R/audio_analysis.R

In jaburgoyne/compmus: Support Functions for Computational Musicology

#' Get Spotify audio analysis tidily
#'
#' Fetches the Spotify audio analysis for a track using list columns rather than
#' lists of lists.
#'
#' See the
#' \href{https://developer.spotify.com/documentation/web-api/reference/tracks/get-audio-analysis/}{Spotify
#' developer documentation} for details about the information included in an
#' audio analysis.
#'
#' @param track_uri A string with a Spotify track URI.
#' @param ... Additional parameters passed to
#'   \code{\link[spotifyr]{get_track_audio_analysis}}.
#'
#' @importFrom magrittr %>%
#' @export
#'
#' @examples
#' get_tidy_audio_analysis("6IQILcYkN2S2eSu5IHoPEH")
get_tidy_audio_analysis <- function(track_uri, ...) {
  spotifyr::get_track_audio_analysis(track_uri, ...) %>%
    tibble::enframe() %>%
    tidyr::pivot_wider() %>%
    dplyr::mutate(
      dplyr::across(
        c(meta, track, bars, beats, tatums, sections),
        purrr::map,
        tibble::as_tibble
      ),
    ) %>%
    tidyr::unnest(cols = c(meta, track)) %>%
    dplyr::select(
      analyzer_version,
      duration,
      dplyr::contains("fade"), dplyr::ends_with("confidence"),
      bars, beats, tatums,
      sections, segments
    ) %>%
    dplyr::mutate(
      segments =
        purrr::map(
          segments,
          . %>%
            tibble::as_tibble() %>%
            dplyr::mutate(
              pitches =
                purrr::map(
                  pitches,
                  purrr::set_names,
                  c(
                    "C", "C#|Db", "D", "D#|Eb",
                    "E", "F", "F#|Gb", "G",
                    "G#|Ab", "A", "A#|Bb", "B"
                  )
                ),
              timbre =
                purrr::map(
                  timbre,
                  purrr::set_names,
                  c(
                    "c01", "c02", "c03", "c04",
                    "c05", "c06", "c07", "c08",
                    "c09", "c10", "c11", "c12"
                  )
                )
            )
        )
    )
}

#' Add Spotify audio analysis to a data frame
#'
#' Fetches and joins the Spotify audio analysis for every Spotify URI in a data
#' frame.
#'
#' @param df A data frame with a \code{track_uri} column.
#' @param ... Parameters passed on to \code{\link{get_tidy_audio_analysis}}.
#'
#' @seealso \code{\link{get_tidy_audio_analysis}}
#'
#' @importFrom magrittr %>%
#' @export
#'
#' @examples
#' library(tidyverse)
#' spotifyr::get_playlist_audio_features("", "37i9dQZF1DX21bRPJuEN7r") %>%
#'   slice(1:5) %>%
#'   add_audio_analysis()
add_audio_analysis <- function(df, ...) {
  df %>%
    dplyr::mutate(
      track.uri = stringr::str_remove(track.uri, "spotify:track:"),
      analysis = purrr::map(track.uri, get_tidy_audio_analysis, ...)
    ) %>%
    tidyr::unnest(analysis)
}