Media Preparation Techniques
From Ara Irititja KMS Wiki
How to Prepare Images
There are two different ways that you will deal with image files when preparing them for the archive:
- digital files straight from the camera or that you receive from other people or institutions
- files that you have scanned yourself
Files received in digital format
- Nothing needs to be done to the digital files you receive straight from a camera if they are in JPEG format (ie. .jpg) unless you want to enhance them or renumber them. Your camera should always be set at the highest possible photo quality.
- Files that are RAW, NEF, or TIFF formats need to be compressed to the highest quality .jpg before you import them into the archive. You can do this in Photoshop by saving as a .jpg 12.
Once files are in high quality JPEG they can be uploaded to the archive, which will generate the correct sized files for optimal viewing. The archive software is customisable and can be set to resize to the size of your choice. The default that we use is 2500 pixels measured along the longest dimension of the image.
Scan your own files at a resolution large enough for your future needs, including publishing. We recommend a 36MB .tiff file which is approx 4500 pixels measured along the longest dimension of your image.
Scanned files should then be compressed to high quality .jpg. This can be done in Photoshop by saving as .jpg 12 into a file of roughly 5MB - 10MB.
Once files are in high quality JPEG they can be uploaded to the archive, which will then generate the correct sized files for optimal viewing. The archive software is customisable and can be set to resize to the size of your choice. The default that we use is 2500 pixels measured along the longest dimension of the image. This means that if you want to resize your images to a lower resolution for quicker upload to FileZilla, that your longest side should never be less than 2500 pixels.
File ordering and numbering
The archive may read files differently from your particular computer configuration. Always check before completing uploading that your files are ordered in the archive as you have them on your desktop. You may want to renumber files with a 001, 002, 003 etc at the beginning of the file name to ensure that the archive reads them in the order you wish them to be.
The archive generates the new archive number of your files.
The archive leaves your original file names on your images until the end of the import process when the archive asks if you want to rename them. Only at this point will you know their archive numbers. It is recommended that you keep a backup of your original files (with their original file numbers), at least until you are happy with the import process.
Once you have renamed your files with the new archive numbers they can be burned to DVD or backed up on external hard drives. 100 high resolution .tif image files and 100 high resolution .jpg files fit onto a DVD. This can be useful for your internal file management and storage system.
It is highly recommended that you keep a written, hard copy log of the files you import into the archive, their collection name, their DVD number along with their archive numbers!
Video and Film
How to Prepare Movie Files
You may receive movies that take many different forms. They might be Hi8, Super 8, 8mm colour, 16mm colour, VHS, BETACAM, mini DV, Movie CD, DVCam, DVD or just straight digital files from a camera or mobile phone. In all these cases you need to process the data into digital form and then compress it into a format suitable for the archive.
Getting your original high quality .mov file or .dv file created from older media types is something that you will probably want to outsource. Special equipment is needed in most cases and it is very time consuming.
Once you have your .dv file or .mov file you can then process it and compress it to the correct specifications for the archive. To do this you need to open it in Quicktime Pro (or any other movie compressing software that you are familiar with). Once it is open, go to Export movie from the File Menu, choose your destination folder, then choose Export - Movie as MPEG-4. A popup window will appear. Choose File Format - MP4, With Video highlighted choose Video Format - H.264.
The Data Rate that you choose in this window depends on the quality of the movie you want to create. A high bit rate means a bigger file and a better quality result but it will be slower to upload and therefore slower to play in your archive. A lower bit rate gives a lower quality movie but a faster upload. In general a bit rate of around 1200 kbits/sec - 1500 kbits/sec will probably work well as a general setting that will suit most movies.
The Image Size should be set to the size of your original movie. Preserve Aspect Ratio should be ticked, the Frame Rate should be on 25/sec and the Key Frame should be set to 25 frames ie one key frame per second. You can enter a name on any key frame in your archive.
You need to do some tests. This way you will become more familiar with the different output sizes, different upload speeds and different quality of your movie files.
If you want to create settings to crop or enhance your movies, or if you are intending to edit and create your own movies for the archive then we recommend that you use suitable software. iMovie, Handbrake, Final Cut Pro (which also comes with a Compressor application which you will find in your applications folder) are all useful. Make sure you always work with your original .dv file or .mov file if you want to edit a movie. Make sure that the file type that you want to export follows the above specifications ie H.264, MP4, bit rate, frames per sec etc etc. Your original file should be kept unchanged in case you want to do something different with it in the future. Compressor and Handbrake have the useful advantage of being able to deinterlace movies. This is particularly important if there is a lot of movement in the movie. Deinterlacing gives a better quality result.
In Quicktime Pro, once you have set the video settings correctly click on Audio. From the popup list that appears choose Format - AAC-LC. The Output Sample Rate should be set on 44kHz. Choose Stereo if your original movie has Stereo sound or Mono if it has Mono sound. If your original movie has no sound at all, as for older movies, set the Audio Format to None. Click on Streaming and make sure Enable Streaming is ticked.
Movie files for uploading into the archive can be named anything you want unless you want several movie clips to go into one item number. If this is the case then each file has to be named the same and then you add -001, 002, 003. EG yourmovie-001.mp4, yourmovie-002.mp4, yourmovie-003.mp4. The computer will recognise the -001, -002, -003 etc and will import them into one item number.
This process will probably mean that you have to change the file name of your original movie so it is important to keep track of these changes. It is often best to rename your movie in FileZilla. This way your original movie name stays intact inside your computer and it is then easy to cross reference it once it has been uploaded into the archive.
How to Prepare Audio Files
We recommend Audacity (free download) for audio file preparation. Any editing of your .wav or .aiff can be done after importing it into Audacity. The archive accepts both these files types as well as .mp3 files and compresses them when necessary.
How to Prepare Document Files
To import Documents into the archive your files can be jpegs or a Pdf file. If you want to import several pages of one document as jpegs it's important to number them correctly so that the archive recognises not to make separate archive records out of your files. eg. example-001, example.002, example-003 etc
Alternatively you can save your multiple paged document as a Pdf file and upload that and the archive will then automatically generate the separate pages.