High-Res FLAC Audio (w. Multi-Channel) - a frustrating adventure

General Discussions Plex Features
, , ,
1

I am trying to (again) get High-Res Audio working in my Plex setup, streaming locally high-res (e.g. 24/96-192 or Multi-Channel 24-96-192 Audio to any Plex client that will do this properly.

Setup 1 (NVIDIA Shield)
PMS (4.62) --> NVIDIA Shield (Plex App) --> HDMI --> Surround Processor (Emotiva XMC-1)
Set HDMI Passthrough.

Setup 2 (PMP)
PME (4.6.2) --> PMP Windows (2.41.0.1010) --> HDMI --> Surround Processor (Emotiva XMC-1)
PMP is configured with 5.1 channels, exclusive mode, no normalization via HDMI.

Setup 3 (Chromecast Audio)
PME (4.6.2) --> Chromecast Audio --> Optical --> Surround Processor (Emotiva XMC-1)

Files:
24-192 Stereo FLAC
24-96 Stereo FLAC
24-192 Multi-Channel (5.1.) FLAC

Experience of 24/192 Multi-Channel FLAC on PMP:
This USED to work. I swear. E.g. the receiver would get 24/192 multi-channel audio.
Now Plex transcodes. Dashboard: ā€œUnknown (PCM 5.1) > OPUSā€”Transcodeā€.
The receiver shows 24/48khz Multi-Channel.
While I am happy to GET multi-channel, there is no reason for it to be transcoded down to 24/48.
Again: this same file used to play without transcoding. Bandwidth is plenty and not the issue.

Experience of 24/192 Stereo FLAC on PMP:
Similar to above I get (Dashboard): ā€œUnknown (PCM Stereo) OPUSā€”Transcodeā€, which leads to 24/48 fed to the receiver. Why transcode??
This is true with all Stereo files that are 96 or 192 kHz. Again, this used to work without transcoding against PMP client. The main reason I kept a second computer around with PMP beside the Shield was the ability to listen to high-resolution files via PMP.

Experience of 24/192 Multi-Channel FLAC on NVIDIA (Plex App)
Nothing. I get in the error log something like: [TranscodeOutputStream] Session appears to have died from under us.
Hmmm. Why would this die, when the transcoder is fine transcoding the same file with a PMP client (see above).
I get that transcoding is necessary. since NVIDIA says as well that with Plex it can only support 6-channel audio up to 48kHz max.

Experience of 24/192 Stereo on NVIDIA FLAC (Plex App)
This boggles my mind: Dashboard says it streams ā€œUnknown (Stereo)ā€, e.g. direct to the NVIDIA Shield. However Plex App on the NVIDIA seems to downgrade to 24/48, since the receiver shows only that quality. why that suddenly?
It should be stated that I can successfully stream using Qobuz via NVIDIA Shield (using Chromecast protocol) 24/192 music. Thus itā€™s not the NVIDIA Shield or the connection/setup with my receiver. Itā€™s in the Plex chain.

Experience of 24/192 Stereo on NVIDIA FLAC (Casting via Chromecast using Android App):
Exactly the same as Experience of 24/192 Stereo on NVIDIA (Plex App).
E.g. it says ā€˜directā€™ but that does not seem to be right.

Now letā€™s test some 24/96 files:

24/96 Stereo on NVIDIA Shield via Chromecast Audio Protocol (controlled from Plex Android App):
Dashboard says: Unknown (FLAC Stereo)
works w. 24/96. Nice.

24/96 Stereo on NVIDIA Shield via Casting to Plex for Android (controlled from Plex Android App):
Dashboard says: Unknown (PCM Stereo) Direct Play.
No sound on the receiver. Nada. No error in Console.

24/96 Stereo on NVIDIA Shield (via Shield Android App):
Dashboard says: Unknown (PCM Stereo) Direct Play.
However no sound to the receiver. Nada. No error in Console.
Why would the same file be identified differently in the Dashboard because the target app is different?

This is beyond frustrating.

In summary:
High-Res used to work without transcode at least against PMP (Windows). Does not anymore.
Trying to get high-Res files to work within the Plex ecosystem is a gamble. Multi-channel high-res is a no-no (used to work). Things work (a bit) better via Chromecast protocol.

