Originally Posted by de8212
It's getting a bit over my head but I'll try to decipher it.
No problem, let's just review the basics
Anyone can correct me but here's how I see it. You AVR is basically a client and it needs files to be served by a server. On some AVR (not current Denons as far as I know) you can simply access Windows network shares and browse your files as if from another computer. This is nice but somewhat impractical for large libraries of content.
DLNA is a protocol that aims to solve that problem. Under that protocol, a device can be either a media server, a media renderer (i.e. a player) or a control point. Or, it could have many of these roles at the same time. For example, your AVR is a media renderer and a control point. Using the AVR remote and GUI, you can control what it will play from any DLNA media server on your network. Serviio and Windows Media Player can both act as a DLNA media server. BubbleUPnP is very powerful as it can act as a media server (for media stored on your mobile device), a media renderer (it can play stuff found on the mobile device or on the network), and a control point all at once. As a control point, you can tell it to fetch media on a different server (e.g. Serviio or WMP on your computer) and send it to another media renderer (e.g. your AVR). A nice feature of DLNA servers is that they typically scan your media library and read the metadata so that you can browse it by music style, artist names, etc. instead of just having a list of file names.
AirPlay works a bit differently. Basically it's a system-level functionality in iOS and OS X that allows a device to send the audio currently playing on the device to a networked player. So when you use AirPlay, you just push all the audio provided by your mobile device (whatever the app producing the audio) to the player. Android currently does not have this cool functionality. Some apps can push audio to an AirPlay player, but it's not a feature that is present system-wise for all apps. This can be enabled, but to do this, system-level functions must be altered, and this requires rooting your mobile device, which many people don't want to do for many reasons.
When your AVR receives an AirPlay connection or a DLNA request from a control point to play a stream, it either wakes up (if it was in standby) or changes its current source (if it was in use) to immediately start playing the requested media. In the case of AirPlay, the media comes from the iOS/OS X device itself. When it's a DLNA request, the AVR receives an URL to the media to play and starts playing it.
I downloaded BubbleUPnP (and will keep doubletwist in mind) so I'll test it as soon as I get a chance. Can I use it if I'm not rooted?
Sure, no problem. BubbleUPnP and DoubleTwist have demo modes but they are paid apps though. You may want to try other free apps too, but personally I just settled on Bubble as it's in active development and features and bug fixes keep coming.
I tried Serviio and get the same result as WMP. I can see Serviio from the Denon but the music folder shows it's empty. In the Serviio console under Library I have the Shared Folders and I added a Local directory which is where I have all my music.
Can't comment on WMP but in Serviio, in the Library tab, Shared Folders tab, you should then see your local directory. You should then check what type of media the directory contains beside the directory name. If it's only music, check the box under the music note. You should also check the box under the circular arrow if you want Serviio to periodically scan the content of the library for new stuff.
Also as your computer now turns into a server, there may be firewall issues but if you actually see the Serviio server from your AVR, then I think you're almost there and you just have to configure Serviio (or WMP). You're almost there