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More => Old Versions => Media Center 15 (Development Ended) => Topic started by: Matt on March 18, 2010, 11:22:58 am

Title: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: Matt on March 18, 2010, 11:22:58 am
Media Center 15.0.6 (and later) adds support for Kernel Streaming output.

Kernel Streaming is a hardware direct, bit-perfect method of communicating with a soundcard. 

It bypasses any Windows mixing.  It holds the card exclusively so other programs can not play music over the top or change the sample rate.

It works well on XP and later.

It works with some high end DACs that do not have good WASAPI or ASIO support.
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: skeeterfood on March 18, 2010, 11:22:30 pm
Is it possible to split the audio to 3 Zones: Left Front/Right Front, Center/Sub, and Rear Surround/Left Surround using Kernel Streaming?  It's not possible at the moment, but I wasn't sure if it was just because Kernel Streaming was new, or it's just not possible?

-John
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: JimH on March 22, 2010, 10:55:22 am
bump
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: fitbrit on March 22, 2010, 04:36:37 pm
How does one activate this, or is it done by default?
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: gappie on March 22, 2010, 04:43:40 pm
How does one activate this, or is it done by default?
you can choose it the same way as asio, wasabi, direct sound, wave out and... kernel streaming. in audio output.

 :)
gab
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: mojave on March 23, 2010, 11:16:38 am
you can choose it the same way as asio, wasabi, direct sound, wave out and... kernel streaming. in audio output.

 :)
gab

I had some wasabi on sushi this week. :)
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: gappie on March 23, 2010, 12:10:10 pm
I had some wasabi on sushi this week. :)
:-[guess i was hungry.  :)
i like wasabi.

ive tested kernel streaming with two soundcards on xp now and it works very nicely, both have asio also, so that is what i will use, but there is no need to advice asio4all anymore.

nice new feature.

 :)
gab
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: neFAST on March 24, 2010, 02:35:24 pm
I have a simple internal soundboard (Soundblaster).
Will Kernel streaming sound better than WASAPI?
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: gappie on March 24, 2010, 03:46:51 pm
I have a simple internal soundboard (Soundblaster).
Will Kernel streaming sound better than WASAPI?
who knows. only you can decide! there are people who want bit perfect playback what they send through there 10 something $ amp with russian tubes from the fourties of the last century. there are people who think there is no difference between 16 bit and 24 bit because science says so. to hell with them, it's your ears, and your ears only. give it a try.

 :)
gab
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: jmone on March 24, 2010, 04:01:36 pm
I have a simple internal soundboard (Soundblaster).
Will Kernel streaming sound better than WASAPI?

They should both sound the same but there are other reasons you may want to pick one over the other based on your OS  / HW config.  Some stuff here http://wiki.hydrogenaudio.org/index.php?title=Foobar2000:Components_0.9/Kernel_Streaming_Output_%28foo_out_ks%29 (and follow the WASAPI Link).  I'd only suggest using Kernel Streaming if you can not (or have an issue with) using WASAPI.
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: murrayp on March 25, 2010, 02:30:35 am
Hi,

Still trying to get Wasapi to run with out ticks and pops here into dCS.  BTW, MC14/15 at 48kHz Wasapi is fine.  But 44.1 still nbg.  So I tried Kernel streaming but just got a message that "playback could not be started....." though I was using the same 24 bit dsp output bit depth that works with Wasapi (sort of) and Asio.  It's probably my dac/usb interface not your program, but anyway, for the record......  tks.

Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: Quest on April 18, 2010, 10:17:22 pm
Hi,

Still trying to get Wasapi to run with out ticks and pops here into dCS.  BTW, MC14/15 at 48kHz Wasapi is fine.  But 44.1 still nbg.  So I tried Kernel streaming but just got a message that "playback could not be started....." though I was using the same 24 bit dsp output bit depth that works with Wasapi (sort of) and Asio.  It's probably my dac/usb interface not your program, but anyway, for the record......  tks.
i have this same problem with MC15 as well, with a benchmark dac-1 pre.
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: MerlinWerks on April 19, 2010, 12:05:21 pm
FWIW, I tried using KS with my ART Legato which uses asynchronous USB transfer technology licensed from Gordon at Wavelength and it was a no go. Song would start playing and part way through would just stop and I would have to hit a stop/play combo to get it playing again. Did not always happen on the first song, sometimes it might be the second or third song.
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: HiBitFan on April 19, 2010, 02:14:33 pm
Hi Matt,

Kernel Streaming is a nice feature when supported but I have some doubts that it's working as promised, at least on Win XP.
I have installed MC 15.0.27 on an ASUS EeeBox with Win XP.
This computer uses the Realtech HD Audio Manager as driver for the onboard soundcard. This driver forces me to set a sampling rate (44.1/48/96/192 kHz) for the SPDIF output. There is no option like 'keep rate of source file' or 'AUTO'.

Then I configured MC for Kernel Streaming to this soundcard. When I now play some music and switch the sampling rate in the driver menu my DAC immediately indicates this change, so sample rate conversion in fact is performed. From the concept of kernel streaming I would have expected that the rate of the source file is kept unconditionally.
However I cannot change volume on the Windows taskbar. Looks like the K-Mixer is really bypassed but the audio driver is still manipulating the audio signal.

This is at least not my understanding of bit-perfectness.

Does WASAPI work different here? If yes it may be worth upgrading to Win7.

 H.



 
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: Matt on April 19, 2010, 02:26:20 pm
Then I configured MC for Kernel Streaming to this soundcard. When I now play some music and switch the sampling rate in the driver menu my DAC immediately indicates this change, so sample rate conversion in fact is performed. From the concept of kernel streaming I would have expected that the rate of the source file is kept unconditionally.
However I cannot change volume on the Windows taskbar. Looks like the K-Mixer is really bypassed but the audio driver is still manipulating the audio signal.  

Kernel Streaming is direct communication with the driver.  So the driver can still change the sound.  Normally this can be disabled in the driver's control panel.

Lots of soundcard drivers, especially for low-end and consumer focused cards, offer lots of extra DSPs they think users will want.  Maybe most users do like these DSPs, but I'm not a big fan.

I don't think WASAPI is any different in this regard.  You always talk to hardware through a driver, whether you use ASIO, WASAPI, or Kernel Streaming.  So the quality of the hardware and driver is relevant.
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: HiBitFan on April 19, 2010, 03:41:45 pm
Looks like the key to bit-perfectness is to find a card or interface where the driver is doing almost nothing.
Otherwise even good hardware may not help.

Unfortunately that's just opposite of what you will find in the according advertisements.

Thanks,
  H.
Title: Re: NEW: Kernel Streaming (MC15) -- Hardware direct soundcard communication
Post by: Rudy81 on October 21, 2010, 03:45:12 pm
I just upgraded to MC15 in order to take advantage of KS in Win XP.  I have a second audio card in my HTPC for bit perfect streaming. The card is the Chaintech AV-710.  Previously I had to use and ASIO wrapper to get bit perfect sound to my pre/pro. 

KS seems to be working perfectly.  All I needed to do was select KS and the correct audio cards.

Very Nice!