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I completely agree…. and the playback machine as well.

Since one only rarely has the original machine that made the recording, I went to considerable effort to try to determine playback machine condition and put information regarding that condition in metadata. In video playback in particular the condition metadata generated will certainly vary depending on the playback machine condition. Dropouts for example  will certainly be worse as the heads wear, tip penetration reduces, and RF level decreases. Documenting all of that for normal migration practice is onerous and not practical in a video production environment where the machine is not open and the measurements very difficult to take. However, if at least hypothetically the playback of the machine was perfect or at least the defects known, then some of the issues of the recording machine become evident as variation from baseline. 

So…. in order to try to establish a baseline I designed an alignment procedure before migration so that the playback results could be tested with some measure of reliability. Essentially where "the rubber hits the road" is the final output. With a known good source or alignment tape and baseline criteria established before playback of the subject tape, one can try to align the system to the tape output of the known good tape so that baseline measurements are met. If those measurements are not met,  then the delta between perfect known good tape performance and actual performance is captured in the metadata as well. One can then judge the playback of the subject tape in context to the delta between the ideal performance of the known good tape and the actual results. 

It does work. Unfortunately users may or may not go to the trouble to do it. The tool is there, whether the user is interested in using it or even understands why they should is another matter entirely. 

While we all know that it is all a system, including both tape and machine, one can tend to forget it because all we are left with is the tape. I sometimes remember a presentation by Sony to a bunch of facility engineers where they explained that the delay in delivering the D1 decks did not involve the machines which were ready to deliver, but rather the delay in getting adequate tape product performance to meet specification. They did not want to delver the machine until there was adequate tape available, and not just quantity, but quality. Easy to forget that holding a reel of sticky muck.



Jim Lindner

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On Oct 28, 2013, at 1:56 PM, JAMES HOWARTH <[log in to unmask]> wrote:

> Chris - 
> I'm getting more and more convinced (as more and more folks suggest it) that the mechanical performance of the original recorder is part of the recording, and indeed is already recorded, and should be considered as an essential metadata element. Your thoughts?
> 
> Jamie
> 
> 
> On Oct 28, 2013, at 10:01 AM, Chris Lacinak <[log in to unmask]> wrote:
> 
>> AVPreserve is pleased to announce the release of Fixity and MDQC, two new free and open-source digital preservation tools available for free download on our Tools page. 
>> 
>> Fixity is a utility for the documentation and regular review of stored files. Fixity scans a folder or directory, creating a manifest of the files including their file paths and their checksums, against which a regular comparative analysis can be run. 
>> 
>> MDQC stands for Metadata Quality Control, and it reads the embedded metadata of a file or directory and compares it against a set of rules defined by the user in order to perform automated review of embedded metadata.
>> 
>> More information and links on the AVPreserve website at http://www.avpreserve.com/blog/avpreserve-releases-fixity-and-mdqc-digital-preservation-tools/
>> 
>> ______________________________________
>> 
>> Chris Lacinak
>> AudioVisual Preservation Solutions
>> 350 7th Ave., Suite 1605
>> New York, NY 10001
>> 
>> office: 917-475-9630 xt. 3
>> 
>> http://www.avpreserve.com
>> Facebook.com/AVPreserve
>> twitter.com/AVPreserve
>