Description

change default video backend to torchcodec

Motivation and Context

torchcodec is faster than the old default pyav

How has this been tested?

Spikes are far less (yellow is old, blue is new):

Loss curves are basically the same:

Additional information (optional, e.g., figures and logs):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Documentation update (Document-only update)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.