adjust_playback_time: Modify playback time of video

In ocean-tracking-network/glatos: A package for the Great Lakes Acoustic Telemetry Observation System

Modify playback time of video

Description

Speed up or slow down playback of video

Usage

adjust_playback_time(
  scale_factor = 1,
  input,
  output_dir = getwd(),
  output = "new.mp4",
  overwrite = FALSE,
  diagnostic_mode = FALSE
)

Arguments

scale_factor	multiplicative factor changes duration of video playback. See details.
input	character, path to video file (any file type supported by av::av_encode_video; e.g., *.mp4, *.wmv, etc)
output_dir	character, output directory, default is working directory
output	character, output file name
overwrite	logical, default is overwrite = TRUE
diagnostic_mode	Logical (default = FALSE). If true, returns FFMPEG output.

Details

A simple wrapper for av::av_encode_video.

adjust_playback_time adjusts playback speed of video. scale_factor controls the magnitude of speed-up or slow-down by modifying the presentation timestamp of each video frame. Values of scale_factor < 1 speed up playback and > 1 slow down playback. In addition to changing playback, function can change output format by specifying a different file extension in output.

Value

One video animation will be written to output_dir and the path and name of output file with be returned.

Note

Input argument 'ffmpeg' was removed in glatos version 0.7.0.

Author(s)

Todd Hayden, Tom Binder, Chris Holbrook

Examples

## Not run: 

# load example frames
frames <- system.file("extdata", "frames", package = "glatos")

# make video animation
out_file <- file.path(tempdir(), "animation_av.mp4")
make_video(
  input_dir = frames,
  input_ext = ".png",
  output = out_file
)

# slow video down by a factor of 10
path <- file.path(tempdir(), "animation_av.mp4")
adjust_playback_time(
  scale_factor = 10,
  input = path,
  output_dir = tempdir(),
  output = "animation_av_slow.mp4",
  diagnostic_mode = FALSE,
  overwrite = TRUE
)

# slow video down by a factor of 10 and change format of output video
adjust_playback_time(
  scale_factor = 10,
  input = path,
  output_dir = tempdir(),
  output = "animation_av_slow.wmv",
  diagnostic_mode = FALSE,
  overwrite = TRUE
)

# speed up video
adjust_playback_time(
  scale_factor = 0.5,
  input = path,
  output_dir = tempdir(),
  output = "animation_av_fast.mp4",
  diagnostic_mode = FALSE,
  overwrite = TRUE
)

## End(Not run)

ocean-tracking-network/glatos documentation built on April 17, 2025, 10:38 p.m.