This function opens a graphics device to record the images produced in the
code expr
, then uses FFmpeg to convert these images to a video.
This function uses system
to call FFmpeg to convert the images
to a single video. The command line used in this function is: ffmpeg -y -r <1/interval> -i <img.name>\%d.<ani.type> other.opts video.name
where interval
comes from ani.options('interval')
, and
ani.type
is from ani.options('ani.type')
. For more details on
the numerous options of FFmpeg, please see the reference.
Some linux systems may use the alternate software ‘avconv’ instead of ‘ffmpeg’. The package will attempt to determine which command is present and set ani.options('ffmpeg')
to an appropriate default value. This can be overridden by passing in the ffmpeg
argument.
library(animation)
oopts = if (.Platform$OS.type == "windows") {
ani.options(ffmpeg = "D:/Installer/ffmpeg/bin/ffmpeg.exe")
}
## usually Linux users do not need to worry about the ffmpeg path as long as
## FFmpeg or avconv has been installed
saveVideo({
par(mar = c(3, 3, 1, 0.5), mgp = c(2, 0.5, 0), tcl = -0.3, cex.axis = 0.8, cex.lab = 0.8,
cex.main = 1)
ani.options(interval = 0.05, nmax = 300)
brownian.motion(pch = 21, cex = 5, col = "red", bg = "yellow")
}, video.name = "BM.mp4", other.opts = "-pix_fmt yuv420p -b 300k")
# higher bitrate, better quality
ani.options(oopts)