still_clip: Render a Still Image as a Video Clip

In compost: Video Compositing via 'FFmpeg'

Render a Still Image as a Video Clip

Description

Turns one image into a video of duration seconds, optionally animated by a deterministic Ken Burns pan/zoom described by motion. Both the static and the animated case go through ffmpeg's zoompan, so the outputs are byte-compatible for concat and crossfade_concat regardless of motion.

Usage

still_clip(image, output, duration, fps = 30, size = NULL, motion = NULL,
           overwrite = TRUE, dry_run = FALSE)

Arguments

image	Path to the input image (png, jpg, ...).
output	Path for the output video file.
duration	Clip length in seconds.
fps	Output frame rate (default 30).
size	Output dimensions as c(width, height), or NULL (default) to use the source dimensions rounded to even.
motion	NULL (default) for a static clip, or a Ken Burns spec: a list with any of zoom_from, zoom_to (numeric >= 1; values below 1 are clamped), from, to (crop-window anchor as c(x, y) fractions of the source, top-left origin; the window is centered on the anchor and clamped to the frame), and ease ("linear" or "smooth", default smooth).
overwrite	If TRUE (default), overwrite the output file.
dry_run	If TRUE, return the FFmpeg command without executing.

Details

zoompan stretches its crop to size without preserving the source aspect ratio, so size should match the source's aspect (or a deliberate crop of it). Renderers letterbox afterwards; see pad.

Value

Invisibly returns the output path. If dry_run, returns the command string.

Examples

## Not run: 
still_clip("slide01.png", "slide01.mp4", duration = 4.2)
still_clip("slide01.png", "slide01.mp4", duration = 4.2,
           motion = list(zoom_from = 1, zoom_to = 1.15,
                         from = c(0.5, 0.5), to = c(0.5, 0.4)))

## End(Not run)

compost documentation built on Aug. 4, 2026, 5:11 p.m.