ffmpeg -i sample.avi -q:a 0 -map a sample.mp3
ffmpeg -i input-video.avi -vn -acodec copy output-audio.aac
# extract single image from timestamp
# -ss : seek to position
# -vframes:v 1 : extract single image
ffmpeg -i input.mov -ss 00:00:15 -vframes:v 1 out.png