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2014/10/15 ¤U¤È 10:08:58
iphone Programming Glossary: fftAurioTouch & FFT for an instrument tuner http://stackoverflow.com/questions/1447059/auriotouch-fft-for-an-instrument-tuner FFT for an instrument tuner I'm trying to write a simple tuner no not to make yet another tuner app and am looking at the AurioTouch.. to know whether the underlying code is functional or whether it is just a crude sample Other options I have are to use FFTW or KISS FFT. Anyone have any experience with those Thanks. iphone audio fft share improve this question FFTs use frequency.. the underlying code is functional or whether it is just a crude sample Other options I have are to use FFTW or KISS FFT. Anyone have any experience with those Thanks. iphone audio fft share improve this question FFTs use frequency bins..
Do you know a good and efficient FFT? [closed] http://stackoverflow.com/questions/1592345/do-you-know-a-good-and-efficient-fft you know a good and efficient FFT closed I am trying to find a very fast and efficient Fourier transform FFT . Does anyone know of any good ones. I need.. you know a good and efficient FFT closed I am trying to find a very fast and efficient Fourier transform FFT . Does anyone know of any good ones. I need to run it on the iPhone so it must not be intensive. Instead maybe you know.. a narrow band vocal audio range up to 10khz max...even 10Khz might be too high . Im thinking also of truncating this FFT to keep the frequency resolution while eliminating the unwanted frequency band. This is for an iphone ...I have taken a..
Using the apple FFT and accelerate Framework http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework the apple FFT and accelerate Framework Has anybody used the apple FFT for an iPhone app yet or know where I might find a sample application.. the apple FFT and accelerate Framework Has anybody used the apple FFT for an iPhone app yet or know where I might find a sample application as to how to use it I know that apple has some sample.. sure how to implement it into an actual project. iphone audio fft share improve this question I just got the FFT code working for an iPhone project create a new project delete all the files except for main.m and xxx_info.plist going..
iPhone FFT with Accelerate framework vDSP http://stackoverflow.com/questions/6358764/iphone-fft-with-accelerate-framework-vdsp FFT with Accelerate framework vDSP I'm having difficulty implementing an FFT using vDSP. I understand the theory but am looking.. FFT with Accelerate framework vDSP I'm having difficulty implementing an FFT using vDSP. I understand the theory but am looking for a specific code example please. I have data from a wav file as below.. a specific code example please. I have data from a wav file as below Question 1. How do I put the audio data into the FFT Question 2. How do I get the output data out of the FFT Question 3. The ultimate goal is to check for low frequency sounds...
iPhone headphone jack - read in data? http://stackoverflow.com/questions/7192473/iphone-headphone-jack-read-in-data audio cards. What would be needed on the iPhone would be to develop a QAM demodulator for the audio input using the FFT library to demodulate QAM audio modulated video back into digital video like H.264 probably at 1 4 VGA resolution. NTSC..
iPhone Accelerate Framework FFT vs Matlab FFT http://stackoverflow.com/questions/10820488/iphone-accelerate-framework-fft-vs-matlab-fft much math background but part of the project I am working on requires the FFT of a single vector. The matlab function fft x works accurately for what I need but after trying to set up the Accelerate Framework fft functions I get completely inaccurate.. vector. The matlab function fft x works accurately for what I need but after trying to set up the Accelerate Framework fft functions I get completely inaccurate results. If anyone has more expertise experience with Accelerate Framework fft I could.. fft functions I get completely inaccurate results. If anyone has more expertise experience with Accelerate Framework fft I could really use some help trying to figure out what I am doing wrong. I based my fft set up off an example I found on..
Detecting noise via mic while playing a song on iPhone http://stackoverflow.com/questions/11993844/detecting-noise-via-mic-while-playing-a-song-on-iphone per timestep the correlation coefficient between the output graphs that are constructed using the live playback fft data and the recorded fft data so the 'squiggly' lines that you see when you put the app in fft mode . This 'sort of' works... coefficient between the output graphs that are constructed using the live playback fft data and the recorded fft data so the 'squiggly' lines that you see when you put the app in fft mode . This 'sort of' works. The correlation coefficient.. the live playback fft data and the recorded fft data so the 'squiggly' lines that you see when you put the app in fft mode . This 'sort of' works. The correlation coefficient is clearly lower when excess sound noise is in the room but it..
