Sorry if this is a dumb question, but I searched the forum for LPCM and multichannel and didn't find anything about it.
Until 0.4.0rc1 dropped, I was using RaspBMC. My configuration there was to check true for "supports LPCM multichannel" or whatever that setting is. My receiver would display "MultiChannel" and 5.1 AAC files played perfectly (I have a good test file for this so I am 100% sure it was working properly).
Under Rasplex the checkbox for LPCM is missing entirely, and my 5.1 AAC plays in stereo. If PlexHT for Ubuntu supports LPCM, and RaspBMC (running XBMC 12.1) supports LPCM, why is it unavailable in RasPlex? Since the Pi isn't strong enough to transcode to AC3, I am plum out of luck for 5.1 AAC audio now, which is practically my entire library.
Sorry if this is a dumb question, but I searched the forum for LPCM and multichannel and didn't find anything about it.
Until 0.4.0rc1 dropped, I was using RaspBMC. My configuration there was to check true for "supports LPCM multichannel" or whatever that setting is. My receiver would display "MultiChannel" and 5.1 AAC files played perfectly (I have a good test file for this so I am 100% sure it was working properly).
Under Rasplex the checkbox for LPCM is missing entirely, and my 5.1 AAC plays in stereo. If PlexHT for Ubuntu supports LPCM, and RaspBMC (running XBMC 12.1) supports LPCM, why is it unavailable in RasPlex? Since the Pi isn't strong enough to transcode to AC3, I am plum out of luck for 5.1 AAC audio now, which is practically my entire library.
You last sentence makes no sense. There is no circumstance whatever when the transcoding is done by a Plex client, like RasPlex. Transcoding is always done by the PMS server, regardless of what platform you run that on (which you didn't mention here). And if the PMS platform is not powerful enough to transcode, then the media with incompatible CODECs can't be played.
I'll assume however that your PMS server could transcode the stream, but doesn't do so because RasPlex doesn't request it.
The CODEC-based transcoding decision of RasPlex is one of the features currently being worked on, so hopefully the next release will deal with this issue better than the current one does. But for the current version you should be able to get around the problem of failed transcoding by selecting one of the high quality bitrates instead of the "Direct Play" setting I assume you now use. With current implementation that should force all media to be transcoded, regardless of which original CODECs the media files contain.
I still can't guarantee 5.1 playback results though, since my own TV setup only has stereo speakers, so I've never tested 5.1 for real.
It's kind of an aside, but yes, XBMC does transcode AAC to AC3 on the client side if the "AC3 Capable Receiver" setting is checked. It's worked like that for a long time. It may be disabled in PlexHT, though I don't know why it would be. I assume it's just disabled on RasPlex, which is perfectly acceptable, given the processor limitations. But if you run XBMC on a regular Ubuntu install or something, it will absolutely transcode the audio client-side for you.
The problem here is that even on the Pi, XBMC (RaspBMC) was able to translate AAC 5.1 to LPCM multichannel with no issue. I don't believe that required transcoding. Now with RasPlex, which is ultimately an XBMC fork, that capability is gone; it's not even in the options anymore. I'm wondering what happened to it.
Another solution would indeed be to ask PMS to transcode the audio server side. That is what I will ask for if we can't figure out how to bring back multichannel audio output.
It's kind of an aside, but yes, XBMC does transcode AAC to AC3 on the client side if the "AC3 Capable Receiver" setting is checked. It's worked like that for a long time.
That may be, but the official info from the Plex team has always been that NO transcoding is ever done in any client.
I just based my reply on that 'party line'.
The problem here is that even on the Pi, XBMC (RaspBMC) was able to translate AAC 5.1 to LPCM multichannel with no issue. I don't believe that required transcoding. Now with RasPlex, which is ultimately an XBMC fork, that capability is gone; it's not even in the options anymore. I'm wondering what happened to it.
Well, the PC version of PHT does have an option related to LPCM, which is not included in the RasPlex port of the same PHT version, so presumably it was removed as such transcoding would be too much of a load on the RPi processor, reducing effective bitrate capability. As for the transcoding work involved, I'm not sure of all the details, but any difference at all in the encoding would require the processor to reshuffle sample bytes continuously, even if it is just a matter of reordering bytes without other alterations. And even that little would have a significant effect on the playback bitrate limit.
Another solution would indeed be to ask PMS to transcode the audio server side. That is what I will ask for if we can't figure out how to bring back multichannel audio output.
I think that's the only satisfactory way of dealing with all transcoding needs of 'weak' client platforms, such as the RPi.
Attempting to do it at the client end would only reduce the ability to play high bitrate media. (bad enough as it is :()
It is of course different for XBMC, which is intended as a stand-alone media player, thus having no server to do such work for it.
Even on a weak platform XBMC has no other choice but to handle everything locally.
I went back and looked at RaspBMC just to be sure. It does play the audio perfectly, but I don't see the option to enable multichannel in the Settings - it just does it, while RasPlex doesn't.
Also, I tried setting a bitrate in RasPlex to trigger server transcoding, I couldn't even get it to start playing. Not sure what the issue is there.
Also, I tried setting a bitrate in RasPlex to trigger server transcoding, I couldn't even get it to start playing. Not sure what the issue is there.
That could be due to the lack of a proper transcoding profile for RasPlex in the PMS Resources\Profiles folder. Perhaps you should discuss this with 'Longchair', who has been working on that stuff for the new releases.
