Re: [Audacity-quality] wasapi problems

[Gale A. <ga...@au...>]

| From Ragnar Jensen <ra...@je...> 
| Mon, 11 Mar 2013 23:59:13 +0100
| Subject: [Audacity-quality] wasapi problems

Hi Ragnar and David

Summary: My main WASAPI finding is that I cannot overdub
at all except with speakers loopback recording, and I confirm
latency increases dramatically after recording a few clicks of
click track. 


> I  took wasapi for spin too. Only Windows 7. Tested at 44.1 and 48 kHz.
> 
> 1. In the input device drop-down, I see all my output devices too.
> The same output devices that are in the output device drop-down
> are repeated in  the input device drop-down, in the same order. 
> Below them the input devices follow. 

I think that is correct, as they are loopback recording devices.   


> 2. My interface has 8 input channels. If I try to record less than 8,
> e.g. I select "2 (stereo)",
> I get the "Error while opening sound device" message box.

Do you get the same with MME, Windows Direct Sound (WDS)
or ASIO? 

 
> I had no problems with latency. I did the same click track test as David,
> with the difference that my microphone was connected to the same interface
> that played the click track. Latency was stable at 149 ms at all times.

Using the built-in sound device on Win 7 I cannot record overdub
at all with WASAPI at the moment (except using the speakers
loopback input). I have rebooted but no difference. I get "error 
opening... check the input device", irrespective of shared or 
exclusive mode, sample rate/project rate or mono or stereo 
recording. 

So this is worse than when I tried it before commit (when I just 
get "error opening" under WASAPI after any change to "Default
Format" in Windows).  

[As reported before, on my machines Leland's Vista detection 
patch r12160 causes overdubbing with different track and 
project rates to fire "error opening input device" sooner or
later in MME and WDS. Under WDS, it's always preceded by a
separate message "Unanticipated host error". So I already
have more overdubbing problems than others - I have only
seen one other report of this to date]. 

Using speakers loopback, I can confirm that latency always 
goes from about 60 ms to 600 ms after recording a few clicks. 
It does then remain constant at about 600 ms. Latency with 
MME and Windows Direct Sound is consistent (recording a 
headset with a mic).

Otherwise I still have the WASPI loopback issues I reported 
before:

* When first used in an Audacity session, loopback recording 
   always hangs the recording cursor if no audio stream is 
   playing. 

* Loopback recording from an Audacity track always hangs
   the cursor unless overdub is on. 


Will try WASAPI with USB turntable later. 



Gale  


> 2013/3/11 David Bailes <drb...@go...>:
> > Had a quick play with wasapi using Gale's build on 11 march.
> > Ran into a few problems both on windows 7 and 8.
> > 1. If the input's device's properties are set so that default sample rate in
> > shared mode is 44100hz and project is set to the same frequency, then when I
> > try to record, I get an error while opening sound device message box.
> > Increasing the default sample rate in properties to 48000 stops the dialog
> > opening.
> > 2. Input slider in audacity is unavailable.
> > 3. Latency seems to have a mind of its own. I've only check this with a usb
> > mike. Generated a click track, with clicks every second for 32 seconds.
> > Recorded using microphone with overdub on. latency starts ok at about 100ms.
> > On windows 7 after 12 clicks, then repeatably went to over 600ms. On Windows
> > 8, often ok, sometimes latency becomes much longer after just a small number
> > of clicks. 100ms buffer used. Using mme or direct sound, latency longer but
> > no erratic behaviour.
> >
> > David.