MPEG4Source: fix fragmented read. am: 6b401a3376 am: 96114e7c5d am: bbc5c8fc60 am: 067ab2f74e am: 218692ec4f am: fa7be9da95 am: b31373e62c am: 2df7cd6571 am: 64e7c6089f
am: 739585fb8d

Change-Id: I5d72f60baaed58bf9deaaefc8b3a607de9a04e11