Surround LPCM 96/24 over UPnP only works for files having a 'native' channel configuration of 5.0 (FL, RF, C, SL, SR), 4.0 (FL, FR, SL, SR) 3.0(FL,C,FR). All other 5.1 files have 'nails on chalkboard' effects added.
It seems obvious that this particular UNnP LPCM playback chain doesn't like the LFE channel. Regardless of delivery mechanism (local file, UPnP) the LPCM headers specify the channel configuration, and there are different bit values to signify 4.0, 5.0, 5.1 etc. As Foobar streams the same files to other devices correctly, this is almost certainly a problem in the Oppo BDP-83. A simple workaround (for Foobar) would be to simply drop the LFE channel - and I've proposed that to Foobar if Oppo doesn't squash what should be a simple deterent to UPnP streamed LPCM 5.1 playback.
I will investigate this issue further if Oppo maintains that they are processing LPCM headers correctly. In any event, even if Foobar developers don't play ball, PS3 developers might make the change to allow 7.1/5.1 --> 5.0 downmixing. At least I can access that source code.Configuration: (see attached image)
1. Oppo BDP-83 with latest firmware (Feb 1, 2011 BDP83-54-0130B)
2. Foobar (v1.1.2) with UPNP server (Foobar module foo_upnp 0.99.29)
3. Foobar setup - No DSP modules applied, set streaming profile to 'oppo'
4. Onkyo TX-SR 805 --> (my custom designed speakers)
Any 'cutouts' are likely due to network issues (ie your Wireless LAN). Playback with 4.0/96/24 from powerful desktop over 802.11n was flawless. Playback from 'thin ULV CPU' laptop over 802.11n with 5.0/96/24 had 3 <1 second 'hiccups' over a 17 minute FLAC file. These hiccups may have been an issue with the laptop CPU and/or HDD access. I'm certain any reasonable computer and network will support this feature - but start your troubleshooting by hooking up to the network with a cable!Foobar configuration details:
1. [OPEN] Preferences>Tools>UPnP>Server>Streaming Profiles
2. [SET] 'Select profile to edit'>New
3. [SET] Use profile when 'User-Agent' contain 'oppo'
4. [SET] Samplerate range '44,100' to '192000'
5. [SET] Max bit depth '24'
6. [SET] 'Stereo Only' to 'unchecked'
7. [SET] "Decoding to PCM">Decode 'always' to 'lpcm'
8. [SET] "Audio processsing"> 'Active DSPs' is
9. [SET] "Apply"
10. Configure Foobar media library under 'Preferences' to include 5.0/4.0 filesOppo Playback
[PRESS] "Home" button on remote
[OPEN] 'My Network'
[OPEN] 'Foobar' (or whatever appears to be your Foobar UPnP server)
[OPEN] 'Media Library'
[OPEN] 'Folders' - Last entry in the list within 'Media Library'
[SELECT] PCM file that corresponds to your 5.0/4.0 file
Note that Foobar sends the file's tag info as the file name if that's populated.
If connected via Analog you will hear music through all channels.
If connected via HDMI, receiver will not display the LFE symbol in your speaker setup icons during playback of 5.0/4.0/3.0 files. Also, via HDMI, 'Display' button on your receiver reveals frequency sample rate and channel configuration of "4.0" , "5.0" or "3.0". Other users can use their bit output methods to confirm this feature, or do some network packet streaming to capture the UPnP output.
For the ultimate proof, your ears will certainly tell you if the music is 'sweet as sally' or 'corrupted with digital demons' (trademark). For your ears sakes, if you test with 5.1 files...please start at a low volume or risk an immediate case of tinnitus (it's that bad).
P.S. Could someone post a link to this in the general Oppo BDP-83 user's forum? I was banned from that forum for being 'disruptive' and perhaps questioning too persistently. @Moderators: sometimes stubborn people can be useful.Update from Oppo
Oppo's statement regarding fact that surround is possible but limited by "LPCM header channel interleaving bit assignment processing bug":
We will take a look at your observations and have the engineers investigate them.
Note that I was pressing Oppo to commit to fixing this bug. Their response falls short but in developer speak it's mild encouragement. Call or email Oppo if you want to mildly (or otherwise) encourage them (beer offers never hurt).