Wasapi cant do 192/24?? - AVS Forum
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post #1 of 39 Old 02-08-2012, 07:38 AM - Thread Starter
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I was reading about this for a couple hours a couple weeks ago but didnt save any bookmarks so i cant post my sources. Il.try to.fimd them.if theres any argument. I found this a few different places but let me know if my info is incorrect. I was under the impression Wasapi could handle all bluray audio. I know theres only a couple titles at 192/24, can it do 96/24? I read that only Asio could do 192/24, but there are no asio video players are there? Only audio? So can one not acheive 192/24 from a bluray in an htpc currently?

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post #2 of 39 Old 02-08-2012, 08:07 AM
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I think it's more of a function of what your audio card can handle, as well as your receiver. I don't think there is a limitation on the WASAPI software model.
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post #3 of 39 Old 02-08-2012, 08:44 AM
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If you are bitstreaming the audio to the receiver, whatever the drivers support is irelevant, the audio is not decoded and sent as a RAW stream to your receiver.

If you are decoding audio locally on the HTPC, it supports whatever your card supports. Most modern GPUs go up to 192/24 , WASAPI is just an API to let the audio decoder bypass windows audio settings and the kernel mixer and send the audio straight to the driver. So you will get 24/192 if your card supports it.
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post #4 of 39 Old 02-08-2012, 05:07 PM - Thread Starter
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Quote:
Originally Posted by GreenEyez View Post

If you are bitstreaming the audio to the receiver, whatever the drivers support is irelevant, the audio is not decoded and sent as a RAW stream to your receiver.

If you are decoding audio locally on the HTPC, it supports whatever your card supports. Most modern GPUs go up to 192/24 , WASAPI is just an API to let the audio decoder bypass windows audio settings and the kernel mixer and send the audio straight to the driver. So you will get 24/192 if your card supports it.

This is the impression that I have been under for quite some time. But thats not what I read recently at all, it said that yhe limitation was on wasapi api itself and the limitation I believe was 96/24. I dont know for sure, but I thimk this is correct, thats the reason so many audiophiles want to use asio instead. Il do some more research and get back to you.

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post #5 of 39 Old 02-08-2012, 05:11 PM - Thread Starter
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Quote:
Originally Posted by Puwaha View Post

I think it's more of a function of what your audio card can handle, as well as your receiver. I don't think there is a limitation on the WASAPI software model.

Same.a.swhat I said to GE, thats what ive always thouhht but not what ive recently read a few places. I would love to be wrong.

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post #6 of 39 Old 02-08-2012, 05:19 PM
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Where are you getting this information? Do you have links?
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post #7 of 39 Old 02-08-2012, 05:22 PM - Thread Starter
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Quote:
Originally Posted by Puwaha View Post

Where are you getting this information? Do you have links?

Lol. Im searching right now but cant find any of the pages. I usually book mark anything like this but I didnt.

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post #8 of 39 Old 02-08-2012, 06:06 PM - Thread Starter
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Quote:
Originally Posted by GreenEyez View Post

If you are bitstreaming the audio to the receiver, whatever the drivers support is irelevant, the audio is not decoded and sent as a RAW stream to your receiver.

If you are decoding audio locally on the HTPC, it supports whatever your card supports. Most modern GPUs go up to 192/24 , WASAPI is just an API to let the audio decoder bypass windows audio settings and the kernel mixer and send the audio straight to the driver. So you will get 24/192 if your card supports it.

Quote:
Originally Posted by Puwaha View Post

Where are you getting this information? Do you aquahave links?

I found one place I read it. Its a 6 page document from cambrigeaudio.com. Its called, "Audiophile guide to bitperfrct usb audio". Its on my phone and I cant copy and paste from my document reader but I can email it to you. I dont want to post this on a fileshare site. One quote from it says the maxium outout of wasapi is 96/24. Il try to keep looking for the other places I read this, I think there were at least a couple forums.

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post #9 of 39 Old 02-08-2012, 08:57 PM
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Lower your buffer size. The higher the bitrate, the lower the buffer size needed.

I've seen the document from Cambridge Audio they are discussing a USB audio device which typically require even smaller buffers. The buffer that would be required for 192/24 on a USB device would be so small that it would result in extremely high system load causing lags in file access, UI refreshes, etc.

