Pitch recognition of a musical note on a smart phone
in [DSP]
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From: mzincali on 22 Sep 2009 07:26 Hi. With limited resources such as slower CPUs, code size and RAM, how best to detect the pitch of a musical note, similar to what a tuner would do? Should I use: - Kiss FFT - FFTW - autocorrelation - zero crossing analysis - octave-spaced filters other? Thank you in advance. -mz
From: Vladimir Vassilevsky on 22 Sep 2009 12:03 mzincali wrote: > Hi. With limited resources such as slower CPUs, code size and RAM, how > best to detect the pitch of a musical note, similar to what a tuner would > do? > > Should I use: > > - Kiss FFT > - FFTW > - autocorrelation > - zero crossing analysis > - octave-spaced filters > > other? > > Thank you in advance. A young guy and young girl came to the rabbi to ask for his advice. A girl: "Tomorrow is my first night with my fiance. What kind of night dress should I put on? Should it be a long dress, or a short dress, or an open dress, or a closed dress, or whatever?" A boy: "I got some money. Will you please give me an advice what to do with it: maybe, invest into something, or buy some real estate, or gold, or put it in a bank?" The rabbi: "My dear children, I have one answer for both of you: whatever you do, you will certainly be fucked." Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
From: Jimmy J on 30 Sep 2009 21:24 Vladimir Vassilevsky <nospam(a)nowhere.com> wrote in news:OvGdnUIafaakaCXXnZ2dnUVZ_tqdnZ2d(a)giganews.com: > > > mzincali wrote: > >> Hi. With limited resources such as slower CPUs, code size and RAM, >> how best to detect the pitch of a musical note, similar to what a >> tuner would do? >> >> Should I use: >> >> - Kiss FFT >> - FFTW >> - autocorrelation >> - zero crossing analysis >> - octave-spaced filters >> >> other? >> >> Thank you in advance. > > > A young guy and young girl came to the rabbi to ask for his advice. > > A girl: > > "Tomorrow is my first night with my fiance. What kind of night dress > should I put on? Should it be a long dress, or a short dress, or an > open dress, or a closed dress, or whatever?" > > A boy: > > "I got some money. Will you please give me an advice what to do with > it: maybe, invest into something, or buy some real estate, or gold, or > put it in a bank?" > > The rabbi: > > "My dear children, I have one answer for both of you: whatever you do, > you will certainly be fucked." > > Vladimir Vassilevsky > DSP and Mixed Signal Design Consultant > http://www.abvolt.com Since it is clear that neither age nor experience have brought you any wisdom, the rabbi's answer applies to you as well.
From: ok1iak on 1 Oct 2009 13:15 Hi mz. You cannot use FFTW, smartphones do not run on processors with floating point unit. Emulation is just too slow to be usable on slower devices. Kiss FFT could be configured to use fixed point arithmetics. You may get an exaple of the fft and spectrogram code for Pocket PC platform at http://pocketdigi.sourceforge.net It uses some fixed point real valued FFT. The real valued fixed point FFT will certainly work and you may use the phase differences between the FFT bins of successive FFT transforms to calculate more precise estimate of the tone captured by the FFT bin. Zero crossing will be sensitive to noise. I suppose you want to detect tone from internal microphone? Vojtech
From: R.Nicholson on 1 Oct 2009 13:33
On Oct 1, 10:15 am, ok1iak <bubn...(a)seznam.cz> wrote: > You cannot use FFTW, smartphones do not run on processors with > floating point unit. Emulation is just too slow to be usable on slower > devices. This is not true on many current smartphones. I've benchmarked a short float FFT on an iPhone as faster than a scaled integer FFT (actual milage will depend on how much you optimize each). The newer Android smartphones use similar ARM CPUs which includes a VFP pipelined or NEON vector floating point unit. The real problem is that musical pitch is very often not related to peak frequency bin results from an FFT at all. Disclaimer: I have several musical pitch estimation and tuning assist apps in the iPhone App store. Search for "HotPaw". IMHO. YMMV. -- rhn A.T nicholson d.0.t C-o-M http://www.nicholson.com/rhn/dsp.html |