Problem with E-AC3 audio tracks

[madmox]

I read that in the previous messages in this topic so I've already tried that, but it didn't work for me. I have the exact same issue with VLC 2.2.8 (portable version), downloaded from here: https://get.videolan.org/vlc/2.2.8/win64/.

[napouser]

Try 2 .2.6 umbrella version

[madmox]

Same results with 2.2.6.

What's strange is that my AV receiver is supposed to support Dolby Digital Plus (E-AC3) through HDMI. So VLC should just be able to pass through the audio stream to the receiver, and it should decode it properly:

Supported Audio Formats
• 2-channel linear PCM (32–192 kHz, 16/20/24 bit)
• Multichannel linear PCM (up to 7.1 ch, 32–192 kHz, 16/20/24 bit)
• Bitstream (DSD, Dolby Digital, Dolby Digital Plus, Dolby TrueHD, DTS, DTS-HD High Resolution Audio, DTS-HD Master Audio)

Even if my AV receiver did not support E-AC3 (which is not the case), VLC should be able to stream the audio in multichannels PCM (possible with HDMI) instead of sending it in 2 channels PCM (which it does, since this is what my AV receiver picks up and scales to Dolby Pro Logic II to emulate surround sound), so the issue should never occur :/

[madmox]

I think I got something. At least I could find a configuration which solves my issue, even though it requires some "tweaking".

I observed that Windows Media Player does correctly pass through the Dolby Digital Plus stream (my AV receiver displays DD+ when I use Windows Media Player to play the file). So it's not a receiver issue nor the other players that silently reencode the stream to AC3.

I decided to try a few different advanced cofigurations:
- Audio -> force S/PDIF support: does not change anything
- Audio -> force detection of dolby surround: does not change anything

Then I tried to change all settings using the "DirectX audio output" module without any luck:


Finally I tried to switch the output module to "Windows Multimedia Device output". The default settings did not resolve my issue, but the following did:


With these settings, the audio stream is being correctly passed through to the AV receiver! You need to make sure you have selected the right output module ("Windows Multimedia Device output"), and set the "HDMI/SPDIF audio passthrough" option to "Enabled" (not "Enabled (AC3/DTS only)"). If you don't, VLC will not perform passthrough when the audio is E-AC3, and instead send a 2-channel PCM stream.

So, there might be a bug with the DirectX output module which makes VLC incorrectly guess the device's E-AC3 decoding capabilities.
But I still don't get why VLC sends a 2-channel PCM audio stream instead of a multi-channel PCM when it does the decoding itself, whether it be when this bug occurs or when passthrough is excplicitly disabled.

[TheBucketOfTruth]

I swear I had found a solution for this once before but am back again with the same issue. Maybe it was fiddling with the audio device before? Perhaps that was a different but similar issue with another codec. Running a five channel what's listed as a eac3 audio file paired with a H265 .mkv video file. Is there an issue with the codec and VLC? My receiver? I'm on Mac OS Catalina 10.15.7 and the latest VLC (updating didn't help). 15 inch MacBook Pro from 2018 running HDMI from my thunderbolt port. I have an Integra DTR-70.4 older receiver. 5.2 system and having that same issue where the dialogue is all being sent to the surround left speaker. Just screwed around googling and messing with all sorts of settings but nothing made a bit of difference. Did anyone find a permanent fix? Is this codec not compatible with VLC? I messed with quite a few things but some of the settings pictured above I wasn't sure where to go. Would be great if VLC preferences had a search function, but I scrolled through everything in the audio section. I've loved this app so much for so long and hate the idea that I would have to look elsewhere for a video player after all this time.

PS: Oddly enough I tested the same files on an old Late 2014 Mac mini running 10.13.6 and VLC 3.0.12 and it works just fine.

[oakprof]

I am also experiencing this issue. E-AC3 appears to become more and more ubiquitous, and struggling to play E-AC3 as AC3 is somewhat unfortunate.

Connection: S/PDIF from HTPC to receiver.
Surround sound not working: VLC (most recent version)

• The audio outputs as stereo.

Surround sound working: Windows Media Player

• The audio outputs as surround sound, so it is easy to assume that this can be made working in VLC as well.

It would seem that there is supposed to be a way for this conversion to work. Would something like this be suitable for VLC?

Is Dolby Digital Plus content backward-compatible?

Because Dolby Digital Plus is built on core Dolby Digital technologies, content that is encoded with Dolby Digital Plus is fully compatible with the millions of existing home theaters and playback systems worldwide equipped for Dolby Digital playback. Dolby Digital Plus soundtracks are easily converted to a 640 kbps Dolby Digital signal without decoding and reencoding, for output via S/PDIF. The 640 kbps bit rate, which is higher than the standard 448 kbps used on DVDs, is fully compatible with all existing Dolby Digital decoding products such as A/V receivers, and can provide higher-than-DVD quality from Dolby Digital Plus soundtracks when played back through existing systems.

Source: https://www.dolby.com/uploadedFiles/Ass ... us-faq.pdf

Any help on this issue would be highly appreciated.

[Impsak]

Hi,

I have a similar issue. Using Windows 10 and HTPC.
I just want to be able to send PCM stream from HTPC to Receiver using VLC.
Since I got a 7.1.4 system and have dolby atmos setup, I need to use the HDMI cable to send sound I guess. I have installed Dolby access and all this. (not sure if I need the dolby access app installed for sending PCM stream / dolby 7.1 / atmos to the receiver as the receiver is capable itself to decode?
Either way, the dolby atmos with my current settings works just fine.

My problem comes to files with "AC3/A52 2 channel content" my receiver does not want to upmix this when using neural or dolby to all channels over the HDMI.

But, I also have a USB connected from HTPC to Receiver. So when I open Sound settings in windows 10 and set USB as main audio source, then tell my receiver that it will be getting audio from USB instead,. when doing this, the 2 channel AC3/A52 audio is upmixable.

Why do I need to do this ?

In windows 10 sound settings:
HDMI output is set to Dolby Atmos Home Theatre (also Dolby Access app is installed)

The USB out only has 2 channel setting.

So the USB connection with only 2 channel setting in the "sound settings" sends a signal to my receiver which is perfectly "upmixable" using Neural X or Dolby to 7.1.4

But the over the HDMI, the recevier cant upmix? whatever post processing I choose its still 2 channel.

In windows 10 sound settings, Do i need it set to dolby atmos home theatre when to send a dolby atmos PCM stream to the receiver using VLC? Do I need the dolby access app if I dont want windows to decode? I basically want the receiver to do the important stuff when it comes to Audio.


Can anybody tell me why i need to change "audio output" to USB to get 5.1+ sound to work with my receiver, when the audio content within a given .mkv file is AC3/A52 Stereo ?

Thanks for all help.