I need to import many PNG files (actually I can use any supported format)
There is 2865 PNG files with pattern “frm_%06d.png”, that “frm_000000.png” is the first and “frm_002863.png” is last.
Project Export is set to custom MP4 (H.264 1080p 29.97 fps)
After the first file is imported “Duration” is calculated to value “00:23:56;26” (from where?).
Then I turn on “Image sequence” checkbox and set “Repeat” to 15 frames per picture.
“Duration” is set to 00:01:35:16
Why “Duration” is not calculated correctly?
Also, if I set “Duration” manually in Properties, in playlist “Duration” is not set, stays old.
Also, when I rclick “Open as Clip”, properties reset to not “Image Sequence”
The settings in the Export panel are not your project settings; they are overrides for the project at the time of export. The project frame rate is controlled in Settings > Video Mode. If that is set to Automatic, then it uses the first clip you add to Playlist or Timeline (or the clip itself if not using those). If the first clip is an audio file or still image, then it defaults to 1080p 25 fps.
I do not know. For me, it gives “00:00:04:00”, which is the inbuilt default, but the default can be changed by clicking Set Default button next to Duration field. If you have used that button in the past, then it is saved as “imageDuration” in the Shotcut settings file/registry (depends on OS and Settings > App Data Directory).
For me it is working correctly. What is your project frame rate?
You need to update the playlist item. When you Open a playlist item in the Source player changes do not apply automatically. This is by design because maybe you want to use the same source clip as a playlist item to cut a different shot or filter in a different manner. Unfortunately, there is a bug with using the checkmark button to update the playlist item after changing an image (sequence) duration. Instead, you have to use the Replace action in the Playlist menu (menu button at end of playlist toolbar).