S7 Class for Single Video Frame Extraction

Usage

VideoFrameExtractor(
  video_path,
  output_dir = file.path(dirname(normalizePath(video_path)), "frames"),
  fps = 1,
  format = "jpg",
  camera_tz_offset = -5
)

Arguments

video_path: character. Full path to source video.
output_dir: character. Directory for extracted frames.
fps: numeric. Frames per second (default 1).
format: character. "jpg" or "png".
camera_tz_offset: numeric. Camera UTC offset in hours (e.g. -5).

Value

An object of class VideoFrameExtractor. This object stores information about a single video file, its output directory, frame rate, and calculated start time based on metadata. It is used to perform frame extraction and metadata stamping.

Details

This function scan a video for its metadata specifically date and time of creation and then extract a number of frames per second, saving the frames as pictures in format JPG or PNG on a specified path. The extracted frames are saved with date and time on Metadata. The function would be useful in situations when you program camera traps to shoot videos, but you need pictures to upload to Wildlife Insights.

Slots

video_path: character. Full path to source video.
output_dir: character. Directory for extracted frames.
fps: numeric. Frames per second (default 1).
format: character. "jpg" or "png".
camera_tz_offset: numeric. Camera UTC offset in hours (e.g. -5).
start_time: POSIXct. Recording start (UTC).
frame_paths: character. Paths of saved frames (after extract).

Examples

video_file <- system.file("extdata", "sample.mp4", package = "photoextractor")
if (video_file != "") {
  extractor <- VideoFrameExtractor(
    video_path = video_file,
    output_dir = tempdir(),
    fps = 1,
    camera_tz_offset = -5
  )
  print(extractor)
}
#> <photoextractor::VideoFrameExtractor>
#>  @ video_path      : chr "C:\\Users\\usuario\\AppData\\Local\\Temp\\Rtmpi6YQIA\\temp_libpath7eecd5b3817\\photoextractor\\extdata\\sample.mp4"
#>  @ output_dir      : chr "C:\\Users\\usuario\\AppData\\Local\\Temp\\RtmpMpib5k"
#>  @ fps             : num 1
#>  @ format          : chr "jpg"
#>  @ camera_tz_offset: num -5
#>  @ start_time      : POSIXct[1:1], format: "2026-04-17 16:23:02"
#>  @ frame_paths     : chr(0)