Plex doesn't always read media with multiple channels as anything other than stereo

[BrianKitt]

Server Version#: 4.74.2
Player Version#: 4.74.2

I use the same Handbrake settings on all media. I see this happen from time to time.
The media:

But when I look at it in Plex, it only sees it as 2 chanel stereo.
I play the media by itself, and it clearly has surround sound. However, when I play it in Plex, it only has Stereo.
I have all 4 Matrix shows, all 4 ripped from BR with the same Handbrake profile, 2 have surround, 2 only are stereo.

I’ve done the plex dance twice, I’ve re-ripped the 2 that have no surround. I’m at a loss.

<MediaContainer size=“1” allowSync=“1” identifier=“com.plexapp.plugins.library” librarySectionID=“1” librarySectionTitle=“Movies” librarySectionUUID=“eccfc4aa-daee-4031-8d27-f20b879509a5” mediaTagPrefix="/system/bundle/media/flags/" mediaTagVersion=“1643696096”>

…tag removed…

<Media id=“423032” duration=“7755936” bitrate=“4165” width=“1920” height=“800” aspectRatio=“2.35” audioChannels=“2” audioCodec=“aac” videoCodec=“h264” videoResolution=“1080” container=“mp4” videoFrameRate=“24p” optimizedForStreaming=“0” audioProfile=“lc” has64bitOffsets=“0” videoProfile=“main”>

<Part accessible=“1” exists=“1” id=“504061” key="/library/parts/504061/1645033540/file.m4v" duration=“7755936” file=“I:\Movies2\M\The Matrix Revolutions (2003)\The Matrix Revolutions (2003).m4v” size=“4422580912” audioProfile=“lc” container=“mp4” deepAnalysisVersion=“6” has64bitOffsets=“0” indexes=“sd” optimizedForStreaming=“0” requiredBandwidths=“14522,12841,10807,8339,7468,7232,5892,5892” videoProfile=“main”>

<Stream id=“1066592” streamType=“1” default=“1” codec=“h264” index=“0” bitrate=“4004” bitDepth=“8” chromaLocation=“left” chromaSubsampling=“4:2:0” codedHeight=“800” codedWidth=“1920” colorPrimaries=“bt709” colorRange=“tv” colorSpace=“bt709” colorTrc=“bt709” frameRate=“23.976” hasScalingMatrix=“0” height=“800” level=“40” profile=“main” refFrames=“4” requiredBandwidths=“14360,12680,10646,8178,7307,7071,5743,5743” streamIdentifier=“1” width=“1920” displayTitle=“1080p (H.264)” extendedDisplayTitle=“1080p (H.264)”> </Stream>

<Stream id=“1066593” streamType=“2” selected=“1” default=“1” codec=“aac” index=“1” channels=“2” bitrate=“161” language=“English” languageTag=“en” languageCode=“eng” audioChannelLayout=“stereo” profile=“lc” requiredBandwidths=“161,161,161,161,161,161,161,161” samplingRate=“48000” streamIdentifier=“2” displayTitle=“English (AAC Stereo)” extendedDisplayTitle=“English (AAC Stereo)”> </Stream>

<Stream id=“1324704” key="/library/streams/1324704" streamType=“3” codec=“srt” language=“English” languageTag=“en” languageCode=“eng” format=“srt” displayTitle=“English (SRT External)” extendedDisplayTitle=“English (SRT External)”> </Stream>

</Part>

… remainder removed…

[FordGuy61]

1. What is the multi-channel audio format you chose in Handbrake? AC3, EAC3, etc.

2. What does MediaInfo show for the files?
   If possible, include the Text View of one of the problematic files.

3. Try ripping the disc with MakeMKV. It will not transcode the video or audio like Handbrake. It copies the tracks unchanged from the disc.
   Does Plex pick up the audio?

[BrianKitt]

Here is the Media Info, and the Handbrake audio section.
I may not have worded my process clearly, but I use MakeMKV to Rip, then Handbrake to compress.
I did all 4 discs the same. I don’t understand why 2 worked and 2 did not.

