vid.to.images2: Extracts images from a video file with ffmpeg

Description

Extract images from video file using ffmpegs flexible video filters and codecs

Usage

vid.to.images2(
  vid.path = NULL,
  out.dir = NULL,
  overwrite = FALSE,
  filt = NULL,
  codec = NULL,
  silent = TRUE
)

Arguments

vid.path

character; path of video file to be processed.

out.dir

character; directory path in which to store images.

overwrite

logical; should path described by 'out.dir' be overwritten if it exhists.

filt

character; video filter that should be applied to ffmpeg operation. See https://ffmpeg.org/ffmpeg-filters.html

codec

character; video codec to apply in ffmpeg operation

silent

logical; should output of system call for ffmpeg operation be suppressed.

Value

Extracts all the images of the video and saves them to an "images" directory with appended number sequence

Details

Particularly useful for resizing images

Examples

Run this code

# NOT RUN {
#make a video with animation package
# }
# NOT RUN {
fun <- function(){
y <- sin(1:50)
x <- 1:50
for(i in 1:50) {
  plot(x[i],y[i],col="red",xlim=c(0,50),ylim=range(y))
  animation::ani.pause()
  }
}
animation::saveVideo(fun(),video.name=paste0(tempdir(),"/wave.mp4"),interval = 0.2)

#reduce the image images to 200 px wide maintaining aspect ratio
#notice the spaces at the beginning/end of string
filt.red <- " -vf scale=200:-1 "
c <- " -c:v libx264 "
dir.create(paste0(tempdir(),"/images"))
vid.to.images2(vid.path=paste0(tempdir(),"/wave.mp4"),
out.dir=paste0(tempdir(),"/images"),filt=filt.red,codec=NULL)

#see the images in the "images" directory
list.files( paste0(tempdir(),"/images"))

#clean up
unlink(paste0(tempdir(),"/images"),recursive=TRUE)
# }