More questions than answers;).
If the levels you are talking about is the number of the surround decoder we tens to play preshow at 3.8 and show between 4-6 so that ties up. Thing is even the difference between 5 and 6 is significant, although I believe it is not linier. I think there is a straight line to about 5 then it has a curve that means the changes in numbers do not make as much difference.

The question is how do I set the levels when I create a DCP. Is there a guide somewhere that is not too technical. I am getting lost very quickly in this discussion. For example if it is mixed to -12db (which seems to be popular) what do I do in DCPOMatic?



On 2 August 2014 17:33, Mattias Mattsson <vitplister@gmail.com> wrote:
Hi all,

One thing that is also useful is to measure the loudness of the source
material (according to the EBU R128 specification). Unfortunately
there is no standard loudness value in LUFS defined for cinema[1] as
there is for TV broadcast. According to my investigations of about 100
professionally mastered DCP:s distributed in the wild the average lies
somewhere around -24 LUFS.

You can use the ebu128 filter in ffmpeg to check the loudness of a
video or audio file:

cat <videofile> | ffmpeg -i - -filter_complex ebur128=peak=true -f null -

To check on a DCP with audio mxfs split into reels, you could use
shell wild cards, e.g.:

cat Naganting_maste_ga_sonder_FTR_F_SV-EN_51_SV_2k_20140121_FT_audio_0*
| ffmpeg -i - -filter_complex ebur128=peak=true -f null -

The nice thing about the "Integrated loudness" (I) is that it changes
along with the audio gain. E.g. If you have material with an
integrated loudness of -16 LUFS (too loud), change the gain -8 dB to
get -24 LUFS.



1. Discussed extensively here:
http://www.gearslutz.com/board/post-production-forum/768373-cinema-playback-levels-mixing-again.html


Best,
-mattias


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