KeithL
Administrator 
Posts: 10,261
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Post by KeithL on Sept 28, 2014 2:21:58 GMT -5
WASAPI Mode
By default, current versions of Microsoft Windows (Windows 7, Windows 8, and Windows 8.1) are configured to use a single user-specified sample rate. Digital audio recorded at this sample rate will be played back without resampling, but digital audio at any other sample rate will be re-sampled to the configured sample rate before being sent to the DAC or other playback device. (So, for example, if you purchase a 24/96 download and play it in Windows, and your default sample rate is set to 44k, the file will be re-sampled to 44k (and your DAC or XMC-1 will correctly display 44k as the sample rate IT is receiving).
If, like most audiophiles, you prefer to have your high-def downloads play at the sample rate in which they were recorded (referred to as “their native sample rate”), you must use a special mode called WASAPI - which is available in Windows 7 and Windows 8. WASAPI mode is part of Windows, and there’s no need to install it or turn it on, but WASAPI mode can ONLY be used by player programs specifically designed to use it, and each such program must be individually configured to do so. (Windows Media Player, the audio player that comes with Windows, does NOT support WASAPI mode.)
NOTE: Apple computers have a similar situation, where by default digital audio files are re-sampled to a single pre-set sample rate, and playing digital audio files at their native sample rates requires you to choose a player program that supports that option and configure it accordingly. (Audirvana, Amarra, and many other Apple programs support this option, and a plugin named BitPerfect adds this capablity to iTunes for the Apple.)
Remember that this option must be configured separately in EACH different player program you use. WASAPI mode is independent of the DAC or other audio playback device you’re using. It will work with any USB audio device (although, if WASAPI mode attempts to send audio to a device at a sample rate which the hardware or drivers don’t support, you will receive an error message). We absolutely recommend using WASAPI mode to get the best audio performance from your XDA-2, DC-1, or other Emotiva DAC, or the “USB DAC” input on your XMC-1 or other pre/pro.
NOTE: WASAPI is a Windows interface mode. Before configuring WASAPI mode in your application, you should install the appropriate USB audio drivers for your DAC or pre/pro into Windows and verify that the drivers and your USB cable are working. There are NO special settings or options in the drivers necessary to allow them to support WASAPI mode. Some players differentiate between WASAPI EVENT and WASAPI PUSH modes. Emotiva’s Unified 6631 USB Drivers support WASAPI PUSH mode (and DO NOT support WASAPI EVENT mode), so you should configure your player program to use WASAPI PUSH mode.
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Post by memotiva on Oct 1, 2014 16:47:54 GMT -5
Doesn't VLC take care of this out of the box? It seems to magically do everything perfect.
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Post by garbulky on Oct 1, 2014 16:54:49 GMT -5
No, you have to configure vlc for wasapi.
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Post by paintedklown on Oct 1, 2014 17:01:04 GMT -5
No, you have to configure vlc for wasapi. I was unaware that VLC could even do WASAPI. I can only get a 2 ch mixdown out of it. I was playing with the free trial of jRiver 20 again last night, and fell in love with it all over again (had used the 30 day trial for 19 as well). What I didn't realize before is that you can send a bitstream signal from jriver (via HDMI anyway) to your processor for decoding. NICE! I have been using XBMC and while I do like it (and that low price  ) it doesn't have a pure bitstream mode like Jriver. Gar, does VLC have a bitstream mode as well, when properly configured? |
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Post by garbulky on Oct 1, 2014 17:53:30 GMT -5
paintedklown: I couldn't tell ya. Sorry. I think there is a way to do wasapi with VLC - which would ben nice, I just have no clue how to. I don't think you could do surround sound bitstream over wasapi though.
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Post by knucklehead on Oct 1, 2014 18:04:12 GMT -5
Doesn't VLC take care of this out of the box? It seems to magically do everything perfect. VLC does video very well - audio not so much. I get audible distortion playing FLAC files with VLC Media Player. I use FooBar2000 - it works very well and delivers CD quality. Oddly enough VLC doesn't seem to distort the audio in movie files. |
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Post by borbafett on Oct 4, 2014 12:17:41 GMT -5
Thanks Keith, I've been wondering how to do this for sometime had no idea about wasapi mode .Configured Foobar and Xbmc to use it and am loving the results.Glad to finally get the windows drivers out of my Musics way.Thanks Again great post.
Al
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Post by pedrocols on Oct 4, 2014 12:31:13 GMT -5
Doesn't VLC take care of this out of the box? It seems to magically do everything perfect. VLC does video very well - audio not so much. I get audible distortion playing FLAC files with VLC Media Player. I use FooBar2000 - it works very well and delivers CD quality. Oddly enough VLC doesn't seem to distort the audio in movie files. I use FooBar2000 as well and works very good. |
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MikeWI
Emo VIPs 
DC-1, ERC-1, USP-1, UPA-2, Sub 10, Emotiva 4S
Posts: 346
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Post by MikeWI on Nov 24, 2014 12:10:51 GMT -5
Keith - Great, succinct post. I tried changing from "Default Audio Device [Direct Sound]" to WASAPI options and got no sound. Any ideas... Works: Default Audio Device (Direct Sound) Doesn't output sound (but spectrum analyzer in JRiver indicates sound playing):JRiver Media Center 20 [WASAPI] or USB2.0 High-Speed True HD Audio [WASAPI] Gear:Computer/OS: Laptop - set to 24/192 in Windows 7 audio settings Software: JRiver Media Center 20.0.41 Connector: Emotiva MUSB USB DAC: Emotiva DC-1 DAC (input USB) WASAPI Mode
By default, current versions of Microsoft Windows (Windows 7, Windows 8, and Windows 8.1) are configured to use a single user-specified sample rate. Digital audio recorded at this sample rate will be played back without resampling, but digital audio at any other sample rate will be re-sampled to the configured sample rate before being sent to the DAC or other playback device. (So, for example, if you purchase a 24/96 download and play it in Windows, and your default sample rate is set to 44k, the file will be re-sampled to 44k (and your DAC or XMC-1 will correctly display 44k as the sample rate IT is receiving).
