BackgroundAudioPlayer and MediaLibrary integration

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C#

Windows-Phone-8.1

Hi,
I have built this app using the MediaLibrary.Songs. My implementation consists of building a collection of songs and feeding them to the Mediaplayer one at a time.

My problem is, that after building this app, I could not get it to play in the background, or under a lock screen. This led me to the newly introduced BackgroundAudioPlayer. I've at all the examples on msdn, however, they are all with local audio files, with paths saved in IsolatedStorage. I want to use the BackgroundAudioPlayer to play a list of songs from the device's internal Song Library. As far as I know the only way to access this is via the MediaLibrary.

So far I've seen that what I want to achieve is not possible because the BackgroundAudioPlayer can only play audio files that are stored with the application or at an external stream.

So how can I play the music files from SD card using BackgroundAudioPlayer ?

Any help would be appreciated. Thanks :)