[Symbian][Linux] Unable to retrieve 'bytes-loaded' info

Try to get the bytes-loaded information by running following code,

if (qmediaPlayer->availableExtendedMetaData().contains('bytes-loaded'))
return qmediaPlayer->extendedMetaData('bytes-loaded').toInt();

The problem is, on both Symbian & Linux, the if condition is always false, so there is no way to retrieve the bytes-loaded info.