Resampling irrational or large rational ratios?

Started by Anonymous in comp.dsp15 years ago 3 replies

Resampling with small integer ratios can be pretty staightforward, like a rate change of 3/2, upsample by 3 -> LPF -> dec by 2. However,...

Resampling with small integer ratios can be pretty staightforward, like a rate change of 3/2, upsample by 3 -> LPF -> dec by 2. However, it's not as simple when it's a ratio of large integers or some arbitrary new sample rate. I started to read this document on resampling: http://ccrma-www.stanford.edu/~jos/resample/ Is this how others are implementing (in hardware), resampling for


Data resampling

Started by Janey in comp.dsp16 years ago 8 replies

Hi All, This query is related to data resampling. I have an ADC whose sampling frequency is 40Mhz now I need two different version of...

Hi All, This query is related to data resampling. I have an ADC whose sampling frequency is 40Mhz now I need two different version of resampled data one being data resampled at 20Mhz while the other being at 22Mhz. Could any one please tell me what would be the best way of doing the resampling of data obtained from the ADC. Thanking you, Regards Janey


Resampling and Filtering Process

Started by hamkanen in comp.dsp10 years ago 4 replies

Hi, i'm designing a resampling process that implement a FIR filter. The resampling rate is 3/2 and the FIR filter has 73 taps , so the step...

Hi, i'm designing a resampling process that implement a FIR filter. The resampling rate is 3/2 and the FIR filter has 73 taps , so the step of processes is 1. Upsampling by 3 2. Filtering with 73-taps filter 3. Downsampling by 2 Let's say i have 2000 array of input signal, so the output of resampling must be 3000 of array signal. But if i follow the step 1. Upsampling by 3 , (number...


Gradual resampling

Started by jon222 in comp.dsp14 years ago 7 replies

Does anyone have Java or C code for a gradual resampling. I already have implementation of Nyquist?Shannon sampling theorem, where I can...

Does anyone have Java or C code for a gradual resampling. I already have implementation of Nyquist?Shannon sampling theorem, where I can resample to any ratio. I know to calculate the amplitude of the signal at any time. Now I need to know at which time to take the amplitude to achieve the gradual resampling e.g. from 100% - 200%. It means at the beginning it is the same signal and gradually to th...


filtering before or after resampling?

Started by sujani in comp.dsp16 years ago 7 replies

Hi all, I have two sets of data captured at frequencies of 100 Hz and 120 Hz.In order to comapre the sets of data,I need to resample them to...

Hi all, I have two sets of data captured at frequencies of 100 Hz and 120 Hz.In order to comapre the sets of data,I need to resample them to the same frequency.I also should filter the data. I am wondering which order is the best-filtering followed by resampling,or resampling followed by filtering? Thanks for your commnets, Sujani.


Re: Resampling and Filtering Process

Started by Jerry Avins in comp.dsp10 years ago

On Friday, January 7, 2011 2:42:19 AM UTC-5, hamkanen wrote: > Hi, Jason, Rick and Jerry, thanks for your responses You're welcome. > ...

On Friday, January 7, 2011 2:42:19 AM UTC-5, hamkanen wrote: > Hi, Jason, Rick and Jerry, thanks for your responses You're welcome. > Since the task is resampling, so i'll need output to be same shape with > input signal. Because there are "beginning" and "ending" transient response > , so i think to remove it. So, here is my scheme Be careful: there's as subtle problem here. The st


Looking for math background to resampling

Started by pslant in comp.dsp17 years ago 1 reply

Im looking for some mathemathical background for resampling (of images in my case) What I'm after are 3 things specifically: (#2 most...

Im looking for some mathemathical background for resampling (of images in my case) What I'm after are 3 things specifically: (#2 most important) 1) How can a wider kernel result in a "better" sometimes "sharper" result. that feals very unintuitive to me. for example sinc 16*16 2) In the all litterature I've seen (Pratt and a lot of articles on the web) nowhere is it mentioned that th...


Huge resampling factors

Started by stilghar in comp.dsp15 years ago 6 replies

Hi, I've to resample a signal from 16.3676 MHz to 4.096 MHz. If I'm not wrong I should interpolate by 10240 and then decimate by 40919. But,...

Hi, I've to resample a signal from 16.3676 MHz to 4.096 MHz. If I'm not wrong I should interpolate by 10240 and then decimate by 40919. But, these are huge numbers! Is there any other way of doing it? By the way, due to performance requirements I couldn't acces the whole signal at a time, so I have to do the resampling process by blocks. Thank you. This message was sent using the ...


Farrow resampling filter

Started by Anonymous in comp.dsp13 years ago 14 replies

Hi all, Do you have a general structure or a documentation how to design and compute the filter coefficients for a Farrow interpolation...

Hi all, Do you have a general structure or a documentation how to design and compute the filter coefficients for a Farrow interpolation resampling filter. It's for a Gardner synchronisation scheme... Thanks


Resampling libs

Started by Ronaldo Souza in comp.dsp10 years ago 12 replies

Can anyone recommend a good resampling lib? I need to handle rather small buffers (100s of Ks of signed 16 bits) but also really long streams,...

Can anyone recommend a good resampling lib? I need to handle rather small buffers (100s of Ks of signed 16 bits) but also really long streams, often covering 24+ hours @250sps, so speed is important. BTW, tipically I'll be downsampling from 250sps to 200sps, but there will be other scenarios within the range 100sps


usage of the library doing audio resampling (libresample)

Started by Viv in comp.dsp10 years ago 5 replies

Hi all, I really hope this is the right place to post my question because I really need some guidance from some experts. I was told to find...

