qt4-mac and phonon

[Michael Dickens]

On Oct 27, 2010, at 7:49 AM, Petr Vanek wrote:
> qt4-mac 4.7 doesn't use its internal phonon. Fair enough. I installed phonon from its dedicated port.
>
> Now apps using phonon can be compiled and linked and run but there are bunch of warnings:
>
> WARNING: bool Phonon::FactoryPrivate::createBackend() phonon backend plugin could not be loaded 
>
> I don't know this library too much, but shouldn't be there something like Qt4 plugin for phonon as well? How to build it in macports?

Hi Petr - Shortest answer is: I know this is an issue and I'm working on it.  I decided to go ahead with the qt4 upgrade to 4.7.0 anyway, knowing I'd have a queue of changes to make w/r.t. this upgrade and having this issue being on the queue (it is).

Longer answer: Qt4 uses a stock 3rd-party install of Phonon, but augments it with QMake build files instead of using the default CMake ones.  Phonon itself (the front end) is written by the KDE developers; the Quicktime 7 (qt7) audio backend is written by the Qt folks, and this is the only backend that works with Phonon and OSX/Darwin.  The front end is written in C++, and thus compiles easily.  The qt7 backend is written in OBJC++, and thus uses automoc4 (and thence moc) to do some of the object coding.  Although I haven't tried this in a while, the latest CMake and automoc4 do not recognize OBJC++ files for 'moc' purposes, and hence the qt7 backend fails to build with various errors -- I'll try building in this manner again this morning & see if anything has changed, but I doubt it.  QMake knows how to handle OBJC++ and 'moc' files, so I'm working on porting Qt's QMake build files into Phonon.  I think once this porting is finished those MP ports that depend on Phonon and the qt7 backend will work correctly; I certainly hope so.

Hope that helps clarify the situation a bit. - MLD