David Esp Video Technical Blog

Sometimes Adobe Premiere may write to a source media file or proprietary folder-structure.  This may be considered a non-problem in most situations, but it is nevertheless worth being aware of.

This is nothing hidden, surreptitious or unheard-of, it’s explained in Adobe’s Help text and documentation.  However the potential consequences may not be obvious to a new user.  It may arise at various points of what we may regard as the greater process (workflow/manual) of ingesting media, consisting not only of Premiere’s Import of media but also subsequent manual updating of metadata or indeed automatic analysis such as speech recognition.  As of CS6 it can also occur as a result of adding Markers in Adobe Prelude.

Premiere likes to add and manage metadata for each media file.

• The good side of this is that it value-enhances these files, making them easier to locate, navigate and use, potentially increasing workflow productivity and asset usage.
• But there’s also a dark side – not necessarily Adobe’s fault (e.g. their approaches may well adhere to official media specifications) – but it may be that so-adulterated media files may cause difficulties to other applications (e.g. that may not fully take on board such standards).
  • In my experience, in the past, some (possibly poorly-written, but nevertheless useful) applications have refused to work with metadata-augmented files, again holding up productivity, in this case while the user figures out the issue and works out how to strip this data out, in order to progress.
  • Technically a non-problem, but potentially consequential to a workflow, backup software will (rightly, from its point of view) see the metadata-change as a file-change (e.g. as a consequent file-size change) and consider that the files have been updated.   Left to itself, the backup process (depending how it works/configured) will overwrite any previous copy of the files (e.g. the original files).   Even if the backup process prompts the user to confirm this, the naive user may be uncertain what to do,

Also, the user has the option at their discretion for Premiere to automatically store additional files (such as cache files and metadata sidecar files) alongside source media files.

• In the case of media represented as a straightforward single file (like a .jpg or .mpg file) this does not affect that media.
• However some media (e.g. TV-playable DVDs or XDCAM-EX video media) are stored as proprietary folder structures with defined contents, part of these contents being essence files (e.g. .vob files or .mp4 files) while other files alongside them etc. in that structure (e.g. DVD’s .IFO files or XDVCAM-EX’s .SMI files) contain metadata or index into them etc.  In this case, the consequence of adding further files into the structure will (in my experience) be acceptable to some applications and media players but not to others, which regard it as “pollution”, and may then reject such structures.  Certainly in the past I have seen this happen in some software applications and also even some (mostly old) TV DVD players.

This is a case for “situational awareness”: if one is aware of the nature and potential consequences of the adulteration (be it regarded as pollution or enhancement, depending on the workflow situation), one is then in a better position to be able to avoid or fix any asociated issues. (more…)