I'd say 99.999% of the "experts" don't want to put their *sses on the line to answer the bitrate question for burning blurays. This is why there is very little info on this around the net. For instance some dude named John Geddes posted on the net between 20 & 25 in one forum, in another he slightly changed his numbers. In the DVINFO FORUM some dude named Khoi Pham gave Geddes a first class SMACKDOWN, yaaaa... What Pham says makes more sense than anything I have seen anywhere written on the net, and I will include this info for the thousands of people out there who like me have had trouble finding the info on this.*** ADOBE FORUM EXPERTS TAKE NOTE*** Because it is obvious that the "experts" do not want to go anywhere near this question, because 99.9% are probably not very sure, and they don't want tp expose themselves... Anyway... This looks like the correct answer to me... Better than any of the other pure garbola and theory I have been reading over the last week or more on the net. Here's the KHOI PHAM SMACKDOWN (makes sense to me) (From DVINFO March 18th 2010) I really like this, and if you go to the forum, you'll see how it all played out between these two...
"Jon, I have been encoding BD for 2 years now with over 100 BD and high bit rate is never a problem, you are still having a framemind of the 90's, with BD it is different, either it plays or it doesn't, their player must have firmware that can play BD-R and that is all, that is why I copy and print out that blue noticed that came with every BD movies informing customer to update their player if it doesn't play, in the begining some BD player can't play BD-R, but after the customer update their player with newer firmware it can play without a problem, so high bitrate is not a problem with Blu-ray like everybody thinks, also Blu-ray data layer are much closer to the surface that DVD standard hence why they required hard coating technology and so pressed or burned it has no problem reading the data, you are wasting time encoding VBR and sacrifice picture quality encoding at low bitrate if you have a project shorter than 1hr. 20minutes."
What PHAM originally said about BITRATE. (He was explaining to some guy on the forum) "H.264 is more efficient than MPEG2 HD, most BD movies are using H.264, if your project is short and under 1 hr. I would use CBR at 38000kb/s for video and 448kb/s for audio, at this rate I don't think you can see a difference between those two codec so I would go with MPEG2 HD cuz it is much faster to encode, for longer project with lower bitrate then I would use H.264, if it is longer you better use a bitrate calcultor to give you the average bitrate."
What Geddes said after Pham wrote what he wrote... And then you saw the SMACKDOWN above. And I loved it, ya... Everybody's an expert... Then after the smackdown, Geddes comes back in and agrees with Pham...lol... http://www.dvinfo.net/forum/blu-ray-authoring/474659-coding-best-blu-ray.html Why spew your B.S. all over the net about bitrates if you are not so sure??? What follows is what the Geddes dude wrote. (DON'T LISTEN TO HIM, LISTEN TO PHAM)
Do not encode higher than 25 mbps, as it can cause playback problems on Blu-ray players.
Just like DVD's, burned Blu-ray media has lower reflectivity than pressed commercial discs (store bought movies), and therefore cannot sustain as high of a bitrate during playback.
Some Hollywood Blu-ray discs exceed 40 mbps, but this is only possible because they are pressed.
When using h.264 codec, you can encode at 20 mbps, and it will be near identical to the source.
Use 2-pass variable bitrate for most efficient encoding. You can set the target bitrate at 20 mbps, with a max of 25 mbps. This will give you excellent results, and not cause playback issues.
The highest bitrate that will allow the program to fit on disk is the best quality you can get.
That is the way most people operate (and Hollywood from what I see). But up to almost 2 and 1/2 hours, you can run to the max (38Mbps video stream). Then the question becomes whether the players can handle it.
I'm curious whether Jon has an update on his experience.
James, with the best will in the world it is an almost impossible question to answer.
The Blu-Ray specifications defines the total video bitrate value of Primary Video and Secondary video streams (including subtitles) must be less than or equal to 40Mbps. In practise though, it is best to keep your overall bitrate under 38Mbps because of inconsistencies in players - they are not all created equally.
Audio streams also need to be factored into the equation.
24/48 LPCM stereo is 2.3Mbps, 24/96 stereo LPCM is 4.6Mbps.
DTS-HD MAS and Dolby True HD are variable bitrate encoders so you will not know the bitrate for these kind of streams until you have encoded them, and uncompressed 24/96 5.1 LPCM (the *only* mandatory supported lossless surround codec as both DTS-HD MAS and Dolby True HD are mandatory for their lossy substreams only) is an eye-watering 13.96Mbps. Of course, you can always use 24/48 5.1 LPCM at a more sedate 6.91Mbps. What this means is that you need to do your sums, as encoding the video at 38Mbps with a 5.1 LPCM 24/96 stream is going to tip you over the limit at almost 54Mbps.
Oh - and whilst it is in the specs that secondary video can be in HD, very few players will actually play it.
The best thing you can do is get yourself a spreadsheet and work out a bit budget before you start encoding anything.
Menus also get complicated, as there is only a limited image buffer available.and yet again this can vary wildly between profiles, BD-J over regular etc.
Let me try to explain.....using BD-J menus allows a maximum graphics buffer size of 45.5mb for profile 1.0/1.1 players and 61.5mb for profile 2 players. But you cannot actually create a menu graphic at this size and still expect the disc to work properly, so again it is a trade off and it is recommended to not exceed 32.5mb for your graphics buffer.
I honestly also recommend getting some text books, as BD is best described as "complicated".