[gst-devel] alsa: poll reports error

Markus Westergren markus.westergren at orexis.se
Wed Nov 6 00:15:08 CET 2002


I have a problem with the ALSA plugin for GStreamer. I want to grab audio 
from a soundcard, code it with lame and then stream it with IceCast. I have 
written a small program which does this and it works for a few hours (it 
works for about 3.5 hours) and then I get the following message, which is 
repeated over and over until I terminate the progam:

** (process:893): WARNING **: alsa: poll reports error.

I made the same pipeline with gst-launch (command below) and got the same 
result. (the number after "process" is different) It doesn't matter if 
someone is listening to the stream or not.

gst-launch alsasrc ! lame bitrate=64 ! shout2send port=9000 password=audio 
name=Test genre=Radio mount=/radio

But it works if I change to OSS instead and run the following:

gst-launch osssrc ! lame bitrate=64 ! shout2send port=9000 password=audio 
name=Test genre=Radio mount=/radio

There is an delay between the input signal and the output stream which 
increases with time. The delay is the same even if I restart the program 
which listens to the stream. It I restart the streaming program I get a much 
shorter dealy for a while. The delay increases with about 1 sec every hour. 
This is the same for both ALSA and OSS. Perhaps a buffer is filling up 
somewhere and when it's full ALSA reports error?

I'm running on Debian Unstable with yesterdays CVS-versions of GStreamer, 
ALSA, libshout and IceCast2. My kernel is 2.4.19 and the soundcard is a 
Soundblaster PCI-128 and I'm using the snd-ens1371 ALSA module.

How good is the support for multiple soundcards in OSS and the OSS module for 


More information about the gstreamer-devel mailing list