The VideoLAN Forums

Hi Guys,

I currently have strange things happening with VLC in combination with Atmos MKVs.
I use an Nvidia GTX 970 via HDMI with passthrough enabled for the output. For some videos with Dolby Atmos, VLC starts but then reacts only very sluggishly or not at all to my inputs. If VLC does switch to full-screen mode, it flickers and jumps to the desktop again and again for fractions of a second, which is why the Windows taskbar becomes visible and disappears again immediately. I can't close VLC either, the program doesn't respond at first and then crashes.

A reinstallation has unfortunately not helped. On other systems I have no problem playing the files.

Can anyone help?

Please open Tools -> Messages (set Verbosity to 2) before you start the playback, and then paste the full resulting log here or on Pastebin.com if it's too long.

And upload a short sample of your original problematic file to Zippyshare.com or to WeTransfer.com and then post the link to the file here.
https://www.zippyshare.com
https://wetransfer.com

If needed cut it with DGsplit and read here about how to do it:
https://forum.videolan.org/viewtopic.ph ... 35#p193335
200 MB max should be enough.

I have this exact same issue. Any chance that anyone could create/get a debug/error report? (I've attempted to get this information, but I haven't been successful.)
[I.E. VLC crashes before I can get a chance to save an error log.]

I got a full resulting log. If this could be used to fix the issue of playing MKVs w/ Atmos, it would be great.
https://www88.zippyshare.com/v/Q7kT9S38/file.html

Maybe because of your Intel UHD Graphics 630. These cards have no dedicated video memory but they use shared memory of your RAM which might cause problems with 4k.
What is your hardware ?
Anyway, post a sample file as explained in my first post.

Maybe because of your Intel UHD Graphics 630. These cards have no dedicated video memory but they use shared memory of your RAM which might cause problems with 4k.
What is your hardware ?
Anyway, post a sample file as explained in my first post.

Well, not only I have an Intel UHD Graphics 630, I also have a Nvidia GeForce 2070 RTX.

Processer: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz 2.59 GHz
Installed RAM: 16.0 GB (15.9 GB usable)

However, I did try to change the settings to High Performance for VLC, but didn't work. (It was still sluggish, unresponsive, and crashed about a min later.)
I changed it via the main Windows Settings, I can't change it on the Nvidia Control Panel.

I can't change it on the Nvidia Control Panel.

Blame Nvidia.
Workaround: make a copy of VLC.exe and rename it to VLC-GPU.exe
Now you add VLC-GPU.exe to the list of programs in the Nvidia control panel, use your 2070 RTX and tweak it as you want.
Of course, you must now run VLC-GPU.exe.
You can either use the right click context menu on the VLC icon and choose "Run with graphics processor" then select the Nvidia card, or create and edit a new VLC shortcut to permanently assign it the Nvidia card.

I can't change it on the Nvidia Control Panel.

Blame Nvidia.
Workaround: make a copy of VLC.exe and rename it to VLC-GPU.exe
Now you add VLC-GPU.exe to the list of programs in the Nvidia control panel, use your 2070 RTX and tweak it as you want.
Of course, you must now run VLC-GPU.exe.
You can either use the right click context menu on the VLC icon and choose "Run with graphics processor" then select the Nvidia card, or create and edit a new VLC shortcut to permanently assign it the Nvidia card.

I tried that, no change whatsoever. Is there a way to update VLC to support the Dolby Atmos more efficiently? Or to have an option to have the Atmos be converted to run in a 7.1, 5.1 or lower format; (without changing the quality of the audio)?

So the stuttering problem is only with audio and not with video ?
If so, what audio hardware do you have ? A receiver ?

So the stuttering problem is only with audio and not with video ?
If so, what audio hardware do you have ? A receiver ?

Yes, no matter what kind of video the media file is (resolution or otherwise), if it has a 7.1 Atmos Audio Track, the problems described above come about.
I have a Realtek Audio setup built-in. And, for the receiver, I don't really know anything about that, nor how it works. I just play the media files straight from my computer, basically I hardly change anything in the settings on VLC; (i.e. mostly default settings).

You should create a new ticket on the VLC Trac with your above report and the link to this thread:
https://code.videolan.org/videolan/vlc/-/issues

Exact same problem. (Windows on iMac 5k i7 7700k, 48 GB RAM, Radeon Pro 580 8 GB) - hdmi passthrogh. Smooth as butter, it will play high bitrate mkvs no problem, but if the Audio is Atmos, the UI becomes unresponsive, sluggish (30 seconds to respond etc) - that ONLY happens with Atmos files.
PS: Windows Media Player has no issue.

What's sad is it will take years for this to be fixed, i really need this to work lol

Someone must create a ticket if you want a fix:
https://code.videolan.org/videolan/vlc/-/issues

I had the same problem only VLC actually crashes BUT "Windows Movies and TV" runs MKV's with Atmos just fine. Windows uses a "Dolby Access" app for headphones and YouTube and my receiver shows Atmos when running the demos. Perhaps the Dolby Atmos for Windows interferes with VLC for some. I'm not messing with my setup anymore. A while ago "Windows Movies and TV" wasn't good for much but now it is outstanding, I have had trouble in the past with both VLC and "Windows and Movies and TV" but maybe the Dolby Access interferes with VLC. Since I doubt everyone has Dolby Access from Microsoft or has the Microsoft video player, it must be something else. I have an Intel NUC with an AMD video/sound source attached directly to the Intel CPU as a single unit. The HDMI goes from my computer to a Yamaha receiver and from there to my 4K TV. BTW the sound is Blu Ray quality with Atmos in True HD indicated on my receiver.

Try doing the following:

1. Hit Ctrl + P to open Preferences and click "All" at the bottom to open the Advanced menu.
2. In the left hand panel click Audio.
3. In the right hand panel where it reads "Force detection of Dolby Surround", change it from Auto to "On".
4. Immediately below that change "Stereo audio output mode" to "Dolby Surround".
5. Save, exit and restart vlc.

Check to make sure you have the 64 bit version of vlc installed. An easy way to do that is to copy C:\Program Files\VideoLAN\VLC, open the Windows Run command (Ctrl + R) and paste it in there and click OK. It should open the vlc directory, If it doesn't then you have the 32-bit version of vlc installed the latter of which can't handle 4K.

If all else fails, contact Dolby support via their online form here: https://www.dolby.com/about/support/

Try doing the following:

1. Hit Ctrl + P to open Preferences and click "All" at the bottom to open the Advanced menu.
2. In the left hand panel click Audio.
3. In the right hand panel where it reads "Force detection of Dolby Surround", change it from Auto to "On".
4. Immediately below that change "Stereo audio output mode" to "Dolby Surround".
5. Save, exit and restart vlc.

Check to make sure you have the 64 bit version of vlc installed. An easy way to do that is to copy C:\Program Files\VideoLAN\VLC, open the Windows Run command (Ctrl + R) and paste it in there and click OK. It should open the vlc directory, If it doesn't then you have the 32-bit version of vlc installed the latter of which can't handle 4K.

If all else fails, contact Dolby support via their online form here: https://www.dolby.com/about/support/

Why would contacting Dolby Support help? This still doesn't work.

Why would contacting Dolby Support help? This still doesn't work.

I would imagine that Dolby will already be aware of the problem and may be able to suggest a course of action.

Dolby doesn't care about VLC problems.
I repeat: someone must create a ticket if you want a fix:
https://code.videolan.org/videolan/vlc/-/issues