Module midi 

Standard MIDI Files, read as a table of their events.

The parser is written by hand over the file’s bytes: MThd and MTrk chunks, variable-length deltas, running status, sysex and meta events. Every length the file states is checked against the bytes that remain before it is used, so a corrupt or hostile file is an error rather than a panic or an allocation sized by a number the file made up.

The rows are an eager DataFrame (one per event) made lazy, as ORC and Excel are: MIDI files are kilobytes. What is not a row — the header, the tracks’ names, the tempo range — is a MidiSummary, carried to the dataset for the Info panel’s MIDI tab.

Structs

Event

One event as the file has it, its bytes borrowed from the file.

MidiSummary

What a MIDI file says besides its events, for the Info panel’s MIDI tab.

Smf

A Standard MIDI File, parsed.

TrackSummary

One track, as the Info panel lists it.

Enums

Body

Division

How a file counts time: ticks per quarter note, or SMPTE frames.

Constants

MAX_EVENTS

The most events read, across every file of one open. Each is a row of a dozen columns held in memory.

MAX_FILE_BYTES

The largest file read. MIDI files are kilobytes; a song with a dense controller stream is a few megabytes.

Functions

build

The table and the summary for parsed files; names are their files, written to a file column when there is more than one.

detail

The MIDI tab: the header, timing and tempo, then the tracks; for a directory of songs, the totals, then the files that could not be read.

looks_like_midi

Whether head starts like a MIDI file: MThd with its length of 6, or a RIFF RMID wrapper.

note_name

A note number as a name, middle C (60) as C4.

notes

What the open has to say about the events: notes that never end, and files that could not be read.

parse

Parse a Standard MIDI File (or one in a RIFF RMID wrapper).

read_midi

Read paths as one table of events, with a file column when there is more than one.