iTunes - PC - Bit Perfect - Virtual Audio Cable

[BEEMB]

 

Before I write about the subject of this thread I'd like to say that the intention here is NOT to discuss whether bypassing the XP or Vista audio engines is worse or better than not doing so. Think that's been discussed elsewhere in plenty of detail.

 

I love the iTunes interface, its so easy to use and works perfectly with the iPod Touch.

I don't love the fact I can't use ASIO or Wasapi (my opinion, right or not).

 

Has anyone heard of VAC - Virtual Audio Cable ? A few posts over on the Hydrogen Audio forum suggests that people are directing iTunes audio through VAC directly to the audio card, bypassing the Window's audio engine (on either XP or Vista). The Virtual Audio Cable becomes your default device which iTunes then uses.

 

I'm still waiting for some confirmation and will continue researching (and pestering).. heck I've even tried it but the trial version says "trial" so often that I can't easily listen without becoming a little frustrated.

 

But I wondered whether anyone on here has tried it ... ?

 

 

 

[BobH]

Yep, used it for many years for various purposes. This was discussed very briefly on a thread recently, I think it was one of the ones that got locked.

 

Anyway, it was mentioned, by me I think, as a possible way of recording the output of a media player with a view to checking bit perfectness-lessness, stuff! PeterST seemed to think that it was a no go because it appeared to be working by 'siphoning' off a feed from the kmixer/audio engine. So, on the basis that the kmixer is the spawn of santa, nothing would be gained. I don't have access to a cupboard full of 'scopes so have no way of checking this, but on the basis that Peter seems to know his stuff, I took it at face value and binned the idea for the time being.

 

The description page confuses me somewhat - on the one hand in mentions that it is a WDM driver and then goes on to say it works with asio. An ASIO/WDM driver? Either way it must pick up its feed from somewhere and it's the 'somewhere' that is hard to find out! My understanding used to be that it acted in the same way a patchbay and just routed stuff through it, in which case it would be fine. But if it acts in accordance with the WDM spec then it has to go through the normal audio engine, which is not fine.

 

Dunno. Any thoughts?

 

BTW - When I used it (v3), it worked flawlessly - I just couldn't swear to the 'bit perfect guaranteed' bit.

 

[BEEMB]

 

Thanks for the reply Bob. I must have missed it before.

 

I agree that the feed has to come from somewhere. And, if selected as the default playback device within iTunes, well, surely k-mixer or Vista's audio engine steps in to alter the sound before it gets anywhere (to the cable) anyway.

 

I decided to e-mail the developer for further information but must say that my line of thinking is in line with yours Bob.

 

Thanks again.

 

Matt.

 

[Roseval]

You might have a look at JACK http://jackaudio.org/ or PulseAudio http://www.pulseaudio.org/

Running it on Win might be a problem

 

[BobH]

Resurrect this when you get an answer, Matt. I'm still really interested in trying it out as a method of 'loopback' recording the output of media players. If VAC can avoid the audio engine then it would be a bona fide way of dong a quick A/B of media players output. Which just might lay a few ghosts to rest!

 

OT - BTW - Did you catch my reply to the Wavelab library question?

 

 

[Roseval]

I love the iTunes interface, its so easy to use and works perfectly with the iPod Touch.

I don't love the fact I can't use ASIO or Wasapi (my opinion, right or not).

 

Bit surprised, in Vista I can configure any play back device to use WASAPI or not (exclusive mode). What does iTunes uses?

 

 

 

[BobH]

Interesting links. Worth a look, methinks.

 

[BEEMB]

 

Roseval,

 

Correct me if I'm wrong, but iTunes does not allow you to select WASAPI as you can within the likes of Foobar. The audio is resampled (per my feedback from the engineer at Microsoft) before it gets to your audio card.

 

 

 

[BEEMB]

 

Sorry Bob, yes I did. And it just got me thinking I wished I had some more time to create something that simply bolted on the front - somehow!

 

M.

 

[Roseval]

Should have been more clear.

If I right click on the speaker icon in the task bar I can select the playback devices. Each of them has a advanced tab where exclusive mode (WASAPI) can be activated and each of them can be set to be the default player.

If I start WMP, it uses the default player and therefore WASAPI if this is checked in the audio device.

So I was wondering what happens if iTunes plays the default audio device when set to Exclusive.

 

 

[BobH]

Agreed!

 

It works, is about all that can be said for it! I was looking a Sidebar Gadgets the other day and wondering about it. We get really quiet at work between May and September - sounds like a project for then!

 

Back to the thread.

 

[BEEMB]

 

I know you can tick this box, I have done so, but this doesn't mean the software supports it.

 

I've just tested the following.

 

Ran i-Tunes with the device set to Exclusive. Ran Windows Media Player at the same time. BOTH were able to play music at the same time.

 

I then opened XXHighEnd, started a song .. opened Windows Media Player, it was UNABLE to play becuase XXHighEnd had exclusive control of the audio card.

 

So from this I conclude that neither iTunes or WMP support WASAPI. XX, Foobar and JRiver allow you to actually select WASAPI.

 

Matt.

 

[BEEMB]

Bob, STOP. Getting me excited!

 

[Roseval]

So from this I conclude that neither iTunes or WMP support WASAPI.

Sounds plausible to me.

On close reading, the check box 'allows' not to be mistaken for 'do'

Excellent posting

Thanks

 

[steveaustin]

Virtual Audio Cable software allows you to transfer audio (wave) streams between applications and/or devices. It creates a set of virtual audio devices named "Virtual Cables", each of them consists of a pair of the waveform input/output devices. Cable Suppliers