Blu-rays with Video Bitrate of 40 Mbps?

[kristoffer]

How many BDs utilise the maximum bitrate of 40 Mbps? I saw somewhere that the upcoming Star Wars would be encoded at 40 Mbps for video.

Most discs are 25-30. Does it make a huge difference?

[4K2K]

Originally Posted by kristoffer

How many BDs utilise the maximum bitrate of 40 Mbps? I saw somewhere that the upcoming Star Wars would be encoded at 40 Mbps for video.

Most discs are 25-30. Does it make a huge difference?

It might not be accurate (and there probably could be more), but the "Blu-ray Stats" site lists just 4 titles that it says are 40 Mbps (if you go to the "tech stats" and filter it by video bitrate), and all 4 of those listed as 40 Mbps there are mpeg2 IMAX titles. Mpeg2 is less efficient than mpeg4/AVC (that site lists 61 that it says are above 35 Mbps though).

By that, that site will mean "average" bitrate. I'm sure there are many titles that utilise 40 Mbps briefly (I'm sure some will peak over 40 Mbps briefly), but average to a lower bitrate.

[kristoffer]

Originally Posted by 4K2K

It might not be accurate (and there probably could be more), but the "Blu-ray Stats" site lists just 4 titles that it says are 40 Mbps (if you go to the "tech stats" and filter it by video bitrate), and all 4 of those listed as 40 Mbps there are mpeg2 IMAX titles. Mpeg2 is less efficient than mpeg4/AVC (that site lists 61 that it says are above 35 Mbps though).

By that, that site will mean "average" bitrate. I'm sure there are many titles that utilise 40 Mbps briefly (I'm sure some will peak over 40 Mbps briefly), but average to a lower bitrate.

Cool didn't know that site.

[Anthony P]

Originally Posted by kristoffer

How many BDs utilise the maximum bitrate of 40 Mbps? I saw somewhere that the upcoming Star Wars would be encoded at 40 Mbps for video.

Most discs are 25-30. Does it make a huge difference?

It depends what one is discussing. Video bitrate on BD is variable. My guess most reach 40 mbps at times but when it is not needed it would be below that and so the average for most or all would be lower. Usually when discussing the bitrate of a movie the average is given.

[kristoffer]

Sorry guys. I should have put it as average bitrate instead.

I just wondered how many BDs that used the format to it's full potential.

[42041]

Originally Posted by kristoffer

I just wondered how many BDs that used the format to it's full potential.

You're oversimplifying things considerably. The only thing a high bitrate can do is accurately reproduce what's going into the encoder. Garbage in, garbage out.
In general, the difference between an average bitrate of 20MBPS and 40MBPS with a high quality AVC encoder would be subtle to most viewers.

[Musashi]

Bitrates oscillate depending on whats in each frame. 40mps average is very unlikely due to this fact. Head over to the Insiders Forum and ask Dr. MPEG for more about compression.

[Clark Kent]

A lot of Paramount and Fox Blu-rays average in the 30's for AVC encodes. Criterion selectively will use around 35 Mbps, if there is a minimal amount of extra features on the BD. Other studios for the most part are much worse, often releasing discs that average under 25 Mbps.

[Anthony P]

Originally Posted by 42041

You're oversimplifying things considerably. The only thing a high bitrate can do is accurately reproduce what's going into the encoder. Garbage in, garbage out.
In general, the difference between an average bitrate of 20MBPS and 40MBPS with a high quality AVC encoder would be subtle to most viewers.

20 seems a bit low, but I agree with the rest. 40mbps average also does not make sense, any normal film will have slow parts (little action) and simple parts (like credits at the end where a screen is mostly black and so can be very efficiently compressed with no loss) so at some point it might not make sense while the hard scenes can't be any better (i.e. hits the 40 ceiling) so they can look better but it can't affect the average by going higher.