makemovie: Produce a movie from frame-drawing function

In graphx: Graphics Routines for Scientific Research

Description

Generates an MP4-movie provided a custom function that plots individual frames. The routine has been developed and tested for MacOS and it requires on a working installation of ffmpeg.

Usage

makemovie(
  frame.draw,
  frame.index,
  output.path,
  output.filename,
  width = 1080,
  height = 720,
  fps = 60,
  smear = NULL,
  keep.frames = FALSE,
  quiet = TRUE,
  separator = "/",
  ffmpeg.cmd = "ffmpeg",
  ffmpeg.opt = "-vcodec libx264 -crf 18 -pix_fmt yuv420p",
  manual = FALSE
)

Arguments

frame.draw	function that plots an individual frame. This function must have exactly one argument 'x', which can be integer (e.g. a simple frame index) or real (e.g. a time).
frame.index	list of frame indices 'x' to be included in the movie
output.path	character specifying the directory, where the movie and temporary frames are saved
output.filename	movie filename without path. This filename should end on the extension '.mp4'.
width	number of pixels along the horizontal axis
height	number of pixels along the vertical axis
fps	number of frames per second
smear	optional number of sub-frames used to smear each frame. If given, the function frame.draw must accept continuous arguments in between the values of frame.index.
keep.frames	logical flag specifying whether the temporary directory with the individual frame files should be kept
quiet	logical flag; if true, all console outputs produced by 'ffmpeg' are suppressed
separator	filename separate of the system ('/' for Mac, Linux, Unix; '\' for Windows)
ffmpeg.cmd	command used to call ffmpeg form a terminal. Normally, this is just 'ffmpeg'.
ffmpeg.opt	compression and formatting options used with ffmpeg
manual	logical flag; if true, ffmpeg is not called from within the code and the frames are never deleted. The suggested linux command line is returned as output.

Value

Linux command line to convert frames into movie using ffmpeg.

Author(s)

Danail Obreschkow

See Also

makeframe

Examples

## Example: Movie of a manual clock

# Function to draw a single clock face with two hands
frame = function(time) {
  par(mar=c(0,0,0,0))
  nplot(xlim=c(-1.1,1.1),ylim=c(-1.1,1.1),pty='s')
  plotrix::draw.circle(0,0,1,col='#aaaaff')
  radius = c(0.5,0.9)
  speed = 2*pi/c(720,60)
  lwd = c(4,2)
  graphics::arrows(0,0,radius*sin(speed*time),radius*cos(speed*time),lwd=lwd)
}

# Produce movie
## Not run: 
makemovie(frame,seq(0,60,0.5),'~/testmovie','movie.mp4',200,200)

## End(Not run)

graphx documentation built on Feb. 3, 2022, 5:07 p.m.