Some questions of audio and passthrough

Hdmi 1.4 to smart tv.
And a toslink to a reciever dts acr
Type yamaha rx-v440 rds
Dts Es, dd digital, pcm, capable.

I started a mkv container acr3 5.1 yatse audio info shows dolby digital h.264.

Audio setting default HDMI and spdiff. Aml-mesonaudio:hdmi, s/pdif&analogue
Watching i noticed i lost the speach track. Englisch and other languages. When i turned on my reciever.
So i enabled some passthroughs for spdiffs.
Passthrough audio device aml-mesonaudio,hdmi blabla.
Enabled ac3 suitable device
Don’t know if E-ac3 can be set
DTS suitable enabled.
TrueHD not i think to new for my oldy.

And all the tracks where there again.
Means passthrough works.

Sofar so good.
One tiny issue.
My HDMI audio on the TV is gone(that good). Same as my volume remote of the vero remote and my yatse.(thats bad)

Does this mean that i have to switch off for normal remote and tv audio and the passthrough on when i encounter a audio decoding problem when i turn on the reciever?.

I understand “pasthrough” concept.
That’s plain sent digital audio info through optical toslink undecoded or touched.
So no more HDMI output. But the audio level cant be controlled by vero remote anymore eihter.
(checked by shutting down reciever to see if hdmi picked up audio al all.)
Nope. Restart movie didn’t provoke hdmi audio eihter.

So my old cubox did support remote control of volume in spdiff output in kodi.
(now it frozen at 94%)
(before i set reciever at 40 and controlled sound bij phone remote yatse.)
Which is great in music playing without needing tv or remote of the reciever…
Which i didn’t test now, mp3 stereo(music) isn’t dts or so so that should be handled as self coded and thus volume control by yatse or vero remote.

So question: Am i right in my conclusions or do i miss a clue in settings?
(i am as thorough as possible in providing information.)
Is this on purpose or a “flaw” or a “error”?

Thanks for any info.

Edit tested music and then remote works by kodi volume.
Mp3 2.0 works on mpeg4
DD 2.0 not.
IT states a fixed volume presentage. 84% or 93% what ever i set volume in kodi béfore i start the movie. I tested 47% (lowering from 93%) and started movie again it freezes on that level.
So it seems to be a “flaw/error” in the userinterface for controling sound.

Kodi has two methods it uses to control volume. The first, if it sees it is connected to a CEC connected amplifier device type it will send a CEC control command when the volume functions are issued through it. Note that most TV’s will not advertise themselves this way so it normally only works this way when you have an HDMI attached soundbar or full AVR. When this is how you are working then volume control and passthrough work just fine together.

If you don’t have the previous type of setup then the volume commands in Kodi will lower the PCM volume level to lower the volume. When you have passthrough turned on it is send unmodified so there is no volume control effectively for audio being send this way. Anything not being sent via passthrough, such as music, is being output via PCM so volume control works for that content.

The OSMC remote does not have the ability to act as a universal type remote such that it could send volume signals directly to your AVR so in this type of situation with a non CEC AVR it may be preferable to switch to a different type of remote.

You may also find additional details in the following guide…

I read that before i posted.
My reciever don’t have HDMI support.
So i am bound to optical spdiff.
The Libreelec kodyv17 and nighlybuilds v19 was set up the same without passthrough enabled. So PCM as you call it, was always in volume control.

In my former setup that wassn’t the case either.

My first question is why do i need to enable passthough in order to get all soundtracks hearable?
From audio hardware config.
You will be able to play stereo LPCM and will most likely be able to play DTS and DD 5.1 surround (but not DTS-MA or TrueHD) depending on your amplifier’s capabilities.

Tested and true. (not dts-ma and tureHD yet.)

Optical is hardcoded levels as zero and one. So you can’t ad volumelevels by turningdown signal.
This means that my former setup did a decoding DTS, and DD-EX (in this case) set volume by PCM and coded it back to optical output. Right?

I have to investigate more about what is invoking passthrough necessity.(due loss of sound by losing tracks or data.)

Stereo mp3 and 2.0 mpeg4 are analoge and does be recoded as optical signal through the toslink with PCM control.

My firts thought is that my libre elec shell had a more extended decoding DD, DTS and recoding of sourcesound to spdiff optical toslink.
This kept control on the PCM volume. (don’t know about quality losses)

Maybe i reconnect the cubox start the same movie and see which settings there are and how it shows in the reciever display.

All and all interesting :yum:

So I think it’s clear, the OSMC remote can only control AVR volume through HDMI (CEC).

Kodi can only control the volume of LPCM signals. So non-passthrough formats like mp3, aac and any you tell kodi your AVR can’t handle are decoded by Kodi to LPCM and the volume control should work.

S/PDIF can’t handle multi-channel LPCM so you will not be able to get multi-channel audio with volume control.

I’m not quite clear on the other distros’ capabilities. It’s just possible you could tell kodi your AVR does not handle DTS, only DD, and by turning on ac3 transcoding the volume might work on the LPCM as DTS is converted to LPCM then DD (ac3). But I’ve never tried that.

