Preparing Op Atom MXF Media Files For Use in Avid Editing Workflows

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Preparing Op Atom MXF Media Files For Use in Avid Editing Workflows

There are now a number of mechanisms available to get media files, acquired outside of traditional Avid capture workflows, into an Avid editorial workflow based on either shared or local storage.

Of course there is Avid’s most recent innovation in this regard – Avid Media Access (or AMA), whereby 3rd party manufacturers can author a plug-in for the Avid editing software that enables the editing platform to use the manufacturer’s acquisition media directly, thus giving much faster access to clips and metadata.

Avid also has their Interplay environment which offers several innovative services for the acquisition of material from 3rd party capture, archive and storage environments. Avid Interplay Transfer and Avid Interplay Web Services (with Avid Media Transfer or AMT) both offer very flexible methods of getting material into an Avid workgroup environment. The latter being a very open environment for 3rd parties to customise delivery of Avid friendly media files to Avid shared storage while simultaneously checking in metadata for each clip to the Interplay asset management database.

How then do you get MXF files into Avid environments if your workflow sits somewhere between these two camps?

Perhaps you are faced with the challenge of working with non-Avid native file based media in a small non-Interplay workgroup on shared storage and you need to create a workflow that enables you to edit this material? Possibly you have looked at workflow automation platforms such as Root6 Technology’s ContentAgent to convert 3rd party media formats based on pre-defined rules and processes or “workflows”, into media that can then be handled by Avid editors. The question is how do I get the media from these 3rd party platforms into the editing environment in a predictable and consistent manner?

I describe a solution to this challenge below but first some background information on how Avid stores media files.

Avid Media File and storage Folder Formats

Avid announced that it would be adopting Material Exchange Format (MXF) as the file format for media interchange in 2002. In order to create a mechanism that delivers high performance for both the reading of and processing of media files, the Op Atom format of MXF media was adopted as the underpinning file technology for Avid editing software. This format uses a group of individual but linked media files, with one file for each component “track” of the media clip (for example, for a clip that has stereo audio and a video track there would be a total of three linked MXF media files – two audio track files and one video track file). When an Avid editing platform creates media files it uses this method to create the media files that represent the captured clip and it stores these files in a structure that is unique to Avid on the target media storage device. The editing application normally uses a pair of small database files to track the contents of the media files in these storage folders which contain a table of each file’s Media Object (MOB) Data which describes the relationship between each file and the higher level “Clip” information and it is this information that is used to link these media files to clips displayed in the Editing Bin.

File based media from non-Avid environments can be delivered to the editing stage in a bewildering variety of formats, some purporting to be MXF while others might be in any number of other proprietary or even “standard” formats. Since the task of converting media files is a processor intensive and complex job, there are several excellent products available now that can be used to convert media files. The task of conversion of media files is split into two slightly different mechanisms depending on the source of the material.

– The first is converting media file formats from the source format to the destination format and is known as “transcoding”. This is most often encountered when using proprietary acquisition format files from a third party device such as a camera which must then be converted into media that can then be used in Avid Composer based workflows (for example the conversion of material from High Resolution digital cameras into Avid format files might be handled by a transcoding platform).

– The second is the unpacking of “encapsulated”, “interleaved” or “wrapped” media formats used by Media Archive and Media Transport systems such as the MXF Op 1a format. Here the source media file is one packaged media file which contains the media information to play out the clip as one composite “transport” file and which must be “un-wrapped” to extract the individual OP Atom format file-per-track format media files required by Avid editing software.

Once a third party device or platform has been used to convert the non-Avid media files into Op Atom MXF media files (which the Avid editing application will understand), these files must then be presented to the editing software in a format that will enable the editing software to find them and extract the metadata to list in Bins.

This process of presenting the media files to the editing application requires creating a folder structure into which media files are then placed. There are then two methods of populating the bin information with the clip information.

The first can be used if the device creating the OP Atom media files also created an AAF composition file for each clip. The second can be used when there are no AAF files and which relies on the Avid application extracting media clip information from the media file MOB information.

Creating the Avid Media Storage Folder Structure:

  1. Exit the Avid Media Composer / Symphony / NewsCutter application (if open).
  2. On the target Media storage location, create a numbered folder using the appropriate formatting (described in the following) depending on whether the folder is located on local storage or shared storage.

Local Storage – The Editing software will create a folder structure on a target drive to store Avid Media Files starting at the root of the drive with a folder called “Avid MediaFiles”. Nested inside this folder will be a folder called “MXF” and inside that folder, the system will create incrementally numbered folders to accommodate the actual media files. By limiting the number of items in media folders, the editing software keeps the resulting database file sizes manageable; the software limits the number of items per sub folder to around 5000 items. Once a target folder approaches this number of files, the software will create a new folder with an incremented number (1, 2,… 99 etc). The full structure looks like this:

[drive_Letter]:Avid MediaFilesMXF[folder_number]media_file.mxf

Example: A firewire drive is mounted as drive letter Z: on a Media Composer platform. The editing software is used to import a graphics file.

