Maybe I have missed something, but from the XNA Gamefest videos I haven't heard one way or the other whether raw sound buffer access will be exposed, like in managed directx. Was there a presentation that addressed this?

I don't recall this being mentioned.

The only *announced* sound changes were that it will pick up a later version of the XACT engine and editor (I don't know if 100% of new features were announced at gamefest) - see ziggys pictures here http://www.ziggyware.com/GameFest2007/2007-08-13_124806.PNG

 

ZMan is right, we didn't announce raw sound buffer access.

That's because it's not going to happen this fall.

Sorry!

Just one of the many cool features that didn't quite make the cut when comparing task lists and time estimates with the number of developers and days we had available :-)

Thats OK, lots of cool features are making it into this next release. Thanks for the hard work!

Hey Shawn,

Thanks to the team for all the hard work put into XNA. I'd just like to echo my own personal desire for this feature. Mainly I'd like to be able to access the sound buffer for the music being played via the dashboard to use interactively for visualization. I can do this on windows using ASIO and some c++, but clearly this approach will fail on XBOX.

Can't wait for this feature though, so keep us posted if it shows up anywhere on the work queue.

Adam

I too would really love to see this feature.

I have it sortof working in my game currently.  I am generating my own wavformdata with 0.25 second length and saving it out as a .wav file.  I then make 4 copies of the file and load all 4 into XACT into seperate wave banks.  This creates 4 .xwb files when you run the game.  At runtime, I am overwriting the raw PCM data in these files in successsion (exactly like a ring buffer).  I then load and play the cues a bit delayed from the audio generation, this gives me dynamic audio playback.

It would be very nice to not have to jump through these hoops and use a hack to play dynamic audio though :)

Fascinating hack... does it work on the 360 too?

"Mainly I'd like to be able to access the sound buffer for the music being played via the dashboard to use interactively for visualization."

If your music isn't dynamic, you should be able to extend the content pipeline to bring a wav file into a good datastructure for use this way.

acid1789:

At runtime, I am overwriting the raw PCM data in these files in successsion (exactly like a ring buffer). 

That's one of the most ridiculously "so evil it wraps around and becomes insanely cool" hacks I've heard about in a long, long time :-)

That hack sounds awesome, but you can't get truly interactive audio with it because of the 4 audio-fps. I think XNA as a whole (and most of the game industry, tho the trend is changing) is more for graphics. Audio is just kind of "tagged on" with XACT. I know this isn't entirely true, and that I am generalizing. I dont mean to offend, XNA team. But with most of XNA, you get the "Wow this is easy to do" along with the "I can do anything." But with audio, I seem to be missing out on the second half. Sure we can use external libraries and unwrapped directx, but... not on xbox. I understand you guys are adding features, but fleshed out audio would be nicer than some sparkles, I would think. Or at least allow us to get to the flesh (audiobuffer access) so we can flesh it out ourselves. Meh, my $0.02

Louis Ingenthron:

Or at least allow us to get to the flesh (audiobuffer access) so we can flesh it out ourselves. Meh, my $0.02

That’s definitely a big feature that is missing in XNA. I need this to be able to generate synthesis sound and music at runtime and having a raw access to audio buffer is the only way to achieve this. The power of modern CPU (and even music generated by the GPU) allow us to imagine new kind of music and dynamic sound experience... Moreover, an api giving access to raw audio is quite easy to develop...

acid1789:

I have it sortof working in my game currently.  I am generating my own wavformdata with 0.25 second length and saving it out as a .wav file.  I then make 4 copies of the file and load all 4 into XACT into seperate wave banks.  This creates 4 .xwb files when you run the game.  At runtime, I am overwriting the raw PCM data in these files in successsion (exactly like a ring buffer).  I then load and play the cues a bit delayed from the audio generation, this gives me dynamic audio playback.

Is this trick suitable to generate a music at runtime ? As i understand, you have to access and modify the files on the disk, but how do you overwrite the raw PCM of this files ? (xwb is a proprietary format) Do you use some kind of data markers in the initial raw PCM to find the range of data to modify in the xwb file ?)

@lx:

Is this trick suitable to generate a music at runtime ? As i understand, you have to access and modify the files on the disk, but how do you overwrite the raw PCM of this files ? (xwb is a proprietary format) Do you use some kind of data markers in the initial raw PCM to find the range of data to modify in the xwb file ?)

That would be good speculation but lets leave this as exercises for the reader.... discussions on reverse engineering MS formats isn't something we want to talk in great detail about here since its EULA breaking territory.