search for: fft

Hi, I am working on DSP module of Ne10. I see there are fixed-point and floating-point FFT inside Opus. Is fixed-point FFT only a fall back for CPU without VFP? On ARMv7-A and ARMv8-A, benchmark result shows that fixed-point (int32) and floating-point (float32) FFT have similar performance. I guess fixed-point version is not often used on these platforms. Is it worth the effort to NEON-o...

...;- ONS$m2     f3 <- ONS$m3     f4 <- ONS$m4     f5 <- ONS$m5      f6 <- ONS$m6     f7 <- ONS$m7     f8 <- ONS$m8     f9 <- ONS$m9      f10 <- ONS$m10   #____________________________________________________________________________________________     # STEP B     g1 <- fft(f1)     g2 <- fft(f2)     g3 <- fft(f3)     g4 <- fft(f4)     g5 <- fft(f5)     g6 <- fft(f6)     g7 <- fft(f7)     g8 <- fft(f8)     g9 <- fft(f9)     g10 <- fft(f10)     #___________________________________________________________________________________________...

Hi chenwj, According to the link, I found that during the compiling process, the option "-emit-llvm" must be added to generate immediate object *.o. [hanfeng at os-wstation02 fft]llvm-gcc -c fft.c -emit-llvm Then using llvm-ld will generate two files - a shell excutable and a llvm bytecode data both of which would run perfect. [hanfeng at os-wstation02 fft]llvm-ld -o FFT fft.o [hanfeng at os-wstation02 fft]$ ls FFT FFT.bc fft.c fft.C fft.o Makefile README.fft [hanfen...

> Hi chenwj, > If it use system pthread library, then it should find it in the stand search path. I also added the option "-L/usr/lib -L/usr/lib64" but it still failed. Don't know if the link below helps or not, http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-November/027274.html Regards, chenwj -- Wei-Ren Chen (陳韋任) Computer Systems Lab, Institute of Information

> According to the link, I found that during the compiling process, the option "-emit-llvm" must be added to generate immediate object *.o. > [hanfeng at os-wstation02 fft]llvm-gcc -c fft.c -emit-llvm "-emit-llvm" emits object file which contains LLVM bitcode (IR). Default file name suffix is .o, but you might want to use "-o fft.bc" to make the suffix self-explained. > Then using llvm-ld will generate two files - a shell excutable and a ll...

Jean-Marc Valin wrote: > There is definitely some use for a Neon fixed-point FFT. How much > exactly I'm not sure. Fixed-point is a bit more than just a fall-back Well, we use fixed-point mode by default in Firefox for both Firefox OS and Fennec (Firefox on Android). The reason is that, although there is some NEON-class hardware where float does finally appear to be a...

I am in the process of dropping the TI DSP lib fft routines into the AEC. Currently, FFTWrap.c uses the USE_SMALLFT and USE_KISS_FFT to select between two packages of FFT routines. ] #ifdef USE_SMALLFT ... #elif defined(USE_KISS_FFT) ... #else #error No other FFT implemented #endif My guess is that every DSP and many other processors will...

Hi Jean-Marc and list, Is the spx_fft function in fftwrap.c a standard fft function? void spx_fft(void *table, spx_word16_t *in, spx_word16_t *out) When I say standard, I mean the input "in" is 128 point short data for example and the output "out" is 128 short complex value which is stored in 256 short array with r...

...transformation for me stupid biologist, i.e. I have a heartbeat signal and would like to decompose it into pure sin waves, getting three vectors, one containing the frequencies of the sin waves, one the magnitudes and one the phases (that's what I get from my data acquisition software's FFT function). I'd be very much obliged, if someone could point out which command would do the job in R. Thanks! Wolfgang

Hi R-users: I want to know if there is an easy way to obtain a Fourier Transform form a vector or an array (just like fft does), but with a more density base. I mean, if I have a vector of 512 of length, I want the Fourier Transform to be 1024, or 2048, etc, in length (de u domain). Or should I modify the fft C code to do that? If I want to modify the precision of the fft function, which parameter of the .Machine...

