显示标题字符串时，前面2个字号放大，后面两个字正常字号

public SpannableString getTitleShow(){
SpannableString msp = new SpannableString(title_show);
int curLanguage;
try {
curLanguage = OSDLanguage.getOSDLanguage();
} catch (RemoteException e) {
curLanguage = Core.OSD_L.OSD_ENGLISH;
}

if (title_show != null && curLanguage == Core.OSD_L.OSD_CHINISE && title_show.length() > 2) {
msp.setSpan(new RelativeSizeSpan(0.6f), 2,
msp.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
} else if (title_show != null && curLanguage == Core.OSD_L.OSD_ENGLISH && title_show.length() > 8) {
msp.setSpan(new RelativeSizeSpan(0.6f), 8,
msp.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
} 

return msp;
}