[putashirton]

i am about to purchase an HDMI extractor, but i am hung up on something.

Panlong has two models I am looking at on amazon.
The first model has a switch with 3 positions, 2.0, 5.1, and passthrough.

"Panlong HDMI Audio Extractor Splitter v1.4 HDM"
This model has a switch with 2 positions. 5.1, and auto.

I don't really understand the difference between the 5.1setting and the passthrough setting so please correct me if i am wrong.
1.the pass through setting uses whatever information the PI sends to the reciever.
2. the 5.1 setting converts/downgrades whatever comes into the extractor to 5.1 audio.


Please help me make the appropriate choice. I don't know which setting to use.
-paso

[popcornmix]

From here I suspect the switch just modifies the EDID to report 5.1 capability or not.
I suspect it doesn't understand passthrough 5.1 audio itself - if it is received it just forwards it to optical - it doesn't decode it.

Kodi doesn't rely on the EDID (typically EDID reporting is poorly implemented and frequently wrong), so GUI settings determine whether 2.0/5.1/passthrough is output.
as such I believe the switch on this device will have effect with Kodi.

[putashirton]

From here I suspect the switch just modifies the EDID to report 5.1 capability or not.
I suspect it doesn't understand passthrough 5.1 audio itself - if it is received it just forwards it to optical - it doesn't decode it.

Kodi doesn't rely on the EDID (typically EDID reporting is poorly implemented and frequently wrong), so GUI settings determine whether 2.0/5.1/passthrough is output.
as such I believe the switch on this device will have effect with Kodi.

so are you saying the pass though setting is alli need (if i have a capable reciever)?
-paso

[popcornmix]

Assuming you are using the optical output and receiver is capable of DTS/AC3 passthrough then yes.
Set "number of channels" to 2.0 and enable passthrough and DTS/AC3 capable reciever options.

I suspect the switch in the splitter will have no effect with Kodi (which ignores the EDID), but you can try it both ways.

[putashirton]

Assuming you are using the optical output and receiver is capable of DTS/AC3 passthrough then yes.
Set "number of channels" to 2.0 and enable passthrough and DTS/AC3 capable reciever options.

I suspect the switch in the splitter will have no effect with Kodi (which ignores the EDID), but you can try it both ways.

The only thing i don't understand about this statement is why i would set the number of channels to 2.0 (on kodi or the machine)? why is this done
paso

[popcornmix]

The only thing i don't understand about this statement is why i would set the number of channels to 2.0 (on kodi or the machine)? why is this done

It changes the EDID so it reports either stereo or multichannel support.
Some devices (e.g. BluRay player) may use that information to determine whether to output stereo audio, or multichannel passthrough audio.

[putashirton]

The only thing i don't understand about this statement is why i would set the number of channels to 2.0 (on kodi or the machine)? why is this done

It changes the EDID so it reports either stereo or multichannel support.
Some devices (e.g. BluRay player) may use that information to determine whether to output stereo audio, or multichannel passthrough audio.

This still really doesn't make sense in that I thought that the passthrough allowed the reciever to decode the 5.1 multichannel (the reciever supports dts, DD), and not 2.0 stereo.

There is someone on the amazon review for one of the boxes who says

"Works well to send iTunes Airplay from a Raspberry Pi loaded with XBMC to external amplifier. Passes HDMI output to TV and the optical digital input of a Home Theater Receiver. Sends 44 MHZ stereo to receiver."

Does that mean i am only getting stereo to the reciever and not 5.1?

[noggin]

Assuming you are using the optical output and receiver is capable of DTS/AC3 passthrough then yes.
Set "number of channels" to 2.0 and enable passthrough and DTS/AC3 capable reciever options.

I suspect the switch in the splitter will have no effect with Kodi (which ignores the EDID), but you can try it both ways.

The only thing i don't understand about this statement is why i would set the number of channels to 2.0 (on kodi or the machine)? why is this done
paso

You set number of channels as 2.0 to avoid multichannel PCM (which can't be carried over optical) being output over HDMI by Kodi. Multichannel PCM can't be carried over a standard Toslink connection, so you want to avoid it.

Not all surround audio can be output as passthrough. Dolby Digital and DTS can, but AAC and FLAC can't for instance. If you play a file with 5.1 or 7.1 FLAC or AAC audio, then Kodi will decode this to PCM. If you have speakers set to 2.0 then it will output this as PCM 2.0 (which can be carried by Toslink), but if you set speakers to 5.1 or 7.1 it will instead output as PCM 5.1 or 7.1 (which can't be carried via Toslink). If you have 5.1 or 7.1 PCM over HDMI fed into an HDMI audio extractor then you may get no audio, just the front stereo pairs, some other combination, or a nasty noise. You won't get 5.1 or 7.1 PCM.

