Audio Processing in Vista Explained

[IronCamel]

Originally Posted by IronCamel

Maybe I missed it, but did Amir ever answer this. This is my only concern as well. Anyone using DVD and CD playback from the same box is going to be annoyed if they have to change the sample rate for each format every time they switch between the two. This would be the same as we have now.

Is there an option to have it simply leave the stream alone and just pass it to the outputs?

Is it possible to completely sidestep ALL of these features or shut them off completely? (e.g. completely gone, never accessed, never used)

90% of the features listed are of no use to me, and I will be VERY annoyed if MS assumes that I want them and makes them non-defeatable, or worse, says they are defeatable but they continue to run in the background anyway. Every time I install XP (without an image) it takes about an extra 40min to make all the changes that I require to have a usable system.

What we have been asking for from the start is for CDs to play at 44.1 and DVDs at 48 with 0 human intervention. That shouldn't be too hard since any $30 APEX can figure out how to do that.

So I'll take that as a no?

[vairulez]

This if from apcstart.com...I guess they announced it at Tech ed 2006

Microsoft revealed today that no 32-bit versions of Windows Vista will be able to play back “next generation high definition protected content” (translation – studio-released BluRay and HD-DVD movies).

By far the majority of PCs use 32-bit processors, because despite AMD’s efforts to push 64-bit CPUs into the marketplace early, Intel’s first widely-promoted 64-bit CPU is the just-released Core 2 Duo.

PC users will now have to choose between a PC that can play high definition content (64 bit) versus one that can potentially run older devices that only have unsigned drivers available (32 bit).

“Signed drivers” are ones that have undergone a Microsoft quality-assurance process and received a digital certificate that certifies them as stable for installation on 64-bit Windows.

Microsoft’s move to drop support for playback of studio-released HD movies on Vista is likely to anger the large number of people who were hoping they could use their existing 32-bit PC with an upgrade version of Vista.

The surprising disclosure was made by Senior Program Manager Steve Riley during a presentation on Windows Vista security at Tech.Ed 2006 Sydney today.

“Any next-generation high definition content will not play in x32 at all,” said Riley.

“This is a decision that the Media Player folks made because there are just too many ways right now for unsigned kernel mode code [to compromise content protection]. The media companies asked us to do this and said they don’t want any of their high definition content to play in x32 at all, because of all of the unsigned malware that runs in kernel mode can get around content protection, so we had to do this,” he said.

Riley then attempted to pre-empt audience concerns over the newly imposed limitation by asking how many of the Tech.Ed attendees currently played high-definition movies at home.

“How many of you have a DVD player that you know can output a proper 1080 line non-interlaced?”

No-one raised their hands.

“OK… look around. By the time that stuff becomes popular, it’ll no longer be an issue because everyone will be running 64-bit Windows,” he said.

However, earlier in his presentation, Riley had explained why Microsoft had decided to let unsigned code run in 32-bit Windows, but not in 64-bit Windows.

“Imagine how difficult it would be for you [the Tech.Ed attendees] to update your environment. It would be a non-starter, right?”

“We can’t do that [lock out unsigned drivers from 32 bit Windows]. The app-compat hit, as we say in Microsoft, would be far too great if we did it in 32-bit Vista.”

In an interview hastily organised by Microsoft public relations staff after they learned APC was planning to run this story, Riley was at pains to point out that Blu Ray and HD-DVD were storage media and “you could put an MPEG-4 movie on them and play them on a 32bit Vista PC just fine.”

But he conceded that a commercially-produced BluRay or HD-DVD movie with next-generation high definition protected content wouldn’t play on a 32 bit PC.

Amir when did you intend to talk to us about this "small" limitation of vista ????

[amirm]

Originally Posted by vairulez

Amir when did you intend to talk to us about this "small" limitation of vista ????

Sorry but it will take me a bit of time to figure out what our person said and what the article claims! Let me ask around and find out what the background on this. If you have a specific concern, ask me and I will definitely address it.

