bassasio contest.exe "Error(0/20): Can't start ASIO output"

[LastExceed]

• Other ASIO applications (e.g. this testing tool, or this other audio library) are working fine
• OS, device driver, and library are all up2date
• Yes, I have tried turning it off and on again

The minimal code that produces this error for me is:

Code Select Expand

// C#

using ManagedBass.Asio;

BassAsio.Init(0, AsioInitFlags.Thread).OrThrow(); // ok
BassAsio.ChannelEnable(false, 0, (_,_,_,_,_) => 0).OrThrow(); // ok
BassAsio.Start().OrThrow(); // error: parameter

static class Util
{
    public static void OrThrow(this bool success)
    {
        if (!success)
            throw new Exception(BassAsio.LastError.ToString());
    }
}
I am out of ideas. How can I debug this further?

[Ian @ un4seen]

When BASS_ASIO_Start fails with BASS_ERROR_ILLPARAM (error code 20), that means the ASIO buffer is too small. Please check the BASS_ASIO_INFO bufpref/bufmin/bufmax/bufgran values with BASS_ASIO_GetInfo, and confirm what buffer size is set in the ASIO driver's control panel.

[LastExceed]

The values reported by BASS_ASIO_GetInfo match the expected capabilities of my device:

version: 1354
inputs: 6
outputs: 6
bufmin: 8
bufmax: 2048
bufpref: 16
bufgran: -1
initflags: Thread

Increasing the preferred buffer size to 32 or above in the control panel seems to solve the problem, but it is unclear to me why. The issue does seem to be specific to bassasio, considering that other asio implementations are able to operate at buffer sizes 8 and 16 just fine. Is there a reason it rejects these values?

PS: Amusingly, trying to check the output of BASS_ASIO_GetInfo eventually led me to the discovery of a bug, just not the one I was looking for https://github.com/ManagedBass/ManagedBass/pull/129 (I am aware that this is a 3rd party wrapper, but I couldn't not mention the irony)

[Ian @ un4seen]

The values reported by BASS_ASIO_GetInfo...

Thanks, that confirms the problem is the buffer size. BASSASIO currently requires a minimum of 17 samples. Here's an update for you to try, which should remove that requirement:

    www.un4seen.com/stuff/bassasio.zip

Let me know if it still gives you any trouble with very small buffers.

[LastExceed]

This build fixes the problem, tyvm