If, like most audiophiles, you prefer to have your high-def downloads play at the sample rate in which they were recorded (referred to as “their native sample rate”), you must use a special mode called WASAPI - which is available in Windows 7 and Windows 8. WASAPI mode is part of Windows, and there’s no need to install it or turn it on, but WASAPI mode can ONLY be used by player programs specifically designed to use it, and each such program must be individually configured to do so. (Windows Media Player, the audio player that comes with Windows, does NOT support WASAPI mode.)
NOTE: Apple computers have a similar situation, where by default digital audio files are re-sampled to a single pre-set sample rate, and playing digital audio files at their native sample rates requires you to choose a player program that supports that option and configure it accordingly. (Audirvana, Amarra, and many other Apple programs support this option, and a plugin named BitPerfect adds this capablity to iTunes for the Apple.)
Remember that this option must be configured separately in EACH different player program you use. WASAPI mode is independent of the DAC or other audio playback device you’re using. It will work with any USB audio device (although, if WASAPI mode attempts to send audio to a device at a sample rate which the hardware or drivers don’t support, you will receive an error message). We absolutely recommend using WASAPI mode to get the best audio performance from your XDA-2, DC-1, or other Emotiva DAC, or the “USB DAC” input on your XMC-1 or other pre/pro.
NOTE: WASAPI is a Windows interface mode. Before configuring WASAPI mode in your application, you should install the appropriate USB audio drivers for your DAC or pre/pro into Windows and verify that the drivers and your USB cable are working. There are NO special settings or options in the drivers necessary to allow them to support WASAPI mode. Some players differentiate between WASAPI EVENT and WASAPI PUSH modes. Emotiva’s Unified 6631 USB Drivers support WASAPI PUSH mode (and DO NOT support WASAPI EVENT mode), so you should configure your player program to use WASAPI PUSH mode. |
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MikeWI
Emo VIPs
DC-1, ERC-1, USP-1, UPA-2, Sub 10, Emotiva 4S
Posts: 346
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Post by MikeWI on Nov 24, 2014 13:35:43 GMT -5
Interesting from JRivers wiki...
WASAPI Event Style
There are two main ways to communicate using WASAPI:
Event Style
Push Style
Both deliver the same audio data and will sound the same. One may work better with specific hardware.
Please Note: As of MC 18.0.183, WASAPI Event Style is now the default. If your audio device does not support this mode, it can be disabled in the WASAPI Device settings dialog.
WASAPI is now just WASAPI. In the options (next item below the selection) you can check "Disable event style..." to get the output mode previously called "WASAPI", used mainly with older hardware. In other words, WASAPI now defaults to Event Style.
Versions prior to 18.0.183
WASAPI output mode pushes data from Media Center to the sound device. It works with nearly all hardware.
WASAPI Event Style lets a sound device pull data from Media Center. This method is not supported by all hardware, but is recommended when supported.
This has several advantages:
It lets the audio subsystem pull data (when events are set) instead of pushing data to the system. This allows lower latency buffer sizes, and removes an unreliable Microsoft layer documented below.
It creates, uses, and destroys all WASAPI interfaces from a single thread.
The hardware (or WASAPI interface) never sees any pause or flush calls. Instead, on pause or flush, silence is delivered in the pull loop. This removes the need for hacks for cards that circle their buffers on pause, flush, etc. (ATI HDMI, etc.).
It allows for a more direct data path to the driver / hardware.
The main 'pull loop' uses a lock-free circle buffer (a system that J. River built for ASIO), so that fullfilling a pull request is as fast as possible.
*UPDATE*
Setting JRivers to "USB2.0 High-Speed True HD Audio [WASAPI] with Device -> "Disable event style (required by older hardware)" -- worked.
Not sure why it didn't work for "JRivers Media Center 20 [WASAPI]" setting.
Thanks again for helping me figure out how to bypass Windows.
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Post by oldmanaudio on Mar 8, 2015 9:51:41 GMT -5
For the gentlemen using Foobar 2000; I'm currently comparing FooBar to JRiver and on "File - Preferences - Output" on Foobar I can choose "Null Output, Primary Driver, Realtek Speakers(my computers), and JRiver(wasapi)". I'm assuming that choosing JRiver(wasapi)will pass the signal through JRiver to Foobar. Since I'm trying to compare the 2 I don't want use this option. The question is, will using "Primary Driver" set the output to wasapi without interference from JRiver or will it set it to direct mode?
Any help would be appreciated.
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Post by oldmanaudio on Mar 8, 2015 9:56:22 GMT -5
Just found the info. Primary Driver is direct. Foobar has a seperate download for wasapi support.
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tommyj
Seeker Of Truth
Posts: 3 
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Post by tommyj on May 16, 2015 15:23:43 GMT -5
Wasapi is also supported in Kodi ( used to be called xbmc). Kodi is a total media center sollution. Will play back just about any format you throw at it. Including 24bit Flac. www.kodi.tv (its 100% free) |
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) it doesn't have a pure bitstream mode like Jriver.
