library(midiblender)A collection of tools for mangling basic aspects of midi files.
mangle_note_wiggler()
This might be a bit unstable, but it’s a goodie. The
semitones input takes a vector of positive semitone values.
These are used to randomly offset every note up or down by the values in
the vector. The keep_same input is an integer that pads the
sampling vector with 0s. During the sampling process, a random value
from the vector is chosen to add to a note value. If the chosen value is
0, then the note is not changed.
notes: this function was way more involved than I expected. Will probably need to be refactored at some point, and may not be very tolerant of different kinds of midi files.
# import midi
mario <- midi_to_object("all_overworld.mid")
list2env(mario, .GlobalEnv)
midi_df <- midiblender::set_midi_tempo_midi_df(midi_df)
copy_df <- mangle_note_wiggler(midi_df, semitones = c(4,7), keep_same = 2)
# update miditapyr df
miditapyr_object$midi_frame_unnested$update_unnested_mf(copy_df)
#write midi file to disk
miditapyr_object$write_file("note_wiggler_mario.mid")mangle_positive_timing()
Add/subtract random ticks to the time column from a uniform
distribution. Set the range of the distribution with
ticks_amount to control the amount of jitter. Any resulting
time values that are negative are set to zero. This function does not
add jitter to spread out simultaneous messages, so chords do not become
jittered triads.
Useful for subtle humanization, or to absolutely wreck the timing information.
Notes: This function was written to work in a dplyr pipe. It might be nice to hide that part inside the function so this can be run directly on the df…not sure yet, maybe both.
library(dplyr)
# import midi
mario <- midi_to_object("all_overworld.mid")
list2env(mario, .GlobalEnv)
# a dplyr pipe to apply jitter non-meta messages
midi_df %>%
mutate(time = case_when(
meta == FALSE ~ mangle_positive_timing(time, ticks_amount = 5),
meta == TRUE ~ time
)) -> copy_df
# update miditapyr df
miditapyr_object$midi_frame_unnested$update_unnested_mf(copy_df)
#write midi file to disk
miditapyr_object$write_file("jitter_mario.mid")mangle_transpose()
Transpose all notes up or down by semitones.
# import midi
mario <- midi_to_object("all_overworld.mid")
list2env(mario, .GlobalEnv)
copy_df <- mangle_transpose(midi_df, -10)
# update miditapyr df
miditapyr_object$midi_frame_unnested$update_unnested_mf(copy_df)
#write midi file to disk
miditapyr_object$write_file("transpose_mario.mid")