[vairulez]

as you ask :

will vista allow a bit perfect output when volume is at 100% or do we still need to use some sort of kernel streaming or asio for that ?

what will be mandated on the audio side to have non donwsampled audio (ex: logo compliant drivers ? WHQL drivers ? special audio chipset ) with hd-dvd and brd

is watermarked audio still in the talk for hd-dvd and BRD ?

[jmschnur]

Given the comments about 64 bit being required for HD DVD/Blu ray output by Microsoft,

will the DRC features work in 32 bit systems?

Joel

[n4cer]

The information in the APCStart article about lack of HD support on 32-bit was wrong.
Check

Clarifying Windows Vista Support of Protected HD Content in 32-bit Systems
http://blogs.technet.com/windowsvist...24/450081.aspx

and
Vista to support HD DVD, Blu-ray after all?
http://news.com.com/2061-10794_3-610...9427&subj=news

[vairulez]

they do not really say it's wrong, they say it's up to the ISV to allow 32 bit playback or not, but this quote

The media companies asked us to do this and said they don’t want any of their high definition content to play in x32 at all, because of all of the unsigned malware that runs in kernel mode can get around content protection, so we had to do this,” he said.

tells me they won't

[amirm]

The part you quoted above is a mis-statement. No content owner had contacted us to make that request. The speaker at TechEd was mistaken in that regard.

BTW, my group developed all of these technologies. But the speaker works in another group so was not privy to full set of information unfortunately.

[augerpro]

This garbage has got to stop. Amir I hope you are right and this won't be implemented. I mean ALOT of us update our video drivers quite frequently for gaming and htpc reasons and considering only 1 out of 10 the recent nvidia/ATI drivers ever get around to being certified and you'll see this isn't just a huge PITA but a total nonstarter. By that I mean I'd rather burn all my new HD movies and sit this round out. I understand Hollywood is a bunch of dolts who don't realize how impractical this is for consumers, but I would hope MS can explain how absolutely ludicrous some of these schemes are.

[amirm]

I hear you.

This is me btw: http://www.microsoft.com/presspass/e...m/default.mspx

So you can put fair amount of trust in what I mentioned above .

[vairulez]

amit, just in case you haven't seen my questions :

will vista allow a bit perfect output when volume is at 100% or do we still need to use some sort of kernel streaming or asio for that ?

what will be mandated on the audio side to have non donwsampled audio (ex: logo compliant drivers ? WHQL drivers ? special audio chipset ) with hd-dvd and brd

is watermarked audio still in the talk for hd-dvd and BRD ?

[eleson]

Originally Posted by amirm

...

BTW, my group developed all of these technologies. But the speaker works in another group so was not privy to full set of information unfortunately.

To me it more sounds like:
But the speaker works in another group and was not up to speed so was not up to speed on what was to be considered privileged information unfortunately.

In the end, I think we are blessed to be able to share and access information from people in the industry.
Keep it goin'.

/Erland

[jmschnur]

Amir,

Thanks so much for going on lline. This has been very useful for me and quite instructive!

I really would like to use the new DRC your developing in my living room with my current set up. This inlcudes a 2.0 p4 chip, an ASUS P4 mother board and a Lynx One with analogue xlr out to my preamp?.

Will this be possible or will I need to upgrade the motherboard and CPU , get a new sound card to use DRC. I control the computer remotely (wifi) and only use if for aduio playback and as my audio server (no use of keyboard, mouse of monitor). I use XP2 professional now.

I have another system in my media proom that I would also like to use-this is an ASUS P5 board and 3.0 P4 chip with an Nvidia card (6600gt). I probably would buy a new sound card for this one-would I need to also change the CPU?



Joel

[scorch123]

Originally Posted by jmschnur

Amir,

Thanks so much for going on lline. This has been very useful for me and quite instructive!

