[alexsisk]

Hi everyone,

Running Kodi v17 RC2 pushed out today, but this isn't totally new - I switched away from Jarvis when Krypton Beta 6 came out, and really the same question applies to Jarvis.

I searched the forum for a solid answer to this audio decoding question, but everything I find doesn't quite touch on what I'm looking for unless I missed it. (Very possible.)

I have the Nvidia SHIELD, and, according to Nvidia's "level 2" aka "escalation team" there is a known issue with audio passthrough that is only affecting certain customers (myself included). It was reportedly discovered early December, I guess because it's not affecting a large portion of the user base. (Plex passthrough fails, Android native video player passthrough fails, ES File Explorer Media Player passthrough fails.) Lucky me.

So with passthrough turned off, my DTS-HD MA / TrueHD capable receiver is of course only showing that it's receiving PCM.

Nearly my entire library is either DTS-HD MA or TrueHD ONLY; of course DTS-HD MA has the core built in, but TrueHD doesn't. A few files are AC3, which I'm guessing Kodi handles without issue within the software itself. I AM getting clearly discrete multi-channel audio with passthrough disabled in Kodi - I just don't know what the heck it is! W/passthrough enabled, it won't even play the file...it just gets stuck - again - known issue at Nvidia, only affecting a small group of unlucky folks. "Our engineers are working on it." kind of thing. Already tried different HDMI cables, ports, etc. Blu-Ray player bitstreams without issue to the same receiver.

I know that in Jarvis, there was a very clear statement in the changelog that support for DTS-HD MA 8-channel decoding received support, and it was also shown in the System Settings ---> Audio section.

The question: What IS Kodi passing via PCM to my receiver with passthrough off, as it sounds fairly decent and, but of course I don't get the format confirmation from my receiver when it's receiving unencoded audio of some sort.

Any insight is appreciated. Thanks!

[nickr]

It should be sending multi channel pcm directly decoding from the HD audio track. It should sound the same as passthrough unless you want Atmos or DTS:x

[fritsch]

The question: What IS Kodi passing via PCM to my receiver with passthrough off, as it sounds fairly decent and, but of course I don't get the format confirmation from my receiver when it's receiving unencoded audio of some sort.

We have lossless decoders of DTS-HD, TrueHD, AC3, DTS and many more. The only thing we currently cannot decode is the Atmos bits. in PCM mode kodi decodes these formats to a 32 bit float intermediate (lossless, large enough data format). Then we search for a output sink. On Android that is always Audiotrack. We open the required number of channels (be it 5.1 or 7.1 or 2.0) and transform the data to the output. This most likely a 16 bit format on Android (if precission is lost here - you won't hear it).

Your Debug Log will show this explicitely.

[da-anda]

without PT Kodi will do the decoding and send the multichannel audio bitperfect to the AVR. With PT enabled the AVR is handling the decoding. There should not be a difference in quality as it's all digital, so it should not matter who is decoding the stream.

edit: what fritsch said

[alexsisk]

It should be sending multi channel pcm directly decoding from the HD audio track. It should sound the same as passthrough unless you want Atmos or DTS:x

Thank you for your reply - that's what I'm trying to clarify, but do so 1000%. With libcadec, I believe it is, DTS Coherent Acoustics (aka standard DTS) and HD extensions....simple DTS-HD and DTS-HD MA, were supported. (Which I thought was odd, because DTS is big about charging for licensing.) Maybe it's because Kodi is non-profit. Anyway, straying off topic....

Nowhere have I seen anyone mention any library included that supports TrueHD decoding (again, not passthrough), and since I don't include AC3 in my MKV TrueHD files (SHIELD ----> receiver should technically handle it.....ugh)...why am I getting multi-channel discrete PCM? I have no idea what the receiver is ACTUALLY putting out, though some movies sound noticeably better than others.

[fritsch]

Post your Debug Log and what AVR you use. If you have ARC enabled with the TV / AVR - disable it.

[alexsisk]

The question: What IS Kodi passing via PCM to my receiver with passthrough off, as it sounds fairly decent and, but of course I don't get the format confirmation from my receiver when it's receiving unencoded audio of some sort.

We have lossless decoders of DTS-HD, TrueHD, AC3, DTS and many more. The only thing we currently cannot decode is the Atmos bits. in PCM mode kodi decodes these formats to a 32 bit float intermediate (lossless, large enough data format). Then we search for a output sink. On Android that is always Audiotrack. We open the required number of channels (be it 5.1 or 7.1 or 2.0) and transform the data to the output. This most likely a 16 bit format on Android (if precission is lost here - you won't hear it).

Your Debug Log will show this explicitely.

Perfect! I wonder why I see no mention of this (especially TrueHD) in the changelogs (all I see is that passthrough is now enabled.) - that's why I was confused. And then the line item saying "Support DTS-HD 8 Channel Decoding" having disappeared in Krypton further confused me. Atmos and DTS:X - I haven't heard yet, but I hear they're phenomenal. Unfortunately it's not in the budget to get a new receiver anyway at this time.

I wish there was perhaps some visual indication within the software that Kodi will "software-decode" these items with passthrough off in addition to the logs, but it's no biggie.

By the way, Nvidia level 2 tech support has been a bit shady - they said the issue is "because of your combination of hardware"...(it's a friggin Onkyo receiver, not an Emerson or Insignia or something) and that the device is reporting back that it can only handle 5.1 while the SHIELD TV is trying to send it 7.1. I have Kodi set to 5.1. My living room receiver is a 7.1 and it does the same thing, so I'm pretty confident they're lying to me.

