aseqdump
Show the events received at an ALSA sequencer port
TLDR
Dump MIDI events from all sources
$ aseqdump
Dump from a specific port$ aseqdump -p [20:0]
List available input ports$ aseqdump -l
Show events with normalized MIDI 1.0 values$ aseqdump -p [20:0] -N
Show events as percentages$ aseqdump -p [20:0] -P
SYNOPSIS
aseqdump [-p client:port,...] [-l] [-u version] [-r] [-R|-N|-P]
DESCRIPTION
aseqdump is a command-line utility that prints the ALSA sequencer events it receives as human-readable text. It is useful for debugging MIDI connections, testing keyboards, and monitoring MIDI data streams.The output shows event type, channel, note numbers, velocity, control changes, and other MIDI message details.
PARAMETERS
-h, --help
Print a list of options-V, --version
Print the current version-l, --list
Print a list of possible input ports-p, --port=client:port,...
Set the sequencer port(s) from which events are received. A client can be specified by its number, its name, or a prefix of its name. A port is specified by its number; for port 0, the ":0" part can be omitted-u, --ump=version
Set the client MIDI version. 0 is for legacy mode, 1 is UMP MIDI 1.0 mode, and 2 is UMP MIDI 2.0 mode-r, --raw
Suppress the automatic conversion of events among UMP and legacy clients-R, --raw-view
Show the raw values as is. Channel numbers and UMP group numbers are 0-based. This is the default-N, --normalized-view
Show normalized values aligned with MIDI 1.0. Channel and group numbers are 1-based, velocity and data values are normalized between 0 and 127-P, --percent-view
Show values as percentages. Channel and group numbers are 1-based
CAVEATS
Only displays ALSA sequencer events, not raw MIDI. Subscribe to specific ports to filter output. Events are displayed but not recorded.
HISTORY
aseqdump is part of the alsa-utils package, providing MIDI debugging capabilities since ALSA's introduction.
SEE ALSO
aconnect(1), amidi(1), arecordmidi(1), aseqnet(1), aplaymidi(1)
