Confusing Example in file format metadata docs

[reinecke]

In the metadata section of the readthedocs file format specification, the example timeline is a bit odd because it starts with a transition that has an in_offset of 10/24 but there is no item before that transition to transition from. Similarly, the last item is a transition with an out_offset of 10/24 but there is no item after to transition to.

These are probably semantically invalid and should either:

• Have a gap or black generator clip before/after to fill at least the in/out offset durations
• Set the in/out offset durations to 0

Additional Questions

If you do have a transition with a zero in offset at the head of a timeline - what is the source media for the A side of the transition? Is it presumed to be transparent for video and silence for audio?