Media

• Duration 2:09:15
• Bitrate 4165 kbps
• Width 1920
• Height 800
• Aspect Ratio 2.35
• Video Resolution 1080p
• Container MP4
• Video Frame Rate 24p
• Web Optimized No
• Audio Profile lc
• Video Profile main

Part

• Duration 2:09:15

• File The Matrix Revolutions (2003).m4v

• Size 4.12 GB

• Audio Profile lc

• Container MP4

• Indexes sd

• Web Optimized No

• Video Profile main

• Codec H264

• Bitrate 4004 kbps

• Bit Depth 8

• Chroma Location left

• Chroma Subsampling 4:2:0

• Coded Height 800

• Coded Width 1920

• Color Primaries bt709

• Color Range tv

• Color Space bt709

• Color Trc bt709

• Frame Rate 23.976 fps

• Height 800

• Level 4.0

• Profile main

• Ref Frames 4

• Stream Identifier 1

• Width 1920

• Display Title 1080p (H.264)

• Extended Display Title 1080p (H.264)

• Codec AAC

• Channels 2

• Bitrate 161 kbps

• Language English

• Language Tag en

• Audio Channel Layout stereo

• Profile lc

• Sampling Rate 48000 Hz

• Stream Identifier 2

• Display Title English (AAC Stereo)

• Extended Display Title English (AAC Stereo)

• Codec SRT

• Language English

• Language Tag en

• Format SRT

• Display Title English (SRT External)

• Extended Display Title English (SRT External)

  "AudioList": [
    {
      "AudioBitrate": 160,
      "AudioCompressionLevel": 0,
      "AudioEncoder": "av_aac",
      "AudioMixdown": "stereo",
      "AudioNormalizeMixLevel": false,
      "AudioSamplerate": "auto",
      "AudioTrackQualityEnable": false,
      "AudioTrackQuality": -1,
      "AudioTrackGainSlider": 0,
      "AudioTrackDRCSlider": 0
    },
    {
      "AudioBitrate": 0,
      "AudioCompressionLevel": 0,
      "AudioEncoder": "copy:ac3",
      "AudioMixdown": "none",
      "AudioNormalizeMixLevel": false,
      "AudioSamplerate": "auto",
      "AudioTrackQualityEnable": false,
      "AudioTrackQuality": -1,
      "AudioTrackGainSlider": 0,
      "AudioTrackDRCSlider": 0
    }
  ],

[FordGuy61]

Thanks for the additional info.

I do not see the AC3 audio in the MediaInfo analysis, meaning there is no AC3 audio in the file.

This looks like a Handbrake configuration or processing issue.

Am I missing something?

Look through the Handbrake logs to see if it missed the audio track for some reason. Search for “audio track” in the log file.

Also, as a test: a) Analyze the MakeMKV rip with MediaInfo. Is the AC3 audio visible? b) If so, make a test movie library in Plex and add the MakeMKV rip. Does Plex see the AC3 audio track?

@BrianKitt

Web Optimized No

If you have not done so, choose Web Optimized on the Summary tab in Handbrake. This re-arranges some bits in the MP4 headers. The client has to buffer less data before playing the video. Google “MP4 Fast Start” for details. Not critical, but a “nice to have.”

[BrianKitt]

Why is it that Windows still thinks it’s a 6 channel media? When I play it in Windows (using VLC), it appears to be surround sound.

I will work on this tomorrow and get back to you.

[FordGuy61]

@BrianKitt

Why is it that Windows still thinks it’s a 6 channel media?

Yeah. I can’t reconcile those differences.

However, if MediaInfo does not see the audio track, I doubt Plex will see it either.

You might try dropping the MakeMKV rip into a Plex library, to make sure Plex sees the source file OK.

[BrianKitt]

I’ve been doing more research. I am finding many dozens of videos, same thing.

VLC shows them as surround sound. (some 5 channel, some 6, some 7, some 8)

Plex says they are only 2 channel stereo.

I downloaded an app called ‘MediaInfo’. It has definitely found 2 audio streams in this file. So there is clearly a bug in Plex scanner, where Plex scanner is not seeing the second audio stream.

I am willing to upload this video somewhere if you want to use it for debugging.

[FordGuy61]

You can upload it to dropbox, etc then PM me the link. Click on my username, then choose Message.

Also, let’s look at the Plex logs. See if they show anything.

1. Make sure your server is set for debug level logs.
   Settings → Server_Name → General
   Check the box for debug logs.
   Do not check the box for verbose logs.
   Save Changes if needed.

2. Plex Dance the movie (so the logs will capture adding it to the system).

3. Wait for Plex to finish re-scanning the movie, downloading metadata, etc.
   Pull the log files: Settings → Troubleshooting → Download Logs.
   Attach the ZIP file to the thread.

