample tool for "filter" when downsampling, but i don't know much more.

For the bit depth convert, the 24 bits -> 16 bits reduction is done without dithering (it's in the todo list to add dither options).
I think you can use dithering VST plugins if it's really needed.

PeterB · Joined: 19 Jun 2008 Posts: 3 Location: UK

Thank you for Wavosaur. It is truly wonderful, and does exactly what I have been seeking for years!
I would be grateful however for an “Idiots Guide” to the cleanest way to convert 24/96 wav files to 16/44.1.
I have tried several ways to do this, some more successful than others, but none with entirely satisfying results. I also have tried using the MDA Dither and some other dithering VSTs , but I’m not sure I’m using them correctly.
Many thanks for any guidance!

Rex · Site Admin Joined: 05 Oct 2006 Posts: 797

Hello peter!

You can use the "resample" feature in the Process menu, but i suggest you to wait for the next release (we have fixed a bug with the filter/interpolation that wasn't active even is you check the "filter/interpolation" box )

I'll make some test with MDA dither and post the results in this thread

PeterB · Joined: 19 Jun 2008 Posts: 3 Location: UK

Thanks!

Rex · Site Admin Joined: 05 Oct 2006 Posts: 797

The procedure may look like this:

- load MDA dither in the VST rack, choose the bit depth destination, and the correct setting depending on your files, here's the help for MDA dither : http://mda.smartelectronix.com/vst/help/dither.htm

- apply the dithering then use menu->process->bit depth convert to set the bit depth to the "destination" value. (check "process quantization")

Wavosaur Main Developer · Site Admin Joined: 30 Sep 2006 Posts: 507 Location: France

Our resample dialog box has a bug: unfortunately the checkbox value is not read, and then the filter/interpolation we coded are always ignored.

Next release will correct this bug, with added, different choices for interpolation and anti alias filtering. Our DSP (Digital signal processing) has worked on this.

For bit depth converter we are working on dithering (ut not for next release...sorry).

For your information for the musicians we know, it's prefered to resample first and after to apply bit convertion.

But it's not a standard and I think each guys has its own habits.
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Wavosaur Main Developer
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http://www.wavosaur.com

acousmad · Joined: 14 Apr 2007 Posts: 6 Location: France

Wavosaur Main Developer · Site Admin Joined: 30 Sep 2006 Posts: 507 Location: France

Yes, good analysis acousmad.

To be honest we saw the resampling "checkbox bug" with this type of drawning (sonogram) you presented here.

In the next release you will find different option to customize your resampling. And we are already sarching other options, but for future!
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Wavosaur Main Developer
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http://www.wavosaur.com

acousmad · Joined: 14 Apr 2007 Posts: 6 Location: France

Hi,

Hum... how to tell it...

The resampling result is always very bad with 1.0.3, to say the least...
With no interpolation, it goes from bad to very bad, and according to interpolation methods, it can go up to astonishing bad !
BTW, with or without antialiasing gives the same result.

The good thing is that Wavosaur remains my best software to show how resampling can destroy the sound Wink

but I suppose that there is some people who would be happy to do a clean resampling with it ?

Try with a sine wave sliding from 20 to 20kH and resample it from 44,1 to 48 or the other way, and listen and look at the sonogram.

Any idea ?

Wavosaur Main Developer · Site Admin Joined: 30 Sep 2006 Posts: 507 Location: France

First the title of this post is downsampling and reducing depth.
So, if you generate a sinus from 48kHz to 44,1kHz, or 96kHz to 44,1Hz, you will see the difference with 1.0.2.0. For better result try bandlimited.

For upsampling, for the moment you could try different type of interpolations, excepted bandlimited.

Then it's not bad: it's just the result of algo types.

It's possible that in the future we will work on different algos.
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Wavosaur Main Developer
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http://www.wavosaur.com

tommyD · Joined: 03 Mar 2008 Posts: 57 Location: on The One

Re: sample rate conversion:

tommyD · Joined: 03 Mar 2008 Posts: 57 Location: on The One

EvilDragon · Joined: 14 May 2013 Posts: 11

Even after all these years (it's 7 years since this thread), upsampling is still horrible in Wavosaur...

Why not implement SoX resampler so everything gets perfectly resampled without annoying artifacts?

Previewing 44.1 files when audio interface is at 48k sounds absolutely horrible. Yes, I'm on latest version of Wavosaur (1.1.0.0, which is two years old by now)...