I keep thinking this can't be right - 7gb for 1080p? Harry Potter movies

[AndyD]

So I've been using Ripbot to rip my blurays using crf 18 and 5.1 640kbs audio - I thought this would lead to the best quality possible with a little bit of a downgrade for the audio.

What I don't understand is the size though. I would expect movies to be around 10-15gbs at least but I keep getting conversions that seem pretty low.

Am I overthinking it? Or is it the audio not being in DTS the reason why the file is smaller?

[lowellriggsiam]

I got something similar using a different method and I had no issues.

[yoda313]

Did you set it to target lock at a specific size? You can do that with 2 pass mode in ripbot. Than it will give you the file size you want.

Usually 7-8gb is actually desired so it can fit on a dual layer dvdr. If you are simply leaving it on a harddrive for a media player or simply computer playback than it really doesn't matter.

[AndyD]

But what difference will it make? I don't know what file size makes sense. I personally don't care about backing it up to disc. I thought CRF 18 would decide what is needed for best quality and produce a file that was near identical to the source while adjusting file size as necessary. Thinking an 8gb file won't do it? I really should have investigated before converting all of my movies.

Anyway, target size means twice as long in processing as well right?

[jagabo]

So I've been using Ripbot to rip my blurays using crf 18 and 5.1 640kbs audio - I thought this would lead to the best quality possible with a little bit of a downgrade for the audio.

No, the best quality possible would be CRF 0. But you wouldn't be happy with the file size. CRF 18 is good enough quality that you'll hardly be able to tell a difference even if you look at enlarged still frames.

What I don't understand is the size though. I would expect movies to be around 10-15gbs at least but I keep getting conversions that seem pretty low.

Who cares how big the files are if they achieve the quality you want? If you really want bigger files use a lower CRF value, say 15 or 12. But you won't notice any difference when you watch the movie.

[AndyD]

I agree that it shouldn't matter what the file size is but I've seen rips online for 720p to be twice as big as most of my files so not sure how much am I losing quality wise. I don't have a 1080p TV at the moment but I will soon after move into my new place

I also though 18 was the lowest setting - didn't even think to just type in something.

So you think CRF 18 is good enough for 1080p with barely any noticeable differences?

[jagabo]

I think CRF 18 delivers more than enough quality for "watchable" backups. I usually work at CRF 20 because the files are smaller and I find the quality still acceptable. But you'll have to decide what CRF value to use for yourself. Compare before and after videos. Zoom into stills and full motion playback. Crank the gamma up a bit to see more details in the dark areas -- that's the first place to develop problems.

I think the larger files you've seen online are either people running 2-pass encodes to fit on a single layer DVD, or people who read somewhere that such-and-such bitrate was "best" and blindly use that.

[AndyD]

Ok. At this point, I might as well accept what I converted everything to because I finished with converting. I'll have to see how things compare when I buy my new TV and decide then if I should re rip.

Thanks for the info