video

write_video_from_frames(path, frames, **kwargs)

Write a list of frames to a video file.

The image size is scaled up to the nearest multiple of 16 for codec compatibility.

Parameters:

Name	Type	Description	Default
path	str | Path	Output file path.	required
frames	list[ndarray]	List of (H, W, 3) uint8 numpy arrays.	required
**kwargs	Any	Passed to imageio.v3.imwrite.	{}

Source code in src/flygym/utils/video.py

def write_video_from_frames(
    path: str | Path, frames: list[np.ndarray], **kwargs: Any
) -> None:
    """Write a list of frames to a video file.

    The image size is scaled up to the nearest multiple of 16 for codec compatibility.

    Args:
        path: Output file path.
        frames: List of ``(H, W, 3)`` uint8 numpy arrays.
        **kwargs: Passed to ``imageio.v3.imwrite``.
    """
    path.parent.mkdir(parents=True, exist_ok=True)

    # Scale image size up to multiples of 16 to enhance compatibility with most codecs
    # and players
    height, width = frames[0].shape[:2]
    new_width = (width + 15) // 16 * 16
    new_height = (height + 15) // 16 * 16
    if (new_width, new_height) != (width, height):
        for i, frame in enumerate(frames):
            pil_frame = Image.fromarray(frame)
            pil_frame_resized = pil_frame.resize(
                (new_width, new_height), resample=Image.Resampling.BICUBIC
            )
            frame_resized = np.array(pil_frame_resized)
            frames[i] = frame_resized

    iio.imwrite(path, frames, **kwargs)