[pulseaudio-discuss] Adding delay in order to sync soundcard with a2dp stream

[Lennart Poettering]

On Thu, 03.12.09 20:33, Alexander H Deriziotis (jackflap at lavabit.com) wrote:

> Hi all,
> 
> I'm outputting audio to both a bluetooth speaker via a2dp and the
> internal soundcard by using module-combine to create a virtual sink.
> 
> The problem is that the sound arrives at the bluetooth speaker I think
> around 0.5 seconds after it's played on the soundcard.
> 
> Is there any way to add a delay to the internal soundcard sink in
> order to synchronize the audio coming out of the wired speakers and
> the bluetooth speaker?

Nope there currently is not.

Ideally we'd determine the latencies automatically. Unfortunately some
interfaces simply don't allow that, such as SPDIF, early HDMI, and BT
audio. 

It should be trivial to write a module for PA that simply piggybacks
on another sink and adds a configurable latency. However, ideally we'd
fix this by implementing a more generic filter framework in PA that
allows plugging stuff like this into an existing sink without
introducing an additional piggybacked sink. There have been some
discussions about that and tanuk even prepared some code for this, but
this hasn't been finished yet.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/           GnuPG 0x1A015CC4