Happy to replicate and provide log files if engineers are interested.

Robert.

5 Likes
2

Letā€™s try to understand a stereo case on PMP like this, which is less complicated.
I need to be brought up to speed on your hardware and what it can do.

Please describe your PC. You said that is has HDMI output?
If thatā€™s the case, what level of HDMI is it?

My computer only has an optical digital out that is limited to passing though AC3 and DTS.

Is your receiver capable of telling you itā€™s getting FLAC at 24/48 (not bothering with 192 yet)?
So you can put a FLAC file on a USB stick and insert it into the receiver and play it?
What is the method you use if not a USB stick to send an encoded FLAC to the receiver where it tells you itā€™s getting a FLAC and is responsible for decoding it.

Sorry for the gory questions, as Iā€™m just trying to get the big picture.

If you want to jump ahead of me and grind through some advanced topics,
search the website for articles about mpv.conf

Start working on debug log files for player and server showing just the 24/48 FLAC output succeed.

3

Thanks for chiming in, appreciated.

And I will dig into mpv.conf a bit further.

In the meantime see some answers to your questions:

  • The receiver is capable of showing channel count and sample rate and source type (e.g. PCM, DTS etc).
  • The receiver and computer support HDMI 1.4.
  • The receiver is capable from factory to handle multi-channel PCM High-Res (should be up to 24/192)
  • There is no direct file playback from a USB stick available on the receiver. Thus have to connect via HDMI or USB/Optical (I am using HDMI). All content (Video, Audio) is sent via HDMI from my computer.
  • The computer is a NUC-type (though ASUS branded) small form factor PC, Celeron Processor, 4GB Mem, running Windows 10.
  • See attached the HDMI configuration in Windows on the Playback machine (using PMP) which shows all the supported formats as reported by the receiver via HDMI: up to 8 channels, up to 24/192. Plus DTS-HD etc etc.
    PMP%20HDMI%20out%20capabilities
    PMP%20HDMI%20out%20capabilities400Ɨ455 9.64 KB

For Stereo:

  • The Receiver is capable of handling 24/192. See screenshot of streaming a High-Res Qobuz file @ 24/192 (via NVIDIA Shield) with the receiver overlay on the TV which shows the bit-depth and -rate (highlighted). When the source resolution switches the receiver follows suit and updates the shown bitrate/depth.

    192%20nvidia%20qobuz
    192%20nvidia%20qobuz943Ɨ530 80.6 KB

  • I am not playing directly a FLAC file to the receiver (though it supports it). I am using a FLAC file as a source on the PMS, to stream to PMP and assume that it decodes to PCM (which is what the receiver then reflects).

  • See a screenshot showing the successful streaming with the PC with PMP for a FLAC audio file which is in 24/96. This works fine. So 24/48 and 24/96 does not need trouble-shooting I assume.

    96%20pc%20pmp
    96%20pc%20pmp943Ɨ530 77.9 KB

  • Playing a 24/192 stereo file, I see the following:
    ā€“ The Server (via Dashboard) shows that it direct-plays the file.

    192%20stereo
    192%20stereo291Ɨ312 43.4 KB

    ā€“ The PMP client shows in the log file curiously the following: ā€œ[in] 96000Hz stereo 2ch s32ā€
    ā€“ Thus the client is getting transcoded content?
    ā€“ I checked the original file on the server and it is definitely 24/192.
    ā€“ Checking the log files on the server I see no associated entry in the transcoder log files for the playback.
    192%20pc%20pmp
    192%20pc%20pmp943Ɨ530 109 KB

  • on the PMP client I see as well entries in the log files that it enumerates through the supported bitrates/depths over HDMI (wasapi). It lists 24/192 as supported.

So for stereo the question is why HDMI clearly (see Qobuz from NVIDIA shield) support 24/192, yet between PMS ā†’ PMP ā†’ HDMI it downgrades to 24/96.

The value of high-resolution audio above 96kHz is another discussion that I think it outside the scope here. But if I have - and paid for - 24/192 audio content I would love to be able to play it back via Plex given that the hardware does supports it. Plex is actually a good audio player. It catalogs music great, I find lyrics useful, the UI is great etc).

