Audio Drop Out

Started by bernie, May 02, 2017, 08:50:35 AM

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bernie

Hello,

We seem to have an odd situation where we sometimes experience an audio drop out for around 100ms which causes the perception on air of a stutter or a skip. We have the main buffer set to 750ms which seems more than enough. Any higher and the buffer starts affecting volume automation.

Administrator

Hello,

the usage of values higher than 500 ms for the BufferLength property is usually intended for fixing issues with troublesome sound cards but it's unfortunately not very compatible for strict timings involved during short fading and volume automation: it must be remarked that stuttering is always an issue with the driver of the sound card in use so, when a similar problem arises, it's always recommended to update the driver to the latest build released by the manufacturer or to change the sound card model in case a new fixed driver shouldn't be available.

Hope this helps.

Kind regards

Severino Delaurenti
MultiMedia Soft

bernie

Thank you.

We are using it in WASPI mode (Non Exclusive) what should the buffer ideally be?

Administrator

You are welcome.

The BufferLength property, introduced when WASAPI was still far to be developed by Microsoft, is only intended for usage with DirectSound.

When dealing with WASAPI the latency is usually far smaller respect to DirectSound and you can establish the buffer length through the nBufferLengthMs parameter of the WASAPI.DeviceStartShared method. This value determines the latency and, if it should be too small, the sound card driver may eventually adjust it to its minimum supported value. You can know if the given length has been accepted by verifying the value of the nLatencyMs parameter after calling the WASAPI.DeviceLatencyGet method. Usually a value around 50 ms should be good but you may try to rise it upon need.

Hope this helps.

Kind regards

Severino Delaurenti
MultiMedia Soft