I really would like to use the new DRC your developing in my living room with my current set up. This inlcudes a 2.0 p4 chip, an ASUS P4 mother board and a Lynx One with analogue xlr out to my preamp?.

Will this be possible or will I need to upgrade the motherboard and CPU , get a new sound card to use DRC. I control the computer remotely (wifi) and only use if for aduio playback and as my audio server (no use of keyboard, mouse of monitor). I use XP2 professional now.

I have another system in my media proom that I would also like to use-this is an ASUS P5 board and 3.0 P4 chip with an Nvidia card (6600gt). I probably would buy a new sound card for this one-would I need to also change the CPU?



Joel

Amir,

Joel brings up another point - legacy pro audio hardware support. Many of us who have built htpcs use pro audio sound cards. What is Microsoft doing to allow companies such as RME, Lynx, etc make sure their drivers will be Vista-compatible?

Thanks,

- Steve O.

[IronCamel]

Originally Posted by Waters_10

I was convinced ASIO wouldn't be necessary any longer, but this got me worried! I don't want to set the default sample rate! I want the mixer to leave the stream untouched. Meaning, it'll output 44.1 when you're listening to ripped cd's and 48 when you're listening to mp3's, dd, etc. Please, clarify a bit on this. Is that what this exclusive mode is intended for?

Amir,

This question has been asked by several people and summarily dodged. I'm going to assume that this is because Vista will NOT have the ability to output bit-perfect audio without intervention or 3rd party software. If this is the case, what is the point of bringing it up? You are here enough to know that this isn't what is desired. How hard is it to program Windows so it doesn't screw with the stream. If I don't want windows doing the processing, why would I want windows to even touch the stream?

It's kind of lame you can't at least give us an answer.

[eLupus]

since ms has standardised the transfer of wma content over s/pdif (can't find the link right now), how about lossless wma -> s/pdif? if you could encode wma lossless in realtime and output it over s/pdif, reciever could take advantage of any processing, while still using a simple connection.

or maybe the bandwidth of s/pdif can't handle multichannel lossless wma?

[Rthoreau]

I kind of feel sorry for ya Amir, at least you are trying to do the right thing!

What I see is it comes down to the bigger fish telling the little fish his place. IronCamel and Viarulez each have valid points, but I think that some of these choices are made in the backroom. I doubt they really have the concerns of the community at heart, that is until it starts to hurt their bottom line.

For me this is just one more reason not to get Vista, with all the DRM and restrictions put on the consumer, like the whole license idea, if you change your motherboard you need a new license, other such nonsense.

Hopefully Open Souce has a good answer when the hardware is available at a good price. Even if it's DRM packed.

[CSMR]

Originally Posted by eLupus

since ms has standardised the transfer of wma content over s/pdif (can't find the link right now), how about lossless wma -> s/pdif? if you could encode wma lossless in realtime and output it over s/pdif, reciever could take advantage of any processing, while still using a simple connection.

or maybe the bandwidth of s/pdif can't handle multichannel lossless wma?

Then you would need a new generation of receivers to process this. I don't know about multichannel issues but I don't think it will standardize on transfer via any sort of lossless encoding. This requires a lot of processing to save only 40-60% space so is useful for storage but not for a high-bandwidth digital connection.

[CSMR]

Originally Posted by Waters_10

I was convinced ASIO wouldn't be necessary any longer, but this got me worried! I don't want to set the default sample rate! I want the mixer to leave the stream untouched. Meaning, it'll output 44.1 when you're listening to ripped cd's and 48 when you're listening to mp3's, dd, etc. Please, clarify a bit on this. Is that what this exclusive mode is intended for?

Well even if it's not possible setting a default rate will be very satisfactory IF there is a good resampling option (SSRC?) and you are interested in analog output or digital out to a DAC (rather than to a digital processor). Just set the rate to 96khz or 192khz and the output should be pretty good, probably better in theory than having no software resampling and using whatever sort of processing or analog filtering your soundcard or dac does.

