cannot change Animations output file type

[Elaine Meng]

The Save dialog that appears when you click the red recording button is weird. The file type is listed as multiple types and no choice to change among them. I thought I could control file type by entering one of the suffixes listed there as the suffix on the file name. However, when I changed it from mp4 to mov the file I got still was reported as MPEG-4 in movie inspector (or whatever that thing in Quicktime Player is called) so I guess maybe that didn't actually change the format??

For behavior of this dialog to be "normal" (as expected) there should be multiple options of video file format given as the file type, not just one. I only resorted to changing filename suffix in hopes that would work, because there seemed to be no other way to do it. but even that didn't work as far as I can tell. Apparently you can only get mp4.

[Zach Pearson]

You should be able to save a file in any format the movie bundle supports (except APNG) today.

[Elaine Meng]

The movie-save dialog does not give choices of which format. It just has one single format choice "Video Files (*.mp4 *.mov *.avi *.wmv)" and the actual file I get after recording is always .mp4. This dialog looks the same as when I reported the bug.

Tested in UCSF ChimeraX version: 1.13.dev202605280103 (2026-05-28)

[Zach Pearson]

The dropdown should now have individual file extensions and changing the extension should change it on the filename