Re: Error -66626

Subject: Re: Error -66626
From: Doug Wyatt <email@hidden>
Date: Fri, 22 May 2009 16:35:55 -0700

The file format is correct. Just construct a correct PCM AudioStreamBasicDescription to pass to AudioQueueSetOfflineRenderFormat, e.g.

AudioStreamBasicDescription orf; // "offline render format" AudioStreamBasicDescription ff; // file sample rate, obtained earlier orf.mSampleRate = ff.mSampleRate; orf.mFormatID = kAudioFormatLinearPCM; orf.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagsNativeEndian | kAudioFormatFlagIsPacked; orf.mFramesPerPacket = 1; orf.mChannelsPerFrame = ff.mChannelsPerFrame; orf.mBitsPerChannel = 16; orf.mBytesPerFrame = orf.mBytesPerPacket = sizeof(SInt16) * ord.mChannelsPerFrame;

On May 22, 2009, at 16:30 , dct wrote:

Bill, thanks.
Apparently I didn't explain my intent -- I want to convert formatted audio ( mp3, etc.) to linear pcm (SInt16 will do nicely).

I do notice that the AudioStreamBasicDescription, asbd, returned with AudioFileStreamProperty has a number of zero values for a given mp3 input , specifically: mSampleRate = 44100 (as expected) mFormatID = 778924083 (mp3 as expected) mFormatFlags = 0 mBytesPerPacket = 0 (is this ok?) mFramesPerPacket = 1152 (seems right, 9 blocks of 128 each, or 8 overlapping of 256 each) mBytesPerFrame = 0 (is this ok?) mChannelsPerFrame = 2 ( seems right, input is stereo) mBitsPerChannel = 0 (is this ok?)
On May 22, 2009, at 3:55 PM, William Stewart wrote:
On May 22, 2009, at 3:00 PM, dct wrote:
OKThe call is:
err = AudioQueueSetOfflineRenderFormat( queue, asbd, &chLayout );
"asbd" is being set by:
err = AudioFileStreamProperty( inAudioFileStream, kAudioFileStreamProperty_DataFormat, &asbdSize, &asbd);

where: asbd is an AudioStreamBasicDescription structure, asbdSize = sizeof(asbd), and

inAudioFileStream is the AudioFileStreamID passed to propertyCallback.
err= 0.
Depends what the format of the data is in the file, but this is not the intention of using the audio queue. The reason that you would use an audio queue here is to transform the data from the file format to an uncompressed format (linear pcm).
If you set the output format of the queue to the same as the file - why have a queue at all? Just read the raw packets straight from the file and you are done.
So, the asbd you want to provide to RenderFormat is a linear pcm, probably 16 bit, probably same number of channels as the file, and the sample rate you want.
"chLayout" is set:
chLayout.mChannelLayoutTag = kAudioChannelLayoutTag = kAudioChannelLayoutTag_Mono;
chLayout.mChannelBitmap = 0;
chLayout.mNumberChannelDescriptions = 1;
?? Would { 0,0,0 } be proper for offline?
You don't need to provide channel descriptions - just the tag is sufficient (the Mono one)
Don
On May 22, 2009, at 2:28 PM, Doug Wyatt wrote:
1718449215 = 'fmt?'
So there's something wrong with the format being set...
Doug
On May 22, 2009, at 14:20 , dct wrote:
I hadn't set an "err = " at the AudioQueueSetOfflineRenderFormat call.
Having done so, I now get an error equal to: 1718449215.
Don
On May 22, 2009, at 1:51 PM, Doug Wyatt wrote:
I hope to document that error in a future release.
But for now, it only comes from two places:
- trying to change kAudioQueueProperty_CurrentDevice when the queue is in offline mode

- calling AudioQueueOfflineRender when the queue is not in offline mode
"In offline mode" means that AudioQueueSetOfflineRenderFormat has been called with a non-NULL stream format and succeeded.
Did you get an error result from AudioQueueSetOfflineRenderFormat?
Doug
On May 22, 2009, at 11:47 , dct wrote:
Doug, thank for the reply.
I don't think that's it; I do call AudioQueueSetOfflineRenderFormat.
My sequence of Core Audio function calls goes as follows:
- AudioFileStreamOpen(self, propertyCallback, packetCallback, hint, &parserID);
- err = AudioFileStreamParseBytes(parserID, inBufSize, inBuffer,
         kAudioFileStreamParseFlag_Discontinuity );
(in propertyCallback)
- err = AudioFileStreamGetProperty( inAudioFileStream,
         kAudioFileStreamProperty_DataFormat, &asbdSize, &asbd);
- err = AudioQueueNewOutput(&asbd, audioQueueCallback, inBuffer,
					        NULL, NULL, 0, &queue);
- AudioQueueAllocateBuffer( queue, nn, &queueBuffer );
-AudioQueueSetOfflineRenderFormat( queue, &asbd, &chLayout );
(in propertyCallback)
- err = AudioQueueOfflineRender( dcdrData->queue, &ts, outBuffer, asbd.mFramesPerPacket );

( ts is a time stamp with ts.mSampleTime=0 & ts.mHostTime = sys clock time)
Here I get err = -66626 and outBuffer seems to contain only 0s.
On May 21, 2009, at 6:24 PM, Doug Wyatt wrote:
Maybe you didn't call AudioQueueSetOfflineRenderFormat first?
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Follow-Ups:

Re: Error -66626
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References:  
  >Re: Error -66626 (From: dct <email@hidden>)
  >Re: Error -66626 (From: Doug Wyatt <email@hidden>)
  >Re: Error -66626 (From: dct <email@hidden>)
  >Re: Error -66626 (From: Doug Wyatt <email@hidden>)
  >Re: Error -66626 (From: dct <email@hidden>)
  >Re: Error -66626 (From: William Stewart <email@hidden>)
  >Re: Error -66626 (From: dct <email@hidden>)




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