Digital Cinema CPL research - Looking for trends in the evolution of Cinema Content

[James Gardiner]

Hi All,
I just finished an interesting tool, free to use. May be of interest to the more geeky readers on here.

Get an overview by watching this video.

https://youtu.be/I76LPOpkvt0

[Harold Hallikainen]

Very nice!

[Steve Guttag]

That's pretty cool. Do you calculate the LEQ(m) by analyzing the tracks? I've been toying with doing that in real time by noting which CPL is playing, and then calculating the LEQ(m) for each CPL. So, once the system (Q-SYS) learns the CPL's LEQ(m), it could adjust the content for future showings to a theatre's preferred level.

[James Gardiner]

That's pretty cool. Do you calculate the LEQ(m) by analyzing the tracks? I've been toying with doing that in real time by noting which CPL is playing, and then calculating the LEQ(m) for each CPL. So, once the system (Q-SYS) learns the CPL's LEQ(m), it could adjust the content for future showings to a theatre's preferred level.

Yes, the system takes the DCP apart, pushes it through ffmpeg, the swiss army knife of digital video manipulation.. Edits the essences according to the CPL edit points, and makes a continuous audio file that is used to push through https://github.com/lucat/leqm-nrt an open source leq(m) tool.. I spend a lot of time with the developer of this tool making sure it actually worked. Dolby did make a rough specifications of the loudness calculation, but it was up to a lot of interpretation in its basic documentation. But, doing a lot of comparisons with Dolby measuring tools and leqm-nrt, some tweaks were needed but the results were seen to be equivalent in measuring a wide set of test files. So I am confident in its results.

[Steve Guttag]

Very good indeed.