WASAPI Exclusive Mode Support

Currently, Audacity does not support Exclusive Mode with WASAPI. It would be great if it did.

Exclusive Mode is required for Audacity to record real float32 samples from the audio device. Without Exclusive Mode, only integer samples are recorded from the device and are then converted to float32 back through Audacity. This is “lossy” in that samples recorded on the actual hardware may have exceeded +/-1.0, which clip in integer formats but do not clip in floating point. If Audacity had the option to request Exclusive Mode from WASAPI, then this problem is automatically solved.

(WASAPI behavior tested with gstreamer and a TASCAM Portacapture X8.)

2 Likes

I’m not an audio programmer, but there MIGHT be more to it…

If you record directly to the recorder and then transfer the 32-bit WAV files to your computer, Audacity should be able to open them losslessly.

…And there are usually advantages to stand-alone recording. There is no multi-tasking operating system to interrupt or “get in the way” and there are fewer things to mess-up!

It’s desirable to actually record in both places, for at least some redundancy. (SD cards fail all the time, and most recorders only have one card slot.)

Currently I can record on the TASCAM and Gstreamer simultaneously. For users who don’t know how to use something like Gstreamer, it would be better if they could just check a box in the audio settings. Since it seems all Audacity has to do is set a flag for Exclusive Mode, this seems like a reasonable feature request to me.

I 2nd that - but for my needs exclusive comms with external DAC would be ideal.