MPEG4Source: fix fragmented read. am: 6b401a3376 am: 96114e7c5d am: bbc5c8fc60 am: 067ab2f74e am: 218692ec4f am: fa7be9da95
am: b31373e62c

Change-Id: I4266df6693d6f6e261e5959f8006f658be57d656