Dcp O Matic DCP creation speed

[nicolasbourgeois]

Hello Everybody

I'm new to DCP o MAtic and to DCP's in general

I'm trying to create dcp from quicktimes.

It's DNX-HD 36 codec 1920x1080 24p
I add 6 mono files as L C R Ls Rs Lfe

I select Rec709 preset, set the good out put for each sound file and launch the job.

I get aprox 9fps on a W10 machine intel i7 6850k cpu.

Is it a good "score" or can I get better results.

Thanks
Nicolas

[Carsten]

Hi Nicolas,


that is within the expected range. Check preferences, how many threads do you have configured for J2K encoding?

https://dcpomatic.com/benchmarks/input.php?id=1

BTW - I usually recommend to NOT use separate files for audio, but to work with an interleaved multichannel file. It makes working much easier.
Of course, if everything is done correctly, the resulting DCP is exactly the same with both methods.



- Carsten

[nicolasbourgeois]

Hello

Thanks for your quick reply
12 threads (it s a 6core 12threads processor) but I can put more ? There is also another setting frame per thread set to 3 by default but I don t know what is it for.

I understand but with interlaced files sometimes you are not sure of which channel is which channel

I very tried to play this dcp on dcp o magic player, it open fine but it drop frames. Is that normal ?

Thanks

[Carsten]

You may get a slightly higher number when setting some more threads, like 14 or 16, but in general, since DCP-o-matic 2.7x or so, it's not worth the effort. The maximum number of frames to store per thread is a bit of a special parameter that allows to tune performance with respect to available memory. I wish Carl had left it out, because I think it is of little use. Typically, fast computers will usually have enough memory. Usually I wouldn't care to have exotic parameters to play with, but users usually do not have an immediate understanding of which parameters influence performance, which quality, which compatibility.

Leave it at 3. It has no impact on DCP quality, and will only impact encoding performance under very special conditions (e.g. very fast CPUs/many cores with very limited memory, maybe very slow discs).

It is normal that the Player stutters if you set the decoding resolution to the highest level. It is a software-only decoder, so it is usually not fast enough to decode full-res without dropped frames when playing back with audio.

Read this for more explanation: https://dcpomatic.com/forum/viewtopic.p ... pped#p4020

- Carsten