ideal_ffmpeg.py

import av
from av import AV

video_codec_opts = {"moov": "start"} # put the moov header at the front of the file
audio_codec_opts = {'codec': 'libfdk_aac'} # default libfaac

with open("source.mov") as fd:
  vid = AV(fd)
  vid.resize(720, 480)
  vid.transcode_video(av.H264, **video_codec_opts)
  vid.transcode_audio(av.AAC, **audio_codec_opts)
  vid.save("output.mp4") # or a file-like