The VideoLAN Forums

Im having trouble getting VLC to play Dolby Digital 5.1 or DTS over the optical output (A/52 over S/PDIF in Audio Device menu). It plays extremely choppy, where it just takes a 0.1s second and loops it for about 2 seconds, then skips ahead, takes another 0.1s segment, and loops it for another 2 seconds, and so on. (the times are an estimate). My receiver is detecting DTS signal, but the audio is unusable. When changing the Audio Device to stereo, it sounds just fine.

Running Vista with the onboard optical audio output on the EVGA 680i.

In the preferences menu: (tab) Audio > Output modules > (check the "advanced options" box) choose "Win32 waveOut extension output" from the drop-list, save and restart VLC. Hopefully this will resolve the issue.

Thanks for a quick reply. The trick ALMOST fixed the problem. The audio is no longer as choppy, but still very noticeable. Anything else I can do to improve it?

Bump, anyone?

Try new audio drivers.

What's the sound card or chip set?

Its the latest driver. The onbroad audio on the evga 680i SLI mobo.

Sorry! That doesn't tell me anything. What is the chip set for the audio?

I'm having a similar problem.

Here's my setup:

AMD64 3500+ @ 2.4Ghz
Asus A8V Deluxe
2GB DDR400 RAM
PNY AGP8X 6600GT
Realtek AC97 onboard audio

XP MCE
VLC 0.8.6c


I'm trying to watch a 720p version of Collateral with 5.1DD.

When I first chose A/52 over S/PDIF it was exteremely choppy. I tried the fix mentioned below by changing the audio module to "Win32 waveOut extension output" and it was better choppiness-wise, but I'm losing sync badly about 10 minutes into the movie.

I updated my chipset driver from Asus with the latest available.


Analog audio is fine. I suppose it is passing it correctly via S/PDIF. I watched a episode of Big Love with no issues... but it was only a 2 channel audio that my receiver received as just Stereo... not DD Stereo.


This is the first time I have used my PC via S/PDIF but to me I think it's functioning ok other than than passing the DD and even possibly DTS streams.


Any advice or input is much appreciated.

Realtek AC97 onboard audio is the problem. Try older drivers.

You will probably need to go back 1 by 1 until you find 1 that works. At least this is what I remember from other users.

It sounds like you're sending an analog sterio signal to your receiver. Try sending the audio stream out to your receiver via S/PDIF (coax or optical cable) to the external DD/dts decoders in your receiver. Make sure to set your sound card to pass the audio signal out to an external decoder. Is your receiver digital with DD/dts sound ability (decoders)?

Realtek AC97 onboard audio is the problem. Try older drivers.

You will probably need to go back 1 by 1 until you find 1 that works. At least this is what I remember from other users.

I'll give that a try. I've been debating getting a soundcard as well. Is the AC97 any good? I know typically onboard anything is relatively poor in quality.

It sounds like you're sending an analog sterio signal to your receiver. Try sending the audio stream out to your receiver via S/PDIF (coax or optical cable) to the external DD/dts decoders in your receiver. Make sure to set your sound card to pass the audio signal out to an external decoder. Is your receiver digital with DD/dts sound ability (decoders)?

It's hooked up via optical cable.

It autosenses analog and digital sources through the receiver. When I change VLC from 5.1 to A/52 over S/PDIF my reciever indicates a 5.1DD signal if the file has the track.

Im also using a realtek audio chipset. Downgrading the driver had no effect.

Another indication of bad Realtec drivers is VLC locking up at exit where the program is left in Memory. Check your Task Manager for this. As far as the older drivers here it has been awhile since the last posts, but it was quite a few revisions back. You can do a search for Realtec!