Edited by Andrew_WOT - 11/17/12 at 10:17am
Even with WASAPI changes to volume in Windows Control Panel affect foobar2000 output, almost like it's still going through kmixer.
KS and WASAPI should be the same, except WASAPI can take higher toll on CPU due to integer to float conversion
KS should only be used on Windows XP since it doesn't support WASAPI, which is also a bitperfect output method, however it's much more stable and with better compatibility with a wide range of DACs. For Windows Vista/7/8, WASAPI should be used instead.
KS is what recommended by M2Tech regardless of Windows version, of course if the player of choice doesn't support kernel streaming, WASAPI will do just as good. Read the link in my reply.
Roller is correct. KS doesn't exist on Windows 7. Anything resembling functional KS is just a driver catch converting to WASAPI. Also, Foobar's WASAPI implementation is a whee bit buggy. JRiver works though, even on Event Style. KS = XP, WASAPI = W7. Technically I have the PWD2 and not the HiFace2 but both are XMOS and use the same driver so... ya.
That's news to me, care to elaborate or point to the source of that discovery. If what you are saying is true, M2Tech has no clue about Windows audio modes as they always recommend KS over anything else and this is how they compare two in their FAQ.
But can you please reveal the source of your intel (KS not SPDIF)? :)
BTW, this one is from Hiface Two manual.
Without boring you with a MSDN article explaining how to code W7 audio...
Also from a player point of view...
Both links says nothing about KS being removed, yes WASAPI is preferred programming model that *allows* avoid kernel programming, that's it.
This article on the other hand provides more insight on changes made to Audio architecture in Vista and beyond
Click on Details, to open the article up, apparently KS is still there with good ole NT days WDM, and still remains the most direct path to audio driver.
Or this article
WDM KS (Windows Driver Model / Kernel Streaming) has been around since Windows 98. WMD is a universal driver structure and behavior making it possible to use a single binary driver for Windows 98 through Win7. Kernel Streaming is just what it sounds like: audio and video streams directly through the Windows Kernel offering extremely low latency. The kernel, if you’re wondering, is really the heart of an Operating System – being the lowest level software that everything else is built upon.
Since Windows 2000, MME and DirectSound are actually built on top of WDM/KS – so obviously you want to go WDM native to remove the extra layer between your software and equipment.
WASAPI (Windows Audio Session API) was introduced with Windows Vista, but hasn’t seen wide adoption because it doesn’t really provide anything that Kernel Streaming doesn’t and generally doesn’t provide better performance than ASIO.
So, WASAPI is in a weird mid point where it overlaps, but doesn’t bring much new to the table. In addition, it doesn’t provide sample rate conversion, so it requires all audio streams to use the same sample rate as the audio hardware (same as Ardour and JACK under Linux) which can either be a confusing pain the ass, or give a hit in audio quality because an application has poor conversion code.
KS wasn't removed on Windows Vista/7/8, it is simply too buggy to be considered on modern OSes. Unfortunately, there are still many audio hardware manufacturers that have guides on how to set up computers in order to have optimal audio playback, but they haven't been updated since legacy Windows XP.
Users that are running modern OSes basically have two options for bitperfect playback, WASAPI or ASIO (yes, even non-ASIO compliant devices work by adding a wrapper).
Oh I don't know, the word obsolete to me tends to indicate that to me. Or that KS specifies working in XP but not Win7. Tell you what, you find me the MSDN article that says KS is alive in Windows 7 and that WASAPI didn't replace it as the exclusive mode ;)