Myujth

I'm developping a UWP audio application. Latest Windows 10 SDK version 1803.

I would like to increase the SamplesPerQuantum used on the AudioGraph of my application.
According to the docs, I should specify the properties DesiredSamplesPerQuantum and QuantumSizeSelectionMode before creating the AudioGraph.

I'm creating the AudioGraph like this :

AudioGraphSettings settings = new AudioGraphSettings(AudioRenderCategory.Media);
settings.DesiredSamplesPerQuantum = 960; // 20ms
settings.QuantumSizeSelectionMode = QuantumSizeSelectionMode.ClosestToDesired;
CreateAudioGraphResult result = await AudioGraph.CreateAsync(settings);
Debug.WriteLine("SamplesPerQuantum=" + result.Graph.SamplesPerQuantum);

I tried everything, the SamplesPerQuantum property is always 480...

It's a problem because I get clicks in the audio output at each garbage collection. I think the default quantum of 10ms is too short...

I tried everything, the SamplesPerQuantum property is always 480...

By default, the quantum size is 10 ms based at the default sample rate. The system will choose a quantum size as close as possible to the one you specify. if your the sample rate of speak device is limited to 48000hz, the SamplesPerQuantum will be limited to 480. For your requirement, you could set sample rate to 96000hz. Then your setting could be available.

I have discussed with media team, and they give the following reply. The general idea is DesiredSamplesPerQuantum related with your hardware.

Update

The behavior the customer is seeing is dependent on the underlying audio hardware. The DesiredSamplesPerQuantum property is only a suggestion to the underlying hardware. If the hardware / driver does not support the requested quantum then it will not be set.
When the GC runs there may be clicks or pops in the audio. This is because managed languages are nondeterministic.

And this is James Dailey's blog that you could refer.