same problem on the C1

FLAC 2.0 works
FLAC 5.1 plays but dialogue channels missing
TRUEHD 2.0 works
TRUEHD 5.1 broken, does not play
PCM 5.1 plays but dialogue channels missing, same as FLAC

this also happens when using DLNA direct play, so it must be an LG issue?

I suspect I ran into the same issue, tried playing video with FLAC 2.1 and got no sound whatsoever.

its an weird, no idea why 2.0 works but not 2.1

I'm seeing the same problem om my C3. Perhaps we should consider FLAC to be broken on webOS so that it gets transcoded? Would that be done in this repo or in jellyfin-web?

I'm seeing the same problem om my C3. Perhaps we should consider FLAC to be broken on webOS so that it gets transcoded? Would that be done in this repo or in jellyfin-web?

I would prefer it if FLAC stereo audio could continue to be played back without transcoding, because that does work reliably and is a popular format for music as well (almost all of which is stereo). If it isn't feasible to distinguish between stereo FLAC and >2 channel FLAC audio streams, then it's probably better to just transcode it in general.

opus audio streams are also affected by this issue in my experience. I don't think that was mentioned yet.

I've just been doing some investigating, and it seems very inconsistent. I can't get FLAC > 2 channels to work properly at all, but even if I transcode it to something else it doesn't seem to want to play properly. Even AAC 5.1 files aren't playing properly if they are in an external file and need to be muxed in. Due to this I think there might actually be something else going on than just FLAC being broken with more than 2 channels.

I've got some Opus 5.1 videos that play fine if the files are muxed in, but not if they are in a separate file, and others where they don't play properly even if muxed in.

The code for determining if a format is supported or not doesn't seem to be able to take the number of channels into account, so without refactoring quite a bit, it doesn't seem possible to distinguish them for transcoding.

It might be worth mentioning that I'm using jellyfin 10.8.13, not the latest nightly, so maybe (hopefully) some of this has already been resolved.

I have the same problem with FLAC 5.1/7.1. Audio is very quiet missing the center channels.

My receiver is connected through ARC (not eARC) which I think only supports 5.1 sound through (E)AC3. Certainly not PCM 5.1.

According to jellyfin audio is direct play so not sure how my LG GX handles it. I assume it transcodes before passing it through ARC, and somehow ignores channels >2.

A solution would be to force transcode to dolby digital.

I'm not sure at all, but I think AAC 5.1 is handled OK by LG webos and is direct played, so this is also an option, but i would have to check this.

Edit: tested with the stable jellyfin docker image (10.8.x), maybe 10.9 solves it?

10.9 doesn't solve it. I'm very confused as to what exactly is going wrong here, as if I play the exact same audio file as music from JF, it does play with the correct number of channels, when it doesn't as part of a video. I've also got an example of AAC and Dolby Digital not playing correctly, so I don't think it's necessarily entirely due to codec.

I'm a bit stumped as to how to go about fixing this. The first step would be to find out exactly when the issue occurs, as that isn't known yet. Does anyone know of a way to generate test audio files with different codecs and channel configurations? Then we could test them alongside different video codecs and container formats to see exactly when it does wrong. From there we might be able to deduce what the exact issue is, and (hopefully) fix it within Jellyfin. Otherwise it might be down to LG to fix.

For the sake of completeness and to determine a common root cause. I encountered the problem with a FLAC 7.1 track. I'm pretty sure I had it with FLAC 5.1 too but I can't confirm.

Media info:
Container: mkv
Video: HEVC Main 10 (HDR10)
Audio track 1: Italian - DTS-HD MA 6.1
-> auto-transcoded to AAC and works perfectly (Denon receiver gets a Dolby Digital 5.1 signal through ARC)
Audio track 2: English - FLAC 7.1
-> quiet sound, missing center channel (receiver gets a stereo signal)

I have the bug that the audio tracks are out of order (fixed in 10.9 I think). The media info displays information about the selected track (e.g., track 2), but the other track is played (e.g., track 1).

