by Peter Withers

Arbil (short for “Archive Builder”) is an application for arranging research material and associated metadata into a format appropriate for archiving. It is basically the successor to the IMDI Editor, which a lot of our readers probably know. This old tool is now almost ten years old and a lot has happened in software engineering in that time. Therefore, instead of simply updating the IMDI editor to incorporate user suggestions and modern software architecture principles, the MPI has decided to create a completely new application that will replace the IMDI editor altogether.

The most obvious difference to the old IMDI Editor is that Arbil has a tabular display, which allows a comparative view on the data and the ability to copy-paste between matching sets of data.

Arbil main screen

While Arbil is primarily a tool to enter metadata, it also has functions to help organise the collected material and create a local well-organised corpus before it is archived. These functions include the ability to search for and compare metadata, and to open the resource files in associated applications, e.g. ELAN for annotations or a media player to watch videos.

Arbil's embedded image viewer

Arbil has been designed as a local application so that it can also be used offline, for instance in remote field sites. The metadata and resource files can be entered in part or as a whole; once an Internet connection is available the previously entered data and associated structures can be exported from Arbil and then be transferred to the main archive via Lamus. As the idea behind Arbil is to deal with a complete corpus or corpus branch Arbil can mirror branches from the main archive on your local computer so that they can still be referred to offline and in the field.

Unlike the IMDI Editor, Arbil incorporates the functionality of a number of separate tools while being designed around the workflow of the user. This means the application is meant to be the one program around which all your archiving work will be centered. In Arbil the metadata is viewed in tables, which can contain a single node of metadata as a list of fields, or many different nodes each with its fields as a separate row in the table. This tabular view of the data allows multiple metadata nodes to be compared across the rows of the table. If the metadata node is editable then these fields can be edited in any table in which they are viewed. Drag and drop is used extensively both for constructing a hierarchical corpus tree structure and for adding nodes to tables for viewing and editing. Bulk editing of metadata can be done primarily via copy and paste, which allows a string of text to be pasted into multiple fields of multiple rows, or to paste multiple fields into the matching fields of multiple rows.

Tabular view of multiple imdi files

The basic user interface of Arbil is highly customisable. For example, you can decide which columns of a table should be visible and save various table layouts to quickly switch between different views to accommodate for different tasks. Furthermore, columns can be resized, sorted on any column and reordered. Rows can easily be added and then dragged from one table to another, and the cells can be highlighted based on matching text.

With all the various metadata fields it is not always easy to see at a glance what a particular fields is intended for and which fields are specifically required. For this reason a description of the intended usage for each field is displayed in a tool tip. Similarly an indication of which fields are required is given by a textual and colour highlight when the data is not filled in. Likewise in the case of fields requiring specific formatting, such as date fields, the cell and the table will be highlighted when the formatting is incorrect.

Arbil window style

In contrast to the IMDI Editor Arbil is more of a team-player, which means that there are various import and export facilities. Any valid IMDI files can be imported into Arbil. If the metadata refers to resource files, they can optionally be imported at the same time, for instance when migrating or merging from one computer to another. All of the IMDI data and the associated resources within Arbil can be exported into a self-contained directory. The exported files can then be uploaded into LAMUS where any new corpus branches can be uploaded and existing sessions that have been edited can be replaced. During both the import and export processes, all of the metadata is validated and a list of warnings are given if there are any errors. The textual data entered into Arbil can be exported in formats other than IMDI, for instance the contents of a table can be copied and pasted into a text editor or into spreadsheet. A custom style-sheet can be used to transform and export the data in a particular format. The tables used in Arbil can also be embedded in a web page, where the table’s contents, size, columns and highlighting will be displayed in the resulting web page.

Arbil continues to be actively developed to extend these features further and to make the user experience as pleasant as possible. Why don’t you try it out yourself?

• Try Arbil
• Read the Arbil Manual
• Go to the Arbil Forum

by Paul Trilsbeek

A lot of compression algorithms in current video codecs are lossy, meaning that they throw away information that is seen as less relevant for the perception of the image in order to reduce bandwidth. This information cannot be reconstructed afterwards which is one of the reasons why archives like ours do not like to use lossy compression formats, since one never knows whether the information that is thrown away might be relevant for future use of the data. Another reason is that every time compression is applied to an already lossy compressed signal, the signal degrades. This happens both when using the same compression algorithm as well as when transcoding to a new (future) compression standard. Since codecs and file formats generally have a limited lifetime, this would mean that if an archive wants to keep their archived content interpretable in the long run, it will degrade over time because of the necessary conversion steps to the latest state of the art.

For these reasons, archives generally want to preserve data in as uncompressed a form as possible. The rapid deterioration of physical audiovisual carriers such as celluloid film and many deprecated video formats have triggered broadcast and film archives but also the film industry to start massive digitization projects. Due to the high costs of these operations and the high economical or cultural value of the material, it makes sense to store this digitized material in the highest possible quality because even if it were at all possible to repeat such digitization operations in the future (e.g. to account for new compression standards), it would be a big waste of time and money. The storage costs for these formats are substantial at this moment but will decrease with the introduction of newer, higher capacity storage technology.

A codec that is being widely used at the moment in the film and video archiving world is Motion JPEG 2000. This codec allows for lossless – i.e. reversible – compression of moving images. It is also used as the standard for Digital Cinema, albeit currently in a lossy variant. In the lossless variant, compression ratios of about 1:2 can be achieved, but the main reason for moving to lossless or uncompressed storage of video is, as stated, to prevent future degradation of the signal if current codecs become obsolete.

The MPI is currently digitizing a large collection of valuable videotapes from the German behavioral scientist Irenäus Eibl-Eibesfeldt. These recordings were originally made on 16mm film and have been transferred to Betacam SP (broadcast quality) video, which was a costly and time-consuming process. The Betacam SP tapes are now being digitized in lossless MJPEG2000 format in order to retain the highest possible quality for this material. In addition, MPEG2 and H.264 distribution copies are created to make the material more accessible over lower-bandwith data connections.