I tried reading the first thread but at 22 pages, it is a bit much
. So is Peter's English
. I read the first page and last two but still not sure what the problem is. Peter seems to be talking at first about a data underrun with ticks. That happens when the CPU falls behind and the DAC runs out of data. It is a problem of lack of buffering in the driver and generally too busy of a CPU. That would not (directly) have an effect on fidelity. Is the "tick" still a problem there or was resolved later?
Unfortunately I don't have a Win8 system or I would measure before and after and report back. Clearly if there is as much at issue it would be measurable.
Hi there Amir,
Sorry for the confusion with ticks, which is not related at all. Mani posted the thread here because two days back I sort of proposed to do that myself, but bailed out because I could see no real W8 experience on your (personal) side. This, while most obviously you would be THE person to know a thing or two, were it about WASAPI and Kernel Streaming, "exclusive mode" in particular. And yes, did we exchange a few things about that in a by now far past.
It may come across odd that right now I'm only here to point out that the problem is not about ticks or anything, but is just about strange sound. Mani merely posed the question to find out whether others exist experiencing similar, since it really seems to be so we at Phasure are alone on this. Maybe it was triggered by me and my judgement as the forum owner, but in the end everybody is able to hear the same : phase oddities (but read : DSP in order).
A cry for "technical help" here on WBF seems out of order, because you really had to be in the middle of the MS media stuff to provide help from the top of your head, while now it needs diving into matters we ought to do ourselves. Your mentioned measuring is an example of that, but this is not so easy.
As is my English.
So, not seeking for help eh ?
Well, we can always try to turn this into an intersesting thread. Not sure if people are interesting in it, but let's try.
WASAPI for half of its part was about Exclusive Mode by official means. Say, the official part of the Windows Audio stack, with underlaying Kernel Streaming which is, say, inherently "exclusive mode". However, this by itself was a target of nobody. "Bit perfect" was. Ehm, is.
And this latter changed per Windows 8. No wait, it just has to be because of all the proof collected by now and this includes listening. Regarding the latter we can easily see that everybody is raving his ass out because of the better sound, but if it were for me this raving is an indication of it all for the worse. It can't be. And, coincidentally we at Phasure listen through different ears and different DACs (for many, like Mani) and if by now one person judges W8 as better sounding, it is much. But, one is there indeed. One.
What I personally lack is the proof of the pudding which is the graphical outlay of the Windows 8 Audio Stack. It does not seem to exist. There's pictures of WASAPI and hardware offloading, but that is all. And funnily enough, because that is all it could be all, and when true it shows what I see from the OS itself. All goes through mixers and DSP everywhere.
Mind you, at the Kernel Streaming level that already is so.
The phenomenon "Exclusive Mode" has lost its value; before it told bit perfect, today it tells just what the words say. The good thing ? hey, now I can let the OS do some DSP stuff for me while working in Exclusive Mode. This was not so before. Most probably including resampling, which I did not try.
It could be a good thing overall. However, this seems impossible because I find no documentation or changelogs about it. Zero. Actually I do : "nothing has changed outside Metro, thus for desktops". I see controls all over the place and they work. By tricks I can shut them off, but can not see whether they now *don't* work. The hard part of it all is that this is all NOT about WASAPI, but sheer Kernel Streaming. So for example, shut off the formal audio stuff and see nothing (no access to the audio department anymore). In the mean time a set volume remains active. So, we can't see it, but sure it still is active.
And it is so much more complicated, because when, for example, things are attempted to shut down trough other audio devices in the system (never mind the real merits of this), the one and only device (our precious DAC) left, receives a formal volume control for the Session and now all seems lost (well, that's how we think). Thus, this control is not there when another device is active (though not addressed). Don't try to understand, but try to grasp that things are strange and no guides exist.
So ... it is all one big mess. Literally out of control.
If the real picture of the audio stack could be coughed up that will be helpful I think. The below is what we have from W7 and W8 respectively but it reflects the change from W7 to W8 (btw, I don't know how to get these picture in outside of thumbnails while now they are quite unreadable. Edit : I added links to them now).
http://ha6.heartprofit.nl/www/transfer/graphics/audiostackw701.png
http://ha6.heartprofit.nl/www/transfer/graphics/audiostackw801.png
Look closely; both pictures are not correct for what this is about : a desired direct line from WASAPI (or even the API) to the output. This *seems* to be so in both pictures, but the lines in both pictures are the loop back streams going into WASAPI again. So, worthless for the merits we seek, because W7 (and Vista) do have this direct line (and no LFX etc. controls IF in Exclusive Mode).
Regards and thanks for watching,
Peter