When I turn off the receiver then the TV also outputs quiet audio for the FLAC track, so I assume we can rule out ARC. Although the receiver is still connected, it shouldn't have any impact.

The problem remains the same when I enable "Prefer fMP4-HLS Media Container".

I did want to modify src/scripts/browserDeviceProfile.js in jellyfin-webos and disable flac for web0s (line 128), but I'm using the jellyfin docker image which has a compiled version of Jellyfin-web. Anyone know if I can just drop a single modified file into /jellyfin/jellyfin-web/src/scripts/browserDeviceProfile.js in the container to override it, or do I need to compile everything from scratch with npm install, ... (and mount the jellyfin-web folder)?

After some experimenting, it seems flac >2.0 is just not supported by webos.

flac is only mentioned for 2 channels on:
https://webostv.developer.lge.com/develop/specifications/video-audio-60
and even not mentioned at all in the video table, so no bug but a LG 'feature'.

I fiddled around with jellyfin-web and managed to disable flac support. It now transcodes automatically to aac which works perfectly. Of course, ideally transcoding should only happen for flac >2.0 (and as flac 2.0 is popular for music).

As a sidenote, I also suspected ARC as that should only support < 1 Mbps for audio (flac is between 800kpbs to 1.8 Mbps), but manually transcoded AAC@1.2Mbps still seems to work (or LG does its own transcoding before pushing it over the ARC).

@ilmc888 did you have to edit the web client itself or was it some kind of configuration option you could pass to force transcoding?

I modified the jellyfin-web folder (part of the jellyfin server). In src/scripts/browserDeviceProfile.js

 if (format === 'flac' || format === 'asf') {
     if (browser.tizen || browser.web0s || browser.edgeUwp) {
        return false; //true;
     }

seems to work. Then compile and mount the dist/ folder inside the jellyfin container.

I also saw the following lines:

videoAudioCodecs = videoAudioCodecs.filter(function (c) {
    return (options.disableVideoAudioCodecs || []).indexOf(c) === -1;
});

Not sure where options.disableVideoAudioCodecs comes from, but perhaps you can define it in config.json in the root web folder. I don't know javascript, but adding something like:
"disableVideoAudioCodecs": ['flac']

Not sure where options.disableVideoAudioCodecs comes from

It comes from here (needs to be added as you wrote):

At the same time, audio codec can be granularly disabled for AudioChannels > 2 using ApplyConditions in CodecProfile (in browserDeviceProfile.js).

Question.
Does FLAC 2.1/5.1 work as music?

You can get some samples from https://github.com/sfiera/flac-test-files

Or you can test this by extracting audio track from the video file. Then place it in the library which handle audio files: Music (not sure since it tries reading metadata), Home Video and Photos, Mixed Movies and Shows (I use this).

Yes, FLAC 5.1 does work as music.

Yes, FLAC 5.1 does work as music.

Isn't that strange? LG webos then supports FLAC 5.1, except if it is in a video container?

I will see if I can test FLAC 5.1 music later (I can try both the given tracks as well as extracting from the video container to rule out any issues with the audio track).

It is indeed very strange. That's part of why I think that FLAC isn't the root cause of this issue. The other reason is that I've got some other video files with other, non-FLAC, formats that have the same issue. I can send the examples in private if you would like them for experimentation.

Unfortunately, I can not confirm normal playback as a music file (Music library) on my setup (ARC). I get the same behavior as before.

For surround51.flac I only get the "Front left" and "Front right" messages (no center, LFE, and back channels). My receiver also indicates a stereo signal. The same is true for the flac extracted from the video container.

With AAC transcoding I do get the full 6 channels. In that case,I also see that my receiver gets a Dolby digital plus signal so I'm fairly sure webos transcodes the AAC track to EAC3, but apparently fails to do so properly for FLAC 5.1. Given that, transcoding to (E)AC3 instead of AAC might make sense for ARC setups to avoid double transcode and loss of detail.

