MLT XML Adapter for OpenTimelineIO

When installed, the plugin adds itself to the available adapters in OpenTimelineIO
The MLT XML adapter produces mlt flavored xml files used in conjunction with melt to preview or render timelines.

The adapter is a write-only adapter and can only produce .mlt files, not parse them. For parsing dialects of the mlt format please check out one of the other adapters listed here.

For more information on MLT please visit: www.mltframework.org

Installation

The easiest way to install the adapter is with pip directly from PyPi

# Install
pip install otio-mlt-adapter

# Check if plugin installed correctly
otiopluginfo mlt_xml

If you choose to download the source code and place the package in an alternative location, make sure you append the full path to the plugin_manifest.json file to the OTIO_PLUGIN_MANIFEST_PATH environment variable.

Usage in command line tools

# Straight conversion from otio -> mlt
otioconvert -i source_timeline.otio -o destination_timeline.mlt

# Pass adapter arguments
otioconvert -i source_timeline.otio -o destination_timeline.mlt -A colorspace=709 -A image_producer=pixbuf

# Play timeline in melt
melt destination_timeline.mlt

Usage in python

import opentimelineio as otio

# Straight conversion
timeline = otio.adapters.read_from_file('source_timeline.otio')
otio.adapters.write_to_file(timeline, 'converted_timeline.mlt')

# Conversion with adapter argument
timeline = otio.adapters.read_from_file('source_timeline.otio')
otio.adapters.write_to_file(timeline, 'converted_timeline.mlt', colorspace=709)

Supported OTIO Features

OTIO Feature	MLT Adapter
Single Track of Clips	W-O
Multiple Video Tracks	W-O
Audio Tracks & Clips	W-O
Gap/Filler	W-O
Markers	✖
Nesting	W-O
Transitions	W-O
Audio/Video Effects	✖
Linear Speed Effects	W-O
Fancy Speed Effects	✖
Color Decision List	N/A
Image Sequence Reference	W-O

Known limitations

• Audio handling is a bit limited. Clips in audio tracks that share the same source as the video clip above will be ignored as MLT will include the audio from the video track by default.

• Effects directly applied on Tracks or Stacks are currently not implemented

Feedback

Please submit bug reports etc. through github issues

License

MLT XML adapter is released under the MIT License