Too restrictive max Bitrate

[JBoisseau-ByDeluxe]

Max j2c bitrate returned by asdcp-info is based on frame stored size in mxf, which includes encryption (when applicable) and j2c main header.
From my understanding of ISO/IEC-15444-1, this bitrate should be calculated from the sum of all tiles size : "Maximum instantaneous bit-rate for all 3 colour components"

The difference between those 2 methods is very small, up to 0.07mbs, but enough to declare a DCP "over" 250, while it's not.

example :
a j2c has a sum tile size = 1301667 B = 249.920064 mbs in a 24fps dcp
once wrapped into an mxf, encrypted, asdcp-info returns 250.01mbs

(NB: max allowed size is 1302083 B for a 24fps dcp = 249.999936 mbs)

I think this max bitrate from asdcp-info should be refined, or should not be used to check the exact conformance to ISO specs.

[jamiegau]

On this topic.
See the image below from the Research section of my portal.
Like clairmeta, from memory, I use asdcp_lib to extract the packet sizes for every packet to generate the graph, I wrote it a long time ago, so the encryption overhead is included.

It must be noted, at ISDCF meetings it has been mentioned that bitrate should not go above 245, or even 240 as numerous older system will now struggle on those bitrates.

But in general, I think looking at the image below shows the trend in where it is going.
The Graph is interactive and the DCP will be listed on rollover when in use.