Extra, I did see the surround51.flac file was encoded as 5.1(side) using sox. I converted it to standard 5.1 using ffmpeg and also tested the audio track of the video in 5.1 and 5.1(side) but with the same results.

ffmpeg -i file for two test files of about 7 I tested:

Input #0, flac, from 'surround51.flac':
  Metadata:
    Comment         : Processed by SoX
  Duration: 00:00:12.00, start: 0.000000, bitrate: 212 kb/s
  Stream #0:0: Audio: flac, 48000 Hz, 5.1(side), s16

Input #0, flac, from 'extracted.flac':
  Metadata:
    encoder         : Lavf60.16.100
  Duration: 00:08:20.00, start: 0.000000, bitrate: 1832 kb/s
  Stream #0:0: Audio: flac, 48000 Hz, 7.1, s16

Edit, worth mentioning that I switched to jellyfin 10.9 (well, master) a couple of days ago.

@FintasticMan Could you please re-test surround5.1.flac and tell me if you hear all channels or just "Front Left" and "Front Right"?

@dmitrylyzo Interestingly, for that file I can only hear Front Left and Front Right. Other 5.1 FLAC files however do play all channels correctly when played as music. Some info that might be useful: my Sonos app shows that the files that do play correctly are Dolby MAT 5.1, and surround51.flac is PCM 2.0.

For further testing, it might be easier to chat on Matrix or Discord (I'm @FintasticMan:matrix.org on Matrix and @FintasticMan on Discord)

Some info that might be useful: my Sonos app shows that the files that do play correctly are Dolby MAT 5.1, and surround51.flac is PCM 2.0.

Could it be that in the case of Dolby MAT 5.1 it is Dolby Atmos (?) encoded in FLAC? So FLAC is just a container. What does ffprobe say?

For further testing, it might be easier to chat on Matrix or Discord (I'm @FintasticMan:matrix.org on Matrix and @FintasticMan on Discord)

Maybe. It's more persistent (documented) here. 🤷
It's more convenient to use chat for troubleshooting though.

ffprobe only mentions that it's FLAC. It is in a Matroska (mka) container. I extracted it from a video affected by this issue. So when it is played in a video container, it only plays 2 channels (Sonos shows PCM 2.0), but when extracted, muxed into an audio container and played as music, it plays all channels (Sonos shows Dolby MAT 5.1).

@dmitrylyzo I've just muxed the surround51.flac into an mka container, and now it does play all the channels!

Could you paste the output of ffprobe (or ffmpeg -i file.mka) of the file that isn't working?

surround51.flac, only plays front left and front right channels:

Input #0, flac, from 'surround51.flac':
  Metadata:
    Comment         : Processed by SoX
  Duration: 00:00:12.00, start: 0.000000, bitrate: 212 kb/s
  Stream #0:0: Audio: flac, 48000 Hz, 5.1(side), s16

The same file, in an mka container, that does play all the channels:

Input #0, matroska,webm, from 'surroundtest.mka':
  Metadata:
    encoder         : libebml v1.4.5 + libmatroska v1.7.1
    creation_time   : 2024-05-22T11:40:03.000000Z
  Duration: 00:00:12.00, start: 0.000000, bitrate: 216 kb/s
  Stream #0:0: Audio: flac, 48000 Hz, 5.1(side), s16 (default)
    Metadata:
      BPS             : 212169
      DURATION        : 00:00:12.000002784
      NUMBER_OF_FRAMES: 141
      NUMBER_OF_BYTES : 318254
      _STATISTICS_WRITING_APP: mkvmerge v81.0 ('Milliontown') 64-bit
      _STATISTICS_WRITING_DATE_UTC: 2024-05-22 11:40:03
      _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES

It seems so far like any FLAC file can be made to play all channels by muxing it into an mka container. This only works for music though, I haven't tried remuxing my video with FLAC audio yet into different containers.

