Hi,
how to start with PLC, adaptive PLC in Asterisk ( stand alone installation on laptop, Asterisk is playing MOH files via a sound card).
I am looking for adaptive PLC app.
Packet loss concealment (PLC)
Wiki
en.wikipedia.org/wiki/Packet_loss_concealment
Google search
google.com/#hl=en&source=hp& … be010d257f
good examples of PLC algorithms implemented
Silence Insertion Replay last packet G.711 Appendix 1
voiptroubleshooter.com/problems/plc.html
Darius
follow-up
voip-info.org/wiki/view/Aste … tterbuffer
reviewboard.asterisk.org/r/688/
from
lists.digium.com/pipermail/aster … 53863.html
"
PLC is also really important when using a dynamic jitter buffer,
because whenever the jitter buffer wants to grow, PLC can hide the
sparse frames. While the current jitter buffer will just give you a
big gap, ideally, if you’re growing, you’d be able to spread the gaps a
bit, and use PLC to hide them. For example, if you have 100ms worth of
frames already queued, and you need to grow the jitterbuffer to 180ms,
you’d intersperse the 80ms gaps into 20ms (or whatever) size gaps, and
use PLC to interpolate them. This would be much less noticable than an
80ms dropout in audio.
-SteveK
"
follow-up 2
In the meantime, as advised, I opened codecs.conf file
coming with both [speex} and [plc} contexts
genericplc => true ( so looks to be enabled)
setting parameters in [speex] context is much more complicated,
as in my case, Asterisk is playing MOH files directly to headphone (via Celliax audio channel),
and sound quality is fine with SIP softphone X-Lite, playing the same files to headphone.
Any idea if [speex] can help if Asterisk is playing sound directlt to sound card ( no ethernet) ?
Darius