XDCAM Proxy and 4K XAVC Conform


The advantage of 4K XAVC shooting is that a proxy can be recorded at the same time on the same card. This facilitates the production workflow by keeping everything in one camera.

The recommendation when shooting 4K XAVC productions is to not use the XDCM proxies as the conform process will involve many file renaming steps in order for Media Composer to match the proxy with the 4K master file. Use AMA to link to the 4K files, or use DMF to create proxies to ensure proper source/reel tracking.

AMA uses the entire filename as the Source/Reel ID in the “Source File” column. They need to match as much as possible as Media Composer does not offer much control over reel identification with syntax control as you may find in dedicated conform processes of DI color correction systems.

4K XAVC filename:         B001C001_1308213D.MXF
XDCAM Proxy filename:     B001C001_1308213DS02.MXF

Notice the addition of S02 at the end of the file. This is currently used to identify the clip as the XDCAM proxy. Because the filenames are different, a relink conform process is not possible. Media Composer only offers the following modifications to the conform process:

  • Ignore characters after last occurrence of (enter text string)
  • Ignore extension (check box)

Using “ignore characters after last occurrence” can be problematic as the filename may have a name such as B001C001_1308213SS02.MXF where there are two S’ in a row. The workaround involves the following steps:

  1. Duplicate Source File column for all files into the Labroll column (or another column if Labroll is already being used)
  2. On the proxy clips that have the S02 at the end, enter an underscore to separate it from the filename as is B001C001_1308213D_S02.MXF.
  3. Select all the 4K clips and the sequence. They do not need to be in the same bin. With everything highlighted, right-click on the sequence and select “Relink”
  4. Check “Selected items in ALL open bins”
  5. In the “Relink by:” section for Original:
    1. Timecode = Start
    2. Source Name = Labroll
    3. Ignore extension = active (checked)
    4. Ignore characters after last occurrence: = “_” (underscore)
  6. In the “Relink by:” section for Target:
    1. Timecode = Start
    2. Source Name = Labroll
    3. Ignore extension = active (checked)
    4. Ignore characters after last occurrence: = (blank)
  7. Click OK.

It is helpful to set a source clip color on the 4K clips to verify the conform process in the timeline when complete. See the Media Composer 7 online help for more detail on setting source color and viewing in the timeline.

This workaround can be process intensive if you have a lot of clips to manage. One can use a text editor to do a search and replace of an ALE file and merge that back into the clips. Be aware that the ALE file must contain all the columns of metadata you want to preserve, as the merge is not a true merge, but more of a replace function. If using 7.0.3, then the merge is no longer “lossy” and will only update/replace columns in the ALE. See the Media Composer 7.x online help for ALE merge functions.

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