[mainerobinson]

Have you got passthrough selected?

Yes. Kodi's volume controls aren't locked out in either case and there's no discernible difference in sound quality. (I got the impression from the settings & the documentation that passthrough applies to AC-3 and DTS, but maybe not MP3?)

[nickr]

Yeah I get a bit confused when we start talking about music formats and passthrough.

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Such hostility towards new posters......

Que?

[mainerobinson]

Yeah I get a bit confused when we start talking about music formats and passthrough.

Right. This is all operating at a level somewhere over my head. Glad i'm not alone. What's not clear to me is why I can't just force all audio to passthrough, regardless of format. Must be missing something.

Such hostility towards new posters......

Que?

Did i get bashed and not even know it?

[mainerobinson]

Yeah I get a bit confused when we start talking about music formats and passthrough.

An admin over at OpenELEC (lrusak) stated that passthrough only applies to DTS, AC3, DTS-HD, TrueHD, and aac.

[noggin]

Yeah I get a bit confused when we start talking about music formats and passthrough.

An admin over at OpenELEC (lrusak) stated that passthrough only applies to DTS, AC3, DTS-HD, TrueHD, and aac.

Think AAC used to be included in XBMC as a pass through option - but people realised that it was a red herring, as no amps with AAC inputs existed, so it has been removed. (A few amps with WMA were available I believe - but not sure if they are still available and don't remember it being an XBMC pass through option.)

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Yeah I get a bit confused when we start talking about music formats and passthrough.

Right. This is all operating at a level somewhere over my head. Glad i'm not alone. What's not clear to me is why I can't just force all audio to passthrough, regardless of format. Must be missing something.

Passthrough is only an option for audio formats where passthrough standards exist. You can't passthrough an audio format if there isn't a SPDIF or HDMI protocol in place to carry it. There are far more audio codecs than there are that have passthrough support - so you can't passthrough all audio formats.

AIUI MP3, MP2, FLAC, ALAC and AAC aren't supported in SPDIF/HDMI for passthrough, whereas AC3, DTS, DTS HD HR/MA and Dolby True HD are (though only the first two via SPDIF). This is presumably because the latter are supported by DVD/Blu-ray, which are the driving forces behind home theatre amps.

Of course MP3, MP2, FLAC, ALAC and AAC can all be decoded losslessly to PCM in XBMC with no quality loss (assuming you can get native sample rate output) whereas many of the passthrough formats HAVE to be passed through as internal decoding isn't always possible.

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Yeah I get a bit confused when we start talking about music formats and passthrough.

Right. This is all operating at a level somewhere over my head. Glad i'm not alone. What's not clear to me is why I can't just force all audio to passthrough, regardless of format. Must be missing something.

Passthrough is only an option for audio formats where passthrough standards exist. You can't passthrough an audio format if there isn't a SPDIF or HDMI protocol in place to carry it. There are far more audio codecs than there are that have passthrough support - so you can't passthrough all audio formats.

AIUI MP3, MP2, FLAC, ALAC and AAC aren't supported in SPDIF/HDMI for passthrough, whereas AC3, DTS, DTS HD HR/MA and Dolby True HD are (though only the first two via SPDIF). This is presumably because the latter are supported by DVD/Blu-ray, which are the driving forces behind home theatre amps.

Of course MP3, MP2, FLAC, ALAC and AAC can all be decoded losslessly to PCM in XBMC with no quality loss (assuming you can get native sample rate output) whereas many of the passthrough formats HAVE to be passed through as internal decoding isn't always possible.

[mainerobinson]

Of course MP3, MP2, FLAC, ALAC and AAC can all be decoded losslessly to PCM in XBMC with no quality loss (assuming you can get native sample rate output) whereas many of the passthrough formats HAVE to be passed through as internal decoding isn't always possible.

@ noggin, thank you, that's incredibly helpful. When Kodi sends a PCM stream, do the volume controls work by multiplying the PCM values by some number? I've been expecting things to work somewhat like thru WASAPI, where computer-based volume controls are locked out.

