PortAudio and Asio4ALL, is "pull mode" supposed to work?

[Dr.Venom]

Hi,

I've been doing some tests with the audio settings and noticed that for PortAudio with Asio4All the WinUAE log says "pull mode", but if I look in the Asio4all panel than it says that it's running in "push mode" (it shows when you do a mouse-over on the audio device in the asio4all panel), even though the "allow pull mode" is ticked. I'm interested because "pull mode" would allow for even lower latency.

So my question is whether "pull mode" when used with PA and Asio4All is actually supposed to work?

WinUAE log:
37-367 [3689 000-000]: PASOUND: CH=2,FREQ=48000 ([ASIO] ASIO4ALL v2) 'ASIO4ALL v2' buffer 16/512 (pull)
2013-11-05 15:00:08

Asio panel when WinUAE is running:

[Dr.Venom]

Hi Toni,

Following up from the previous post. I read somewhere that there may be an issue with pull-mode when used with a 32-bit application on a 64-bit OS (I'm on W7 x64).

So I thought I'd give the 2.6.1 64-bit version from winuae.net a try, to see if that would make a difference, but unfortunately that x64 version doesn't show any of the Portaudio modes (the pull-down is empty where normally it shows all "PortAudio:" modes).

I have both portaudio_x64.dll and portaudio_x86.dll in plugins directory. Any idea what the issue may be? Thanks..

[Toni Wilen]

Pull mode isn't fully implemented, I think pull mode wasn't working correctly when portaudio support was added long, long time ago or something like that.

[Dr.Venom]

OK, thanks for the answer.

I did a little digging around earlier and found two interesting documents:

- Windows 7 Changes Related To Audio Drivers (Win7Changes-Audio.docx)
- WaveRTport.doc

Please see the first document from page 27 onwards "WaveRT Pull mode support". There's example code there for the adjustments needed to add pull mode support to a driver, assuming it already has push mode support.

It's not clear to me whether this would be of use to an application developer, or whether it's purely targeted to hardware driver writers. Maybe it's interesting?

Lastly, any idea why the PortAudio selection won't show in the 64-bit WinUAE?