No S/PDIF output :(

[Lurker]

Sound card - Abit UA-11, which is "USB-to-S/PDIF" device. Detected as "KC USB Audio Device", module snd-usb-audio.

With Mplayer

mplayer -ao alsa:device-hw=0.0 -ac hwac3, filename.avi
mplayer -ao alsa:device-hw=0.0 -ac hwac3, dvd://

all works just fine - a Dolby Digital decoder connected to the sound card via an optical cable detects AC3 stream.

VLC (0.8.6a) is set to use ALSA and that sound card (in ALSA preferences, hw:0,0). There is "A/52 over S/PDIF" in the menu, so that VLC detects S/PDIF. But whenever I select it, my decoder has no a signal on its input. Just silence.

Messages are full with "main debug: audio output is too slow (-412177), trashing 32000us". As I understand, this is the reason...

All the same with AVI and DVDs.

Fedora Core 6, if it matters, with all the latest updates.

So what can I do do pass AC3 (and, ideally, DTS) stream to the S/PDIF? Please don't offer to stick with MPlayer

[Lurker]

One more note: when I choose "A/52 over S/PDIF", VLC shows Mute sign on its volume control. Dunno if it matters...

[Hubris]

Exactly the same experience. If you temporarily choose the 'Stereo' audio device....I bet you get sound over your SP/DIF, but it won't include AC3. When it detects A/52....it doesn't work. I've run into a number of people with the same issue....different sound devices...even different kernels. No answer yet!

[vlcuser01]

Same problem here with Linux and VLC Player version 0.8.6c. What I did:

Settings > Preferences > Audio:
- [tick mark] 'Advanced options'.
- [tick mark] 'Use s/pdif when avaliable'.
- Output modules: [pull-down box] Audio output module: 'ALSA'
- Output modules > ALSA: [pull-down box] ALSA device name: 'C-media PCI iec958 hw:0,2'.

No sound through my s/pdif.

What does work:
- The above settings and Right-mouse > Audio device > Stereo. And adjust the sound volume up!

Then I have sound through my s/pdif, however it is "downchanneled" to stereo (pcm 48 kHz).

Is this a bug or am I missing something here?

P.S. I would like to report this as a bug, made an account, but I am afraid that entering of a bug is not possible if you're not 'validated' or something....

[Hubris]

If you do a search, there's another thread on this exact topic. It IS already a bug....it was reported many months ago, but the developers for VLC are volunteers, and so far nobody has volunteered to tackle it.

[vlcuser01]

If you do a search, there's another thread on this exact topic. It IS already a bug....it was reported many months ago, but the developers for VLC are volunteers, and so far nobody has volunteered to tackle it.

Thanks for the info. I did a search of course, but could only find this topic on it, and no bug report/ticket.

However, I did a search again and found this topic. I think that is the topic you mean.

VLC is used by so many peaople on so many platforms that I thought it was a (semi)professional developped aplication. Lets hope the volunteers with programming skills tackle this problem some day.

At least it's not my "fault" that I cannot get spdif passthu working. So I'll stop trying until I read in the change-logs that it is fixed (under Linux).

Bye.

[nubunty]

Hello, just adding my voice.

Same problem -
Late model KUBUNTU (7.04)
Nforce2 soundsystem (onboard on Gigabyte mobo - it may be old but it works PERFECTLY under Winblows)
SPDI/F out is wired up fine and drives my Boston Acoustics digital speakers.

Analog out works fine.
No SPDI/F out no matter what combos of the switches and sliders in KMix and alsamixer I try.
Briefly took the system to OSS instead of ALSA but no joy there either.

Jon