Encodes the frames to ProRes 4444 (prores_ks, yuva444p10le): writes
them as PNGs in a temporary directory, runs ffmpeg, and removes the
directory. FfmpegNotFound when no ffmpeg is on PATH; FfmpegFailed
(with ffmpeg's stderr in details.stderr) when it exits with a failure.
Encodes the frames to ProRes 4444 (
prores_ks,yuva444p10le): writes them as PNGs in a temporary directory, runsffmpeg, and removes the directory.FfmpegNotFoundwhen noffmpegis onPATH;FfmpegFailed(with ffmpeg's stderr indetails.stderr) when it exits with a failure.