Hi. Simple question, I hope. Can't seem to find answers on how to make AE auto-adjust duration to the clip I imported. Duration is set to a default 897 frames (I didn't do that) and a) cnnot be converted to time, as far as I can tell, and b) cannot be auto-adjusted to clip duration. Obviously I can do each of them manually, but I feel like that will take a lot of work after awhile. Plus I'm just gnereally curious. Nothing seems to change this and I've played around and for quite awhile. Thanks.
If you create a composition from footage trimmed in the footage window, the new comp will respect the in and out points of the trimmed footage.
If you do not trim footage, or you open it again and set new in and out points, the comp created from the clip will also respect the new trimmed footage length.
Any new comp you create after creating a comp from footage will be the same duration as the last comp created. There is no feature that allows you to select a layer in the comp and set the new comp duration to match the layer. You can, however, drag footage longer than the comp into the timeline, select the new layer, press 'o' to jump to the layer out point, double-click the time display in the timeline to open it, copy it, then open the composition settings and paste the copied end time to the comp duration.
Holding down the Ctrl/Cmnd key will change the time display in the timeline from frames to timecode. No need to open any other panel.
Because of the odd frame rate, your footage is probably from a mobile or consumer device and it may have a variable frame rate. That won't cause a problem with changing the duration of a composition, but you should probably interpret the footage by selecting the footage in the Project panel and pressing Alt/Option + Ctrl/Cmnd + g or use the File/Interpret Footage/Main menu and force the frame rate to 30 fps. That's the closest standard frame rate. 29.97 fps would also work. That is the NTSC standard.