24-Bit Recording Status

Help for Audacity 2.x.x on Windows.

ImageThis forum is for Audacity 2.x.x on Windows.

  • Please state which version of Windows you are using, the exact three-section version of Audacity from Help > About Audacity and whether you obtained the .exe installer or the zip.

  • Audacity 1.2.x and 1.3.x are obsolete and no longer supported. If you still have those versions, please upgrade at http://www.audacityteam.org/download/.
    The old forums for those versions are now closed, but you can still read the archives of the 1.2.x and 1.3.x forums.

Re: 24-Bit Recording Status

Permanent link to this post Posted by Gale Andrews » Mon Jun 06, 2016 2:04 pm

UweB wrote:Hi Gale, I made such a recording and added it to the article I mentioned above (http://beis.de/Elektronik/DA2USB/AudacityMMEvsWASAPI/Audacity_MME_vs_WASAPI.html).

It is interesting. It is possible that MME being emulated over WASAPI on Vista and later has removed the 44100 Hz restriction.

You might find a different result on XP.


Gale
________________________________________FOR INSTANT HELP: (Click on Link below)
* * * * * Tips * * * * * Tutorials * * * * * Quick Start Guide * * * * * Audacity Manual
Gale Andrews
Quality Assurance
 
Posts: 25825
Joined: Fri Jul 27, 2007 12:02 am
Operating System: Windows 10

Re: 24-Bit Recording Status

Permanent link to this post Posted by UweB » Mon Jun 06, 2016 6:37 pm

>>> UweB wrote:
>>> Hi Gale, I made such a recording and added it to the article I mentioned above (http://beis.de/Elektronik/DA2USB/Audaci ... ASAPI.html).

It is interesting. It is possible that MME being emulated over WASAPI on Vista and later has removed the 44100 Hz restriction.

You might find a different result on XP.

I made a test on XP. The results are identical(!). I can make a screenshot and a WAV file as before, that's easy, but I guess that you'll believe me. And I would have been very, very much surprised when the result had been different because in the past I often used 192/16 on XP.

But I'm still desperately hoping that there will be a solution that not only 48/24 but also 96/24 will work on Win 10, Audacity and WASAPI.
UweB
 
Posts: 22
Joined: Sat May 02, 2015 10:43 am
Operating System: Please select

Re: 24-Bit Recording Status

Permanent link to this post Posted by Gale Andrews » Tue Jun 07, 2016 1:01 pm

UweB wrote:
>>> UweB wrote:
>>> Hi Gale, I made such a recording and added it to the article I mentioned above (http://beis.de/Elektronik/DA2USB/Audaci ... ASAPI.html).

It is interesting. It is possible that MME being emulated over WASAPI on Vista and later has removed the 44100 Hz restriction.

You might find a different result on XP.

I made a test on XP. The results are identical(!). I can make a screenshot and a WAV file as before, that's easy, but I guess that you'll believe me. And I would have been very, very much surprised when the result had been different because in the past I often used 192/16 on XP.

Hmm. I can only assume that at some time MME was limited to resampling everything to 44100 Hz, or it would not be said so often.

Can you identify the MME sample rate limit? In Audacity, the MME "actual rate" at bottom right says the same as the Audacity project rate for rates up to 384000 Hz. Until now, I did not believe that.

For DirectSound, "actual rate" for project rates above 192000 Hz shows 192000 Hz, indicating resampling.

UweB wrote:I'm still desperately hoping that there will be a solution that not only 48/24 but also 96/24 will work on Win 10, Audacity and WASAPI.

Well I think that works for some devices now.


Gale
________________________________________FOR INSTANT HELP: (Click on Link below)
* * * * * Tips * * * * * Tutorials * * * * * Quick Start Guide * * * * * Audacity Manual
Gale Andrews
Quality Assurance
 
Posts: 25825
Joined: Fri Jul 27, 2007 12:02 am
Operating System: Windows 10

Re: 24-Bit Recording Status

Permanent link to this post Posted by Gale Andrews » Tue Jul 05, 2016 5:17 pm

For others who have real 24-bit recording devices, please test this commit under Windows DirectSound and let us know if you get real 24-bit samples: https://github.com/audacity/audacity/commit/18eb2bb.

