File Plugin seems to drop data when writing to FIFO

18 Jun 2020


      alsa-project/alsa-lib issue #63 was opened from riggiding:
Hi,
we're using the file plugin to pipe data for use in a vu-meter application. This worked well but since updating to 1.1.4.1 the data received is incomplete (tested using sine test tones and Audacity to playback / inspect the data that went through the fifo).
**When writing to a normal file all is fine.**
Also tried using tee, same result.
Any hints or ideas would be great!
**The fifo is created by:**
#! /bin/sh
if [ ! -p "$ALSA_FIFO" ]; then
    # create a fifo for alsa -> vumeter
    mkfifo "$ALSA_FIFO"                                           
    chmod 666 "$ALSA_FIFO"
fi
cat <>"$ALSA_FIFO"
**asound.conf:**
pcm.hiface {
    type hw
    card 0
    device 0
}
pcm.vumeter {
    type rate
    slave {
    	pcm "alsaFifo"
    	rate 44100
    	format "S16_LE"
    }
}
pcm.alsaFifo {
    type file
    slave.pcm "null"
    file "/tmp/alsa-fifo"
}
pcm.alsaFifoTee {
       type empty
       slave.pcm "tee:null,'/tmp/alsa-fifo',raw"
}
pcm.direct {
    type route
    slave.pcm "split_direct"
    ttable.0.0 1
    ttable.1.1 1
    ttable.0.2 1
    ttable.1.3 1
}
pcm.split_direct {
    type multi
    slaves.a.pcm "hiface"
    slaves.a.channels 2
    slaves.b.pcm "vumeter"
    slaves.b.channels 2
    bindings.0.slave a
    bindings.0.channel 0
    bindings.1.slave a
    bindings.1.channel 1
    bindings.2.slave b
    bindings.2.channel 0
    bindings.3.slave b
    bindings.3.channel 1
}
Issue URL     : https://github.com/alsa-project/alsa-lib/issues/63
Repository URL: https://github.com/alsa-project/alsa-lib

File Plugin seems to drop data when writing to FIFO

GitHub issues - opened