I just have a crazy idea. I think Premire can take a batch of still image files as frames and generate a movie from them? Otherwise, there are definitely other software to do this quickly.
So, what about making all those frames yourself from the loooong original image and then import them? I know there will be A LOT OF frames but you do this only once.
I quickly pieced together a small programme to do this. You may download it from here. A quickly generated 70000 x 720 tested image is included. You can double click test.cmd to see how things go. Beware that for moving 100 pixels per frame in that test case around 700 images will be generated and it will take some time, and it will take even longer if you need more frames. Also it's poorly written, and not thoroughly tested, so it may fail.
So, what about making all those frames yourself from the loooong original image and then import them? I know there will be A LOT OF frames but you do this only once.
I quickly pieced together a small programme to do this. You may download it from here. A quickly generated 70000 x 720 tested image is included. You can double click test.cmd to see how things go. Beware that for moving 100 pixels per frame in that test case around 700 images will be generated and it will take some time, and it will take even longer if you need more frames. Also it's poorly written, and not thoroughly tested, so it may fail.