pngs_to_video#

pngs_to_video(inputs, output_path, fps=24, resize_to=None)[source]#

Convert a sequence of PNG images into an MP4 video using imageio with the PyAV plugin.

This function reads a list or folder of PNG images, ensures that each frame is RGB (uint8), contiguous in memory, and has even pixel dimensions, then encodes them into an H.264 MP4 video file. Optionally, images can be resized before encoding. It provides a fully pure-Python workflow using imageio and Pillow.

Parameters:

  • inputs (str or list of str) –

    Either:

    • a directory path containing PNG files,

    • a glob pattern (e.g., "./frames/*.png"), or

    • an explicit list of file paths.

  • output_path (str) – Path to the output video file (e.g., "./output.mp4").

  • fps (int, optional) – Frames per second of the output video. Default is 24.

  • resize_to (tuple of int, optional) – Target video frame size (width, height) in pixels. If None, uses the size of the first image. Default is None.

Returns:

The video is written directly to output_path.

Return type:

None

Notes

  • The output codec is H.264 (requires pyav plugin in imageio).

  • Any unreadable or malformed image will raise a RuntimeError.

Examples

>>> pngs_to_video("./frames/*.png", "movie.mp4", fps=30)
>>> pngs_to_video(["frame1.png", "frame2.png", "frame3.png"], "out.mp4", resize_to=(1280, 720))