Understanding “Write XMP ID to Files on Import”

[Petrula]

In PPro CS5,

Edit | Preferences | Media

There is the check box “Write XMP ID to Files on Import”

These are discussed in the CS5 help at

Rendering and previewing sequences

Adobe Media Encoder - Export and thin XMP metadata

Adobe Media Encoder may add metadata to source video files

The help says “Adobe video applications can automatically insert a unique document ID into each imported file.”

In which files does it insert the ID?

For example,

Does it insert it in the Preview files?

Does it insert it in the CFA files?

Does it modify the original source file such as the original AVI file?

(I don’t want my original AVI file modified in any way just as RAW photo files are never modified.)

Etc, Etc

Some of the threads like

   Premiere Creates New .CFA files every time I open the project

   See the comment by Adobe employee Wil Renczes

indicate that you should uncheck (disable) writing the XMP ID since every time you reopen PPro, it may regenerate the audio CPA files.

Is this a good idea?

What are the trade offs?

Adobe Media Encoder may add metadata to source video files

vaguely discusses some of the trade offs, but I am still unclear.

The other check box is

“Enable Clip and XMP Metadata Linking”

It is unclear which specific files are effected and what are the trade offs between enabling and disabling this.

Thanks in advance.

[Todd_Kopriva]

The Write XMP ID To Files On Import option tells Premiere Pro to add a single piece of XMP metadata to the source file itself. This is basically a unique identifying number that can then be used by the various applications that understand XMP metadata to tell which file is being used where. So, yes, it does modify the source file. If you don't want that to happen, then make sure that this checkbox is unchecked.

You refer to a post in which you say that Wil Renczes says that you should turn this option off to avoid regenerating media cache files. Wil was referring to a small number of cases in which a bug/misbehavior could be worked around. In general, having the XMP metadata ID in the file prevents redundant operations because---simply put---the applications know that this is the same file that they've seen and dealt with already.

Regarding linking of clip and XMP metadata: Premiere Pro has had various kinds of metadata for a long time---long before we intriduced the XMP metadata platform acrosss several applications. Linking the clip and XMP metadata means that the clip metadata gets added to the XMP metadata, so these things are no longer separate.

To put it a little differently, here's a quote from "Link clip data to XMP metadata":

"In the Metadata panel, the Clip property value fields are internal. They reside in the Premiere Pro project file, and are readable by Premiere Pro alone. However, some of the property value fields in the Clip section have a link option box next to them. After you select the link option, Premiere Pro automatically enters the information that you enter into the Clip value field into a corresponding XMP field."

[Huntrex]

Todd, In my HDV projects Premiere will create separate .xmp files beside each one of the clips. Now on a large project, this really makes going through clips more difficult and time consuming. Is there a way to avoid this inconvenience, even if it means disabling xmp altogether? Thanks!

[Todd_Kopriva]

> Todd, In my HDV projects Premiere will create separate .xmp files beside each one of the clips. Now on a large project, this really makes going through clips more difficult and time consuming. Is there a way to avoid this inconvenience, even if it means disabling xmp altogether? Thanks!

Yes, in the cases in which Premiere Pro can't get inside the source file to inject the XMP ID, it will use a sidecar XMP file instead. If you don't want these, then just turn of the option to write XMP IDs on import.

[pjseyler]

I'm trying to resolve some of the same inconsistencies, and

have a couple of questions

• There appear to be two or three conflicting settings governing the placement of audio preview or .CFA files.  The first is under Project Settings>Scratch Disks>Audio Previews.  This one appears to have little or no effect.  The second is under Edit>Preferences>Media>, which also purports to let us control the placement of Media Cache files.  The there's the check-box that lets us put the CFA files "beside" the clip files, "when possible".  My question is this:  What is the intended relationship between these controls?  How are they meant to work with each other.
  
• Regarding the issue of repeatedly making CFA files for the same clip:  I'm using CS4 and find that if I'm using the media encoder to process a batch of output from the same project, Premiere (or the "headless" version) will recreate another complete set of CFA and PEK files for each item being encoded.  On large projects, this can add an hour or more to each item in the encoding queue.  It appears that there is a similar problem with CS3 and CS5, so upgrading will not solve the problem.  This looks like a case of advanced features that worked well in the Development environment, but breakdown under the weight of real conditions.  My question is this:  Is there a way to completely disable this feature, and essentially roll back to the ignorant, feature-deprived CFA system that actually worked with version 2?

