I really appreciate your reply.
About "roll/crawl titles cannot be initialized with a non-default length".
-> I Understand. I hope to become able to initialize it in the future.
*I hope that a new type is added to the 'ImporterDurationType'.
for example 'imNoDurationVidDurationDefault' ---> use supplied vid duration and duration on the timeline can be changed freely.
Normal video does not seem to fit as a solution.
Because I would like to adjust duration freely on the timeline.