a2i: Audio to Image Spectrogram Utility

Table of Contents

• Changelog
• Overview
• Features
• Requirements
• Installation
  • Linux
  • Windows
  • macOS
• Usage
  • Command Line Options
  • Controls
  • Examples
• Configuration
• API Reference
  • Initialization
  • Customizing Parameters
  • Generating Spectrograms
• FAQ
• Troubleshooting
  • Common Issues
  • Reporting Issues
• Future Plans
• Contributing
• License

Overview

a2i is a powerful utility and library for generating and visualizing audio spectrograms. It leverages the capabilities of raylib for audio processing and OpenCV for image manipulation and visualization, along with the a2i library for spectrogram generation.

Features

• Convert audio files to spectrogram images.
• Real-time spectrogram visualization from microphone input.
• Customizable spectrogram parameters (window function, amplitude range, etc.).
• Various visualization options (colormap, grid, line types, etc.).
• Control playback with keyboard inputs.

Requirements

Ensure your system is up to date and has the necessary dependencies:

sudo apt update && sudo DEBIAN_FRONTEND=noninteractive apt install -y make build-essential pkg-config git libfftw3-dev libopencv-dev pulseaudio pulseaudio-utils python3-pip libx11-dev libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libgl1-mesa-dev cmake

Installation

Linux

1. Clone the repository:

git clone https://github.com/d33fur/a2i.git && cd a2i

2. Build and install:

make

3. Run the executable:

a2i <audio-file> [options]

Windows

To be added.

macOS

To be added.

Usage

Command Line Options

Usage:
  a2i <path> [options]
Options:
  -a <range>              Amplitude range (default: -90,50)
  -w <int>                Window function (0-9, default: 9)
  -l <int>                Line type (0-2, default: 0)
  -g <int>                Graph mode (0-1, default: 1)
  -m <int>                Normalize multiplier (default: 20)
  -mic                    Use microphone
  -f <int>                Frame size (>=512, default: 65536)
  -n <int>                Number of previous frames (>0)
  -size <height,width>    Window size (default: 400,2100)
  -grad <int>             Colormap (0-21)
  -fill <int>             Fill type (0-2, default: 2)
  -border                 Border line
  -line <color>           Line color (default: 255,255,255)
  -underline <color>      Underline color (default: 127,127,127)
  -grid                   Grid
  -grad_coef <int>        Gradient coefficient (0-255, default: 127)
  -grid_line_color <color> Grid line color
  -grid_text_color <color> Grid text color
  -h, -help               Show this help message

Controls

• Space: Pause/Resume
• Left Arrow: Rewind 5 seconds
• Right Arrow: Fast Forward 5 seconds
• Esc: Exit

Examples

Visualize a real-time spectrogram from an audio file

To visualize a spectrogram with specific settings, use the following command:

a2i myaudiofile.wav -a=-90,100 -n=20 -size=400,1000 -grad=17 -grad_coef=255 -grid

Real-time microphone input visualization

For real-time spectrogram visualization using your microphone:

a2i -mic -a=-90,100 -n=20 -size=400,1000 -grad=17 -grad_coef=255 -grid

Changing the window function and amplitude range

a2i myaudiofile.wav -w=7 -a=-80,70 -size=500,1200 -grad=10 -grid

Configuration

You can configure various parameters in config.ini to customize the behavior of a2i. Here's an example configuration:

[General]
AmplitudeRange=-90,50
WindowFunction=9
LineType=0
GraphMode=1
NormalizeMultiplier=20
FrameSize=65536
NumberOfPreviousFrames=10
WindowSize=400,2100
Colormap=17
FillType=2
BorderLine=1
LineColor=255,255,255
UnderlineColor=127,127,127
Grid=1
GradientCoefficient=127
GridLineColor=128,128,128
GridTextColor=200,200,200

API Reference

Initialization

<code>

Customizing Parameters

#include "raylib.h"
#include <opencv2/opencv.hpp>
#include <opencv2/highgui.hpp>
#include <a2i/spectrogram.hpp>

int main(int argc, char** argv) 
{
    InitAudioDevice();
    Music music = LoadMusicStream("myaudiofile.wav");
    PlayMusicStream(music);
    SetMusicVolume(music, 0.8f);
    AttachAudioStreamProcessor(music.stream, callback);

    g.setAudioInfo(music.stream.sampleRate, {-90, 50});
    g.setFreqRange({20, 20000});
    g.setFrameSize(FRAME_SIZE);
    g.setWindowFunc(9);

    cv::namedWindow("a2i", cv::WINDOW_NORMAL);
    cv::resizeWindow("a2i", WINDOW_WIDTH, WINDOW_HEIGHT);

    cv::Mat img(WINDOW_HEIGHT, WINDOW_WIDTH, CV_8UC3, cv::Scalar(22, 16, 20));

    while (true)
    {
        UpdateMusicStream(music);

        if (show)
        {
            img = cv::Mat(WINDOW_HEIGHT, WINDOW_WIDTH, CV_8UC3, cv::Scalar(22, 16, 20));
            g.drawSpectrum(img, 0, 1, 2, true, {255, 255, 255}, {127, 127, 127}, 127);
            cv::imshow("a2i", img);
        }

        if (cv::waitKey(1) == 27) break; // Exit on ESC key
    }

    UnloadMusicStream(music);
    CloseAudioDevice();
    cv::destroyAllWindows();

    return 0;
}

Generating Spectrograms

#include "raylib.h"
#include <opencv2/opencv.hpp>
#include <a2i/spectrogram.hpp>

int WINDOW_WIDTH = 800;
int WINDOW_HEIGHT = 600;
unsigned int FRAME_SIZE = 65536;
a2i::Spectrogram g;
int multiplier = 20;
bool show = false;

typedef struct 
{
    float left;
    float right;
} Frame;

void callback(void *bufferData, unsigned int frames) 
{
    if (frames < 512) return;

    Frame *fs = static_cast<Frame*>(bufferData);

    if (g.in.size() == FRAME_SIZE)
    {
        g.in.erase(g.in.begin(), g.in.begin() + frames);
    }

    for (size_t i = 0; i < frames; ++i) 
    {
        g.in.push_back((fs[i].left + fs[i].right) / 2);
    }

    if (g.in.size() == FRAME_SIZE)
    {
        g.addWindow();
        g.fft();
        g.normalize(multiplier);
        show = true;
    }
    else
    {
        show = false;
    }
}

FAQ

How do I install additional dependencies?

Follow the instructions in the Requirements section to ensure all dependencies are installed.

Can I use a2i on Windows or macOS?

Support for Windows and macOS is planned. For now, a2i is primarily tested on Linux.

Troubleshooting

Common Issues

(добавить про пульсаудио)

• Audio file not found: Ensure the path to the audio file is correct.
• Dependency issues: Make sure all dependencies are installed as specified in the Requirements section.

Reporting Issues

If you encounter any issues, please open an issue on the GitHub repository.

Future Plans

• Support for more platforms (Windows, macOS)
• Enhanced visualization options
• Integration with more audio formats

Contributing

Contributions are welcome! Please fork the repository and submit a pull request with your changes. For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the MIT License. See the LICENSE file for details.