[pulseaudio-discuss] bluetooth latency gets gradually worse over time

mudrunka at spoje.net mudrunka at spoje.net
Sun May 1 02:37:01 UTC 2016


Hello,
i have issue with bluetooth speaker. it creates loud pop when it's 
(un)suspended by module-suspend-on-idle. so i proceeded to disable 
suspend-on-idle, but when i leave it on for few hours, the latency gets 
huge. Like 2 seconds or more. I suppose it has something to do with DAC 
clock (or samplerate) in bluetooth speakers being little bit slower than 
nominal. And the error adds up over time resulting in growing latency.

When i manualy reconnect to speaker it gets fixed.

Do you have any idea how to fix this? I think it needs something that 
will reset the stream when no audio is played, pretty much like 
suspend-on-idle does, but without powering the bt device off (which 
causes pop). it's really annoying. sometimes it scares the crap out of 
me, when speakers are on full volume and it pops when i eg. receive IM 
mesage. :-) also it's probably not healthy for the speakers (i use 
conventional speakers with amp and bt receiver).

I know the popping is mostly HW error. But it can be worked around by 
disabling suspend-on-idle, which then causes latency problems (also 
somehow HW related). And i think the latency problem can be somehow 
fixed in SW by restarting the stream or cleaning some buffer that causes 
the latency...

BTW 2 seconds of latency are quite a lot... Is there even chance, that 
cheap BT device has 2 second buffer? Maybe it's pulse audio that has 2 
second latency. And it would be easily fixed by not buffering silence. 
Or by deleting this buffer when idle.

Any ideas?

THX
   Tomas


More information about the pulseaudio-discuss mailing list