[Volts]

Slightly interesting, but probably not related to the root problem:

The MediaInfo screenshot of The Matrix Revolutions (2003).m4v you provided shows two audio streams - 2 channels AAC and 6 channels AAC.

But the Handbrake preset snippet above should produce two streams - 2 channels AAC, and the original AC3 Passthru.

I suspect the screenshot wasn’t produced using that preset.

[OttoKerner]

Please show the complete Plex media XML info of an affected file. Don’t remove anything out of it or cut parts off.

[FordGuy61]

So is the second audio stream supposed to be AC3 5.1 or AAC 5.1?

FYI, the forum does not support XML attachments. Save the file as .txt or zip it before attaching to the thread.

[OttoKerner]

The dance should not be needed. Start with triggering “Analyze” on the item.

[BrianKitt]

I started the analyze on this one item only, more than an hour ago, and it’s still running.
I noticed that Plex has started a full library scan. A full library scan takes about 10 hours or so. I’m going to have to come back to this in the morning. Sorry.

[Volts]

@BrianKitt

A full library scan takes about 10 hours or so

!!!

Is the library very very very large? Hundreds of thousands of items?

Or is it stored on floppy drives, and connected over dialup?

That’s astonishingly slow.

Can you share a little bit more info?

[BrianKitt]

This is not relevant to the topic, but I’ll answer it.
It used to take an hour, but after the last major update, it went from ‘1 hour’ to now 10 to 12 hours.

I agree, it’s horribly slow. After the last update, Plex is almost unusable, and it’s honestly now a piece of crap. I have nearly 1,000 unmatched or mismatched movies because of the new scanner logic. I could give a list of at least a dozen bugs I have found on the new release.
But I’m living with it hoping that the developers will fix it soon.

[BrianKitt]

Scanner logs and XML
250743.xml.txt (59.2 KB)
Plex Media Scanner Matcher.log (6.1 KB)
Plex Media Scanner Analysis.log (9.4 KB)

[Volts]

That looks normal to me. Maybe @OttoKerner can see something else. The XML clearly has both streams. The first stream is AAC 2.0, the second is AAC 5.1.

Though again - it’s not AC3. If your encoding goal was AC3 passthru, check that out. I wonder too - you might prefer to make the multichannel stream the first and default stream, to help clients choose that one.

<Stream id="1066593" streamType="2" selected="1" default="1" codec="aac" index="1" channels="2" bitrate="161" language="English" languageTag="en" languageCode="eng" audioChannelLayout="stereo" profile="lc" requiredBandwidths="161,161,161,161,161,161,161,161" samplingRate="48000" streamIdentifier="2" displayTitle="English (AAC Stereo)" extendedDisplayTitle="English (AAC Stereo)"></Stream>
<Stream id="1379540" streamType="2" codec="aac" index="2" channels="6" bitrate="384" language="English" languageTag="en" languageCode="eng" audioChannelLayout="5.1" profile="lc" samplingRate="48000" streamIdentifier="3" displayTitle="English (AAC 5.1)" extendedDisplayTitle="English (AAC 5.1)"></Stream>

What appears on the movie information / pre-play screen? Does it only show a single audio option? When Plex sees multiple audio stream options, it should be YELLOW and possible to choose which is played.

Do you see the same behavior in different clients? Plex Web, vs. whatever set-top or mobile players you might use?

[Volts]

I just noticed that the second stream does not have requiredBandwidths calculated.

That’s interesting - I wonder if it indicates a problem with the file/stream, and if it could be contributing to the “only one stream option” problem.

Can you share a sample file?

[BrianKitt]

Holy cow, it now works??? I now see the 5.1

I haven’t recoded this stream for a couple of days. I have done the plex dance on it twice, making sure to empty the media, and making sure it’s no longer there. I even made sure the media id increments when it loads it back in.

Nothing worked. But it now has 5.1

Wow.

I don’t mean to be insulting, but Plex has become VERY unstable. It has become VERY unreliable.

At any rate, I guess what I need to do is go to my media that is not showing 5.1, and just continue to do Analyze until it works? Not sure what else to say?

I’ve spent a lot of hours trying to get this one to work, and it just magically started working.

I don’t know what to say.

Thank you so much for looking into it, it appears we are just chasing Plex ghosts.

[Volts]

Hahahah lol well, good.

Heisenbug! It changes when you look closely at it!

I’m wondering if the very-slow-scans could be related to some underlying problem, that could be impacting other operations. Gigantic database or database errors?

I want to encourage you to share the full server log package.