[pulseaudio-discuss] Issue migrating to pulseaudio8.0: Audio streamed through gsteamer pulsesink pulgin starts to play delayed

[Ahmed S. Darwish]

On Thu, Nov 24, 2016, Mahendran, Dandapani (D.) wrote:
> Hi All,
> 
> Following is the issue we are facing while using Pulseaudio8.0 along
> with gstreamer pulsesink plugin.  This issue was not seen while using
> Pulseaudio4.0.
> 
> Audio streaming started with an initial delay of 1.5 to 2 Secs.
# Attached are the pulse & gst logs during the issue case.
> 
> "route_andautonav" is the sink in which the problem is seen.
# Configuration for this sink in default.pa is load-module module-null-sink
# sink_name="route_andautonav"   format=s16le rate=44100 channels=2.
>

Hmm...

- Can you re-send the pulse logs with time-stamps attached? So far it's
  not clear where the delay exists

- How was the delay measured? Since this is just an initial delay, and
  this seems to be an automotive embedded board, it would be easiest to
  just reserve a GPIO pin and sprinkle some alternating high/lows: one
  in gstreamer pulse sink, one in libpulse, and one in the PA daemon
  itself at protocol-native.c different commands (AUTH,
  CREATE_PLAYBACK_STREAM, etc.)

- Was pulse socket-activated, or automatically started by SYSV/systemd?
  If it's the latter, are you sure there's no race conditions in the
  init system sequence?

- Is Pulse running with real-time scheduling priority? If not, can you
  reproduce with RT scheduling ON?

  Since this is an embedded board, are they any *other* processes in
  the system that are running with RT priority? If so, can you
  reproduce while they're disabled?

- One big change from PA 4.0 to PA 8.0 was srbchannels. Does disabling
  them make any difference?

- As Tanu stated, reproducing with a smaller program like pacat would
  be much much easier indeed.

Best of luck,

-- 
Darwish
http://darwish.chasingpointers.com