Re: [pygame] Pygame Mixer Crackle noise not an SDL_Mixer problem

[Lenard Lindstrom <len-l@xxxxxxxxx>]

I found a couple of postings about enabled notification events. In one it had 
no effect on sound quality. In the other it prevented the driver from going 
into an infinite loop, but the sound quality was "horrible". Both are older 
postings though (2002). There's been a patch since then. As for DirectX 5 
support, the SDL tries to enable notification events and falls back to a busy 
loop if it fails. And I doubt anybody still has DirectX 5. Newer DirectX 
versions are (supposedly) backwards compatible anyway.

Does it makes sense to keep the current SDL.dll as standard and make the 
notification version available as an alternate for anyone wishing to try it?

Lenard



Quoting René Dudfield <renesd@xxxxxxxxx>:

> Ah, that sounds like it could be a good thing to use.  Is it easy
> enough to make a version check for directx first?
> We would need to test it a fair bit, in case that's a crashy path I think.
> 
> I remember directx version checking being a bit hard... They don't
> just have a get_version() function... you need to do weird hacks...
> 
> 
> Well there is a function in the directx samples for getting the direct
> x version:
> "Rather than provide a detailed list here of each version's
> characteristic interfaces and objects, you should refer to the
> DirectXsoftware development kits (SDKs) sample section. One of the
> samples is a function, GetDXVersion, that includes tests for all
> DirectX versions. GetDXVersion returns an integer that corresponds to
> the DirectX version that is present on the system. As long as this
> integer is greater than or equal to your desired version number, your
> application will run normally. You can find the sample code under your
> SDK root folder at \Samples\Multimedia\DXMisc\GetDXVer."
> --
> http://msdn.microsoft.com/archive/default.asp?url=/archive/en-
us/directx9_c/directx/intro/program/version/versioncheck.asp
> 
> According to that page win98 came with directx 5.1
> 
> Anyone have access to the directx samples?  I found this one:
> http://www.worldfoundry.org/doxygen/html/getdxver_8cc-source.html
> 
> But looking at that GetDXVersion function(there's all sorts of
> weirdness in there), it might be safer to just enable the option?
> 
> 
> 
> 
> On Thu, Apr 24, 2008 at 3:06 PM, Lenard Lindstrom <len-l@xxxxxxxxx> wrote:
> > There is a feature I can enable in SDL's DirectX driver. It uses event
> >  notification to tell when a buffer is free. The default is a DirectX 5
> >  compatible semi-busy wait. I tried it while debugging and it did clear up
> the
> >  sound somewhat. It went from slow and crackly to just crackly. Maybe this
> would
> >  take care of any problems that still exist after increasing the chunk
> size.