MrMC

I have many AAC 5.1 that work just fine in my setup... davilla is our resident audio and video guru, post your debuglog and lets see what he can fish out from it

AAC would get converted to PCM, is your speaker setup to 5.1 configuration?

No Amp handles AAC 5.1 via HDMI. It will be decoded to PCM by MrMC. The number of channels you get will depend on the number set in settings/audio. So if set to 2, you get two, if 5.1, you get 5.1 but the also depends on your amp handling multichannel PCM. You could also transcode AAC 5.1 to DD 5.1 and send that.

mikehadfield wrote:Have checked all the settings. The config is set to 5.1 in MrMC.

But something you have mentioned has given me a thought. My amp is connected to the TV using the Audio Return Channel HDMI. This is because I have a number of apps on the TV (an LG 4K Smart TV) that I need the audio output coming out via the amp.

The FireTV connects to one of the HDMI ports on the TV, so the signal is being sent via the ARC to the amp. So, is it possible that the TV is not sending multichannel PCM via ARC-HDMI?

yep, think of ARC has an optical port. It does not have the bandwidth to handle multichannel PCM.

easy to test , plug it in direct

mikehadfield wrote:Yes, going to try that when I can get the TV to myself for half-an-hour!

when this happened, I bought another TV just for myself

davilla wrote:No Amp handles AAC 5.1 via HDMI. It will be decoded to PCM by MrMC. The number of channels you get will depend on the number set in settings/audio. So if set to 2, you get two, if 5.1, you get 5.1 but the also depends on your amp handling multichannel PCM. You could also transcode AAC 5.1 to DD 5.1 and send that.

This reminds me of another question... Is transcoding to Dolby Digital always to 5.1, regardless of the number of channels set under Settings/Audio? Because it says the # of channels is ignored by passthrough, but the transcoding option is only enabled when # of channels is set to 2. I presume this is just to force transcoding to a SPDIF- or HDMI ARC-compatible format, rather than reflecting the actual number of channels being decoded at the other end?

I guess the user interface just seems a little backwards to me - since one has to enable DD passthrough first to even enable transcoding, I would think turning transcoding on would disable the channel # setting as ignored and irrelevant, since *all* audio would become DD and passed through.

Thanks...

yea, audio settings are a bit confusing. linux devs going nuts and offering too many options DD/DTS passthrough is always 2 chan even though you get out 5.1. Something we eventually hope to clean up.

davilla wrote:yea, audio settings are a bit confusing. linux devs going nuts and offering too many options DD/DTS passthrough is always 2 chan even though you get out 5.1. Something we eventually hope to clean up.

No problem, just wanted to confirm. Much of my IT career was spent translating between developers and users, since they rarely understood each other.

So, since DD transcoding is always to 5.1, does it include automatically upmixing stereo sources to DD 5.1? Or are they just encapsulated as the right and left channels of a DD 5.1 signal (I think that's technically different than an actual DD 2.0 signal)? And if they are upmixed, does that mean the "Stereo Upmixing" setting is actually ignored when DD transcoding is enabled?

Thanks...

jbennett wrote:

davilla wrote:yea, audio settings are a bit confusing. linux devs going nuts and offering too many options DD/DTS passthrough is always 2 chan even though you get out 5.1. Something we eventually hope to clean up.

No problem, just wanted to confirm. Much of my IT career was spent translating between developers and users, since they rarely understood each other.

So, since DD transcoding is always to 5.1, does it include automatically upmixing stereo sources to DD 5.1? Or are they just encapsulated as the right and left channels of a DD 5.1 signal (I think that's technically different than an actual DD 2.0 signal)? And if they are upmixed, does that mean the "Stereo Upmixing" setting is actually ignored when DD transcoding is enabled?

Thanks...

I'd have to check.