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
UweB wrote:
Hi Gale, I made such a recording and added it to the article I mentioned above (> Audacity Recordings with MME (or DirectSound) vs. WASAPI> ).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.
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.
Well I think that works for some devices now.
Gale
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
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.
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.
See “Recording” in Redirecting to: https://www.audacityteam.org/FAQ#features.
The commit to make Windows Direct Sound support 24-bit is here Bug 193 - Audacity can't record at > 16-bit under MME or Windows Dire… · audacity/audacity@18eb2bb · GitHub (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
Actual 24 bit would require packing and unpacking unaligned bytes and would be inefficient.
Gale
Thank you for the additional info and links.