So if I understand you correctly - what you're saying is that I am not
using the correct format in my ABL, or more specifically, I am not
allowed to use a single buffer with two channels in it when I call
ExtAudioFileRead()?
I could not find anything in the documentation indicating that channel
interleaved data buffers are not allowed when reading from an
ExtAudioFile - could you please provide a reference for this?
Also, I have rewritten the code to use a separate buffer for each
channel as you have suggested, but it does not seem to make a
difference. The crash after 26 seconds is still there, it just happens
a bit deeper down at the same place in the bowels of the CA code...
#0 0x91f62978 in MPEGAudioFile::ReadPackets
#1 0x91f6284c in MPEGAudioFile::ReadPackets
#2 0x91f81440 in ExtAudioFile::ReadInputProc
#3 0x91ef9794 in AudioConverterChain::DirectCallInputProc
#4 0x91ef9598 in CodecConverter::CallInputProc
#5 0x91ef90ac in CodecConverter::DecoderFillBuffer
#6 0x91eef0dc in BufferedAudioConverter::GetInputBytes
#7 0x91eeef58 in CBRConverter::RenderOutput
#8 0x91eeece0 in BufferedAudioConverter::FillBuffer
#9 0x91eeee50 in AudioConverterChain::RenderOutput
#10 0x91eeece0 in BufferedAudioConverter::FillBuffer
#11 0x91f02d04 in AudioConverterFillComplexBuffer
#12 0x91f83bd8 in ExtAudioFile::Read
#13 0x91f77488 in ExtAudioFileRead
#14 0x000027c8 in -[EAFRead readFloatsConsecutive:intoArray:] at
EAFRead.mm:130
#15 0x00002a80 in -[EAFRead init] at EAFRead.mm:188
#16 0x000023cc in main at main.m:11
Btw. what your modification does is reading samples into the same
(overlapping) memory space, potentially overwriting buffer boundaries
in the process...!
Thanks again for your input
Stephan Bernsee
2008/1/7, Adrian Pflugshaupt <email@hidden>:
> Hi all,
>
> I'm currently doing the (almost) same thing and in my opinion the
> problem is how you set up the buffer list.
> I think you need to use two buffers, not one buffer with two
channels.
> I changed a section in your code to this and then the crash was gone:
>
> bufList.mNumberBuffers = 2;
> bufList.mBuffers[0].mNumberChannels = 1; //extAFNumChannels; //
Always
> 2 channels in this example
> bufList.mBuffers[0].mData = data; // data is a pointer (float*) to
our
> sample buffer
> bufList.mBuffers[0].mDataByteSize = samples * sizeof(float);
> bufList.mBuffers[1].mNumberChannels = 1; //extAFNumChannels; //
Always
> 2 channels in this example
> bufList.mBuffers[1].mData = data + kSegmentSize/2; // data is a
> pointer (float*) to our sample buffer
> bufList.mBuffers[1].mDataByteSize = samples * sizeof(float);
>
> I had lots of crashes as well initially, but then I switched over to
> using all the CA... classes which make my life a lot easier and they
> use the ExtAudioFile calls internally. The whole thing then just
> becomes:
>
> CAAudioFile audioFile;
> audioFile.Open("/test.mp3");
> CAStreamBasicDescription format = audioFile.GetFileDataFormat();
> format.SetCanonical(format.NumberChannels(), false);
> audioFile.SetClientFormat(format);
>
> UInt32 numSamples = 512;
> AUOutputBL outputBuffer(format, numSamples);
> outputBuffer.Allocate(numSamples);
> outputBuffer.Prepare();
> audioFile.Read(numSamples, outputBuffer.ABL());
>
> // Then the actual samples can be accessed this way (for a stereo
file)
> void* channel0data = outputBuffer.ABL()->mBuffers[0].mData;
> void* channel1data = outputBuffer.ABL()->mBuffers[1].mData;
>
> Best Regards,
>
> Adrian Pflugshaupt (apulSoft)
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