gui: ffmpeg.calcBitmapThumbnail in different process via multiprocessing
gui: ffmpeg.calcBitmapThumbnail in different process via multiprocessing

kingsj/music-player,albertz/music-player,kingsj/music-player,albertz/music-player,albertz/music-player,albertz/music-player,kingsj/music-player,albertz/music-player,kingsj/music-player,kingsj/music-player,albertz/music-player