How to definitively determine any Bin Item's start TC?

[communque]

What I'm looking to achieve is the PyAvb equivalent of being on Avid, executing the "Find Bin" command (i.e. reveal bin item), and reading what's in the Start column.

In PyAvb that's proving challenging, requiring different approaches depending how the clip was generated.

For instance a drag-and-drop imported master clip requires an elaborate iteration of components to get the component of the component of the component that "knows" the start frame.
Meanwhile a drag-and-drop imported .png file with alpha channel, although similar, requres a nuance to the above
Meanwhile an ALE-generated master clip imported to Avid by way of drag and dropping a media files databases has the bin info available immediately without much complication.

Gleaning all this through trial and error. Wondering if anyone is aware of a single reliable way to get any source clip's start TC.

[mjiggidy]

I think there's no way around a bit of "elaborate iteration" (I like that term!), although I'm sure Media Composer must have a faster way.

My method has been to write a recursive method that mimics Avid's "Matchback" function, first to get to the original masterclip, and then dig deeper to get to the SourceMob to get the tape/file and start timecode info.

I have limited resources to test, since for "real world" examples I only have the show that I'm working on at that time as an AE, but the technique I mentioned has been working in most cases for me so far (dailies from a lab, "hard imported" things, UME-linked things).

It might be helpful to enable the wiki on this repo so we can more easily share tips and tricks?

[communque]

RE "recursive method" -- hah, you too. Was hoping there was a method "getStartTcNoMatterWhat()" that I'd somehow overlooked.
So far I've been able to handle drag-imported master clips, drag-imported png files, and the ALE-generated files mentioned above.
But for an AMA-linked ProRes file no luck whatsoever.

[communque]

@mjiggidy How about group clips?

[mjiggidy]

@mjiggidy How about group clips?

Group clips you can treat like subclips with the addition of a "selected track" index. So I just do the usual matchback process on the selected track to eventually get to the selected masterclip and derive the info I need. (As far as I know, a Group Clip doesn't have its own timecode or source mob, it just adopts from whichever source is selected at the time, I believe?)

I'm most certainly not an expert on this topic, but that's what has generally been working for me so far.