alsa_delay - measure round-trip latency of a soundcard
alsa_delay playdev captdev fsamp frsize nfrags
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.
- 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)
This will measure and display the round-trip latency of soundcard
hw:0
using 48kHz samplerate, and 10 fragments each 2048 samples.
alsa_delay hw:0 hw:0 48000 2048 10
alsa_delay is a port of
jack_delay (by the same author) to ALSA.
zita-alsa-pcmi was written by Fons Adriaensen <
[email protected]>.
This manual page was written by IOhannes m zmoelnig <
[email protected]> for
the Debian project (but may be used by others).