Thanks Timothy and Jean-Marc, I will start NEON optimizing fixed-point FFT. Is it int32 good enough? Benchmark data shows that FFT using int16 is much faster than FFT using int32. > -----Original Message----- > From: Timothy B. Terriberry [mailto:tterribe at xiph.org] > Sent: Friday, December 26, 2014 6:52 AM > To: Phil Wang; opus at xiph.org > Cc: Zhongwe...

I am puzzled by a filtering problem using fft(). I don't blame R. I have a waveform y consisting of the sum of 2 sinewaves having freqs f1 and f2. I do s = fft() of y. Remove s's spike at freq=f2 Do inverse fft on s. The resulting waveform still has a lot of f2 in it! But the filtering should have removed it all. What is going on, and...

...29 April 2015 at 17:22, Timothy B. Terriberry <tterribe at xiph.org> wrote: > > Viswanath Puttagunta wrote: >> >> This patch series is follow up on work I posted on [1]. >> In addition to what was posted on [1], this patch series mainly >> integrates Fixed point FFT implementations in NE10 library into opus. >> You can view my opus wip code at [2]. > > > Thanks, and I apologize for being slow here. > >> - This was surprising to me because test_unit_dft passes for all >> nfft including 60, 120, 240, 480. May be there are...

Hello! thank you for your efforts creating R! While preparing the next lessons I found that I had to multiply with 1/length(x) by hand if I want to get the inverse Fouriertransform. The help states it will do it by itself. Version R-0.60.1, Linux Seems to be pretty easy to correct either the fft or :-) the help(fft)! Cu Detlef Detlef Steuer Universitaet Dortmund /////// LS Computergestuetzte Statistik U N I D O /// steuer@gigamain.statistik.uni-dortmund.de ______/////// Tel: ++49 +231 755 3139 Fax: ++49 +231 755 4387 \_\_\_\/////...

Dear Experts, I want to know if the KISS FFT in opus can be replaced with fast FFT. What are the implications & things to be taken care if this is done. Also, I saw in FFT code comments that in-line FFT not supported. Please let me know the reason for this. Thanks in advance. Regards, Mahantesh -------------- next part -------------- A...

There is definitely some use for a Neon fixed-point FFT. How much exactly I'm not sure. Fixed-point is a bit more than just a fall-back for CPUs with no FPU. There are CPUs for which fixed-point is still faster. It depends on the exact model but also on what you run. For example, even on x86 I believe that SILK encoding is slightly faster in fixed-p...

...cratching my head, these are done comparing the result from the _float versions (which is how both resamplers work internally anyway). What I did was this: Load speex_wb.wav as one large chunk of data. Pad data with as many zeroes as there are samples. Convert to long double. Use one long double FFT for the entire thing. Insert or chop off zeroes so the new length is (input_length)*(sample_target)/(sample_source) Use one long double iFFT for the entire thing. We'll call the FFT and iFFT of this our reference. Then, for each resampler below, I've reported the maximum numerical differ...

Hi everyone, I have profiled Opus on AArch64. I just run opus_demo with some pcm files. Following is time proportion of FFT with different bitrate. Bitrate | Time cost by FFT/iFFT 24kb/s | 15% 48kb/s | 15% 96kb/s | 13% Any comment? I want some data close to real application, any suggestion? Thanks, Phil Wang -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipe...

Hi! I am using the fft() function the base package to transform some 1d signal. If I use this standar fucntion I get a very huge first fourier coeficient. I think this dues to the handling of the borders of the signal. Usually in fft especially in image processing the signal is simulated to be continuous by adding the s...

...explaination. Please see my questions and comment in lines. On 4/16/07, Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> wrote: > (keeping this on the list) > > William Zhang wrote: > > I read the mdf.c an my understanding is that N is actually window size for > > the FFT. The actual length L = N/2 which is the frame length. The > > second part of the buffer is padded with the new frame data. So this is > > like the overlap-save method for improving the acuracy in calculating > > the fft of > > long sequence of data? > > The reason fo...