MidiFramer class

The class MidiFramer can be used to read midi files to dataframes in order to facilitate to manipulate the data from R. You can also create midi data from R without reading it from a file. The data is transformed to various formats. One of the MidiFramer fields is a MidiFrames object of the python miditapyr package. Its method write_file() can be used to write the data back to a midi file.

Details

See the vignette("pyramidi") for a brief usage introduction how to manipulate midi data.
The vignette("compose") shows a more extended example how to generate midi files from scratch.
vignette("package_workflow") shows in detail the structure of the MidiFramer class.
vignette("functions_usage") illustrates the low-level functions of the pyramidi package. that MidiFramer objects use under the hood.

Public fields

midi_file_string: Path to the midi file.
mf: miditapyr$MidiFrames object.
dfm: result of tab_measures().
df_notes_long: Result of pivot_long_notes().
df_meta, df_not_notes, df_notes_wide: Results of split_midi_frame().
midi_frame_mod: Result of merge_midi_frames().
params: Parameters used in internal functions; Named list; params$columns_to_add is passed to tab_measures(columns_to_add).

Active bindings

df_meta, df_not_notes, df_notes_wide: Results of split_midi_frame().
ticks_per_beat: Set ticks per beat of MidiFrames()$mf$midi_file. The value of ticks_per_beat passed should be integer. When a value is passed, the field mf$midi_file$ticks_per_beat is modified.

Methods

Method `new()`

Initialize a MidiFramer object

Usage

MidiFramer$new(midi_file_string = NULL)

Arguments

midi_file_string: Path to the midi file; if NULL (the default), an empty MidiFramer object is created.

Method `update_notes_wide()`

Update a MidiFramer object with modified notes

Usage

MidiFramer$update_notes_wide(mod)

Arguments

mod: Dataframe or function returning a dataframe of the format of df_notes_wide.

Examples

\dontrun{
midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
mfr <- MidiFramer$new(midi_file_string)
# Function to replace every note with a random midi note between 60 & 71:
mod <- function(dfn) {
  n_notes <- sum(!is.na(dfn$note))
  dfn %>% dplyr::mutate(note = ifelse(
    !is.na(note),
    sample(60:71, n_notes, TRUE),
    note
  ))
}
set.seed(123)
mfr$update_notes_wide(mod)
mfr$play()
# You can pass functions to the $update_notes_wide() method (as above), but
# you can also modify the dataframe directly and pass it. Therefore, the
# following results in the same:
set.seed(123)
df_mod <- mod(mfr$df_notes_wide)
mfr$update_notes_wide(df_mod)
mfr$play()
}

Method `populate_r_fields()`

Populate the fields of a MidiFramer object

This can also be used to recalculate all the object's attributes, when a value in params is changed (see examples).

Usage

MidiFramer$populate_r_fields()

Examples

\dontrun{
midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
mfr <- MidiFramer$new(midi_file_string)
mfr$params$columns_to_add <- c("m", "b", "t", "time")
mfr$populate_r_fields()
}

Method `play()`

Play midi from MidiFramer object. Writes a midi file and either playing it in the R console (live = TRUE), or otherwise (live = FALSE) writes an audio file and adding an html audio player in an Rmarkdown (/quarto?) document. Calls player() helper function.

WARNING: Setting overwrite = TRUE (the default!!) will DELETE the specified audio files!!! (see more details below)

Usage

MidiFramer$play(
  audiofile = tempfile("mf_out_", fileext = ".mp3"),
  soundfont = fluidsynth::soundfont_path(),
  midifile = gsub("\\....$", ".mid", audiofile),
  live = interactive(),
  verbose = FALSE,
  overwrite = TRUE,
  ...
)

Arguments

audiofile: Path to the audiofile to be synthesized. If audiofile of type mp3, it will first be synthesized to wav, and then converted to mp3 with ffmpeg; (character string).
soundfont: path to sf2 sound font (character string); if not specified, the default soundfont of the fluidsynth package (fluidsynth::soundfont_path()) will be (downloaded if not present and) used.
midifile: Path to the midi file to synthesize on; (character string).
live: logical; if TRUE the synthesized midi is directly played in the console. If FALSE an audio html tag is written. This will generate a small audio player when knitting an Rmd document (and probably also Quarto qmd files; I didn't check).
verbose: logical whether to print command line output; defaults to FALSE
overwrite: logical; defaults to TRUE; if file exists and overwrite = FALSE, the existing files will not be overwritten and the function errors out.
...: Arguments passed to the fluidsynth functions (fluidsynth::midi_play or fluidsynth::midi_convert depending on the value of live).
@seealso: player

