[openal] setting source latency

[Chris Robinson]

On 01/27/2015 02:34 PM, Miroslav Andel wrote:
> Hi, is it possible to set the source latency (not offset) somehow? My
> problem is that I'm trying to stream live video with a very small audio
> buffer and I want to delay the audio to lipsync the video.

The actual latency, as reported by the source_latency extension, is a 
function of the backend device, which is dependent on the user's system 
configuration (different backends, audio devices, and CPUs may have 
different buffer metric requirements). If you want to lower this latency 
for your system, you can play around with the "period_size" and 
"periods" config options (the Buffer Metrics in the alsoft-config GUI).

For latency in general, you can control the size of the source's buffer 
queue. Two buffers at 25ms each is a fairly safe minimum, as long as you 
don't get stalled with updating.