CODEWITHSUNDEEP
loopsbufferopenal-soft
jujumbura
jujumbura

Reputation: 423

OpenAL Soft - Loop with Intro

I have been using OpenAL soft for Win32, and I I ran into a particular problem.

My goal is to play a looping sound that has a one-shot intro portion, similar to a .WAV file with a loop marker. As I understand it, this must be achieved in OpenAL by using multiple buffers on a source. In general, my approach is to queue up both buffers, then wait until the second buffer is playing, and set the source to loop. This works, but the problem is that once I am ready to stop the sound, I don't seem to be able to unqueue the last buffer. My code looks roughly like this:

// set up the sound
alSourceQueueBuffers(source, 1, &buffer1);
alSourceQueueBuffers(source, 1, &buffer2);
alSourcePlay(source);

...

// check to loop sound in update
ALint buffer;
alGetSourcei(source, AL_BUFFER, &buffer);
if (buffer == buffer2)
{
    alSourcei(source, AL_LOOPING, true);
}

..

// check to stop sound in update
if (shouldStop)
{
    alSourcei(source, AL_LOOPING, false);
    alSourceStop(source);

    alSourceUnqueueBuffers(source, 1, &buffer1);
    alSourceUnqueueBuffers(source, 1, &buffer2); // AL_INVALID_OPERATION
}

The result seems to be that the buffer is not properly unqueued, and will be heard the next time I play this source. I know that typically you can only unqueue a buffer after it finished playing, but I would think that I could freely unqueue any buffers on a stopped sound. I am wondering if perhaps my use of the loop flag is causing this behavior?

I'd greatly appreciate any advice.

Thank you, Mike

Upvotes: 1

Views: 1143

Answers (2)

Tim Beaudet
Tim Beaudet

Reputation: 807

I believe the proper use of alSourceUnqueueBuffers(source, 1, &buffer1); is to create an array of your buffers and send it in, instead of calling it twice, you call it once on the array like so:

ALuint buffers[2] = { buffer1, buffer2 };
alSourceUnqueueBuffers(source, 2, buffers);

Note we are using a size of 2 to indicate 2 buffers.

Upvotes: 0

jujumbura
jujumbura

Reputation: 423

It looks like there is a way around this. I can't unqueue the playing buffer, but I can completely clear out the queue with this line:

alSourcei(source, AL_BUFFER, AL_NONE);

This will work just fine after stopping the sound.

Upvotes: 0

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