AV Prototype Project Working Documents

Explanation: DigiProv (Digital Provenance) Extension Schema

February 2003

Conceptual Example
Comparisons to the AES approach.
Actual Example

Introduction. Our digiProvMD (digital provenance metadata) elements and schema owe a great debt to work in progress under the auspices of the Audio Engineering Society (AES), especially the contributions of David Ackerman of the Harvard University Library Digital Initiative Group. Our prototyping has been mostly concerned with audio, and as we began to implement digiProvMD, our experiences led us to rearrange some elements within the emerging AES approach, and to introduce a few simplifications that seemed possible in our particular circumstances.

One of our applications for digiProvMD concerns the physical preparation of source materials we are reformatting, e.g., a 1/4-inch magnetic tape or a 78 rpm disc. In our METS structMap we assign one level (div) to the original item, for example, Tape or Disc (actual wording may vary). We associate one instance of sourceMD (metadata about the thing we start with) and one instance of digiProvMD with that node in the structMap. For example, if we baked the tape (to combat sticky-shed syndrome) or cleaned the disc side, then the instance digiProvMD at this node in the structMap documents the baking or cleaning of the original item.

Our second common application for digiProvMD has to do with how a specific file was made. When we reformat a sound recording, for example, we make three digital audio files:

These three files are referenced in the structMap "below" the original item, i.e., Disc is the parent of Side A, which is in turn the parent of three file children. The references takes the form of fptrs (file pointers) that link back to the METS fileGrp (file group) section and thus to the individual files. Associated with each file are instances of (1) techMD (technical metadata) that provides information about file characteristics, e.g., how many samples per second, what compression, and (2) digiProvMD that documents the devices and settings used in the reproduction process. (To be perfectly accurate, we try to always provide an instance of digiProvMD for masters; this provision is optional for service files.)

As we have carried out our prototyping, we have seen (but not yet realized) an intimate relationship between workflow management and the use of workflow management systems and software to capture the data that would finally emerge in instances of digiProvMD. This is something for the future.

Conceptual Example. The following example is illustrative and is intended to communicate some of the concepts we have used.

Most of our processes are used again and again. Therefore, our data-capture software permits an operator build a process template, e.g., Joe's lp digitizing process. In data entry, the template is referenced by the operator in the database's instance table along with organization and individual identifiers and today's date. Later, when the XML is output, all of the information from the process template and the instance table is incorporated into the digiProvMD section of the final METS document.

Comparisons to the AES approach. The following comments are not exhaustive but describe our understanding of some relationships between our approach and that of the AES:

AES element group(s) LC variant (tables in the database used for initial metadata capture)
Event Instance plus Task
Device, Module (hardware), and Channel Tools
Settings, Parameter, and Preset Settings
Module (other than hardware) and Auxiliary File Configuration File (Table name: ConfigFile)

Actual Example.

<?xml version="1.0" encoding="UTF-8"?>

<!--Sample XML file generated by XML Spy v4.4 U (http://www.xmlspy.com)-->
<DIGIPROVMD xmlns="//www.loc.gov/PMD/"

<process_creator>Joe Smith</process_creator>
<process_description>This is the process that describes taking a physical source (lp in this case) and digitizing it into the Master audio file.</process_description>
<process_label>Digitize Audio Master from LP</process_label>

<task ID="ID000001">

<task_label>Digitize Audio Master from LP</task_label>
<task_description>This takes the physical source (lp) and converts it into a 96/48 uncompressed wave file.</task_description>
<task_individual>Joe Smith</task_individual>

<tool ID="ID000002">

<tool_description>Simon Yorke Turntable Precision Analog Disc Transcription System</tool_description>
<tool_make>Simon Yorke</tool_make>


<tool ID="ID000003">

<tool_label>Phono Cartridge</tool_label>
<tool_description>Phono Cartridge</tool_description>


<tool ID="ID000004">

<tool_label>Phono Preamp</tool_label>
<tool_description>Phono Preamp</tool_description>
<tool_make>EQS Mark12</tool_make>

<settings ID="ID000005">

<settings_description>Standard RIAA equalization for LPs</settings_description>



<tool ID="ID000006">

<tool_label>A/D Convertor</tool_label>
<tool_description>Analog to Digital Convertor</tool_description>


<tool ID="ID000007">

<tool_label>Sadie DAW</tool_label>
<tool_description>Sadie Digital Audio Workstation</tool_description>
<tool_version>96/24 w/ Software: 3.4</tool_version>




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