Phonon problems using MediaObject created with QIODevice

I raised this bug back in December 09 (http://bugreports.qt.nokia.com/browse/QTBUG-6933) which was a problem I was having on Windows. Things seem to be OK now, but I'm having a similar problem on the Mac.

So, Qt 4.7.1, I'm trying to play a divx movie using the mediaplayer demo. The movie is 1.6gb in size.

If I play it using the qmediaplayer demo out of the box, all is OK.

But if I change MediaPlayer::setFile (const QString &filename) from:
m_MediaObject.setCurrentSource (Phonon::MediaSource (filename));

to
m_MediaObject.setCurrentSource (Phonon::MediaSource (new QFile (filename)));

it fails. Ignoring the memory leak this will introduce (as I'll ultimately manage things a bit differently), has anybody else experienced anything similar?

From what I can tell (using top), it looks like this approach attempts to load the entire movie into memory, and the crash occurs when the program reaches the RAM limit (as expected).

On Windows this isn't a problem. The file responds almost as soon as I tell it to start playing. The Mac, however, is slow for all files (as I presume it's loading them in to RAM), but if they are too big I get this crash.

I must use the QIODevice version of MediaSource constructor, as I've extended QFile to do some pre-processing of the file.