Writing an OTIO Media Linker

OpenTimelineIO Media Linkers are plugins that allow OTIO to replace MissingReferences with valid, site specific MediaReferences after an adapter reads a file.

The current MediaLinker can be specified as an argument to otio.adapters.read_from_file or via an environment variable. If one is specified, then it will run after the adapter reads the contents of the file before it is returned back.

#/usr/bin/env python
import opentimelineio as otio
mytimeline = otio.adapters.read_from_file("something.edl", media_linker_name="awesome_studios_media_linker")

After the EDL adapter reads something.edl, the media linker “awesome_studios_media_linker” will run and link the media in the file (if it can).

Registering Your Media Linker

To create a new OTIO Adapter, you need to create a file mymedialinker.py. Then add a manifest that points at that python file:

        "OTIO_SCHEMA" : "PluginManifest.1",
        "media_linkers" : [
                "OTIO_SCHEMA" : "MediaLinker.1",
                "name" : "awesome_studios_media_linker",
                "execution_scope" : "in process",
                "filepath" : "mymedialinker.py"
        "adapters" : [

Then you need to add this manifest to your $OTIO_PLUGIN_MANIFEST_PATH environment variable (which is separated with : for POSIX or ; for Windows).

Finally, to specify this linker as the default media linker, set OTIO_DEFAULT_MEDIA_LINKER to the name of the media linker:

setenv OTIO_DEFAULT_MEDIA_LINKER "awesome_studios_media_linker"

To package and share your media linker, follow these instructions.

Writing a Media Linker

To write a media linker, write a python file with a “link_media_reference” function in it that takes two arguments: “in_clip” (the clip to try and add a media reference to) and “media_linker_argument_map” (arguments passed from the calling function to the media linker.

For example:

def link_media_reference(in_clip, media_linker_argument_map):
    # you'll probably want to set it to something other than a missing reference
    in_clip.media_reference = otio.schema.MissingReference(
        name=in_clip.name + "_tweaked",

For Testing

The otioconvert.py script has a –media-linker argument you can use to test out your media linker (once its on the path).

env OTIO_PLUGIN_MANIFEST_PATH=mymanifest.otio.json:$OTIO_PLUGIN_MANIFEST_PATH bin/otioconvert.py -i somefile.edl --media-linker="awesome_studios_media_linker" -o /var/tmp/test.otio