What a weird behavior. 😅
I wonder what if you mux some video + surround51.flac into MKV? Will it work? 🤔

For now, we've blocked FLAC with >2 channels in video.

Funnily enough, I can confirm :)

I remuxed surround51.flac using
ffmpeg -i surround51.flac -c copy surround51.mka

    Input #0, matroska,webm, from 'surround51.mka':
      Metadata:
        COMMENT         : Processed by SoX
        ENCODER         : Lavf60.16.100
      Duration: 00:00:12.00, start: 0.000000, bitrate: 213 kb/s
      Stream #0:0: Audio: flac, 48000 Hz, 5.1(side), s16
        Metadata:
          DURATION        : 00:00:12.000000000

In the Music library of Jellyfin, surround51.flac only outputs stereo (left and right front). surround51.mka gives me all channels and my Denon receiver indicates dolby digital. I assume it takes a different processing path in LG webos (where mka is still seen as video by webos?).

I'm using the v10.9.z branch (with the changes of #5452 included).

Putting it into a video doesn't work.

Input #0, matroska,webm, from 'Big Buck Bunny (2008) - test.mkv':
  Metadata:
    title           : Big Buck Bunny, Sunflower version
    encoder         : libebml v1.4.5 + libmatroska v1.7.1
    creation_time   : 2024-05-22T14:04:49.000000Z
    MOVIE/COMMENT   : Creative Commons Attribution 3.0 - http://bbb3d.renderfarming.net
  Duration: 00:10:34.53, start: 0.000000, bitrate: 8010 kb/s
  Stream #0:0: Video: h264 (High), yuv420p(progressive), 3840x2160 [SAR 1:1 DAR 16:9], 60 fps, 60 tbr, 1k tbn (default)
    Metadata:
      BPS             : 8002640
      DURATION        : 00:10:34.534000000
      NUMBER_OF_FRAMES: 38072
      NUMBER_OF_BYTES : 634743440
      _STATISTICS_WRITING_APP: mkvmerge v81.0 ('Milliontown') 64-bit
      _STATISTICS_WRITING_DATE_UTC: 2024-05-22 14:04:49
      _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
  Stream #0:1: Audio: flac, 48000 Hz, 5.1(side), s16 (default)
    Metadata:
      BPS             : 212169
      DURATION        : 00:00:12.000000000
      NUMBER_OF_FRAMES: 141
      NUMBER_OF_BYTES : 318254
      _STATISTICS_WRITING_APP: mkvmerge v81.0 ('Milliontown') 64-bit
      _STATISTICS_WRITING_DATE_UTC: 2024-05-22 14:04:49
      _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES

I've also tried muxing it into an mp4 container, and that for some reason doesn't play any audio at all??

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Big Buck Bunny (2008) - test2.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf60.3.100
    comment         : Processed by SoX
  Duration: 00:10:34.57, start: 0.000000, bitrate: 8011 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 3840x2160 [SAR 1:1 DAR 16:9], 8002 kb/s, 60 fps, 60 tbr, 60k tbn (default)
    Metadata:
      handler_name    : GPAC ISO Video Handler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](und): Audio: flac (fLaC / 0x43614C66), 48000 Hz, 5.1(side), s16, 212 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]

You are mixing streams with different duration in one container. Is that a problem for jellyfin or webos?

You could specify -t 12s to make video and audio equal?

Funnily enough, I can confirm :)

I remuxed surround51.flac using ffmpeg -i surround51.flac -c copy surround51.mka

    Input #0, matroska,webm, from 'surround51.mka':
      Metadata:
        COMMENT         : Processed by SoX
        ENCODER         : Lavf60.16.100
      Duration: 00:00:12.00, start: 0.000000, bitrate: 213 kb/s
      Stream #0:0: Audio: flac, 48000 Hz, 5.1(side), s16
        Metadata:
          DURATION        : 00:00:12.000000000

In the Music library of Jellyfin, surround51.flac only outputs stereo (left and right front). surround51.mka gives me all channels and my Denon receiver indicates dolby digital. I assume it takes a different processing path in LG webos (where mka is still seen as video by webos?).