Hi all, I really hope this is the right place to post my question because I really need some guidance from some experts. I was told to find out a library, preferably LGPL, but in a worst case scenario also a commercial one would be ok, that would do resampling. Some scenarios where I will have to use this would be: 1) I get a file with some audio with the following attributes: Frequ...


combined arbitrary resampling and match filtering for timing recovery

Started by Awan in comp.dsp11 years ago 1 reply

Hi DSP Guys, Can you please help on polyphase matched filter which is doing arbitrary resampling and timing recovery at the same time...

Hi DSP Guys, Can you please help on polyphase matched filter which is doing arbitrary resampling and timing recovery at the same time ? regards Awan


Announce: Fast real-time-stretching and resampling algorithms (Procrustes/Sylea)

Started by DSP team in comp.dsp14 years ago 17 replies

Here are some excerpts from an old comp.dsp thread article: > What I did was using the Pitch Shifter example from the page > (finetuned...

Here are some excerpts from an old comp.dsp thread article: > What I did was using the Pitch Shifter example from the page > (finetuned it/speeded it up a bit with some different FFT algorithm) > to change the pitch. Afterwards I altered the samplerate so the pitch > would be back to where it was, but now the duration has changed. Instead of shifting the pitch and resampling, you can do i


resampling

Started by mikejones in comp.dsp14 years ago 1 reply

I need advice on resampling. I sampled a signal at 512*50Hz. Then by using numerical differntion with lagrange interpolation, i found the...

I need advice on resampling. I sampled a signal at 512*50Hz. Then by using numerical differntion with lagrange interpolation, i found the frequency of the fundamental. I need to resample the siganl at a frequency of 512*fs Hz where fs is the off nominal frequency of the fundamental (usually slightly greater than 50Hz). how do I go about implementing it in code?


Resampling (by non integer factors) algorithm - can someone tell me why this works?

Started by David Reid in comp.dsp16 years ago 7 replies

Hi all, i've been asking question about how to do proper resampling in c++ on wave audio data. After all the excellent and intelligent...

Hi all, i've been asking question about how to do proper resampling in c++ on wave audio data. After all the excellent and intelligent replies, my manager (who has no dsp background) suggested the following algoritm, which works perfectly, as i've tested it out viewing the output on a spectrum analyzer. Here's the concept: Assume the following: -wave data loaded and stored in a buffe...


Low Frequency Noise from Resampling?

Started by firstcranialnerd in comp.dsp14 years ago 2 replies

Hi, I am looking at some simulated heart rate data and it is unevenly sampled events, so I resample the data at say 4Hz or 7Hz or thereabouts....

Hi, I am looking at some simulated heart rate data and it is unevenly sampled events, so I resample the data at say 4Hz or 7Hz or thereabouts. When I take the fft of the resampled data (it has been zeromeaned, filtered, hamming windowed etc) I see a huge amount of noise, especially from approximately .01 to 1Hz. Does anyone know if this Low frequency noise is due to the resampling process? If so...


A General Framework for Semi-Lossless Resampling

Started by Anonymous in comp.dsp7 years ago 5 replies

A problem I had while doing graphics, a short time ago, is that while doing repeated up/down-sampling cycles, there was continual degradation....

A problem I had while doing graphics, a short time ago, is that while doing repeated up/down-sampling cycles, there was continual degradation. This of course leads to the idea: a general framework for resampling that avoids this problem. Specifically, let M -> N denote the operation (and its matrix) for sampling from positive sizes M to N. The ideal situations are that: * M -> N s


How to get rid of resampling artifacts ?

Started by John McDermick in comp.dsp10 years ago 14 replies

How do you get rid of resampling artifacts? The P/Q fixed-point resampler algo I am working on takes as input a signal which has been...

How do you get rid of resampling artifacts? The P/Q fixed-point resampler algo I am working on takes as input a signal which has been upsampled by P (zero insertion) and low-pass filters the upsampled signal (fc = min[1/P,1/Q] ). In the final step every Qth filter output sample is kept. The artifacts seems to get worse when P/Q is much larger than 1...for example when P/Q = 6. The low-pass...


Cutting and Resampling

Started by kingdavid3 in comp.dsp14 years ago 2 replies

I am reading a full length (duration of the speech) audio wave file sampled at 44.1KHz, 16 bit stereo. I want to cut a 15 second segment from...

I am reading a full length (duration of the speech) audio wave file sampled at 44.1KHz, 16 bit stereo. I want to cut a 15 second segment from the audio and resample it to 16000 Hz. So far I managed to do the resampling. Please help on how to cut 15 second length portion of the audio. Thank you [s, fs]=wavread('test.wav); %%cut to 15 seconds s=resample(s, 16000, fs); %downsam...


easy resampling bandwith question ...

Started by sammy davis jr. in comp.dsp17 years ago 5 replies

hi all, let's say i want to resample to 4/5 the input samplerate, i.e. interpolate 4X then decimate 5X. for both steps lowpass filters need...

hi all, let's say i want to resample to 4/5 the input samplerate, i.e. interpolate 4X then decimate 5X. for both steps lowpass filters need to be designed. according to dspguru.com, it is sufficient to 1. determine cutoff freq. for the interp. filter 2. determine cutoff freq. for the decim. filter 3. choose the lower of the 2 cutoff freqs to design *one* resampling FIR filter. so...