How to calculate bitrate for 1080p encode

[lchiu7]

Up till now I have been encoding my BluRay rips as 720P. But thinking down the line I might upgrade to a 1080p set thought I might start encoding as 1080P instead. But using the bitrate calculator in Megui gives the same bitrate for 720p and 1080p and from what I have seen if I use the rate given for 720p for 1080p encode, the outputs shows obvious macroblocking, especially in darker scenes.

I guess I could take the value given by the bitrate calculator and scale it up 50%. I am not shooting for a specific target size the content resides on my server - just want something that works for 1080p and looks good.

Any other methods that could be used?

Thanks

[Kurtnoise]

I am not shooting for a specific target size the content resides on my server
why you need to calculate the bitrate then ?

[lchiu7]

why you need to calculate the bitrate then ?

Well I do want to save space but also not have too many artifacts like macroblocking. So I am just adding about 40% to the value calculated by the bitrate calculator. Not scientific and will see how it goes.

[poisondeathray]

Why don't you use crf mode then ? It's faster to encode (1pass), and should give you the same average quality that you set, but the filesize may vary greatly between titles. A slow drama movie generally requires less bitrate to look the same "quality" than a fast paced action movie with explosions. If you arbitrarily pick a bitrate, it might be too little for some movies, or too high for others depending on the source material

(But if this is targetted for a device, then VBV isn't optimal unless you use 2pass encoding)

[lchiu7]

Did a quick look on the documentation for CRF and it isn't clear how to set it. All I can see is that it should be between 18-26 which seems like a large range. Is there a some method for making a more precise setting?

Agree that if I have constant bitrate I might too much or too little so while space isn't an issue, I don't want to have not enough of a bitrate and see macroblocking. And wildly varying spaces between titles isn't an issue also - so long as it's not the same as the source(!) when I might has well copy the entire contents of the disc (BD or HD-DVD) to the server and just remove the extraneous tracks (other languages, subtitles, etc.)
BTW this is targeted for a device - the Popcorn Hour.

[Who Am I ?]

might be offtopic but would'nt cqm's help with the bitrate distribution on scene's / regions ( mostly dark ones ) on which u're worried about ?

[movmasty]

Did a quick look on the documentation for CRF and it isn't clear how to set it. All I can see is that it should be between 18-26 which seems like a large range. Is there a some method for making a more precise setting?
Yes: testing....

range 21-24 is ok for you?