Even if the resampling is not good you can at least resample yourself in key programs - audio, video - and have them output at the windows frequency.

What you seem to want is for windows to change the soundcard setting and send sound at that freqency but that isn't even possible for many professional soundcards which is mostly what we are interested in. I don't know how my soundcard would react on being told to change to 44khz say. It would need drivers to be redesigned to accomodate this.

[johnren]

Amir

I am looking for a way to programmatically set the sound device for playback in Windows Vista per application (useful for apps that don't have a way to do this directly). In XP, you could set the SoundMapper registry setting “Playback” key to the name of the device you wanted the program to use as long as you set it before program startup. Once the program started, you could set the “Playback” key to a different device and have all the other applications loaded after that point to use that newly set device. This helps keep sound secluded for recording audio calls and things of that nature.

The only caveat is that you couldn’t use the mmsys.cpl to reset the device otherwise the program would default back to the device you set it back to once the program stopped outputting audio.


Does anyone know if there is a registry key in Vista that will do the same thing as in XP? Or if they are going to be adding the ability to specify the output device for each "session' shown in the new volume control? They let you set the volume per app, I think it would be very beneficial to be able to set the audio device per app and make this doable programmatically.

Any help would be appreciated.

Thank you,

John

[CSMR]

Amir:

This is great stuff. I didn't know there was any Microsoft interest in high quality audio playback but this is really quite impressive. I am certainly eager to try out the new system. I have one quesion about the DSP business:

Suppose you have more than one destination for audio. For example:
a soundcard with two stereo outputs, one for headphones, one for speakers
one output used for both headphones and speakers

Would it be easy to accomodate these things: in the first instance by processing in one way for the first output and in another for the second; and in the second instance easy switching of settings?

(Note if the first thing is possible that would be a point scored over foobar!)

One more thing actually: is it a convolution method that you use for audio processing?

[amirm]

Originally Posted by vairulez

amit, just in case you haven't seen my questions :

Sorry for the late reply. Hang in there if you don't mind a bit longer. I have asked the developers to chase some things down for me.

But for now, this is how it works. As I mentioned, to have high fidelity digital volume control, we change the values in floating point, not integer. That way, we can maintain very high resolution. The conversion to and from floating point is lossless. So we get the same value in and out. But anythime you change resolution (i.e. going form float to integer), you don't want to just truncate the extra bits. You want to do something kind of dithering. And that is what we are doing. What I have asked the team to do is to run through your scenario of 100% volume and see if the dithering ever makes the values different.

My guys are busy getting Vista out, and I am supposed to be on vacation . So it takes a bit of time to investigate things like this.

[amirm]

Originally Posted by IronCamel

Amir,

This question has been asked by several people and summarily dodged. I'm going to assume that this is because Vista will NOT have the ability to output bit-perfect audio without intervention or 3rd party software. If this is the case, what is the point of bringing it up? You are here enough to know that this isn't what is desired. How hard is it to program Windows so it doesn't screw with the stream. If I don't want windows doing the processing, why would I want windows to even touch the stream?

It's kind of lame you can't at least give us an answer.

Hey come on guys. I never shy away from answering questions on AVS Forum. Anyone who follows me in HD forums knows this by now. It is just that I am on vacation, and had to drive the family to the vacation home all yesterday. And as I noted in the other post, my guys are really busy with RC-1 so asking detailed questions takes some time.

As to your comment, no it is not easy to do what you say. Our average customers want convenience, so they don't tolerate media player playing music, and not hearing some other system sound. Yes, I know as audiophiles you hate this and I hate it too. But mixing is a required functionality in the OS. And as soon as you mix audio, you have to worry about headroom as two full bandwidth audio streams can go past 100% digital values. So you have to do some kind of dynamic leveling. Per my original post, we have a much more sophisticated leveling algorithm in Vista so performance should be good. But it is not a transparent path. At least it doesn't seem to be until I get to end of the analysis with the team.

