after some tests on
I finally understood what was happening.
This block give all the sources path on device, as the name itself says. :P
I put the textblock to start working from there.
Its show this:
/storage/82C3-E96C/
/storage/emulated/0/
The first path is external flash drive SERIAL NUMBER, and second is internal memory.
If i put the first path on any test, video or image, the blocks works, but only for this flash drive, because the SERIAL NUMBER changes for each flash drive.
I belive I need a variable to copy the path and paste on my blocks:
I search the way how to copy the external path, because the "availablestoragedirectories" show this: "/storage/82C3-E96C/ /storage/emulated/0/"
and I need only the first 19 letters.