"While files will play from the USB port from a USB drive, some HD video may not play well from some USB drives. For high bit rate files we recommend using the SD port with an SD card of sufficient speed to match your video file’s bit rate. For some HD video files a Class 4 may be ok, while others may need a faster Class 6 or Class 10. Test your video." ---Quote from "DV-S1 Sprite Manual revision 4.00 for firmware version 20210416" (Source: medeawiz.com/Downloads.html)