Thanks, Robert.

1 Like
4

Ok that all looks good. Itā€™s fairly certain the PMP can decode a 24/192 FLAC into PCM,
and youā€™ve shown the cables and hardware supports it. Thanks.

Now letā€™s make a test case using PMP and get log files.

  1. Settings - General (lower one) - Show Advanced
  2. Check DEBUG logging (set it on)
  3. Uncheck VERBOSE logging (set this off)
  4. Click SAVE
  5. Settings - Debug - Debug Level - Enabled
  6. Click SAVE
  7. Quit out of PMP.
  8. Reboot the PMS hardware, and wait 10min.
  9. Start Playback
  10. Play 30 seconds or until failure
  11. Wait 30 seconds
  12. Settings - Troubleshooting - Download Logs
  13. Quit out of PMP.
  14. ZIP the entire server log folder it gave you, and attach it with your next post
  15. Grab the PMP log file. Directions are somewhere in the Log Files articles.
  16. Zip that and attach it too.

That series of reboots, waits, and quit makes for clean logs.
Might be something there.

5

Thanks for the instructions. Traveling right now - will assemble the info coming weekend.

6

Iā€™ve been unable to play any multichannel audio (flac, dts, etc) through Plex on Nvidia Shield for months now. Worked for years and now nothing. It works fine on PLex for Kodi though. When will Plex fix this? Itā€™s becoming very frustrating waiting and Iā€™m starting to feel very pessimistic that it will be fixed.

1 Like
7

@plexcapacitor please make a new topic for your issue, and use the post below as a guide
Thank you sir. That will help people help you much more effectively. How to get Help in the Forums

@robohofo whatā€™s the status of testing the method I described? Was I off the mark?

8

Was this resolved?

9

What I can tell you is that transcoding to multichannel FLAC is being discussed here.

Check it out.

1 Like
10

Thanks but the thread is unfortunately not helpful. Like the OP on this post, this USED to work - I swear.

11

Hi @nibbles: I sent a direct message with the relevant debug/log files.
Played back via PMP two high-res files with either stereo or 5.1 @ 24/184

Hope these help narrow down the issue.
Both played at 24/96ā€¦

12

I donā€™t do any multichannel FLAC audio, but I have plenty of 96kHz and 192kHz music files. With the Plex app on the Shield they get down converted to 48kHz. The Plex add-on in Kodi passes them through with no frequency change.

Using the Plex DLNA feature with my Denon receiver to play the high bitrate FLAC files, also plays them at their original bitrate.

Need a FLAC bitstream/pass through feature.

2 Likes
13

This USED to work, for years. Itā€™s been broken for months now. I wonā€™t renew my annual Plex Pass plus Tidal if it doesnā€™t get fixed.

14

I gave up on this with the Shield TV years ago as I have a large collection of 5.1 FLAC music. I think this would require effort from both PLEX and nVidia.

I use Vimeo or VLC to do this. Using a Windows PC works fine as well.

I also stream direct to my Pioneer SC-99 to take the Shield TV out of the loop. My Oppo BDP-203 can stream ANYTHING!

1 Like
15

I also own an XMC-1, two Nvidia shields and have also bitched about this not working for several years which has fallen on deaf ears for sure! I use mxplayer to stream my HiRes music resulting in the exact correct bitrate of the source. Plex and Emby BOTH downsample to 48Khz because beneath the GUIā€™s is ffmpeg.

1 Like
16

Hi I was away for Plex for a bit, my apologies that I left without replying to your mail. You PMā€™d me the log files, thanks.