Thanks in advance for any guidance.

[Jim_Simon]

Audio previews are those created when you render a sequence.

CFA files are those created by Premiere when you import an audio file (or the audio portion of an A/V file) that requires conversion to a 32 bit floating point format for editing.  PEK files are waveform drawings for display within Premiere, and are also generated upon import or rendering.

The Media Cache Database is something different, though I'm not sure what specifically it's used for.

[Todd_Kopriva]

The media cache database is a (small) database that keeps track of where these files are and what they're associated with.

[Ann Bens]

Todd_Kopriva wrote:

> Todd, In my HDV projects Premiere will create separate .xmp files beside each one of the clips. Now on a large project, this really makes going through clips more difficult and time consuming. Is there a way to avoid this inconvenience, even if it means disabling xmp altogether? Thanks!

Yes, in the cases in which Premiere Pro can't get inside the source file to inject the XMP ID, it will use a sidecar XMP file instead. If you don't want these, then just turn of the option to write XMP IDs on import.

Unchecking that option still makes Premiere write all these files.

[Todd_Kopriva]

> Unchecking that option still makes Premiere write all these files.

That seems like a bug.

[Colin_Brougham]

> Unchecking that option still makes Premiere write all these files.

That seems like a bug.

Is it, though? I guess I'm curious as to what an "XMP ID" is or construes. Is that the actual metadata itself (any and all information that is part of the file originally, or added externally), or is it a small bit of metadata that serves as a tracking mechanism for the Adobe software so that any program knows where any particular file is and can quickly identify it? The Help Docs only proffer, "Check this box to write ID information into XMP metadata fields." I'm not calling your expertise and knowledge of this into question, but rather the fact that it's really not clear what this means, or what enabling it or disabling it actually does.

I have had instances where certain media types (SWF files recorded with Jing, for example) were corrupted if this option was checked on. The file would import once, and play back properly, but open closing and returning to the project, it would be reported as 72x72 pixels, with a 12-hour duration, and the video would be replaced with black. Trying to playback the file externally would show a duration of -1 (!!!) and display only white. The file size was a couple kilobytes larger, as well--and there is no fixing it once it's had its metadata mangled. No XMP file is generated, regardless of how the option is set.

Anyway... just wondering.

[Todd_Kopriva]

The XMP ID is just one number. It's a single ID value that is added to a file to uniquely identify that file.

Other XMP stuff is a whole 'nother story.

The preference regarding writing XMP IDs to files on import is just supposed to refer to this very simple, minimal tagging with a single number.

[Colin_Brougham]

OK, that makes sense. So does this still imply that the XMP sidecars won't be generated if the option is turned off? Or, for that matter, that metadata is injected into a media file when possible?

Not trying to be a pain, really Just trying to wrap my head around this concept better, as I have a huge-mongous archiving project coming in which we'll be using Premiere (though using a different application for cataloging), and I want to best leverage usable metadata where I can.

Thanks Todd...

[Ann Bens]

Filed a bug report.

[Another_Photographer-qoO2PF]

If an xmp file is deleted or never created to begin with, how do you tell Premiere to create a new one?

In my case, Premiere is not creating xmp file for .mts import an as a result not allowing me to edit metadata.

[Ann Bens]

In Windows Explorer you can se the order to TYPE in the Details view (i think that's the English name) then set it back to Thumbnails.

XMP files are now at the bottom of the page.

[WebOfWebs]

I just came across this thread, and wanted to say thanks.

you succinctly explained what i wanted to know.

Thanks.

[Gala_Ur]

Hi everyone, I'm working as assistant editor on a project and I have these 2 drives with almost the same footage that I have to mirror so tow people can work remote and simultaneously in the same project. The problem is that these 2 editors have previously worked with the footage in these drives and each one have diferente generated files. Drive A has .XMP files alongside the media and Drive B has .PEK, .CFA and .MXFINDEX files alongside the media. Is it save to get rid of any of these generated files, for example .PEK, .CFA and .MXFINDEX ?