Python ~ffmpeg 5_second_video.mp3: No such file or directory Conversion failed -

here python code :

    call(['ffmpeg', '-loop', '1',  '-y', '-i', '5_second_video.jpg', '-i','5_second_video.mp3' , '-acodec', 'copy', '-vcodec', 'libx264', '-shortest', song +'.mp4'], shell=false) 

there file called 5_second_video.mp3 in desktop returning me error

5_second_video.mp3: no such file or directory conversion failed!

the problem solved changing '-o '+song2file(song)+'.%(ext)s' '-o'+song2file(song)+'.%(ext)s'. space problem.