1. How to init dir for three apps: gallery, fileexplorer, video player.

mkdir 'DCIM' at the run directory and put jpg/png/mp4 in it.

eg. ./out/simulator/bin/qmdemo
---qm_xos
-------|
-------|
------./out/simulator/bin/qmdemo
-------|
-------|
------./DCIM/birds.mp4


2. birds.mp4 already exist at: ./lvgl/examples/libs/ffmpeg/birds.mp4