#63 OGG Transcode segfault

Recently compiled/installed fuppes to stream ogg tracks to my 360. When selecting a track from the albums list, fuppes would segfault.

I've tracked this down to a configuration setting. The ogg entry had <encoder>lame</encoder> set, which I didn't have installed, it should have been set to twolame.

However, fuppes isn't checking whether the specified encoder actually exists, so in src/lib/Transcoding/TranscodingCache.cpp line 174 where it runs

m_pAudioEncoder = CTranscodingMgr::Shared()->CreateAudioEncoder(pDeviceSettings->GetEncoderType(sExt));

There is no check as to whether the returned pointer is null or not. The m_pAudioEncoder->LoadLib() call then causes a segfault.