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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Possible to learn and process audio using Tensorflow?

I'm just starting to look into Deep Learning for an idea I have for a project. I'm very new to it and have a general question I hope someone can answer for me before I start down what is undoubtedly going to be a long dark path. If I provide the NN…
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How to improve quality of sound when I generate it using AudioTrack?

I wish to improve quality of beeps, which generated by class AudioTrack. I tried to use stereo format, but it don't help. How can I improve quality of sounds, which generated by AudioTrack? Below you can see code, which shows, how I generated sound…
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Python) "Real time Audio signal processing" How to plot x-axis in seconds?

I want to plot real time original audio signal and fft signal. my code is, socket_server.bind(server_address) print "Listening...\n" while(True): packet, client = socket_server.recvfrom(buffer_size) count=count+1 if…
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Maximum Amplitude when silence - Wave file processing

I created a wav parser. I read the sample information out of the data chunk like this: while (offset < size) { var value = 0; switch (bits_channel) { case 8: value = data.SubArray(offset, 1)[0]; break; …
Tom Doodler
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Imprecise output when calculating dBFS value from 16-bit audio sample value using C#

I am calculating a dBFS value from a 16-bit wave file sample (-32768 to +32767) using c# as follows: int sampleValue = -32700; double dBFSvalue = 20 * Math.Log10(Math.Abs(sampleValue) / 32768); But when I try to print the dBFS value, a sampleValue…
Quantum_Kernel
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How i recognize a unique sound in a noisy environment?

I am developing app to detect the inability of elderly people to unlock their rooms using IC cards in their daycare center. This room doors has an electronic circuit that emits beep sounds d to signal the user failure in unlock the room. My…
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Rewriting audio data to wav file adds a lot of noise

I want to make an application that reads the audio samples one by one manipulate them and than writing the new samples to a WAV file. However, when I tried to do this I only received white noise. I tried to find whether the problem was with the…
efrat
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C# values differ from MATLAB values

I am working on a project with audio files. I read a file and parse it. I compare my parsed values with other sources and everything seems fine. (FYI : wav file with 16 bits per sample, 44.100 Hz and 7211 sample points.) Since my every data point is…
user3021830
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Sox - couple actions at once

Let's begin with an example. Assume that we have 3 audiofiles: first.mp3, second.mp3, third.mp3. I would like to merge first with second and then concatenate 3.mp3 to merged audio. Is it possible to make with one command? I tried to invoke such…
Lukas
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Android realtime output sound processing

I am building a regional language android app (hindi) with text to speech support. Android has only female voice for hindi tts. I need a male voice as well. Is there anyway I can route the sound output of TTS to some audio processor in my app and…
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Getting uniform audio levels from AudioRecord across different devices

I am trying to put together a voice recording app, and I noticed a huge discrepancies in the audio samples levels returned by the AudioRecord when the same code is run on different devices (tried with LG G4, Samsung S4). Just FYI, I am targeting API…
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How is the sound converted to matrix in Matlab?

I am using the audioread(filename,y,Fs) function of Matlab and it converts an audio file to a matrix. I want to know how is each value of that matrix generated. Is it possible to produce a specific sound like the sound of a guitar by giving your own…
Jordan
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inaccurate fundamental frequency(peak, pitch) with cepstrum of stft at high frequency

I'm trying to detect fundamental frequency of sound I use cepstrum to find the frequency. It works great except high frequency. I want to detect highest frequency of piano, C8(4186Hz) However, to detect 4186Hz with sample rate 44100, I need…
SounBum Song
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real time audio processing tool in C++

I am trying to record and calculate its spectrum in real time. I wonder what library I should use for this purpose. I need to integrate it into my original C++ code and combine with my image feature. I looked into OpenSmile and it seems not suit for…
Geoffrey Wu
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Mel-frequency function: error with matrix dimensions

I'm trying to make a prototype audio recognition system by following this link: http://www.ifp.illinois.edu/~minhdo/teaching/speaker_recognition/. It is quite straightforward so there is almost nothing to worry about. But my problem is with the…
Dang Manh Truong
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