No audio and 1080p video

[harisj16]

hi i have installed openelec 6.0 on my m8 2gb box. installation went fine. but the video output is 720p. i was unable to change it to 1080p. when i go to video output setting it is fixed in 720p . i got no option to change. audio was same thing stuck at spdif. when i play audio no audio either. then i install olderversions of openelec 5.95 and 5.08. now the audio is comong but the video resolution remains 720p. i couldnt change anything . audio is playing but the setting still locked. can some one please help me