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DV Analyzer: Frequently Asked Questions
BACK TO DV ANALYZER

  • Why should I use DV Analyzer?
  • The primary function of DV Analyzer is to report on the quality of migration from DV tape to file. DV tapes are not a preservation medium. As the support for DV tape technology gradually declines it is imperative to begin migrating DV content from tapes to files for storage and ongoing preservation of the content. In the migration process, the technical nature of DV tapes frequently causes issues generally described as glitchy or finicky. DV tapes often perform differently from one play to the next and across playback devices. DV Analyzer provides an automated way to monitor and report on the accuracy of the migration process.

    • What does DV Analyzer do?
    • DV Analyzer evaluates media files that use the DV video codec in order to discover and report on a set list of potential errors or abnormalities. DV Analyzer also summarizes temporal metadata within a DV codec such as scene specific recording data and source timecode.

      • Do you support analysis tools for other codecs besides DV?
      • Currently DV Analyzer only offers analytical information on the DV codec (as documented in SMPTE 314M and IEC 61834). In future development we intend to support other codecs. We would like to hear from you if you are interested in one in particular.

        • What is the license of DV Analyzer?
        • AudioVisual Preservation Solutions has released DV Analyzer under a GPL version 3 or higher license. DV Analyzer extends the libmediainfo library which has been released by Mediaarea.net under a LGPL license.

          • Why is DV Analyzer so slow?
          • In order to fully assess and report on the file, DV Analyzer has to read through the entire DV portion. Typically 95% of the time used to operate DV Analyzer is spent reading the file from the hard drive. Operation speeds will vary based on your hard drive revolutions per minute speed.

            • What information ends up in the Final Cut Pro XML v4 and v5 tabs and what can I do with the Final Cut Pro XML outputs?
            • These essentially create a reverse EDL, or Edit Decision List that can be imported into Final Cut Pro with markers representing the locations of errors reported on in the file. The reverse EDL information is gathered through capturing of metadata that is embedded within each individual frame of DV. As a DV camera records to tape, each frame contains information about the camera settings, timecode, and recording date and time. When DV frames are migrated from tape to file, this information remains within each frame (unless the capture process intentionally blocks it). Furthermore, in DV workflows as DV content is edited into new materials, the same date, time, and timecode information remains attached to the individual frames, although it becomes difficult to access.

              Since DV Analyzer reads through the entire DV track in search of errors and abnormalities, it also evaluates patterns in the recording time and timecode information from one frame to the next. When the recording time jumps to a non-sequential value, it indicates that either the camera was stopped and restarted at that point or the content was edited at that point. The reverse EDL feature will also note frames marked by the camera to represent the beginning or ending of a recording and non-sequential jumps in the frame’s embedded timecode.

              The resulting data can be used to identify clips and their associated datetime stamp and timecode along the timeline of the tape. Blocks of frames sharing one date and consecutive time stamps can be assumed to be one clip. A series of clips along the tape’s timeline effectively creates a reverse EDL. Any errors that are identified in the file are also tagged as markers with the timestamp value of the error. You can output the appropriate Final Cut Pro XML document and import it into Final Cut Pro to view the file and the markers within a sequence.

              • Who can download DV Analyzer?
              • DV Analyzer was originally conceived for audiovisual archivists in order to provide quality control to tape-to-file transfer procedures for DV formats. However, if our tool is helpful to media production, editing, or metadata workflows, please feel free to use it where it may be useful.

                • Is DV Analyzer free?
                • DV Analyzer if both available free of charge and provided as “free software”. DV Analyzer is licensed by AudioVisual Preservation Solutions under the open source GNU General Public License.

                  • Where can I find DV Analyzer technical documentation/instructions?
                  • Documentation is gathered at http://www.avpreserve.com/dvanalyzer.

                    • Whom should I contact with questions/problems/comments/bug reports?
                      • Can I export data out of DV Analyzer?
                      • Yes, currently DV Analyzer supports various exports including a custom XML to DV Analyzer as well as XML documents that can be utilized within Final Cut Pro to facilitate the inspection of digitized DV content. DV Analyzer also can export data as a CSV document that can be interpreted in Microsoft Excel and similar spreadsheet programs.

                        • I ingested my DV tapes to uncompressed (or other non-DV) video files, can I use DV Analyzer?
                        • Unfortunately not. Transferring DV data from DV tape to DV files migrates video, audio, timecode, and other metadata within the DV stream. If you ingest from DV tapes in a workflow that results in files that do not use the DV codecs, it is likely that the key metadata that was sent from the deck was lost in the transcoding process. Thus DV Analyzer works best when applied to DV files that came from DV tapes.

                          If for some reason, it is necessary to store video from DV tapes in a non-DV format, then we’d recommend ingest DV tapes to DV files, then using DV Analyzer to assess the ingest, then performing the transcode to a non-DV format.

                          • How does DV Analyzer differ from other video analysis systems?
                          • DV Analyzer is not a traditional video signal analysis tool. Traditional video signal analysis tools use algorithms to make educated guesses about issues in the video signal and results in major over and under reporting of errors. To turn this into meaningful data requires a significant amount of human labor and expertise. DV Analyzer reports on errors that are documented within the stream, including video error concealment, audio errors, and structural problems. Thus it provides accurate information about the quality of the tape to file transfer. In this way, a DV file may be analyzed to identify areas where errors occur to facilitate targeted quality control and allow for problematic transfers to be identified early in the DV workflow.