Too big audio file

[mxpv]

** Hi Max, thanks for this good service! One of my concern is: The podcasting file is too big. Take https://www.youtube.com/watch?v=XxXxxXXxX for example, each episode is about 45 minutes. I set the podcast to audio format and worst quality, it's still 900M each file: http://podsync.net/Xxxxx (actually the size doesn't change whatever format/quality I set)

Thanks Max! I opened the feed using "Pocket Casts" App on android, and it shows ~900M for each file. Now I using another app "Podcast Go", the size is normal. Another question, why the "length" in "enclosure" tag of the xml is very big, such as "500150000"?