Determing when all buffers played (WASAPI)

Question

In WASAPI shared event driven mode, what is the best way to determine when all buffers have been played?

Is it safe to do:

while(1)
{
hr = mpClient->GetCurrentPadding(&i);
if (FAILED(hr) || i == 0)
{
break;
}
}

This is after the rendering loop when I know all my buffers have been sent using GetBuffer/ReleaseBuffer, in a scenario where using Sleep() is not desired.

Thanks.

Answer 1

You can use IAudioClock to see what sample is currently going out of the speakers.

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Matthew van Eerde

Answer 2

Thanks for the reply.  However, I didn't mention that I am using IMFSourceReader::SetCurrentPosition(), and according to the documentation this is not accurate.

So, given that I have an audio file of 03:18 (198357ms), and I start it at 170000 using SetCurrentPosition(), this:

while(1)
{
	hr = mpClock->GetPosition(&pos, NULL);

	diff = (double)pos / miClockFreq;

	diff *= 1000.0f;

	if (dwTotalLength - dwStartPosition <= diff)
	{
		break;
	}
}

gets into an infinite loop. diff remains at 26776.66666 recurring, while dwTotalLength - dwStartPosition is obviously 28357.  I have assumed that SetCurrentPosition was out by 2 seconds (ish).  That's quite a lot of audio.

Given this fact, is my original method better?

Thanks.