I'm using the v10.9.z branch (with the changes of #5452 included).
,

OK, seems jellyfin is transcoding the surround51.mka to aac. That's why it works.

Surround51.flac is direct played.

That is quite an important observation! I'm sorry for not noticing that myself 😅

I've just tested with jellyfin/jellyfin-web#5452, and while it almost seems to work with videos, the OS seems to be downmixing it to 2 channels... and discarding the subwoofer channel. The Sonos app shows PCM 2.0 and the rear left and rear right channels are definitely not playing from the rear speakers.

I also created a couple of videos based on surround51.flac and just a black screen for video:

Keeping the surround:

ffmpeg -f lavfi -i color=c=black:s=640x480 -i surround51_flac.flac -c:v libx264 -shortest -c:a copy surround51_mkv.mkv 

ffmpeg -f lavfi -i color=c=black:s=640x480 -i surround51_flac.flac -c:v libx264 -shortest -c:a copy surround51_mp4.mp4 

For both, audio is transcoded to aac and plays perfectly.

Downmixing to stereo:

ffmpeg -f lavfi -i color=c=black:s=640x480 -i surround51_flac.flac -c:v libx264 -shortest -c:a flac -ac 2 surround20_mkv.mkv 

ffmpeg -f lavfi -i color=c=black:s=640x480 -i surround51_flac.flac -c:v libx264 -shortest -c:a flac -ac 2 surround20_mp4.mp4 

The whole file is direct played and I can hear all channel shoutouts, but obviously it is played as stereo so, e.g., the back channels are played by the front speakers. This wasn't tested yet for the PR, but so video with 2.0 FLAC is processed correctly.

I think this is all according to expectation and solves the problem for me, but happy to test some things for others (otherwise this can be closed).

Note, the difference between surround51.flac (not ok) and surround51.mka (ok) is probably because jellyfin takes different transcoding paths for music vs video? Where mka/mkv/matroska are all seen as a video container regardless of the streams it contains, and also ignoring the fact both files are played as Music in jellyfin (no transcode for music files as is for the plain flac, aac transcoding for video files as is for the flac embedded in mka). Just making some assumptions here.

Are you sure the first one works correctly? Running the exact same command gives me the issue I described above (no subwoofer audio and downmixed to 2.0).

The mkv one? Yes, that does work correctly as well as the mp4 one. The audio is transcoded to aac because of the patch of @dmitrylyzo . Are you running without the patch?

You can download the files from wetransfer if you want to test:
https://we.tl/t-l4KAWHYf0V

I used Ubuntu's ffmpeg (not ffmpeg-jellyfin):
ffmpeg version 6.1.1-3ubuntu5

I am using the latest version of jellyfin-web, with the patch, so it is transcoding to AAC. Testing with your files shows the same as my testing.

I tested some of those Dolby 5.1.2 atmos test files (E-AC3), I have no idea how to check if my Denon receiver still gets an atmos signal. I do get all channels (but I only have a 5.1 setup).

On the other hand, I finally figured out that I can get more info (signal / audio format) in the web interface of Denon. AAC 5.1 audio is received as Dolby digital 5.1, so LG webos indeed transcode it.

This of course rises the question whether we should directly transcode to (E-)AC3 (instead of AAC) on the jellyfin side to avoid an extra webos transcode. In that case, the client should detect ARC and set an enabledARC / enabledEARC variable?

I've been redirected here from the Jellyfin chatroom, seems like I have an LG webOS related audio issue too.

My setup:
-Jellyfin Server 10.9.3 on Ubuntu VM,
-LG C3 TV (webos) running Jellyfin client app from the webos store
-Samsung Q990C soundbar connected via to TV's eARC and audio set to passthrough

I noticed recently that .mkv videos with Dolby Vision (DV/HDR10) will result in remuxing and I’m able to see the “Dolby Vision” badge appearing on the LG tv, which is a very welcomed improvement.