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I’ve played with those settings (with OSMC) and what happens is that anything other than AC3 gets volume control, but sources with AC3 don’t as that format is sent unmodified. I’m pretty sure I also spent some time looking to see if there was some viable workaround to make Kodi act different and came up empty.

It is all zero’s and ones. The main distinction here is that PCM is kind of like a large raw data file and AC3 and DTS use compression (think MP3 file) to be able to squeeze six channels into the same amount of space. When you turn on passthrough Kodi is literally just passing along those zero’s and ones without touching them at all, hence, why you loose the ability to control volume via Kodi’s internal source volume control mechanism.

Everything that is not already PCM or being sent via passthrough is getting decoded from its original format and then converted to PCM. Any device with a digital input can only understand certain formats and PCM is the most universal. There is no standard for transmitting a mp3 or AAC file so it must be converted. Also, I don’t think you understand what the word analog means because a mp3 file is pretty far removed from analog.

There is a loss of quality when you do this. whether this is noticeable or not is going to vary from person to person.

The long and short of it is that in your situation without changing hardware to get surround sound your best bet is to enable AC3 and DTS passthrough along with AC3 transcoding and then leave Kodi’s volume turned all the way up and don’t ever use the volume buttons on the OSMC remote. This means that to change the volume you need to use the remote for your receiver. If your not a fan of having more that one remote then getting a universal remote would be the way to go.

Sorry wrong frase of words
i ment it’is already 2 channel audio so no conversion needed to the TV (HDMI) to give stereo sound.
any file on pc is digital sampled. only a LP and a table and a preamp and (plain)reciever would be analog. :slight_smile:
i ment it’s run through a kind of “fax like handsake” to transport it to the reciever by optics. all duck in a row with control front and back.

this would be the endresult i am afraid.
The volume percentage is only effecting music and other non passthrough audio coding.
the passthrough is completely volume of “recording” and sampling of the movie container.
(i think i set up tomorrow my old kodibox. just to see what’s different and why.)
in volume and reciever icons.

on the “good site” passthrough modes is much more “clear” and better 5.1. and it shut down TV audio at ones.
new batteries in the old remote and go.
Just need to find the ideal split in this.
mp3/ 2.0 mpeg AAC vs DTS DD-EX and such.
try out True HD.

i do have a drawer full of them!
i use:
Yatse mobile phone for master edit library and switching audio and sub tracs, or info of movieactors.
my reciever remote (type of sound rendering and volume)
my veroplus remote plain select start stop for less techisch in the house.
tv remote to switch inputpoort and audio level if needed.
One remote does always seems to have empty battery’s: the get me a beer please button doesn’t work properly i think it needs rewiring, when i press that button the room gets colder… :thinking:


first the old system.
passthrough was off, tested numeral spdiff passthrough non worked.
(my reciever did decoded it as spdiff 2.0 L—R to semi 5.1PCM)

no passthrough enabled.
So that question is answered, it has a software “passthrough” 2.0 PCM audio no matter which source.
then the veroplus

The dolby digital-ex 6.1 or 7.1. source.

and a DTS 5.1 movie:

So real passthrough. better!
i think i have all capable coding checked as passthrough:

DTS-HD (?) not sure, true HD probably not.

(edit: e-AC3 no sound so no decoding by my reciever.)

And for people who has recievers which can connect to internet… (wifi/ maybe bluetooth don’t know.)
Yatse has a option for that.

not a rxv440dts that’s too old i am afraid.

anyway sound is sorted out, new knowledge gained.
one question remains, say i find a nice reciever HDMI 2.0 (4K capable) dts dd-ex true-hd 5.1 6.1 for a great bargain would the HDMI cover the decoding of audio to the surroundset? or do i need still spdiff?

HDMI does everything S/PDIF does and more. Lots more.

You need to uncheck DTS HD and E-AC3 for passthrough as a Toslink connection does not have enough bandwidth to carry them at full quality. You might find some sources in those formats that will work as they have been tweaked to a smaller size, but your not really getting anything extra quality wise at that point over just passing the core formats.

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I have a similar older system…Yamaha HTR5650 AVR, Yatse , Vero4K

The Vero is connected to the display using HDMI.
There is a TOSLINK cable from the display’s SPDIF output port to the Yamaha’s SPDIF input.
Vero’s system audio is set to HDMI-SPDIF, 2.0 channels, passthrough is ON, DTS-MA and TrueHD are disabled.
Dolby Digital 5.1 ,and DTS 5.1 surround works just fine…DTS-MA and TrueHD tracks are converted to 5.1.

I use a Harmony universal remote to control volume. Yatse will not control volume in this configuration.

Yatse does have plugins to control network capable receivers…but I do not recommend them.
You can get network lag on the Yatse volume control. You will be turning up the volume using Yatse plugin, but it can be delayed. Next moment you are way too loud and have blown a speaker driver.

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