Thanks to Carsten and Uwe for proposing a fix.


Gale
________________________________________FOR INSTANT HELP: (Click on Link below)
* * * * * Tips * * * * * Tutorials * * * * * Quick Start Guide * * * * * Audacity Manual
Gale Andrews
Quality Assurance
 
Posts: 25825
Joined: Fri Jul 27, 2007 12:02 am
Operating System: Windows 10

Re: 24-Bit Recording Status

Permanent link to this post Posted by UweB » Tue Jul 05, 2016 5:54 pm

You may know that for this test Edit ➝ Preferences ➝ Quality ➝ Default Sample Rate must be set to 24-bit.

In order to check for true 24 bit without special equipment, I recommend to record any signal, possibly noise only, and to export is as a 32 bit WAV file. In this WAV-file you can easily figure out whether it is 16 or 24 bit when you view it with a hex-editor. 16 bit: 2 columns out of 4 are set to 00, 24 bit: 1 column out of 4 is set to 00.
UweB
 
Posts: 22
Joined: Sat May 02, 2015 10:43 am
Operating System: Please select

Re: 24-Bit Recording Status

Permanent link to this post Posted by hans-jürgen » Wed Apr 19, 2017 11:31 am

Hi, I just checked the Release Notes of version 2.1.3 for related fixes of this issue, but could not find one. Is this still being developed maybe, or does "full support of Windows 10" indirectly means full support of the WASAPI interface at all possible combinations? I'm using the latest Windows 10 Creators update on several PCs, most of them with the internal Realtek HD Audio chip, and now I wonder if I should simply use 24bit 48kHz with WASAPI as the audio host in my future recordings, because Uwe's tests showed this as the only "perfect" method.
hans-jürgen
 
Posts: 7
Joined: Wed Jul 22, 2009 12:54 pm
Location: Hamburg, Germany
Operating System: Windows 10

Re: 24-Bit Recording Status

Permanent link to this post Posted by Gale Andrews » Wed Apr 19, 2017 2:32 pm

See "Recording" in http://www.audacityteam.org/about/features/.

The commit to make Windows Direct Sound support 24-bit is here https://github.com/audacity/audacity/commit/18eb2bb (as it already says in a previous post in this topic).

WASAPI already supported 24-bit recording, and still does. The error opening sound device at 96000 Hz under WASAPI is specific to Uwe's custom sound device.

Note that Audacity always captures audio at 32-bit float even when Default Sample Format is 24-bit. So the recording will be dithered down to 24-bit if you have dither on in Quality Preferences (which you should for general purposes). The dither will be very quiet (about -120 dB). A note in the code says
Code: Select all
Actual 24 bit would require packing and unpacking unaligned bytes and would be inefficient.



Gale

hans-jürgen wrote:Hi, I just checked the Release Notes of version 2.1.3 for related fixes of this issue, but could not find one. Is this still being developed maybe, or does "full support of Windows 10" indirectly means full support of the WASAPI interface at all possible combinations? I'm using the latest Windows 10 Creators update on several PCs, most of them with the internal Realtek HD Audio chip, and now I wonder if I should simply use 24bit 48kHz with WASAPI as the audio host in my future recordings, because Uwe's tests showed this as the only "perfect" method.
________________________________________FOR INSTANT HELP: (Click on Link below)
* * * * * Tips * * * * * Tutorials * * * * * Quick Start Guide * * * * * Audacity Manual
Gale Andrews
Quality Assurance
 
Posts: 25825
Joined: Fri Jul 27, 2007 12:02 am
Operating System: Windows 10

Re: 24-Bit Recording Status

Permanent link to this post Posted by hans-jürgen » Wed Apr 19, 2017 6:01 pm

Thank you for the additional info and links.
hans-jürgen
 
Posts: 7
Joined: Wed Jul 22, 2009 12:54 pm
Location: Hamburg, Germany
Operating System: Windows 10

Previous

Return to Windows



Who is online

Users browsing this forum: No registered users and 8 guests