And then there is the issue of mis-aligining the playback machine to match the recording...that is a great joy. Audio azimuth is the easy part of that. A client of mine had a hugely important (to him) DV tape and I subcontracted to a well-known video tape machine expert who was able to misalign two camcorders of the same type as the original to replay the tape. One got destroyed in the process, so another had to be procured on eBay. It was very expensive and he never wants to do it again. Cheers, Richard On 2013-10-28 5:38 PM, Jim Lindner wrote: > 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 > > Email: [log in to unmask] > > Media Matters LLC. 450 West 31st Street 4th Floor New York, N.Y. > 10001 > > eFax (646) 349-4475 Mobile: (917) 945-2662 > > www.media-matters.net Media Matters LLC. is a technical consultancy > specializing in archival audio and video material. We provide advice > and analysis, to media archives that apply the beneficial advances in > technology to collection management. > > > > > > 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/ -- Richard L. Hess email: [log in to unmask] Aurora, Ontario, Canada 647 479 2800 http://www.richardhess.com/tape/contact.htm Quality tape transfers, even from hard-to-play tapes.