I agree with faldzip, but just for fun I would try.

QVector<qint16> vector;
vector.reserve(6);//one extra for safety.
in.readRawData((char*)vector.data() , 5*sizeof(qint16) );

sizeof might be redundant here. from qt assistant:

typedef qint16
Typedef for signed short. This type is guaranteed to be 16-bit on all platforms supported by Qt.