SIMPLE SOLUTIONS

ALSA_DELAY(1) - Linux man page online | User commands

Measure round-trip latency of a soundcard.

Chapter
July 2013
zita-alsa-pcmi(1) General Commands Manual zita-alsa-pcmi(1)

NAME

alsa_delay - measure round-trip latency of a soundcard

SYNOPSIS

alsa_delay playdev captdev fsamp frsize nfrags

DESCRIPTION

This tool can be used to measure the round-trip latency of a soundcard. To do this, start the program and connect like this: alsa_delay -> playdev -> cable from soundcard output to input -> captdev -> alsa_delay alsa_delay should be able to measure the round-trip latency with an accuracy of around 1/1000 of a sample. The assumption is, that the latency is more or less independent of frequency, and that the cable between soundcard output and input has virtually zero latency.

ARGUMENTS

playdev ALSA playback device (e.g.: hw:0) captdev ALSA capture device (e.g.: hw:0) fsamp Sample rate (e.g.: 48000) frsize Period size (e.g.: 256) nfrags Number of fragments (e.g.: 2)

EXAMPLES

This will measure and display the round-trip latency of soundcard hw:0 using 48kHz sam‐ plerate, and 10 fragments each 2048 samples. alsa_delay hw:0 hw:0 48000 2048 10

NOTES

alsa_delay is a port of jack_delay (by the same author) to ALSA.

AUTHOR

zita-alsa-pcmi was written by Fons Adriaensen <@linuxaudio.org>. This manual page was written by IOhannes m zmoelnig <@iem.at> for the Debian project (but may be used by others).
July 2013 zita-alsa-pcmi(1)
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