We have developed an exclusive access path in Vista. So apps can now use this and not resort to another third-party stack like ASIO. This way, it is all supported by us using one driver. This is the solution for absolute fidelity where nothing is touched. Yes, it is not as convenient as having our cake and eat it too. But if you want perfection, sometimes you have to spend $10K on an amp, and here, use a dedicated path.

Again, I might come back with better news later.

For now, note that when we do process, the processing this time is designed by people who understand audio. Our resampler for example, has very high performance. This is nothing like XP.

[amirm]

Originally Posted by eLupus

since ms has standardised the transfer of wma content over s/pdif (can't find the link right now), how about lossless wma -> s/pdif? if you could encode wma lossless in realtime and output it over s/pdif, reciever could take advantage of any processing, while still using a simple connection.

Actually, you don't need to do that for stereo WMA Lossless. S/PDIF is fine for carrying stereo PCM. So you can just let the PC decode and process it and send the output digitally to your receiver. ALL receivers can handle PCM uncompressed this way.

or maybe the bandwidth of s/pdif can't handle multichannel lossless wma?

So you mean WMA Professional, our multi-channel codec. If so, then yes, you would need a new receiver. Currently, only Pioneer receivers can do this. Other companies may also bring out products. But the trend is to not use S/PDIF, but your home network. That way, you don't have to put them in the same room. Today, these implementations are for regular WMA only. But Onkyo in Japan has a WMA Pro implementation I believe and there will be more soon.

[amirm]

I am also chasing the sample rate question. But CSMR's suggestion is an excellent one. Per my note before, Vista resampler has very high quality with excellent SNR. So you should be able to have it resample to a setting that gets the best out of the DAC in your receiver.

[amirm]

Originally Posted by Rthoreau

For me this is just one more reason not to get Vista, with all the DRM and restrictions put on the consumer, like the whole license idea, if you change your motherboard you need a new license, other such nonsense.

I want to be very clear on this: Vista does not put any DRM restrictions on the user. It simply adds more capabilities for applications to use, or ignore.

[jmschnur]

Amir,

When this is done, would you use Vista to process sound as described for your high end audio system? If not what compromises do you envision?

I really thank you for the time you are spending on this-but take some time to relax a bit too while you are on vacation.

joel

[jsm88]

Amir

Ok - I appreciate you being forthright up to this point about this BR/HD-dvd issue, and I assume you've noticed that you've gotten some attention and credit from a few tech sites for addressing this issue. However - lets get down to the real point here:

You say that Vista will not play, or refuse to play, any content - fair enough, it's the operating system and really shouldn't make that determinaton - but that it will be up to the individual makers of the playback software whether it will function in 32bit vista. Ok, you can't speak for any other software manufacturer but will Windows Media Player, or whatever it's Vista version is called, play back Hidef content from those sources in 32bit Vista? That is what most of the world interpreted your man's comments to mean - that windows software itself would not allow the mentioned playback, whether it is official a "part" of Vista or an ancillary, but generally viewed as intergral, product.

Saying that 32 bit vista won't refuse to play back anything is just a little too cute, since, of course 32 bit vista doesn't actually play back anything.

[Jim Miller]

wmp doesn't play dvds now. probably to avoid such contentious issues.

why would you expect wmp to play hd versions of dvd?

jtm

[lymzy]

Originally Posted by Jim Miller

wmp doesn't play dvds now. probably to avoid such contentious issues.

It is because MPEG2 doesn't provide a royalty cap from Microsoft and it doesn't make business sense to provide MPEG2 decoder for every edition of windows XP.

Originally Posted by Jim Miller

why would you expect wmp to play hd versions of dvd?

jtm

It is because Microsoft doesn't want to be marginalized for the next generation, or bigger picture-consumer media delivery chain. It is also why MS is one of the key founders of AACS and major force behind iHD and VC-1. Also, Vista based MS-DRM would be AACS approved to enable managed copy of HD DVD and thus provide a complete home streaming solution.