[gamerdude239]

Today I was thinking about upgrading my netflix plan to bluray. I want some hd movies on my pc. Is it worth it though? How big are blurays? I hear they average 20-40gb in size. can you compress a bluray down to 3-4gb and still retain quality? If so what's the best program to do this?

[sialivi]

A full Blu-ray .iso with nothing stripped out is usually around 40-50gb.

A remux, which is when you re-package the movie, stripping out menus, extras and unneeded audio/subtitle tracks, but leave the video and audio untouched, is usually around 20-30gb. For remuxing, use something like MakeMKV which is very userfriendly, or mkvtoolnix if you want more advanced control over the process.

Recompressing down to 3-4gb is way too much compression for a 1080p video, but 8gb will be fine. For recompressing, use x264. You'll probably want to get some userfriendly frontend, like HandBrake (x264 is included).

[Prof Yaffle]

How big is a bluray? About 120mm from side to side, I think :-)

To add to sialivi's post: it does depend on your material. Fast-moving, live-action, 140-minute films with 8-channel HD audio soundtracks plus commentary tracks will inevitably take up more room than 90-minute cartoons with lots of static backgrounds and a single 6-channel AC3/AAC. It also thus depends on what you want to include in your final file, since compressing audio and/or dropping channels will reduce file size significantly without affecting the video quality (obviously).

[calev]

I agree with the other two post. For files around 3 gigs i would use handbrake with the following settings,

-picture size down to 720p with loose anamorphic and modulus 16,
-RF of 21
- audio set to multichannel aac at 448 Bitrate (quality sounds like a 640 bit-rate ac3 track)

that will usually give you a decent file between 1.8 and 4 gigs. You may want to lower the RF to 20 or 19 if the video looks to compressed but that will significantly raise the file size. Check the Preview feature in a dark scene before encoding the whole thing. Grainy movies come out bigger