Questions tagged [audio-processing]

Audio processing involves the study of mathematical and signal processing techniques to understand or alter the nature of audio signals. The different kind of audio signals under study include speech, music, environmental audio and computer audio. Audio is analyzed in the temporal or spectral domain by applying various filters.

Key concept is to transform the audio into PCM format so you have access to the raw audio curve. Each channel will have its own curve.

Digital audio is represented by a series of points on this curve. Each point is called an audio sample. Numerical value of each sample can be represented in either integer or floating point.

Be aware to map each audio sample numerical value to memory typically requires several bytes of storage. One byte can store only 2^8 distinct values (256) which will result in noticeable distortion. High quality audio is typically stored using at least two bytes of storage per audio sample. When we use two bytes this gives us 2^16 possible values of the raw audio curve height as the audio wobbles up and down. The more bytes we use for storage the higher fidelity we gain as this reduces the gap between each distinct curve height measurement. This called bit depth. CD quality audio uses two bytes per audio sample per channel. The other fundamental aspect of digital audio is Sample Rate with determines the number of samples per second of time.

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First Derivative of MFCC Coefficients in Matlab

I have extracted mel frequency cepstral coefficient (MFCC) features (in Matlab) for some speech classification. I'm currently thinking of adding the first and second derivatives of MFCC coefficient features. How can we get first and second…
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Audio Processing Server Workflow with Python

I typically reside on the front-end of the stack, but I need to do some audio processing work on a server and download the results. I want a user to be able to upload an MP3 file to a server and have it process the file using a Python script and…
procload
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What is the amplification factor required for android's media recorder to match the output of iOS's AVAudioRecorder?

I have a cross-platform(iOS and Android) app where I will record audio clips then send it to the server to do some machine learning operations. In my iOS app, I use AVAudioRecorder for recording the audio. In the Android app, I use MediaRecorder for…
Kautham Krishna
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How to make length of two audios of same name equal?

I have two audios in different directories but having same name say a.wav But both the audios having different length, i want to make there length same and i'm not getting how do i do that. Please find below the audio configurations. Channels …
Rishabh Ojha
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Output audio is nothing but static

below is a code that takes an audio file, applies a filter to it then plays the sound back to the user. The "create audio" section of the code is supposed to take what was played in Python and output an audio file. When I listen to the outputted…
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Magnitude responses of parametric equalizer

I am trying to combine several freqz plots which relates to magnitude responses of parametric equalizer filters in MATLAB. I based my function equalizer on formulas from audio-processing book. The problem is that I don't know how to make plots which…
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Analog of str.replace in audio processing

I have a long audio file divided into segments by one (I assume it is always the same) sound, and I want to split it into these segments. I've tried using code from this question - Split speech audio file on words in python but playing with…
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Resampling after filtering on successive blocks with initial conditions (to avoid discontinuity)

I actually work on a real time graphic equalizer on python. I'm using pyaudio module, scipy, numpy. My equalizer is based on a third octave band filter bank from 25 Hz to 20 kHz (so 30 bands). This filter bank divides an input signal into 30…
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Extracting F0, jitter and shimmer from an audio file using Python

Recently I got the task: to extract such features as F0(fundamental frequency), Jitter and Shimmer from a given chain of short audio files (around 5-10 sec, a voice singing on one note). And, unfortunately, I am good for nothing in Audio Signal…
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Applying Effects on audio (e,g robot sound, big robot sound) in android

I am using SoundPool to change the pitch of sound. A value of 1.0 means playback at the original frequency. A value of 2.0 means playback fast as with double speed, and a value of 0.5 means playback at half speed, but I want to to change the pitch…
Adeeb karim
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keras: how to aggregate over frame-level predictions to song-level prediction

I am doing a song genre classification. For each song, I have chopped them into small frames (5s) to generate spectrogram as input features for a neural network and each frame has an associated song genre label. The data looks like the following: …
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fundamental frequency of female voice

According to what I have read on the internet, the normal range of fundamental frequency of female voice is 165 to 255 Hz . I am using Praat and also python library called Parselmouth to get the fundamental frequency values of female voice in an…
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How to obtain Mel Filterbank?

What is the logic behind the calculation of Mel filterbank? Is there any good example for it ? I could not find any good example on internet.
yasser
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How to record a gunshot?

My graduation work is basically to write a software to recognize a gunshot in open ambients (e.g. a city). I also need to develop the "audio capture" device. My idea for prototyping is to write an Android app to stream an audio format to a server…
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Are there other than FFT ways to implement Guitar Tuner?

I want to do precise guitar tuner, this is usually done by many via computing FFT and getting peak. But this is of low appliance for several reasons: Discrete precision, gives insuffient resolution for tuning bass guitar. High computation time and…
xakepp35
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