Cambridge Audio document: http://www.cambridgeaudio.com/assets...tober_2011.pdf
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post #10 of 39 Old 02-08-2012, 09:50 PM - Thread Starter
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Quote:
Originally Posted by vladd View Post

Lower your buffer size. The higher the bitrate, the lower the buffer size needed.

I've seen the document from Cambridge Audio they are discussing a USB audio device which typically require even smaller buffers. The buffer that would be required for 192/24 on a USB device would be so small that it would result in extremely high system load causing lags in file access, UI refreshes, etc.

Cambridge Audio document: http://www.cambridgeaudio.com/assets...tober_2011.pdf

I realize its about a product but that doesnt change the fact about whats stated about wasapi in the document. Im.not sure what the rest of what your saying has to do with, if wasapi does 192/24 or not though. Im not saying that you cant do 192/24 with wasapi, im just trying to figure out if it can or cant.

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post #11 of 39 Old 02-08-2012, 10:08 PM
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I'm saying that WASAPI can and will work with 192/24 but not with a USB audio device or S/PDIF. An HDMI or capable analog audio (Realtek ALC883) device is needed due to the bandwidth and latency.

The Cambridge Audio document is worded poorly and misleading in regards to WASAPI with other devices.
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post #12 of 39 Old 02-08-2012, 10:12 PM - Thread Starter
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Quote:
Originally Posted by vladd View Post

I'm saying that WASAPI can and will work with 192/24 but not with a USB audio device or S/PDIF. An HDMI or capable analog audio (Realtek ALC883) device is needed due to the bandwidth and latency.

I see, im sure you are correct but I am going to continue to research. They probably meant wasapi cant output 192/24 through usb. Ive contacted them about it and im still trying to find the couple other places i read about it.

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post #13 of 39 Old 02-08-2012, 10:15 PM - Thread Starter
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Quote:
Originally Posted by vladd View Post

I'm saying that WASAPI can and will work with 192/24 but not with a USB audio device or S/PDIF. An HDMI or capable analog audio (Realtek ALC883) device is needed due to the bandwidth and latency.

The Cambridge Audio document is worded poorly and misleading in regards to WASAPI with other devices.

Do you have any idea why noone is trying to implememt ASIO with video players, or are they?

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post #14 of 39 Old 02-08-2012, 10:28 PM
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Sorry, no idea. Probably because ASIO doesn't lend itself well to DirectShow but I haven't really looked into it so that would just be a guess.
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post #15 of 39 Old 02-08-2012, 10:35 PM
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Here are two examples of WASAPI 192/24:

http://yabb.jriver.com/interact/index.php?topic=49536.0 (was still working out some issues but that was 2009)

http://www.hydrogenaudio.org/forums/...dpost&p=609765
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post #16 of 39 Old 02-08-2012, 10:35 PM - Thread Starter
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Quote:
Originally Posted by vladd View Post

Here are two examples of WASAPI 192/24:

http://yabb.jriver.com/interact/index.php?topic=49536.0 (was still working out some issues but that was 2009)

http://www.hydrogenaudio.org/forums/...dpost&p=609765

Yeah ive found lots of examples of it, thats what ive always thought. I was just trying to find the other examples because after reading a couple things on it not being able to I wanted to find the truth. Thankyou though for the examples, I will check both out

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post #17 of 39 Old 02-08-2012, 10:43 PM
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Just remember that it also requires the audio device driver to support it. Sorry I can't be more help. I haven't messed with WASAPI/ASIO in a couple of years.
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post #18 of 39 Old 02-09-2012, 12:37 AM
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Quote:
Originally Posted by joeydrunk View Post

Do you have any idea why noone is trying to implememt ASIO with video players, or are they?

To implement ASIO, the driver of the audio device also needs to support it (as vladd wrote). Of course AMD, NVIDIA and Intel are not interested in it.

There is no problem in passing 192kHz/24bit in WASAPI exclusive mode. It's the audio device/driver that can or cannot handle such sample rate/bit depth. Many sound cards do not support it. Every latest HDMI audio device in AMD, NVIDIA and Intel supports 192kHz/24bit (NVIDIA does not support 88.2/172.4kHz however), but cheaper AVR many not be able to process it.
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post #19 of 39 Old 02-09-2012, 12:58 AM
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Quote:
Originally Posted by joeydrunk View Post

Do you have any idea why noone is trying to implememt ASIO with video players, or are they?

Winamp? Haven't tried it myself though.

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post #20 of 39 Old 02-10-2012, 07:36 AM - Thread Starter
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edit: messed up the copy and pasrte of emails

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post #21 of 39 Old 02-10-2012, 07:50 AM - Thread Starter
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AGAIN, NOT SAYING THIS IS CORRECT, JUST SHOWING 2 EMAILS SENT TO CAMBRIGE AUDIO AND THERE RESPONSE.

1ST EMAIL "I've always thought bluray audio was capable of 192/24 using wasapi. After reading the above titled document im not so sure. In the document it states the windows audio and wasapi is only capable of outputting 96/24. Does this only apply to usb and/or the device driver mentioned in the document or does it apply to wasapi in general. When I play a 192/24 bluray and as my avr and gpu/sound card and all hardware and software player support 192/24 will it work or can wasapi just not do 192/24 no matter what? Or will it just do audio.192//24 but not video.192/24?"

ANSWER: "Dear Joe,

Thank you for your email.

Via USB from a computer given the track you can playback up to 24/192 using the USB audio driver.

The driver will allow up to 24/192 via USB for audio only.

Wasapi significantly improve the sound and is limited to 24/96.

If you install the USB audio driver and use ASIO you can stream 24/192 via USB if you so wish.

Regards,
Josh Armstrong"



AFTER THE FIRST QUESTION I WAS STILL UNSURE IF HE THOUGHT I WAS JUST TALKING ABOUT WASAPI AS REFERED TO IN THE ARTICLE. I THOUGHT HE MIGHT THINK I WAS TALKING ABOUT IT JUST FOR THE USB DRIVER IN THE DOCUMENT, SO I TRIED TO BE MORE SPECIFIC AND SENT ANOTHER ONE.

2ND EMAIL: "In the document first mentioned it says"Using WASAPI gives a maximum output of 96/24." Does this refer to WASAPI in any form or just through usb with the cambridge driver? My question is, is it possible to do 192/24 with wasapi? Either through the hdmi of of a gpu/sound card that supports it, or through usb, etc. A sacd, a sacd rip, a bluray, a bluray rip etc. As long as the source is 192/24 and all the hardware can support 192/24 & the player can support it. Can wasapi do 192/24??"



Answer: "It is WASAPI as a format. Joe it is not possible to do 24/192 through WASAPI as we state in the USB Audio guide.

ASIO can support this however, let me reiterate WASAPI can do a maximum of 24/96.

Regards,
Josh"

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post #22 of 39 Old 02-10-2012, 08:05 AM
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I think it's dependant only on the capability of the equipment. I just tried WASAPI at 192 kHz and my Sony receiver shows that it's receiving and playing at 192.

I am upsampling a FLAC file from 88.2 to 192.

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post #23 of 39 Old 02-10-2012, 10:25 AM
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Quote:
Originally Posted by jriver View Post

I think it's dependant only on the capability of the equipment. I just tried WASAPI at 192 kHz and my Sony receiver shows that it's receiving and playing at 192.

I am upsampling a FLAC file from 88.2 to 192.

Same here using Foobar2000 with Flac upsampled to 192. WASAPI from HTPC to my Elite receiver, no issues.

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post #24 of 39 Old 02-10-2012, 11:43 AM
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@joeydrunk

Are you interested in a USB audio device? Then what Josh Armstrong wrote is true. With USB Audio Class 1 device, the max audio data rate is 96kHz/24bit. USB Audio Class 2 allows up to 192kHz/24bit. But even Windows 8 seems not to support USB Audio Class 2 devices. Perhaps that's why USB Audio Class 2 devices support 192khz/24bit only in ASIO, not in WASAPI exclusive mode.

The discussion is specific to USB audio devices. Every lastest HDMI audio device from AMD, NVIDIA, and Intel supports up to 192khz/24bit. And WASAPI exlusive mode transmits audio streams at whatever sample rate/bit depth the audio device supports.
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post #25 of 39 Old 02-10-2012, 02:59 PM
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Just going to say that my Onkyo TX-SR875 doesn't support 6 channels of 192kHz 24 bit but only stereo a this resolution/bit depth. I think the highest it could do in 6/8 channels is 96kHz 24bit. I think this was changed with the 876

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post #26 of 39 Old 02-11-2012, 06:36 AM - Thread Starter
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Quote:
Originally Posted by renethx View Post

@joeydrunk

Are you interested in a USB audio device? Then what Josh Armstrong wrote is true. With USB Audio Class 1 device, the max audio data rate is 96kHz/24bit. USB Audio Class 2 allows up to 192kHz/24bit. But even Windows 8 seems not to support USB Audio Class 2 devices. Perhaps that's why USB Audio Class 2 devices support 192khz/24bit only in ASIO, not in WASAPI exclusive mode.

The discussion is specific to USB audio devices. Every lastest HDMI audio device from AMD, NVIDIA, and Intel supports up to 192khz/24bit. And WASAPI exlusive mode transmits audio streams at whatever sample rate/bit depth the audio device supports.

I was trying to make it a clear as possible to the guy I was talking about wasapi in general. After his first response I made it clear in my second question I didnt just mean usb but in any form. With his second respinse it sounds like he is clearly stating that wasapi cant do 192/24 wich from most everything ive read seems to not be true. The discussion was not about usb devices or at least my side wasnt, I was tryging to get the point across to him but I dont know if he belives wasapi cant do 192/24 or if he just couldnt comprehend my question. By the way do you knkw of any documentation stating wasapi standards/specs besides just a forum conversation? Also if.youll read my emails in my post below youll see that I ask him a couple times about not only usb devices but if the hardware, avr, software, players, gpu w/hdmi etc. playing a bluray rip, SACD, etc. w/192/24, it should be pretry obvious
Im not talking about usb.

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post #27 of 39 Old 02-11-2012, 06:48 AM
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If you are not interested in USB audio device, why bother with Cambridge Audio's document? It's about USB audio device and the document is 100% correct (it never says WASAPI in general is limited to 96kHz/24bit). However Josh Armstrong has no clue what WASAPI can do in general. Perhaps he is so narrow minded that "USB" audio device is everything in the world to him.
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post #28 of 39 Old 02-11-2012, 07:05 AM - Thread Starter
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Quote:
Originally Posted by renethx View Post

If you are not interested in USB audio device, why bother with Cambridge Audio's document? It's about USB audio device and the document is 100% correct (it never says WASAPI in general is limited to 96kHz/24bit). However Josh Armstrong has no clue what WASAPI can do in general. He is so narrow minded that "USB" audio device is everything in the world to him.

I dont even know who he is, sounds like you do. Was one of many places I looked for an answer. It was the most "legitamate" seeming document stating wasapi cant do 192/24. Its under a usb heading but it sounded like he is talking about it in general. So it got me curious and So I decided to email and ask cambridge audio about it and post the findings of the response. I believe what you say much more than some guy but I always check as many avenues for answers as possible. Thats why I would like to see some Wasapi standards/specs.

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post #29 of 39 Old 02-11-2012, 07:14 AM
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Well, experimenting yourself is usually quicker than asking somebody whom you don't know very well. Here is a clip of 5.1 192kHz 24bit audio. Try it and see yourself.

As already stated, WASAPI can transmit audio streams at whatever sample rate/bit depth the audio device/driver accepts. Every latest AMD, NVIDIA or Intel HDMI audio device supports up to 7.1ch 192kHz 24bit.
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post #30 of 39 Old 02-11-2012, 07:22 AM
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Joey, the guys at Cambridge audio still think you are talking about their USB devices since you didn`t mention audio via HDMI cards in your mail. Hence the response.

You won`t find any WASAPI standards/specs because there are none, only tehnical info for developers on Technet on how to develop and use WASAPI compatible decoders. WASAPI is just an API which handles the audio stream tranzition from the decoder to the audio driver, bypassing the standard Windows Audio mixer. It does not touch or alter the audio stream in any way.

Basically i goes like this : The audio decoder calls the WASAPI API transmiting info about the audio stream (sample rate/bitdepth). WASAPI then makes a call to the audio driver, checking is the PCM stream sample rate/bitdepth is compatible with the driver specs. If the hardware supports 192/24bit it passes the audio stream to the driver. If the formats are incompatible (say the audio driver says it can only do 24bit/96hz max) the sync between WASAPI and the driver fails, and WASAPI sends a callback to the decoder to resample the audio to the appropiate sample rate/bitdepth that the audio driver supports.
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