amidi (Experimental)

Name: mido.backends.amidi

Resources:

• The Advanced Linux Sound Architecture (ALSA) project

• ALSA Opensrc Org amidi

Features

• Linux only.

• very basic implementation.

• no callbacks

• can only access physical ports. (Devices that are plugged-in.)

• high overhead when sending since it runs a new amidi command for each message.

• known bug: is one behind when receiving messages. See below.

Operation

The amidi command (part of ALSA and the alsa-utils package) is used for I/O:

• amidi -l to list messages (in get_input_names() etc.)

• amidi -d -p DEVICE to receive messages. amidi prints these out one on each line as hex bytes. Unfortunately it puts the newline at the beginning of the line which flushes the buffer before the message instead of after. This causes problems with non-blocking receiption using select.poll() which means messages are received one behind. This needs to be looked into.

• amidi --send-hex MESSAGE_IN_HEX -p DEVICE to send messages. Since this is called for every message the overhead is very high.