File size for 46 minute movie?

[dingo_xxx]

Hi new friends .
Have made a home movie for 28 seat cinema shot in 1080 MXF.
I need to get the finished movie to the cinema but how large should the file be to avoid roo much loss?
It's HD but not 4K.
8Gb?
4Gb?

(made in Premiere Pro)

I'm aiming for Pro Res 422 .MOV

thanks!

[rahmani]

Hi, the most important factors for file size are; codec bit rate and your signal specification e.g if you have 1920x1080 30fps, prores 422 HQ with 220mbps the file size for one hour is equal (220/8)*60*60=99GByte for 46 mins is about 76GB. But you can use less bit rate between 100mbps till 140mbps for decreasing the file size.
Any how you can convert the format file by Adobe Premier Pro to choose different Export configs.
Of course DOM can do it very nice but I don't know the details of bit rate which has been used for Prores export format file.


Soleyman

[Carsten]

I'm aiming for Pro Res 422 .MOV

Go with that, but keep in mind that cinemas can not play ProRes - that's why DOM is there. So, if ProRes is your finishing codec, and you want to convert that to DCP, DCP-o-matic is the right tool, and ProRes422 a suitable codec.

For a 46min movie, I'd say 50-100 GByte ProRes would be an appropriate size. It will probably still look good far below this, but, who cares...

The DCP generated from that will probably have roughly the same size. Choose 200MBit/s in DCP-o-matic for J2K conversion, and don't think too much about it - you will have more important things to think about...

- Carsten

[dingo_xxx]

Thank you Carsten and Soleyman.

My problem now is that the particular cinema here in Australia appears to have a rather old PC which I suspect doesn't have USB3. I originally had a beautiful looking file of 140Gb but they said it would take way too long to transfer to their DCP creating machine.
It's a lovely classic old fashioned cinema, highly respected in the community and rightly so and they do lots of corporate stuff as well as screening films.
The staff have been very helpful and supportive.
So if I create the DCP myself for the next viewing (Dec 13th) they might say "sorry, it will clog up our machine for two days just transferring"
We had the preview viewing last night and no-one complained about the video quality but it wasn't nearly hd enough for my liking.

Also I endeavoured to keep the audio to a ceiling of -6dB. There were parts when I couldn't hear certain parts of dialogue over the cinema's air conditioning system! I'm thinking now that I should bring it up a couple of dB and definitely raise the bottom audio up to a closer range.
So useful seeing it in a cinema!

I'm a music teacher, not a film maker!

[dingo_xxx]

also re file size, yes I figured if a DVD is about 7 GB for 90 minutes then a cinema screen should be ten times the size so the file should be ten times the size!

[Carsten]

That's too rough a calculation, as the codecs are very different. In cinemas, we see vast differences in file sizes - just a few days ago, I have seen the tiniest full length DCP ever - an animation feature film with only 30GBytes. Other more 'typical' sizes are between 100 and 250Gbytes for real life footage.

I don't understand the issue you have with the local cinema. Most cinema playout servers only offer USB2.0 connections, and that is used regularly for DCP ingest. While some projectionist prefer the faster CRU or network ingests, ingest over USB2.0 works, and usually takes around 2hrs for a typical feature. Copying >100GB won't take much longer. These machines usually are running idle over longer periods of the day, and even during playout of features, they are able to ingest in the background (though slower).

As I understand your post, they have a PC there that could be used for the conversion of ProRes to DCP, but are not fond of the idea to block that machine for a longer period of time. That is probably not related to USB/transfer speed, but conversion speed. Creating a DCP from a Prores file can indeed take multiple days on older machines. That doesn't change with input file size. It's because the DCP/J2K conversion is slow. If you create the DCP on your own, depending on your machine, you face the same challenge. On a fast machine, it may be finished within a few hours, or it may take 5 days.


- Carsten