Media Purveyor is built upon a proprietary metadata storage technology that takes development to the next stage of functional simplicity. Media Purveyor's storage technology (SDM: Self-Describing Media) was built from the ground up to simplify the process of normalizing embedded description support, both keywords and custom entry screens (media schemas), for many file formats. With Media Purveyor the same description schema used for images can be applied to movie and audio file formats in the same library; the file format is entirely transparent and the content is uniform across media boundaries.

Developer - Under the Hood

Media Purveyor uses the Self-Describing Media (SDM) data object to hold and model information for each media item (video, audio or image file). The SDM data object is translated back and forth from and to a structured XML document which is written as a raw binary stream (ASCII) to the Metadata Persistance Abstraction (MPA) layer. The MPA layer delegates the work of actually reading and writing to the file to an object capable of providing storage services for the given file format (similar to a MIME-Type handler).

The SDM scheme is superior to other metadata storage architectures in its complexity management. The structure of the metadata is abstracted away from the storage mechanism, which renders cross format support nearly effortless. Find a method for reading and writing an ASCII data (character codes 32-127) stream into and out of a file format and that format immediately supports SDM functionality. Write Development@MediaPurveyor.com for the headers and documentation on coding your own MPA plugin. Examples of included MPA modules:

• JPEG is supported by storing data in an application block.
• PNG is supported using the very key/value system built into the PNG format.
• GIF89 is supported using the application extension area.
• Postscript files (.PS) supported by simply making use of a structured comment which is supported by the postscript language.
• Many other file formats are supported by simply appending a structure to the end of the file (similar to ID3) while respecting those formats that makes use of a footer structure (such as TGA) and maintaining the integrity of an ID3 footer if one has been added.

Safety is a priorty: All persistence mechanisms have been deemed perfectly safe i.e. will not corrupt media files for the majority of applications.

In addition to reading and writing its own proprietary metadata the SDM architecture supports the reading of external storage technologies using an Adapter system. The Adapter layer translates other schemes into the SDM model, including

• IPTC
• EXIF
• JPEG Comments
• PNG Key/Values
• ID3
• File Information (file related metadata from the OS)
• Image Metrics

ATTENTION!!!

An ActiveX object is freely available to any developer that writes with a request. This object allows an application to read the SDM data object from a file. Write development@mediapurveyor.com with questions or requests.

The SDM XML schema will be documented and the individual persistence modules released as open sourced C code. If you are a developer or other IT professional interested in leveraging this technology please write development@mediapurveyor.com.

NOTE: Any attempt to reverse engineer the workings of Media Purveyor itself is strictly prohibited and illegal. Media Purveyor is NOT an open sourced application. The underlying metadata persistence methodoloy and technology is open to the public but not the application layers above.