HOWEVER - there is also an option in Kodi to transcode to AC3 (it's below the AC3 passthrough option ISTR). This will allow you to replay AAC and FLAC 5.1 (and files like multichannel WAV or PCM or other non-bitstreamable over Toslink connections) and transcode them to 5.1 Dolby (aka AC3) (I think 7.1 will be down sampled to 5.1?) so you get multichannel still.

[noggin]

The only thing i don't understand about this statement is why i would set the number of channels to 2.0 (on kodi or the machine)? why is this done

It changes the EDID so it reports either stereo or multichannel support.
Some devices (e.g. BluRay player) may use that information to determine whether to output stereo audio, or multichannel passthrough audio.

This still really doesn't make sense in that I thought that the passthrough allowed the reciever to decode the 5.1 multichannel (the reciever supports dts, DD), and not 2.0 stereo.

There is someone on the amazon review for one of the boxes who says

"Works well to send iTunes Airplay from a Raspberry Pi loaded with XBMC to external amplifier. Passes HDMI output to TV and the optical digital input of a Home Theater Receiver. Sends 44 MHZ stereo to receiver."

Does that mean i am only getting stereo to the reciever and not 5.1?

EDID is the data sent by displays/amps to sources (like a Raspberry Pi 2 running Kodi). The TV will send an EDID block, and an Amp will add additional data to this EDID to add what audio formats it supports in addition to the TV.

As I understand it the HDMI audio splitter device you are looking at pretends to be an amp. It will either not do anything to the EDID (which I think is passthrough - and so if a source can send HD Audio or multichannel PCM it will - but things will then probably go wrong?) in case things go wrong with how it processes EDID, alter the EDID so that it only supports 2.0 (telling the source that it can only accept PCM 2.0) or that it supports 5.1 (telling the source that it can accept PCM 2.0, DD and DTS - but not HD Audio or PCM multichannel)

However as Kodi may ignore the audio support flagged in EDID this may make no difference if all the switch does is flag via EDID. However if the switch does other things to to the audio path, then it may still be important.

Not sure what the 'passthrough' option really helps you with - unless it is to avoid the EDID processing causing problems (which some AMPs do with some sources) - particularly if you can configure the source not to output audio formats that would cause problems with Toslink bitstreaming instead (so not need the EDID flagging to force the source not to output incompatible audio)

For reference :
PCM 2.0, DD, DTS (including ES) can be carried via Toslink.
PCM 5.1, 7.1 etc., Dolby True HD, DTS-HD MA and HRA can't be carried via Toslink.

[putashirton]

when you say set the number of channels to 2.0. is that On the extractor device or on kodi?

[popcornmix]

when you say set the number of channels to 2.0. is that On the extractor device or on kodi?

Kodi. You must *always* set number of channels to 2.0 when using toslink/optical.
It only supports two channels (but passthrough dts/ac3 can be carried through two channels).

We suspect the switch on the device is irrelevant when using kodi (but it's easy to try it both ways).

[fritsch]

It

means Toslink / optical.

[mistermaggi]

HOWEVER - there is also an option in Kodi to transcode to AC3 (it's below the AC3 passthrough option ISTR). This will allow you to replay AAC and FLAC 5.1 (and files like multichannel WAV or PCM or other non-bitstreamable over Toslink connections) and transcode them to 5.1 Dolby (aka AC3) (I think 7.1 will be down sampled to 5.1?) so you get multichannel still.

Hi there,

as it happens this is what I'm trying to accomplish at the moment, having Transcode switched on and hoping that the AAC sound 5.1 is transcoded to 5.1 AC3, but I still only get lpcm which doesn't work with my hdmi-toslink-splitter.
Is there another thing we need to check for this to work?

Thanks,

MisterMaggi

[mistermaggi]

Or to put it in a better way, Dolby Digital Transcoding is only available when having configured 2.0 channels.
When having set to 5.1 output channels, this item is not available.
So, there is no transcoding of 6 channel audio from AAC to AC3?

Thanks for getting that cleared up,

MisterMaggi

[popcornmix]

Or to put it in a better way, Dolby Digital Transcoding is only available when having configured 2.0 channels.
When having set to 5.1 output channels, this item is not available.
So, there is no transcoding of 6 channel audio from AAC to AC3?

Set number of channels to 2.0 if you want to transcode to AC3.
As has been said many times, DTS/AC3 passthrough is carries over 2 channels. You will still hear 6 channels when decoded.

It makes no sense to transcode when number of channels is set to 5.1 as you can output 6 channel PCM audio directly
(assuming you receiver accepts multichannel PCM - i.e. hdmi and not optical/toslink).