[noggin]

Of course MP3, MP2, FLAC, ALAC and AAC can all be decoded losslessly to PCM in XBMC with no quality loss (assuming you can get native sample rate output) whereas many of the passthrough formats HAVE to be passed through as internal decoding isn't always possible.

@ noggin, thank you, that's incredibly helpful. When Kodi sends a PCM stream, do the volume controls work by multiplying the PCM values by some number? I've been expecting things to work somewhat like thru WASAPI, where computer-based volume controls are locked out.

Believe so - and when the volume is at 100% (I think) this is bit perfect.

[mainerobinson]

Believe so - and when the volume is at 100% (I think) this is bit perfect.

Interesting. So bit perfect output doesn't require locking out the system's audio controls. Best to turn up the volume to max, turn off menu sounds, and let 'er rip?

[noggin]

Believe so - and when the volume is at 100% (I think) this is bit perfect.

Interesting. So bit perfect output doesn't require locking out the system's audio controls. Best to turn up the volume to max, turn off menu sounds, and let 'er rip?

I think there will be a volume setting that is 'parity' i.e. no scaling of audio fed into it, so what goes in is what comes out. Think this is 100% but it might be some other figure.

[mainerobinson]

This is a dual boot with OpenELEC. I used the directions from the wiki to do it. The weird thing is, that switching between Chrome and OE worked for a few days and then it just started doing this. OE still works fine but still cannot get into Chrome. As mentioned before, it started happening prior to the release of OE 4.0.1 which I am currently running. Thanks

back up your OE/XBMC settings using the OE settings add-on, copy to USB, factory reset, reload OE dual boot, restore settings.

Bummer. OK will give it a shot. Thanks

@deathtical, did that solution work for your "639k of low ("DOS") RAM" problem? I'm having the same issue and am going to try a factory reset and a fresh install. However, I changed my boot options to default to OpenELEC after ~1 second with @matt Devo's awesome script. I can't get into ChromeOS to change it back (which the wiki suggests is necessary). Is there a way to SSH into OE and restore that boot option setting? Or can i proceed anyway? How did things work out for you?

Thanks in advance.

[Matt Devo]

@deathtical, did that solution work for your "639k of low ("DOS") RAM" problem? I'm having the same issue and am going to try a factory reset and a fresh install. However, I changed my boot options to default to OpenELEC after ~1 second with @matt Devo's awesome script. I can't get into ChromeOS to change it back (which the wiki suggests is necessary). Is there a way to SSH into OE and restore that boot option setting? Or can i proceed anyway? How did things work out for you?

Thanks in advance.

you both need to hit [CTRL-D] earlier, before SeaBIOS loads. That may mean before your display turns on, in some cases. There's no way to modify the boot flags from OE, since it involves reading/writing the firmware, and the tools to set the boot flags are only available under ChromeOS.

[mainerobinson]

you both need to hit [CTRL-D] earlier, before SeaBIOS loads. That may mean before your display turns on, in some cases. There's no way to modify the boot flags from OE, since it involves reading/writing the firmware, and the tools to set the boot flags are only available under ChromeOS.

Great, thanks. I think i've got it sorted out now.

[Meatwallet]

I apologize if this is the wrong place for this but I wasn't sure where to ask it. I just picked up the Asus Chromebox and love it so far. I would however like to upgrade the SSD and the ram before I really start dialing in Kodi. I'm currently running a dual boot setup. How big are people going with their upgraded SSD's? I was thinking 64 but the 128 isn't that much more, I'm just not sure if the 128 is going to be completely overkill or not. I plan on running 8gb or ram as well. Any help would be appreciated.

[Matt Devo]

I suspect most users are running OpenElec and simply streaming media from external sources, so have no need to upgrade the ssd

[Meatwallet]

I suspect most users are running OpenElec and simply streaming media from external sources, so have no need to upgrade the ssd

Thanks Matt. Maybe I will throw some extra RAM in it and be done with it. I appreciate all of your help!