The integration of a media asset management system into the entire workflow is important for the avoidance of media disruptions. One of the most important tasks of a content management system in general is the retrieval and reuse of archived material. This helps reducing the costs for new productions.
Depending on the usage of a media archive, the individual workflow differs. A standardized "master workflow" can no longer be easily defined today, as users pursue a wide variety of objectives.
However, the basic steps remain the same:
- Annotation (manual, semi-automatic, fully automatic)
- If required, transfer to long-term archive according to ageing parameters
- If necessary, recovery
These basic steps from the original source material to the final archiving occur with many complements in all archive solutions. A fingerprinting or watermarking solution must be integrated into these customer-specific workflows at a suitable position.
In addition to archiving, the goal of media asset management is the efficient searching and browsing of reference content, its metadata and its corresponding rights. Typically, all reference content inserted into the media archive is linked to specific metadata. The basic procedure consists of assigning a set of additional information to the entire media object. This limits the search for specific scenes within a longer reference clip. To overcome this limitation, an additional indexing process is required. There are two strategies for indexing reference material, stratification and segmentation.
The process of segmentation is simple. The original reference material is automatically cut into smaller, independent media objects. This facilitates the assignment of different metadata to parts of the original clip and independent access to these sub-clips from the media archive. This procedure poses challenges regarding the granularity of the segments and the correct annotation with the corresponding metadata.
The second approach, stratification, consists of using the spatial-temporal properties of the reference clips. Stratification does not require cutting the material, instead it uses virtual sections explicitly defined and accessible by the corresponding timecode (each frame of the reference clip has a unique identifying timecode). Metadata can be assigned to a specific area in the timecode (temporal). This enables a completely unrestricted and overlapping assignment of different information to the reference clip. This process can be executed manually or supported by semi-automated processes (e.g. face recognition, pattern recognition, speech-to-text algorithms). In addition to temporal layering, it is even possible to spatially segment the frames and assign independent metadata.
In the case of archives, a distinction must also be made among purely static, no longer changing parts, and dynamic parts, which are permanently augmented and also changed in the area of the near past, e.g. in the metadata part. With dynamic archives, the efficient allocation and creation of new entries becomes very important.
The retrievability of the material is the actual reason for the existence of the archive.
In addition to the obvious method of searching directly via textual annotations, video and audio-based search methods have also become established in parallel or in a complementary manner.
In both video and audio, a distinction must be made between fingerprint and watermark based methods.
The generally accepted terminology is used here. This defines the Watermark methods as the methods in which an invisible or inaudible identification code is written into the material (a "watermark" in the literal sense). And the fingerprint procedures are then the methods in which a characteristic, unique code is generated from the material itself using an algorithm (a "fingerprint" in the literal sense). This characteristic makes it possible to recognize the material without having to insert anything into it.
Today, modern fingerprinting methods recognize not only identical but also similar contents if the parameters are set appropriately. The latter is, as explained in more detail in the following chapter, an important feature in some applications. (Therefore, it should be noted that the term "DNA" in analogy to criminalistics would now be more appropriate than the established term "fingerprint”, because these methods also find "relatives").
For important copyright reasons, it should be mentioned that the content can be unambiguously re-identified with the help of fingerprints. However, with all mature methods, it is mathematically impossible to recreate the source material from the fingerprint. (here in contrast to the "DNA" from which one can theoretically recreate the living being).
This characteristic implies significant degrees of judicial freedom when sending fingerprints.