Re: AudioConverter 8.24 to Float32
Re: AudioConverter 8.24 to Float32
- Subject: Re: AudioConverter 8.24 to Float32
- From: William Stewart <email@hidden>
- Date: Thu, 13 Nov 2008 18:17:25 -0800
Yes - using floating point on the phone/touch is not a good thing for
general DSP work - that is why we provided the 8.24 canonical version
and why we would recommend that audio DSP is done in fixed point. It
can be done in floating point of course, but it is slow
Bill
On Nov 11, 2008, at 11:08 PM, Mark's Studio wrote:
On 11/11/2008, at 23.10, William Stewart wrote:
(Oh and just to be clear, float is not currently supported on
iPhone - it is on the desktop)
??? do you mean i can't use the AudioConverter to convert to float
on the iPhone ?
Float64 sampleRate;
size = sizeof(sampleRate);
XThrowIfError
(AudioSessionGetProperty
(kAudioSessionProperty_CurrentHardwareSampleRate, &size,
&sampleRate), "couldn't get new sample rate");
CAStreamBasicDescription destFormat;
CAStreamBasicDescription srcFormat;
outFormat.mSampleRate = sampleRate;
srcFormat.mSampleRate = outFormat.mSampleRate;
srcFormat.mFormatID = outFormat.mFormatID;
srcFormat.mFormatFlags = outFormat.mFormatFlags;
srcFormat.mBytesPerPacket = outFormat.mBytesPerPacket;
srcFormat.mFramesPerPacket = outFormat.mFramesPerPacket;
srcFormat.mBytesPerFrame = outFormat.mBytesPerFrame;
srcFormat.mChannelsPerFrame = 1;
srcFormat.mBitsPerChannel = outFormat.mBitsPerChannel;
destFormat.mSampleRate = outFormat.mSampleRate;
destFormat.mFormatID = kAudioFormatLinearPCM;
destFormat.mFormatFlags = kAudioFormatFlagIsFloat |
kAudioFormatFlagsNativeEndian | kAudioFormatFlagIsPacked;
destFormat.mBytesPerPacket = outFormat.mBytesPerPacket;
destFormat.mFramesPerPacket = outFormat.mFramesPerPacket;
destFormat.mBytesPerFrame = outFormat.mBytesPerFrame;
destFormat.mChannelsPerFrame = 1;
destFormat.mBitsPerChannel = outFormat.mBitsPerChannel;
outFormat.Print(outFormat);
srcFormat.Print(srcFormat);
destFormat.Print(destFormat);
XThrowIfError(AudioConverterNew(&srcFormat, &destFormat,
&audioConverter), "couldn't get AudioConverterNew");
and then in PerformThru()
AudioUnitRender()
AudioConverterConvertBuffer(....ioData->mBuffer[0].mData,...)
i get a -50 error from AudioConverterConvertBuffer()
is this not possible ?
On Nov 11, 2008, at 2:08 PM, William Stewart wrote:
float is not supported
On Nov 11, 2008, at 7:26 AM, Mark's Studio wrote:
In the aurioTouch sampleCode the format is 8.24 i have tried to
add a AudioConverterNew to convert to float, but either i get a
-50, or a !fmt error,
it look's like there is already an AudioConverter running maybe
for the 16bit to 8.24,
how do i setup the format for the AudioConverterNew so i can have
Float32 instead of 8.24,
i am mostly interested in converting the input buffer.
Peter Mark
Mark's Recording Studio A/S
Lundeskovsvej 3
2900 Hellerup
Denmark
Tel: +45 35366078
Fax: +45 35366038
Mobile: +45 20416018
www.marks-studio.dk
email@hidden
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Peter Mark
Mark's Recording Studio A/S
Lundeskovsvej 3
2900 Hellerup
Denmark
Tel: +45 35366078
Fax: +45 35366038
Mobile: +45 20416018
www.marks-studio.dk
email@hidden
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Do not post admin requests to the list. They will be ignored.
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