Avg Bitrate or RF for BD backups?

General questions or discussion about HandBrake, Video and/or audio transcoding, trends etc.
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cliffee
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Joined: Tue Apr 06, 2010 11:33 pm

Avg Bitrate or RF for BD backups?

Post by cliffee »

Ive been using Handbrake to backup my Blu-Rays for NAS archives and have wondered about using the RF or just set avg bitrate. Reason I'm asking is on occasion using the RF20 setting (High) yields and avg bitrate way higher than other movies with the same RF20. Thus giving me a much bigger rip. For instance I just backed up Saving Private Ryan RF20 High 1920 x 1080 and came up with a Overall bitrate around 20 Mbps, Maximum 35.5 Mbps. This gave me a 22gig rip. Not much less than the original comparative to others.
Is is smarter to just shoot for a certain bitrate? I don't want to sacrifice quality but wonder if the program or .264 is getting a little carried away?

Thanks in Advance
thompson
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Re: Avg Bitrate or RF for BD backups?

Post by thompson »

RF20 is probably too high for BD. Try something in the 23-25 range. RF is definitely the way to go. In a sense, it is average bitrate, except that the average is over your entire movie collection. By only using the bits it needs (for a certain quality) some movies will come out smaller, some larger; in comparison, if you use ABR you're telling it to use the same amount of bits regardless of whether it needs more or fewer.
mduell
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Re: Avg Bitrate or RF for BD backups?

Post by mduell »

RF 20 is excessive for 1080 material. I start at RF 24 and I've used up to RF 28 when appropriate.
nightstrm
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Re: Avg Bitrate or RF for BD backups?

Post by nightstrm »

I agree with what others have already posted... RF20 is probably too high for 1080p output. I use RF20 for my Bluray->AppleTV encodes (more so I can use a single preset for everything than anything else), but would look at using RF23/24 if I were maintaining the source resolution.

I can't think of a single reason why you'd want to use average bitrate for HDDVD/Bluray encodes.
dynaflash
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Re: Avg Bitrate or RF for BD backups?

Post by dynaflash »

RF 20 is really huge considering saving private ryan is exceptionally long and extremely grainy. No wonder it ended up massive.
cliffee
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Joined: Tue Apr 06, 2010 11:33 pm

Re: Avg Bitrate or RF for BD backups?

Post by cliffee »

In the past and recently I have experimented and I typically start to notice some artifacts at 24 and above. I will play around in the 23-22 range and start from there.

What RF do you guys recommend when downsizing 1080P to 720P?

Thanks for the help.
mduell
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Re: Avg Bitrate or RF for BD backups?

Post by mduell »

Low 20s.

RF is sort of like quality per pixel. Since most people have a fixed size screen, you use lower quality per pixel when you have more pixels for the same overall picture quality.
moviebuff
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Re: Avg Bitrate or RF for BD backups?

Post by moviebuff »

On Blu Rays I go 24rf with grainy video on normal preset and 22 on other less grainy also on normal preset
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