[alexsisk]

Before you look at the log file, I just wanted to mention that it behaved differently than it ever has before...on TrueHD, it played the video file with audio, but didn't illuminate my Dolby TrueHD indicator on the receiver. I tried a DTS-HD MA track, and it played, but simply illuminated the DTS icon (Normally it says DTS-HD MSTR).

The Receiver is not high end, but it should be doing the job nonetheless, as it does with the Blu-Ray bit streaming. It's an Onkyo HT-R391 Receiver, which came in a HTIB package I bought my mom a few years back - she never used it.

Here is the logfile: http://paste.ubuntu.com/23721089/

I do not use ARC at all. Everything is HDMI ---> Receiver, Receiver----> TV.

[alexsisk]

The reason I was skeptical is that these companies (Dolby/DTS) charge licensing fees for decoding their audio, and I know Kodi is legit and above-board. Does Kodi have an agreement with them because Kodi is a non-profit organization or something?

[alexsisk]

Post your Debug Log and what AVR you use. If you have ARC enabled with the TV / AVR - disable it.

Thank you for your previous responses. I've supplied the requested info and done what you requested, @fritsch. Can you or anyone help me out with a definite answer?

The changelogs make it seem as though only pass-through audio has been enabled, but comments made by others as well as the phantom discrete audio with pass-through off would indicate software processing. With DTS, it could just be processing the Core. With TrueHD, it's not that simple (I don't have any AC3 tracks since my receiver is SUPPOSED to decode the HD formats. My files are almost all HEVC/DTS-HD MA or HEVC/TrueHD only) - yet it's playing something that sounds quite like discrete audio.

Does Kodi v17 RC2:
A) 110% FOR SURE, have built-in Dolby TrueHD and DTS-HD Master Audio decoders OR
B) no longer have these decoders built into the software with the new AE? I never saw mention of TrueHD, but DTS-HD MA was definitely in the Jarvis audio options.

If A is the case, GREAT! Since my SHIELD TV and Receiver don't want to cooperate on passthrough, at least I can know that the PCM indicator isn't just playing games with my ears.
If B is the case, that would explain the removal of the line item that was in Jarvis settings: "Support 8-channel DTS-HD decoding", but would not explain what the clearly discrete 5.1 audio I'm hearing with passthrough turned off actually is.

Again, not attempting to play Atmos or DTS:X at this time.

[fritsch]

kodi uses ffmpeg for decoding. So everything ffmpeg supports kodi supports. We don't implement a single dts / dolby / whatever decoder. You run android, there is no exclusive mode on the output. AudioTrack is free to resample / mix / alter everything you send through it without a kodi influence. If you want an audiophile system - don't use Android.

[alexsisk]

kodi uses ffmpeg for decoding. So everything ffmpeg supports kodi supports. We don't implement a single dts / dolby / whatever decoder. You run android, there is no exclusive mode on the output. AudioTrack is free to resample / mix / alter everything you send through it without a kodi influence. If you want an audiophile system - don't use Android.

I'm still a rookie, but I'm learning as fast as I can. I genuinely appreciate that you took the time to answer my question. Unfortunately, we're all noobs at one point or another.

Looks like ffmpeg decodes TrueHD and Core DTS. DTS-HD is listed next to "RAW" - I saw that somewhere while ago, either Jarvis or SPMC.
https://ffmpeg.org/general.html#Audio-Codecs

Trust me - I can't stand Android - I've never owned an Android device until the Nvidia SHIELD, and it's unbelievably buggy. Unfortunately, there's nothing within my budget that will allow me to save space with HEVC compression, and still have decent quality Video/Audio for $199. My desktop has a 2.6 GHz Haswell Core i5, and I can't afford an upgrade to a new Skylake (HEVC decoding) machine with the all the power and needs that go into a good HTPC. Hell, I was on a Raspberry Pi 3B 6 months ago.

If you hear of machine as powerful as the SHIELD TV for $199 USD or less, I have until 15 January to return it.

[fritsch]

It decodes all of them TrueHD, DTS-HD, DTS and so on - check the right column. First is encoding, second is decoding. The second is relvant for us.

Here: http://forum.kodi.tv/showthread.php?tid=...pid2485434 (You get a complete apollo lake solution for < 180 euro)

[alexsisk]

It decodes all of them TrueHD, DTS-HD, DTS and so on - check the right column. First is encoding, second is decoding. The second is relvant for us.

Here: http://forum.kodi.tv/showthread.php?tid=...pid2485434 (You get a complete apollo lake solution for < 180 euro)

Thanks Fritsch!

[alexsisk]

Here: http://forum.kodi.tv/showthread.php?tid=...pid2485434 (You get a complete apollo lake solution for < 180 euro)

Thanks to you for the recommendation, Fritsch!

I'm now the happy owner of a NUC6CAYH. I was completely unaware of the NUCs, but you had really really good timing telling me about them, since they were just about to release new models. Since the budget models like mine finally became powerful enough to use, I jumped at the chance and got the NUC6CAYH + a Crucial 8GB DDR3L 1866 MHz SODIMM Memory Kit (2 x 4GB) for a total of 218.98 USD... plus I had a spare 2.5" 1TB HDD already.