AurioTouch & FFT for an instrument tuner http://stackoverflow.com/questions/1447059/auriotouch-fft-for-an-instrument-tuner sample Other options I have are to use FFTW or KISS FFT. Anyone have any experience with those Thanks. iphone audio fft share improve this question FFTs use frequency bins and the bin frequency width is based on the FFT parameters. To find..
Do you know a good and efficient FFT? [closed] http://stackoverflow.com/questions/1592345/do-you-know-a-good-and-efficient-fft FFT or not which i really dont feel like doing...plus aurio touch uses a radix 2 FFT which is not that great . iphone fft share improve this question The performance of the FFTW sets the standard for arbitrary length FFT's especially for..
Determining the magnitude of a certain frequency on the iPhone http://stackoverflow.com/questions/2921674/determining-the-magnitude-of-a-certain-frequency-on-the-iphone e.g. FFT functions if needed. Update I updated the question to be more clear as per Conrad's suggestion. iphone audio fft share improve this question If you only need to test for one frequency you can just calculate the corresponding point..
Using the apple FFT and accelerate Framework http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework apple has some sample code posted but I'm not really sure how to implement it into an actual project. iphone audio fft share improve this question I just got the FFT code working for an iPhone project create a new project delete all the.. it is generously commented but the comments don't actually make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then.. actually make life any easier. Basically at the heart of it is vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE FFT on n real floats and then reverse to get back to where we started. ip stands..
iPhone FFT with Accelerate framework vDSP http://stackoverflow.com/questions/6358764/iphone-fft-with-accelerate-framework-vdsp 2 A 1 nOver2 Set up the required memory for the FFT routines and check its availability. setupReal vDSP_create_fftsetup log2n FFT_RADIX2 if setupReal NULL printf nFFT_Setup failed to allocate enough memory for the real FFT. n exit 0 Carry.. failed to allocate enough memory for the real FFT. n exit 0 Carry out a Forward and Inverse FFT transform. vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE Verify correctness of the results.. FFT. n exit 0 Carry out a Forward and Inverse FFT transform. vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD vDSP_fft_zrip setupReal A stride log2n FFT_INVERSE Verify correctness of the results but first scale it by 2n. scale float 1.0 2..
FFT on iPhone to ignore background noise and find lower pitches http://stackoverflow.com/questions/7181630/fft-on-iphone-to-ignore-background-noise-and-find-lower-pitches float Convert ... divide the signal into even odd configuration vDSP_ctoz COMPLEX outputBuffer 2 A 1 nOver2 apply the fft vDSP_fft_zrip fftSetup A stride log2n FFT_FORWARD convert split real form to split vector vDSP_ztoc A 1 COMPLEX outputBuffer.. ... divide the signal into even odd configuration vDSP_ctoz COMPLEX outputBuffer 2 A 1 nOver2 apply the fft vDSP_fft_zrip fftSetup A stride log2n FFT_FORWARD convert split real form to split vector vDSP_ztoc A 1 COMPLEX outputBuffer 2 nOver2.. divide the signal into even odd configuration vDSP_ctoz COMPLEX outputBuffer 2 A 1 nOver2 apply the fft vDSP_fft_zrip fftSetup A stride log2n FFT_FORWARD convert split real form to split vector vDSP_ztoc A 1 COMPLEX outputBuffer 2 nOver2 Demetri..
Generating DSP filter coefficients in C/Java for time-domain convolution http://stackoverflow.com/questions/8014018/generating-dsp-filter-coefficients-in-c-java-for-time-domain-convolution shifted low pass filter. How can I programmatically generate these coefficients java android iphone signal processing fft share improve this question I have found a tutorial that generates filter coefficients in C code which should be relatively..
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