Engifification in R with {gifski}

I personally don’t evolve Lotad, because it’s already perfect.

tl;dr

Use {gifski} to make gifs—real quickly!—using R.

Intergalactic pizza sloths

You and I both know that the world needs more gifs of sloths riding through space on a slice of pizza, for example.

Great news: ‘the fastest gif encoder in the universe’ has come to R via the {gifski} package built by Jeroen Ooms for rOpenSci. It’s built on Gifski package for Rust, hence the speed.

The obvious analytical application is for creating gifs from plots, as in the following example from the rOpenSci announcement, which shows life expectancy by GDP per capita with a different year for each frame of the gif.

But no-one can stop us having fun with it too.

Engifification proclamation

So I’ve made a quick function that takes a folder of PNGs and stitches them into a gif using the gifski::gifski() function. I’ve called it make_gif() because it… makes gifs. It’s not optimised because it’s just for fun, okay?

make_gif <- function(png_dir, gif_path, ...) {
  
  png_dir_is_char  <- inherits(png_dir, "character")
  gif_path_is_char <- inherits(gif_path, "character")
  
  if (!png_dir_is_char | !gif_dir_exists) {
    stop("png_dir and gif_path must be character class.", call. = FALSE)
  }
  
  png_dir_exists <- dir.exists(png_dir)
  gif_dir_exists <- dir.exists(dirname(gif_path))
  
  
  if (!png_dir_exists | !gif_path_is_char) {
    stop("png_dir and gif_path directories must exist.", call. = FALSE)
  }
  
  path_is_gif <- tools::file_ext(gif_path) == "gif"
  
  if (!path_is_gif) {
    stop("gif_path must be a file path ending with .gif.", call. = FALSE)
  }
  
  files <- list.files(
    path = png_folder,
    pattern = ".png$|.PNG$",
    full.names = TRUE
  )
  
  if (length(files) < 2) {
    stop("You need two or more PNGs to make a gif.", call. = FALSE)
  }
  
  png("frame%03d.png")
  
  par(ask = FALSE)
  
  dev.off()
  
  gifski::gifski(png_files = files, gif_file = gif_path)
  
}

Basically, you must supply two things:

1. A path to a folder containing the images (.png or .PNG only).
2. A path for where the gif should be written (including the ‘.gif’ extension).

Optionally you can provide a third: use the dots (...) to pass further arguments to gifski::gifski() (see ?gifski for details).

Note that you should make sure your PNGs are ordered alphabetically or numerically in the named directory so that they’re engiffed¹ in the desired sequence. Don’t worry if your folder has other filetypes; make_gif() only extracts PNGs.

Hexapod lilypad-frog evolution

I used the make_gif() function to create the important gif at the top of this post, featuring the evolution chain of Lotad, the best and most special Pokémon.

make_gif(
  png_folder = "~/Documents/pokemon/lotad/images",  # folder of images
  gif_path   = "~/Desktop/lotad.gif"                # path to save gif
)

Maybe you’ll find the function useful too. So get out there and get engiffing!²

Environment

Session info

Last rendered: 2023-08-08 22:14:03 BST

R version 4.3.1 (2023-06-16)
Platform: aarch64-apple-darwin20 (64-bit)
Running under: macOS Ventura 13.2.1

Matrix products: default
BLAS:   /Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/lib/libRblas.0.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/lib/libRlapack.dylib;  LAPACK version 3.11.0

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: Europe/London
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
 [1] htmlwidgets_1.6.2 compiler_4.3.1    fastmap_1.1.1     cli_3.6.1        
 [5] tools_4.3.1       htmltools_0.5.5   rstudioapi_0.15.0 yaml_2.3.7       
 [9] rmarkdown_2.23    knitr_1.43.1      jsonlite_1.8.7    xfun_0.39        
[13] digest_0.6.33     rlang_1.1.1       evaluate_0.21    

Footnotes

1. I am endorsing the phrase ‘to engif’, as in ‘I am engiffing a bunch of PNGs’. There’s no way this doesn’t take off.

2. Actually, it doesn’t sound right does it?

Reuse