After effects reset fps of a jpg sequence when saving project

[Dario Trevisan]

I just noticed an update to 14.0.1, i’m updating. let you know if it solves the problem. thank you

[Dario Trevisan]

the bug is still there, is due to the new jpeg importer. Here is a workaround.

https://forums.adobe.com/message/9124077#9124077

[Tim Kurkoski]

There is a bug in After Effects CC 2017 where JPEG sequences are the wrong duration. This was not fixed in the 14.0.1 update; we are working on a fix for a future update. Our apologies for this bug.

What is happening is that when you save the project, the Interpret Footage > Frame Rate setting for the JPEG sequence is being reset to the frame rate value in Preferences > Import > Sequence Footage.

The preference value defaults to 30fps. For example, if you interpret a JPEG sequence as 25fps, and then the bug causes the value to reset to 30fps, the sequence will be only 83% (25/30 = 0.83) as long as expected.

There are a few different ways to work around this problem until we release a fix:
1. Set the Preferences > Import > Sequence Footage frame rate value to the value you wish to use. This makes sure that when the bug happens, the interpretation frame rate isn’t changed. This may not be convenient if you work with sequences of different frame rates.
2. When you import JPEG footage, in the Import dialog change the Enable option to “All Files” and the Format option to “JPEG” (instead of “ImporterJPEG”). This will avoid the problem.
3. For footage that you have already imported, use the File > Replace Footage > File command, follow #2 above, then change the interpret footage frame rate as desired (if you have not already done #1).
4. Use a different file format instead of JPEG, such as PNG or TIFF.
5. Use Time Stretch or Time Remapping to change the duration of footage already used in a comp. Time Stretch is simpler, just calculate the stretch factor between the two frame rates (in the example above, the stretch factor is 120%, or 30/25).

The reason this problem occurs is because After Effects CC 2017 now uses the same JPEG importer (“ImporterJPEG”) as Premiere Pro. There should be no difference in the rendered results, the difference is only in how the importer module code is wrapped; this change is a part of an internal project to reduce code redundancy between applications. The bug is in how the new code is wired into After Effects. The legacy JPEG importer (“JPEG”) is still available, and does not have the bug.

I hope that helps. Again, our apologies about the bug.