Z:Avid MediaFilesMXF1media_file.mxf

To use this structure in the suggested workflow, create a new folder under the MXF folder level, named with a unique number that fits your needs for example on the Y: drive create 4 folders for cameras 1 and 2 for days 3 and 4 of shooting. Populate each of the created folders with the appropriate files:

  • Y:Avid MediaFilesMXF31
  • Y:Avid MediaFilesMXF32
  • Y:Avid MediaFilesMXF41
  • Y:Avid MediaFilesMXF42

Shared Storage – Here again, the Workspace will contain a folder called Avid MediaFiles, and in here will be an MXF folder. This MXF folder will contain a folder structure where the platform name of the device creating the media will be used to name the folders into which media files created by that platform will be placed. By limiting the number of items in media folders, the editing software keeps the resulting database file sizes manageable; the software limits the number of items per sub folder to around 5000 items. Once a target folder approaches this number of files it will create a new folder will an incremented suffix ([platform_name].1, [platform_name].2 etc). The full structure looks like this:

UNC Path:

\[System_Director_Name][Workspace name]Avid MediaFilesMXF[Platform_Name].1media_file.mxf

Drive Letter:

[Drive_Letter]: Avid MediaFilesMXF[Platform_Name].1

Example: The “Ingest” Workspace is mounted by a platform called Ingest-1 as drive letter Z. This machine creates media files as a result of capturing several clips from tape:

Z:Avid MediaFilesMXFingest-1.1media_file.mxf

To use this in the suggested workflow create a new folder under the MXF folder level, named for the creating platform and with a unique numbered suffix that fits your needs, for example on the Ingest Workspace mounted as the Y: drive by platform named edit-1 create 4 folders for cameras 1 and 2 for days 3 and 4 of shooting. Populate each of the created folders with the appropriate files:

  • Y:Avid MediaFilesMXFedit-1.31
  • Y:Avid MediaFilesMXF edit-1.32
  • Y:Avid MediaFilesMXF edit-1.41
  • Y:Avid MediaFilesMXF edit-1.42

Placing the Media Files:

  1. Place the .MXF media file items inside the new folder location (you should aim to limit the number of items in this folder to 5000 files).
  2. Launch the Avid editing software and allow it to index the contents of this newly created folder (thus creating the necessary .pmr and .mdb media database files for this folder).
  3. Once your project is open, create a new bin and open it (or select and open an existing bin).
  4. If you have an AAF file that was created at the time of the creation of the MXF media files and which describes the Media information that “points” to the media files you placed earlier, drag that/those AAF file(s) into the opened bin. The editing software will link to the media files and clip information will be created and listed in the bin.
  5. If you do not have an AAF file for the MXF media files, navigate to the folder that you created and populated in the previous section, locate the msmMMOB.mdb media database file in the newly created folder and drag that file into the bin – this will process and list out each of the clip items in the folder location that your created (note that if the .mdb file does not exist in the newly created folder location, launch Media Tool and have it scan the drive letter in which you created the new folder  – this will force creation of or updating of the msmMMOB.mdb media database file for your folder).

Thanks to Bob Russo who is an Avid Editing specialist working out of their Burlington USA office and to Simon Cull of Serious Facilities in Glasgow.


 

 



By | 2016-10-29T08:55:49+00:00 January 25th, 2012|Categories: Support, tips|Tags: , , , |3 Comments

3 Comments

  1. gert van den cruijce February 15, 2012 at 7:42 pm - Reply

    Do you know software that can convert media to avid compliant media files?

    • Neal February 15, 2012 at 9:41 pm - Reply

      Dear Gert,

      DVS Venice and DVS Clipster can transcode a variety of file types into Avid Op-Atom material. Root6 Technology Content Agent can similarly do this very effectively. Telestream Flip Factory can also do this.

      With warm regards,

      Neal

  2. Lew May 22, 2014 at 12:48 pm - Reply

    Hi Neal

    Are you proficient in Interplay? Do you know how to import MXF Op-Atom files into AVID Interplay. I have mapped AAF file and MXF Op-Atom files. The questions are:
    1) Must I copy my MXF files on ISIS storage before import AAF to Interplay?
    2) How to do the Import AAF command from Avid Web Services? Do you have any examples of code? (C++ and qSOAP or C# .NET)

    Best regards,
    Lew

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