Examples

midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
mfr <- MidiFramer$new(midi_file_string)
mfr$play()
# The play method does basically this:
\dontrun{
midi_out <- "my_output.mid"
mp3file <- "test.mp3"
mfr$mf$write_file(midi_out)
fluidsynth::midi_convert(midi_out, output = mp3file)
# `overwrite` = TRUE overwrites midi_out & mp3file
}

Method `clone()`

The objects of this class are cloneable with this method.

Usage

MidiFramer$clone(deep = FALSE)

Arguments

deep: Whether to make a deep clone.

Examples

if (FALSE) {
## Create a MidiFramer object from a midi file:
midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
MidiFramer$new(midi_file_string)

## ------------------------------------------------
## Create empty MidiFramer object to illustrate
## the use of the `ticks_per_beat` active binding:
## ------------------------------------------------

mfr <- MidiFramer$new()
# Print default value of empty MidiFile object:
mfr$mf$midi_file$ticks_per_beat
# Modify it with the active binding ticks_per_beat:
mfr$ticks_per_beat <- 960L
# Print it again:
mfr$mf$midi_file$ticks_per_beat
}

## ------------------------------------------------
## Method `MidiFramer$update_notes_wide`
## ------------------------------------------------

if (FALSE) {
midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
mfr <- MidiFramer$new(midi_file_string)
# Function to replace every note with a random midi note between 60 & 71:
mod <- function(dfn) {
  n_notes <- sum(!is.na(dfn$note))
  dfn %>% dplyr::mutate(note = ifelse(
    !is.na(note),
    sample(60:71, n_notes, TRUE),
    note
  ))
}
set.seed(123)
mfr$update_notes_wide(mod)
mfr$play()
# You can pass functions to the $update_notes_wide() method (as above), but
# you can also modify the dataframe directly and pass it. Therefore, the
# following results in the same:
set.seed(123)
df_mod <- mod(mfr$df_notes_wide)
mfr$update_notes_wide(df_mod)
mfr$play()
}

## ------------------------------------------------
## Method `MidiFramer$populate_r_fields`
## ------------------------------------------------

if (FALSE) {
midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
mfr <- MidiFramer$new(midi_file_string)
mfr$params$columns_to_add <- c("m", "b", "t", "time")
mfr$populate_r_fields()
}

## ------------------------------------------------
## Method `MidiFramer$play`
## ------------------------------------------------

midi_file_string <- system.file("extdata", "test_midi_file.mid", package = "pyramidi")
mfr <- MidiFramer$new(midi_file_string)
#> Error in python_config_impl(python) : 
#>   Error running '/home/runner/.virtualenvs/r-reticulate/python': No such file.
#> The Python installation used to create the virtualenv has been moved or removed:
#>   '/opt/hostedtoolcache/Python/3.11.8/x64/bin'
mfr$play()
#> <audio controls="">
#>   <source src="/tmp/RtmpcdQMVt/mf_out_1e2a725f17d7.mp3" type="audio/mp3"/>
#> </audio>
# The play method does basically this:
if (FALSE) {
midi_out <- "my_output.mid"
mp3file <- "test.mp3"
mfr$mf$write_file(midi_out)
fluidsynth::midi_convert(midi_out, output = mp3file)
# `overwrite` = TRUE overwrites midi_out & mp3file
}

Details

Public fields

Active bindings

Methods

Public methods

Method new()

Usage

Arguments

Method update_notes_wide()

Usage

Arguments

Examples

Method populate_r_fields()

Usage

Examples

Method play()

Usage

Arguments

Examples

Method clone()

Usage

Arguments

Examples

Method `new()`

Method `update_notes_wide()`

Method `populate_r_fields()`

Method `play()`

Method `clone()`