ari_stitch: Create a video from images and audio

In seankross/ari: Automated R Instructor

Create a video from images and audio

Description

Given a vector of paths to images (preferably .jpgs or .pngs) and a flat list of Waves of equal length this function will create an .mp4 video file where each image is shown with its corresponding audio. Take a look at the readWave function if you want to import your audio files into R. Please be sure that all images have the same dimensions.

Usage

ari_stitch(
  images,
  audio,
  output = tempfile(fileext = ".mp4"),
  verbose = FALSE,
  cleanup = TRUE,
  ffmpeg_opts = "",
  divisible_height = TRUE,
  audio_codec = get_audio_codec(),
  video_codec = get_video_codec(),
  video_sync_method = "2",
  audio_bitrate = NULL,
  video_bitrate = NULL,
  pixel_format = "yuv420p",
  fast_start = FALSE,
  deinterlace = FALSE,
  stereo_audio = TRUE,
  duration = NULL,
  video_filters = NULL,
  frames_per_second = NULL,
  check_inputs = TRUE
)

Arguments

images	A vector of paths to images.
audio	A list of Waves from tuneR.
output	A path to the video file which will be created.
verbose	print diagnostic messages. If > 1, then more are printed
cleanup	If TRUE, interim files are deleted
ffmpeg_opts	additional options to send to ffmpeg. This is an advanced option, use at your own risk
divisible_height	Make height divisible by 2, which may be required if getting "height not divisible by 2" error.
audio_codec	The audio encoder for the splicing. If this fails, try copy.
video_codec	The video encoder for the splicing. If this fails, see ffmpeg -codecs
video_sync_method	Video sync method. Should be "auto" or '"vfr"' or a numeric. See https://ffmpeg.org/ffmpeg.html.
audio_bitrate	Bit rate for audio. Passed to -b:a.
video_bitrate	Bit rate for video. Passed to -b:v.
pixel_format	pixel format to encode for 'ffmpeg'.
fast_start	Adding 'faststart' flags for YouTube and other sites, see https://trac.ffmpeg.org/wiki/Encode/YouTube
deinterlace	should the video be de-interlaced, see https://ffmpeg.org/ffmpeg-filters.html, generally for YouTube
stereo_audio	should the audio be forced to stereo, corresponds to '-ac 2'
duration	a vector of numeric durations for each audio track. See pad_wav
video_filters	any options that are passed to -vf arguments for ffmpeg
frames_per_second	frames per second of the video, should be an integer
check_inputs	Should the inputs be checked? Almost always should be TRUE, but may be useful if trying to do customized stuff.

Details

This function uses FFmpeg which you should be sure is installed before using this function. If running Sys.which("ffmpeg") in your R console returns an empty string after installing FFmpeg then you should set the path to FFmpeg on you computer to an environmental variable using Sys.setenv(ffmpeg = "path/to/ffmpeg"). The environmental variable will always override the result of Sys.which("ffmpeg").

Value

A logical value, with the attribute outfile for the output file.

Examples

## Not run: 
if (ffmpeg_version_sufficient()) {
  result <- ari_stitch(
    ari_example(c("mab1.png", "mab2.png")),
    list(tuneR::noise(), tuneR::noise())
  )
  result <- ari_stitch(
    ari_example(c("mab1.png", "mab2.png")),
    list(tuneR::noise(), tuneR::noise()),
    ffmpeg_opts = "-qscale 0",
    verbose = 2
  )
  # system2("open", attributes(result)$outfile)
}

## End(Not run)

seankross/ari documentation built on July 18, 2023, 4:35 p.m.