While Iā€™d like to comment on how your system is handling hi res files, I canā€™t yet tell what itā€™s doing because your PMS is overcome by a missing audio track. The result when it canā€™t find the file is it repeats trying to find and analyze the file, non-stop, filling your logs and leaving an unstable system. Here is what I mean:

Nov 17, 2019 18:24:15.901 [0884] ERROR - Error opening file '"D:\Downloads\Movies\Otto 50 Jahre Disc 2\title_t03.mkv"' - No such file or directory (2)
Nov 17, 2019 18:24:15.901 [10800] DEBUG - Media Analyzer: Performing on-the-fly analysis on 1 item.
Nov 17, 2019 18:24:15.901 [10800] DEBUG - Job running: EAE_ROOT='\\?\C:\Users\HTPC\AppData\Local\Plex Media Server\Cache\Transcode\Sessions\EasyAudioEncoder' FFMPEG_EXTERNAL_LIBS='C\:\\Users\\HTPC\\AppData\\Local\\Plex\ Media\ Server\\Codecs\\395e79c-2735-windows-x86\\' X_PLEX_TOKEN='xxxxxxxxxxxxxxxxxxxx' C:\Program Files (x86)\Plex\Plex Media Server\Plex Media Scanner.exe --analyze --log-file-suffix " Analysis" --item 77818 
Nov 17, 2019 18:24:15.901 [0956] ERROR - Error opening file '"D:\Downloads\Movies\Otto 50 Jahre Disc 2\title_t03.mkv"' - No such file or directory (2)
Nov 17, 2019 18:24:15.901 [0956] DEBUG - Media Analyzer: Item 77818 is already in progress.

Fix these and anything similar.

Nov 17, 2019 13:22:13.463 [20868] ERROR - Error opening file '"D:\Downloads\Movies\Otto 50 Jahre Disc 2\title_t02.mkv"' - No such file or directory (2)
Nov 17, 2019 13:22:13.838 [15244] ERROR - Error opening file '"D:\Downloads\Movies\Offo 50 Jahre Disc 1\title_t00.mkv"' - No such file or directory (2)
Nov 17, 2019 13:22:13.854 [17248] ERROR - Error opening file '"D:\Downloads\Movies\Offo 50 Jahre Disc 1\title_t00.mkv"' - No such file or directory (2)
Nov 17, 2019 13:22:13.854 [21196] ERROR - Error opening file '"D:\Downloads\Movies\Offo 50 Jahre Disc 1\title_t00.mkv"' - No such file or directory (2)
Nov 17, 2019 13:22:14.151 [21332] ERROR - Error opening file '"D:\Downloads\Movies\Otto 50 Jahre Disc 2\title_t03.mkv"' - No such file or directory (2)

For fixing that, I guess you will have to Plex Dance the album.

As far as everyone still having the problem of music not being Direct Played, we should definitely keep perusing this against the most recent PMS beta. To do a good job, we need well crafted log files that express the issue. Anybody can follow these directions and post log files.

Iā€™m having temporary difficulties here recreating your problem because I need to upgrade my AV Receiver. I was going to grab the Wirecutter pick, which is a Denon AVR-X3500H but if someone has a good suggestion, please let me know. That Pioneer Elite SC-99 must be a treat, but itā€™s a bit more than Iā€™d like to spend. I just got finished making a Burr-Brown DAC with a Raspberry Pi for my old NAD with analog inputs. Thatā€™s off topic though.

Letā€™s start using for this thread two public hi-res test tracks from Headroom or somewhere that are 24/192 2ch and 5.1ch. That way the devs will have their own copies once we enumerate the issue. For video I use jell.yfish.us but for audio I donā€™t know where those are atm.

Thanks. I look forward to some clean logs and your suggestions.

17

Chiming in because Iā€™m new to the High Res music game. Iā€™ve been using Kodi and Plexkodiconnect or the Kodi Plex add-on to get my multichannel music to play. As I understand it, plex,(official app), has a video player and a music player. Two separate players depending on what youā€™re playing.
I do like the look of the Plex music player and it better supports multiple music libraries. (I keep multichannel and stereo separate).
I hope this gets addressed.

18

FLAC 5.1 definitely used to direct play through an nvidia shield to a Denon AVR. Iā€™ve just moved house and set up the surround system again and now Plex is sending stereo to the client. Absolutely gutted.

19

I have run into this problem too and am trying to play back a 5.1 channel .wav albumb. The Plex server says it is 5.1 PCM, when I play it in Kodi Plex I get multi channel but on the native Shield client it just plays in Stereo.

20

Same here but it also does not downmix the rear to the front. Iā€™m hearing only the left and right of the 5.1 mix. Itā€™s a messā€¦