• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Synchronization problem in 10.2: physical memory
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Synchronization problem in 10.2: physical memory


  • Subject: Re: Synchronization problem in 10.2: physical memory
  • From: Michel <email@hidden>
  • Date: Sat, 5 Oct 2002 01:34:10 +0100

On Friday 04 October 2002 23:37, Michel wrote:
> What I SUSPECT happends is that when the second client arrives, the
> calculation as to where it's samples should go fails because their time
> stamp is too old, thus it's destination wraps back the buffer into the
> 'future' of it. and thus gets overriten by the mixer when it arrives at
> that point for the client 1.

There, I tried 2048 samples, and the mixing problem vanished. Completely. I
play with up to 5 clients and the sound is perfect.

Maybe that could be documented. somewhere, "do not use < 2048 samples" in the
IOLog ;-)

For the other problem related to the memory, I'm building a class that throws
together IOMallocContiguous and IOMemoryDescriptor. You configure it with a
minimum segment size, and a wanted size. It uses IOMallocContiguous to make
up segments, builds up an IOMemoryDescriptor with those, map() them for
IOAudioEngine sake.

That way I can limit the frequency of the swapping interrupts. Further tests
with IOMalloc + IOMemoryDescriptor::getPhysicalSegments are all showing the
same: it is impossible to get a segment bigger than ONE page.

Michel


--
Linux yawn 2.4.19-ac4 #49 Tue Aug 6 10:13:51 BST 2002 i686
_______________________________________________
coreaudio-api mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/coreaudio-api
Do not post admin requests to the list. They will be ignored.

References: 
 >Re: Synchronization problem in 10.2 (From: Mark Cookson <email@hidden>)
 >Re: Synchronization problem in 10.2: physical memory (From: Michel <email@hidden>)

  • Prev by Date: Re: ANN: Audio IB Palette
  • Next by Date: Re: ANN: Audio IB Palette
  • Previous by thread: Re: Synchronization problem in 10.2: physical memory
  • Next by thread: Re: Synchronization problem in 10.2
  • Index(es):
    • Date
    • Thread