[Openal] Get Audio time or buffer position

[Chris Robinson]

On Saturday 24 November 2007 03:46:43 pm Casey Borders wrote:
> I want to be able to "save" the current position in an audio stream so I
> can come back and start that source right where it left off.  I want to be
> able to do this because I am working on some code to manage hardware
> sources and I'll need to steal sources and shift them around from time to
> time, so when I start a sound back up I'll need to know where to start it
> up at.  Does anyone have any suggestions?

You can use the AL_SAMPLE_OFFSET (or AL_BYTE_OFFSET or AL_SEC_OFFSET(*)) 
source attribute. eg:

ALint stop_source(ALint source)
{
    ALint pos;
    // Pause the source to prevent the offset from incrementing between
    // getting it and stopping the source (alSourceStop rewinds the source
    // back to 0)
    alSourcePause(source);
    alGetSourcei(source, AL_SAMPLE_OFFSET,  &pos);
    alSourceStop(source);

    return pos;
}

void restore_source(ALint source, ALint pos)
{
    alSourcei(source, AL_SAMPLE_OFFSET, pos);
    alSourcePlay(source);
}

(*) Using AL_BYTE_OFFSET may behave a little quirky with compressed formats, 
but should be fine otherwise. AL_SEC_OFFSET uses a float (ALfloat, 
alGetSourcef, alSourcef).