• 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: Problem with CAPlayThrough and Tiger
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Problem with CAPlayThrough and Tiger


  • Subject: Re: Problem with CAPlayThrough and Tiger
  • From: Jeff Moore <email@hidden>
  • Date: Tue, 02 Dec 2008 12:35:56 -0800

This sounds like the same issue that is being discussed in the "Switching Device Programmatically and Subsequent call to AudioDeviceGetCurrentTime" thread. Rather than repeat myself, I recommend you read that thread.

On Dec 2, 2008, at 3:35 AM, Stephan Bernsee wrote:

I have run into a strange problem that only seems to occur on Tiger
(works ok on Leopard) and I just can't figure out what the problem is.
What I want to do is basically use CAPlayThrough to intercept system
audio. For this, I need to switch the default system output device to
my own device (loaded as a KEXT) and use this as an input to my
program.

So far so good - if I switch the device manually everything works.
However, if I attempt to do this programmatically I am getting a
'stop' error on a subsequent call to AudioDeviceGetCurrentTime() (the
one that drives the Varispeed AU for matching in and out sample
rates).

I have narrowed down the problem and created a small test project
based on the original CAPlayThrough that demonstrates this. All I did
was add a call to AudioHardwareSetProperty with a selector of
kAudioHardwarePropertyDefaultOutputDevice to -awakeFromNib in
CAPlayThroughController.mm and it would exhibit the exact same problem
as the product I am working on.

Does any of you have any idea what is wrong with setting the device
programmatically on Tiger? Any known bugs that I should be aware of?
...hopefully with a workaround..?
As I said, the same code works great on Leopard. I'd appreciate any
thoughts on this as I really have no idea what is going on here, and I
wasn't able to find anything on the web or in the archives.

Here's my little test project:
http://stephan.bernsee.com/CAPlayThrough-Test.zip



--

Jeff Moore
Core Audio
Apple


_______________________________________________ Do not post admin requests to the list. They will be ignored. Coreaudio-api mailing list (email@hidden) Help/Unsubscribe/Update your Subscription: This email sent to email@hidden
References: 
 >Problem with CAPlayThrough and Tiger (From: "Stephan Bernsee" <email@hidden>)

  • Prev by Date: Re: Switching Device Programmatically and Subsequent call to AudioDeviceGetCurrentTime
  • Next by Date: Re: IOAudioEngine::performFormatChange cannot be triggered by change of I/O Buffer Size
  • Previous by thread: Problem with CAPlayThrough and Tiger
  • Next by thread: Starting in the middle of an mp4 file
  • Index(es):
    • Date
    • Thread