However, it seems like this potentially introduced quite a few audio issues whenever it remux .mkv DV media:

1. The audio is either very soft or not audible at all (tested both on the TV internal speakers as well as the samsung soundbar)
2. The audio format shown on the samsung Q990C soundbar’s tiny display is STEREO PCM, which is very weird as the media files have 6 audio channels. I’m able to reproduce this issue with various EAC3, Dolby Digital Plus, Dolby Atmos media files. The expected soundbar display should be DOLBY DIGITAL/MULTI CHANNEL PCM/DOLBY ATMOS etc instead of just STEREO PCM.

I have tested non-DV media files with the exact same setup and the audio level sounds normal, with the audio format displaying correctly on the soundbar.

Here's an example with mediainfo:

When playing this media, the Dolby Vision and Dolby Atmos via Sound bar badge appears on the top right of my LG C3 TV, however my Samsung Q990C soundbar shows the audio is STEREO PCM.

Mediainfo of the media file:

General
Complete name                            : media[DV HDR10Plus][EAC3 Atmos 5.1][h265].mkv
Format                                   : Matroska
Format version                           : Version 4
File size                                : 5.11 GiB
Duration                                 : 52 min 4 s
Overall bit rate                         : 14.0 Mb/s
Writing application                      : mkvmerge v79.0 ('Funeral Pyres') 64-bit
Writing library                          : libebml v1.4.4 + libmatroska v1.7.1

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5@Main
HDR format                               : Dolby Vision, Version 1.0, dvhe.08.06, BL+RPU, HDR10 compatible / SMPTE ST 2094 App 4, Version 1, HDR10+ Profile B compatible
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 52 min 4 s
Bit rate                                 : 13.5 Mb/s
Width                                    : 3 840 pixels
Height                                   : 1 600 pixels
Display aspect ratio                     : 2.40:1
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.091
Stream size                              : 4.90 GiB (96%)
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : Display P3
Mastering display luminance              : min: 0.0001 cd/m2, max: 1000 cd/m2
Maximum Content Light Level              : 409 cd/m2
Maximum Frame-Average Light Level        : 162 cd/m2

Audio
ID                                       : 2
Format                                   : E-AC-3 JOC
Format/Info                              : Enhanced AC-3 with Joint Object Coding
Commercial name                          : Dolby Digital Plus with Dolby Atmos
Codec ID                                 : A_EAC3
Duration                                 : 52 min 4 s
Bit rate mode                            : Constant
Bit rate                                 : 576 kb/s
Channel(s)                               : 6 channels
Channel layout                           : L R C LFE Ls Rs
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 SPF)
Compression mode                         : Lossy
Stream size                              : 215 MiB (4%)
Language                                 : English
Service kind                             : Complete Main
Default                                  : Yes
Forced                                   : No
Complexity index                         : 16
Number of dynamic objects                : 15
Bed channel count                        : 1 channel
Bed channel configuration                : LFE

and the playback info that's shown on TV:

Playback Info
Player Html Video Player
Play method Remuxing
Protocol http
Stream type Video

Video Info
Video resolution 3840x1600
Dropped frames 0
Corrupted frames 0

Remuxing Info
Video codec HEVC (direct)
Audio codec EAC3 (direct)

Original Media Info
Container mkv
Size 5.1 GiB
Bitrate 14,6 Mbps
Video codec HEVC Main 10
Video bitrate 14.0 Mbps
Video range type DOVIWithHDR10
Audio codec EAC3
Audio bitrate 576 kbps
Audio channels 6
Audio sample rate 48000 Hz

TLDR; I suspect the recent update that remuxes Dolby Vision mkv files has somewhat negatively affected the audio portion, reducing it to just Stereo somehow.