Upload the MKV and open the options. Frame Extraction has two modes: Single Frame saves one BMP from the second you enter (for example 1, 5 or 10.5), and All Frames saves every frame of the video as a BMP image. There is no every-Nth-frame or one-per-second mode. MKV ແມ່ນ Matroska, ບັນຈຸການເປີດທີ່ໄດ້ອອກແບບໃນປີ 2002 ໂດຍບໍ່ມີຂໍ້ຈຳກັດໃບອະນຸຍາດ ແລະ ບໍ່ມີຂອບເຂດທີ່ມັນສາມາດເກັບໄວ້ໄດ້. BMP ແມ່ນ Windows Bitmap, ຮູບແບບ raster ທີ່ບໍ່ໄດ້ປຸງແຕ່ງທີ່ໄດ້ສ້າງຂຶ້ນໃນ Windows ນັບແຕ່ປີ 1985.