Re: [ecasound] ecasound- does not wait long enough for data to come from a named pipe

From: Kai Vehmanen <kvehmanen@email-addr-hidden>
Date: Fri Aug 08 2008 - 21:43:43 EEST


On Thu, 7 Aug 2008, Sergei Steshenko wrote:

> ~/AFSWD/install/ecasound- -f f32_le,2,44100 -i
> diagnostic_audio/diagnostic_audio_fifo.raw -f 16,2,44100 -b 4096 -o alsa
> (audioio-db-server) wait_for_full failed
> (audioio-db-client) WARNING: Underrun in reading from "diagnostic_audio/diagnostic_audio_fifo.raw". Trying to recover.
> (audioio-db-client) WARNING: Underrun in reading from "diagnostic_audio/diagnostic_audio_fifo.raw". Trying to recover.

you can disable this with "-z:nodb" -- this turns off the threaded disk
i/o subsystem of ecasound.

> Is there a way to make ecasound to wait for data to appear in the
> diagnostic_audio/diagnostic_audio_fifo.raw named pipe forever ?
> I mean, to make it behave like simple 'cat' would do ?

While "-z:nodb" can help, using pipes this way (in setups with real-time
devices, e.g. "-o alsa" in this case) will not be very reliable. When
real-time devices are included, ecasound expects all input/outputs to
provide/consume samples at the rate set by the real-time objects. If some
device blocks (is unable to consume/provide samples), this will block the
entire engine. Some real-time devices will handle this better, but you
will gets all kinds of issues from this.

To receive, potentially discontinuous, audio streams over pipe/sockets,
some sort oF RTP receiver/send object would be needed. Ecasound doesn't
currently provide this, but for instance GStreamer does... (and it also
has an element for loading LADSPA plugins.. .although I haven't personally
tried this). But hopefully '-z:nodb' works sufficiently well for you so
you don't have to switch tools at this point.

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Received on Sat Aug 9 00:15:03 2008

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