Re: Set kAudioUnitProperty_StreamFormat seems to be broken
Re: Set kAudioUnitProperty_StreamFormat seems to be broken
- Subject: Re: Set kAudioUnitProperty_StreamFormat seems to be broken
- From: Bill Stewart <email@hidden>
- Date: Sat, 29 Sep 2001 15:17:59 -0700
On Thursday, September 27, 2001, at 10:19 PM, Brian Barnes wrote:
Alright. I've got it to play AIFFs. I'll post my code as soon as
somebody tells me what this problem is (and answers any of my
other outstanding questions!)
I queried the AU "kAudioUnitProperty_StreamFormat" and got this:
austream.mSampleRate=44100;
austream.mFormatID=kAudioFormatLinearPCM;
austream.mFormatFlags=kLinearPCMFormatFlagIsFloat|kLinearPCMFormatFlagIsBigEndian|
kLinearPCMFormatFlagIsPacked;
austream.mBytesPerPacket=8;
austream.mFramesPerPacket=1;
austream.mBytesPerFrame=8;
austream.mChannelsPerFrame=2;
austream.mBitsPerChannel=32;
So, I make an AIFF just like that, 44.1, 16-bit, stereo. Works
like a charm!
Then, I redo the AIFF to make it mono, and run this code:
austream.mSampleRate=44100;
austream.mFormatID=kAudioFormatLinearPCM;
austream.mFormatFlags=kLinearPCMFormatFlagIsFloat|kLinearPCMFormatFlagIsBigEndian|
kLinearPCMFormatFlagIsPacked;
austream.mBytesPerPacket=4;
austream.mFramesPerPacket=1;
austream.mBytesPerFrame=4;
austream.mChannelsPerFrame=1;
austream.mBitsPerChannel=32;
err=AudioUnitSetProperty(audiounit,kAudioUnitProperty_StreamFormat,kAudioUnitScope_Input,
0,(void*)&austream,sizeof(AudioStreamBasicDescription));
AudioUnitSetProperty returns WITHOUT an error, but the sound AIFF
plays twice as fast (the default settings are still in effect.) I
moved around the places I call this, to no effect. I can give my
sample code if somebody at Apple wants to check this out.
The unit isn't dealing with mono data - we've done some work with
this formatting stuff in 10.1, but there may still be lingering
bugs - please check this out in 10.1 and let us know what unit is
having trouble with the mono input...
Bill
[>] Brian
_______________________________________________
coreaudio-api mailing list
email@hidden
http://www.lists.apple.com/mailman/listinfo/coreaudio-api
mailto:email@hidden
tel: +1 408 974 4056
__________________________________________________________________________
Cat: "Leave me alone, I'm trying to nap... Ah, What's that clicking
noise?"
__________________________________________________________________________