After I encoded my movie in Flaskmpeg its like a gigabyte too big?!
This is usually because you forgot to change the audio to MP3 or somehow it got reset to PCM by accident. Check that you set the correct bitrate on your original movie encoding. It is possible that because of this your movie cannot be opened and you will need to start again. Otherwise you can try opening the movie in VirtualDub and reencodeing the audio to Mp3 or WMA again.