downsampling

I have the recorder.js which will record the audio and takes buffer inputs but I want to downsample the audio buffers but I am lot confused where to call it though I have written it. Please check my function and if possible please suggest where to call it. import InlineWorker from 'inline-worker'; export class Recorder { config = { bufferLen: 4096, numChannels: 2, mimeType: 'audio/mp3' }; recording = false; callbacks = { getBuffer: [], exportWAV: [] }; constructor(source, cfg) { Object.assign(this.config, cfg); this.context = source.context; this.node = (this.context.createScriptProcessor ||

I am trying to downsample a pandas dataframe in order to reduce granularity. In example, I want to reduce this dataframe: 1 2 3 4 2 4 3 3 2 2 1 3 3 1 3 2 to this (downsampling to obtain a 2x2 dataframe using mean): 2.25 3.25 2 2.25 Is there a builtin way or efficient way to do it or I have to write it on my own? Thanks Andy Hayden One option is to use groupby twice. Once for the index: In [11]: df.groupby(lambda x: x/2).mean() Out[11]: 0 1 2 3 0 1.5 3.0 3 3.5 1 2.5 1.5 2 2.5 and once for the columns: In [12]: df.groupby(lambda x: x/2).mean().groupby(lambda y: y/2, axis=1).mean() Out[12]: 0 1 0

So here is my problem: I have an image, that image is large (high resolution) and it needs to be small (much lower resolution). So I do the naive thing (kill every other pixel) and the result looks poor. So I try to do something more intelligent (low pass filtering using a Fourier transform and re-sampling in Fourier space) and the result is a little better but still fairly poor. So my question, is there a perceptually motivated image down-sampling algorithm (or implementation)? edit: While I am aware of a number of resampling techniques, my application is more concerned with preserving the

Hi I need to downsample a wav audio file's sample rate from 44.1kHz to 8kHz. I have to do all the work manually with a byte array...it's for academic purposes. I am currently using 2 classes, Sink and Source, to pop and push arrays of bytes. Everything goes well until I reach the part where I need to downsample the data chunk using a linear interpolation. Since I'm downsampling from 44100 to 8000 Hz, how do I interpolate a byte array containing something like 128 000 000 bytes? Right now I'm popping 5, 6 or 7 bytes depending on i%2 == 0, i%2 == 1 and i%80 == 0 and push the average of these 5,

I have to downsample a wav file from 44100Hz to 16000Hz without using any external python libraries, so preferably wave and/or audioop . I tried just changing the wav files framerate to 16000 by using setframerate function but that just slows down the entire recording. How can I just downsample the audio file to 16kHz and maintain the same length of the audio? Thank you very much in advance You can use Librosa's load() function, import librosa y, s = librosa.load('test.wav', sr=8000) # Downsample 44.1kHz to 8kHz The extra effort to install Librosa is probably worth the peace of mind. Pro-tip: