5.1 DTS surround sound working incorrectly
When playing any Dolby DTS 5.1 file, the surround channels are not working correctly. The rear left channel will cause the rear left and front left speakers to both sound. The rear right channel will cause the rear right and front right speakers to both sound. Clearly, VLC is doing something with the surround sound which is better than pure stereo, but the bug causes the surround effect/image to be massively diminished.
On Windows "Movies & TV" app, the same exact test file causes each speaker to sound on its own, as expected.
The issue occurs when playing 5.1 Dolby DTS files such as demo videos in https://www.demolandia.net/cinema/dolby-demo-trailers-hd/page-8.html or https://drive.google.com/file/d/0B4nYAKUiVpepY1NuQW5ER3l3SXc/edit
The issue does NOT occur when playing 5.1 files which aren't DTS, such as those in https://www2.iis.fraunhofer.de/AAC/multichannel.html
Windows 10, VLC 3.0.8
More details: https://www.reddit.com/r/VLC/comments/g74c3y/unfortunate_big_flaw_in_51_surround_sound_which/
Activity
Okay, I found a version that has the best of both worlds: 2.2.5. This version of VLC supports the 4k codec, and still does not have the surround sound bug.
Edit: Spoke too soon. The video is very unstable and consumes unreasonable amount of CPU with version 2.2.5, whereas version 3.0.8 runs smoothly. The audio issue should be fixed ASAP. Honestly, it is a travesty that the bug existed for so long. How can I be the first person in the world to notice this very fundamental problem with sound? People just don't care about sound and only care about video.
Please share the logs, since it could be a lot of issues.
Edited by Jean-Baptiste Kempfadded Status::needs more info label
If your home has a surround 7.1-sound system, you may be aware that configuring speakers is hard. To have the finest sound experience, you need to put multiple speakers in the right position. 7.1 surround sound test speakers in windows 11. Although a new surround sound setting is somewhat complicated, Windows 11 from Microsoft contains an integrated software that removes any problems. Windows 11 also features a simple tool that allows you to easily test the surround sound speakers.
This problem is still present.
I am detailing my use case, but I think a lot of my setup is not relevant to this issue and is only visible as I do not use S/PDIF passthrough.
Reproducible test case :
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Windows 11 - All patches applied as of 19/1/22
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Creative Labs SoundBlaster Z - Driver Version 6.0.102.0075 (current as of 19/1/22)
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Logitech Z906 speakers using S/PDIF output from SoundBlaster Z
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DTS Connect / Interactive for DTS Encoding for speakers - see here
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VLC 3.0.16
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Playback File : https://mega.nz/#!oMwQmaQK!YFk6yiWSC6j1yuMyaCIJaa_7pjifas-PTT0v0T-yk4M
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Playback File source : https://thedigitaltheater.com/tools/
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Both DTS rear channels playback through front channels.
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Front Left/Centre/Right/LFE DTS channels play correctly.
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All Dolby Digital Channels playback correctly.
I do not believe this is relevant to the issue, but to explain the use case, SoundBlaster Z, using DTS Connect, takes the 5.1 analogue Speaker output, and encodes it to DTS 5.1 for the speakers. In the case of Dolby Digital, which is working correctly, it is being decoded by VLC to the 5.1 analogue speaker output, DTS Connect/interactive then re-encodes to DTS 5.1 and this plays correctly through the S/PDIF output on the SoundBlaster Z card. This is not using S/PDIF passthrough, as S/PDIF cannot overlay multiple audio tracks into a single stream, such as combining Windows sounds with 5.1 audio, DTS Interactive is relied upon to encode a single stream for the speakers.
It would seam VLC is decoding the DTS 5.1 signal, but playing the rear channels through the front channels, resulting in an incorrect playback, so I suspect this is a VLC audio decoding/playback issue.
Edited by kravena-
