Introduction

This is a standalone program to run the beautiful SpectrogramWidget of the juce-spectroscope19 library. Go there if you want to include the widget in your own project, look here in this repository on how it is done.

I also use this as a super-repository to document the use of the SpectrogramWidget including a proper build with git submodules, and hooking it into the appveyor CI.

Example

Here is a screenshot of the program in action rendering a youtube video of a performance of Pergolesi's Stabat mater:

Usage

This repository allows us to build the demo of the SpectrogramWidget library independantly in an easy way. First checkout recursively:

cd <whereever>
git clone --recurse-submodules -j8 https://github.com/christofmuc/juce-spectroscope19-ci.git

On Windows

Then use CMake to build the makefile for Windows (use other generators as you see fit, here I am using Microsoft Visual Studio 2017, which is available as a Community edition as well). We will need a recent version of CMake, at least version 3.14 is required.

cd <whereever>\juce-spectroscope19-ci
cmake -S . -B Builds\Windows -G "Visual Studio 15 2017 Win64" 

Building with cmake:

cmake --build Builds\Windows --config=Release

or for the Debug build:

cmake --build Builds\Windows --config=Debug

On Unix

The build process on Unix is slightly different. We tested only on Debian 9 so far, and this is how it works:

Install CMake. At the time of writing, the packaged version of cmake for Debian is way too old. Remove the old cmake in case it is there with

sudo apt remove cmake
sudo apt purge --auto-remove cmake

Installing CMake from binary distribution (x86)

Then you need to download the binary distribution from the website and install it according to the instructions:

wget https://github.com/Kitware/CMake/releases/download/v3.15.5/cmake-3.15.5-Linux-x86_64.sh
chmod +x cmake-3.15.5-Linux-x86_64.sh
sudo ./cmake-3.15.5-Linux-x86_64.sh --skip-license --exclude-subdir --prefix=/usr/local 

Building CMake yourself

In case you are running on something that is not supported by the binary CMake distribution (like a Raspberry Pi), or the install process for whatever reason fails, you have to build CMake yourself.

On some vanilla Linux distributions, the libcurl is deployed without support for SSL, and this will lead to subsequent failures during CMake configuration when it tries to download stuff with https. To be really really sure you will not run into this problem, build yourself a libcurl with SSL support like this:

wget https://curl.haxx.se/download/curl-7.67.0.tar.gz
tar -xzf curl-7.67.0.tar.gz && cd curl-7.67.0 && ./configure --with-ssl && make -j4 && make install && ldconfig

With the libcurl in place, we can now build CMake itself with

wget https://github.com/Kitware/CMake/releases/download/v3.15.5/cmake-3.15.5.tar.gz
tar -xzf cmake-3.15.5.tar.gz && cd cmake-3.15.5 && ./bootstrap && make -j4 && make install

This will take awhile, especially on a Raspberry.

Testing CMake

Test that the cmake is now on the path:

cmake --version

should output something similar to

cmake version 3.15.5

CMake suite maintained and supported by Kitware

Preparing the system

We need to install a list of prerequisite development packages in case they are not present yet. This is best done with the following command:

sudo apt-get install -y build-essential pkg-config libwebkit2gtk-4.0-dev libglew-dev libcurl4-openssl-dev libasound2-dev libjack-jack2d-dev

Building with CMake

Now we can run the cmake build command and keep fingers crossed that we will build without errors

cd <whereever>/juce-spectroscope19-ci
cmake -S . -B Builds/Debug -DCMAKE_BUILD_TYPE=DEBUG
cmake --build Builds/Debug

The resulting executable that you can start is found in the folder Builds/Debug.

For a release build, run

cd <whereever>/juce-spectroscope19-ci
cmake -S . -B Builds/Release -DCMAKE_BUILD_TYPE=RELEASE
cmake --build Builds/Release

This will produce the result in the folder Builds/Release.

Third party libraries used

Please understand that this example software uses the following third party libraries, and you are implicitly accepting their license terms as well when using this software. Please visit the links and familarize yourself with their conditions.

For the sake of easy accessibility, the cmake build of this example software automatically downloads and uses the following components:

1. The awesome JUCE library for cross-platform C++ development.
2. For wrangling OpenGL in its complexity I say thank you to the GLEW library.
3. For building complex projects I use CMake, and with juce-cmake this becomes much easier!
4. On Windows, nothing beats for me ASIO drivers for high-quality low-latency audio drivers, and our thanks go to the company Steinberg for still providing their ASIO SDK. Please check out their licensing especially!

Licensing

As some substantial work has gone into the development of this and related software, I decided to offer a dual license - AGPL, see the LICENSE.md file for the details, for everybody interested in how this works and willing to spend some time her- or himself on this, and a commercial MIT license available from me on request. Thus I can help the OpenSource community without blocking possible commercial applications.

Contributing

All pull requests and issues welcome, I will try to get back to you as soon as I can. Due to the dual licensing please be aware that I will need to request transfer of copyright on accepting a PR.

About the author

Christof is a lifelong software developer having worked in various industries, and can't stop his programming hobby anyway.