WP7 BackgroundAudioPlayer plays only while attached to debugger - debugging

Question

I'm working on music app for WP7. It downloads music from our servers in form of little segments (each track is devided into 128k encrypted pieces). I'm using AudioPlayerAgent and AudioStreamingAgent to download, decrypt and play music.
Everything works fine, while I start application from visual studio via F5. When I start app from menu on emulator or device, everything works fine except of music is not playing. BackgroundAudioPlayer never starts. Doesn't metter if I try debug or release build, or if I try it on emulator or real device(Nokia Lumia 710 and HTC HD7 Pro).
I think that I have everything correctly setted up in AppManifest:
<Capabilities>
<Capability Name="ID_CAP_GAMERSERVICES" />
<Capability Name="ID_CAP_IDENTITY_DEVICE" />
<Capability Name="ID_CAP_IDENTITY_USER" />
<Capability Name="ID_CAP_LOCATION" />
<Capability Name="ID_CAP_MEDIALIB" />
<Capability Name="ID_CAP_MICROPHONE" />
<Capability Name="ID_CAP_NETWORKING" />
<Capability Name="ID_CAP_PHONEDIALER" />
<Capability Name="ID_CAP_PUSH_NOTIFICATION" />
<Capability Name="ID_CAP_SENSORS" />
<Capability Name="ID_CAP_WEBBROWSERCOMPONENT" />
</Capabilities>
<Tasks>
<DefaultTask Name="_default" NavigationPage="Panorama.xaml" />
<ExtendedTask Name="BackgroundTask">
<BackgroundServiceAgent Specifier="AudioPlayerAgent" Name="AudioPlaybackAgent1" Source="AudioPlaybackAgent1" Type="AudioPlaybackAgent1.AudioPlayer" />
<BackgroundServiceAgent Specifier="AudioStreamingAgent" Name="AudioStreamAgent1" Source="AudioStreamAgent1" Type="AudioStreamAgent1.AudioTrackStreamer" />
</ExtendedTask>
</Tasks>
After some research I found that I can enable hidden console for emulator to see debug log. I tried to track what happens when I start app from emulator menu. In point where BackgroundAudioPlayer should start playing track following message appers:
PID:0E8500C6 TID:0EEE006A Sentinels are Disabled for all processes.PID:0E8500C6 TID:0EC500DE Exception 'Raised Exception' (0xc0008005): Thread-Id=0ec500de(pth=c0654930), Proc-Id=0e8500c6(pprc=c05f3160) 'HeadlessHost.exe', VM-active=0e8500c6(pprc=c05f3160) 'HeadlessHost.exe'
PID:0E8500C6 TID:0EC500DE PC=42a629f7(mscoree3_7.dll+0x000529f7) RA=42ac3ae5(mscoree3_7.dll+0x000b3ae5) SP=0634f6b8, BVA=00000000
I also tried to test app in MarketplaceTestKit if any unsupported Api is causing it, but app passed all test fine.
So my question is: does anybody know, while app is playing only when attached to debugger?
Thank You,
Jan.

Answer 1

You should only have one type of background audio agent in your app.
Based on your description of how you're getting the tracks, it seems that using the streaming agent will be more appropriate.
If you're playing each segment directly (treating it as a separate track) and there isn't an issue with gaps as you switch between segments (tracks) then you could use the playback agent.
Having multiple background audio agents specified can cause your app to crash. Note. You'll have to edit the WMAppManifest file directly to remove the one you don't want.