Here are some tips on downloading and uploading DCPs and other large files like prores quicktime files:
-I recommended using a fast wired internet connection. (20/20 mbit/s).
-I recommend using these free download managers:
–Easyget Lite on Mac
–Free download manager on Windows.
Filemail links and many other download links can be resumed, so a download manager is important when downloading large files.
On filemail.com you can send 30 GB files for free.
With a Filemail Pro or Business account you can send files with unlimited size.
-I recommend setting up your own Filemail business account if you ask people to upload a lot of files to you.
-With a Filemail business account you will have access to the files for longer and people can use a branded upload web page.
Filemail md5 hash check
Filemail shows the md5 checksum on the download page if you enable it in the settings for the business download page. This way you can check if the uploaded file is correct. You can find the MD5 checksum of a file with utilities like Hash Tab for windows and Hash Tab for mac You also use the command
md5 "file" in a terminal on a Mac to generate a md5 file hash value.
You can use the command
certutil -hashfile "file" md5 on windows 7, 8, 10 in a command prompt.
You can use md5sum “file” in linux
If the sender checks that the MD5 checksum is the same you will know that the file is OK.
Amazon S3 can be used to deliver and receive big files on the internet.
-You can use the s3 web uploader or use CrossFtp and similar programs to upload to S3. Crossftp Pro can use multipart and integrity checks when uploading so you will know the uploaded file is working.
-After uploading you can make the link accessible (public) and give the clients the S3 download link.
-S3 storage is very reliable and scalable. You pay for each download.
-If you want a client to upload a file to a s3 upload bucket you can make an upload user in https://console.aws.amazon.com/iam/home#users with a policy that enables the user to upload to that upload bucket.
Like this policy:
– then give the client the access key and secret key for the upload user. (with this policy the user will see all buckets, but can only upload to the examplebucket bucket.
Send 7z archive files
-I ask people to make a 7z archive of the quicktime file or DCP folder before they send it. I recommend Keka on mac or 7zip on Windows.
-7z archives can be protected with encryption and a password and have a built in hash check.
-The 7z file can be uncompressed when sending prores files but if you want to send a uncompressed quicktime file or text files I suggest using normal compression. A uncompressed quicktime file will be reduced to half the size after 7z compression.
-In Keka, choose 7z and store, then drag the folder to the Keka window
-You can also split the archive in parts and upload the file in parts. Example 20 GB.
Use a PAR2 recovery file as backup
-You can use MultiPar or MacPAR Deluxe PAR 2 recovery file with 1-5 percent redundancy. PAR2 files with 1 percent redundancy are 1 percent of the size of original file. If the downloaded file is 0,5 percent corrupted, you can use the 1 percent PAR 2 recovery file to recover the file instead of downloading again.
Multipar with 5 percent redundancy.
Macpar Deluxe with 3 percent redudancy.
Choose File – New Par 2 set
Drag the file and save.
DCP and quicktime specific advice
-When downloading a DCP folder in Filezilla from a FTP server, I downloaded the XML files and the rest of the files as binary to get them to pass the file hash check in Easydcp Player.
-Ask people who submit DCPs to use the archive format 7z instead of zip. This way you can avoid the (large) Mac OS archive utility zip files that can only be opened by the Mac OS archive zip utility. Both Keka and 7-Zip can make 7z archives.
-Sometimes I get a error message when opening a quicktime file on windows pc that was made on a mac. If I rename the file it works.
-I recommend checking DCPs in Easydcp player. The trial version will let you know if the DCP fails some checks. You can also run a file hash check.
You should also make a DCP quality checklist that may include:
-Is the DCP named correctly?
Is it in the correct scope or flat format? The DCP should have a correct digital naming convention name. Example: The DCP is called Dcpname_SHR_S but is actually Dcpname_SHR_F because the subtitles are burned in too low and will be cropped at a scope preset in your cinema.
-Is the DCP in the correct language/subtitle language?
-Will the DCP play at your venue. Example: You may have a server with old firmware that can play 25 SMPTE DCPs with burned in subtitles, but not SMPTE 2010 subtitles. I only work with updated servers that will accept SMPTE 2010 subtitles.
-If you have downloaded a DCP folder archive like DCP.7z on a mac and want to ingest in on a digital cinema media block/server/player you can extract it to a DX115 hard drive or similar.
-If you get an error message extracting a zip file in Keka that says error code 2 using p7zip, you probably need to extract the zip file with mac os archive utility.