Continuing my exploration of possibilities MPS can offer, I wonder, is it possible to extract MPS repl component/module into some standalone application which would use some external model files?
I would think that extracting components from MPS would be really complicate. While it is feasible to basically strip down MPS and get a more focused IDE, just getting out a component does not seem easy. MPS is a massive piece of technology with a lot of dependency. What you can do easily is to edit models in MPS and then generate some other format to be processed outside MPS. You can also write some code to read the MPS format (it is just some convoluted XML after all). But getting a component out seems hard.
Source: I am using MPS since several years, currently consulting most of my time on MPS
Related
I was told this belongs in programming, not in the Signal Processing sub-exchange.
Is there a way to implement spectrum analysis (specifically FFT) on live audio in Windows?
I want to be able to read in audio from a microphone, and have a display on the screen that shows the resultant Fourier Transform.
It would also be useful if I could execute a program if a certain set of FFT characteristics occurred.
Thanks guys!
To do this you have a couple of options depending on your most preferred language/framework basically. I'm not sure how new you are to signal processing so I'll suggest a few options.
Visual Programming
These are all visual programming environments which don't actually require any writing of code, however Simulink and Pure Data both require a runtime for the user to run the program.
Simulink (Paid)
MathWorks/Matlab's visual programming tool that works really well in real-time (in my opinion). Using the Audio System Toolbox, you can easily capture microphone input from your system in realtime and carry out the FFT processing, plot the spectrum and, like you said, if certain FFT conditions are met then to carry out some further processing.
This isn't free software and requires having the Matlab/Simulink run-time installed to be used. You can also script your processing in Matlab's .m language as desired (a cross between Java, JS and C).
Max MSP (Paid)
A similar version to Simulink but developed as a standalone visual programming tool. This will allow you similar freedom to Simulink but I think it will be easier for re-distribution.
You can compile MAX MSP into executables to give to someone straight away. Here is a reference to get you started on using the FFT in MAX. Again, this isn't free but if you wanted to learn more about it then I think it's worth the money (if I recall it's not too expensive).
If you need some more custom processing than the built in modules, I believe you can design custom MAX modules using C or JavaScript. Max is designed to easily get system audio input / outputs and here's a link to get you started.
Bonus: You can design your own Ableton Live plugins with the Max4Live addon which just lets your MAX MSP projects get compiled into .VST format. So you can build custom FX if you are into music production.
Pure Data (PD) (Free)
A very bland open source version of MAX MSP but completely free. It may look dull at first but a lot of researches I know use it to build fairly complex systems that can do some serious data processing. There are also lots of community built extras for PD if you ever needed a custom module. Here is a link to get you started on the FFT in PD. You cannot compile applications with PD, but since it's completely free to install anyone can run your program after installing PD. Another link for troubleshooting audio I/O in PD (if it isn't working right out of the box).
Programming Languages
Now the visual stuff is a really good way to get started if you aren't already introduced to DSP or audio programming. Otherwise here a just a few options and links to get started and where I would recommend.
Matlab & Octave
Like before, the Audio Systems Toolbox supports realtime audio I/O within a Matlab script. This combined with Matlab's built in FFT function can have you setup programming realtime FFTs and plotting the response in no time at all (less than 10 lines of code or something).
Octave has it's own version of the FFT function and different backends for rendering plot responses, but no Audio Systems Toolbox. However, Playrec is also an opensource alternative for audio I/O in Matlab/Octave that supports realtime audio input and output.
(Octave is an open source equivalent to Matlab (Matlab needs a paid license to develop a program), but does not support all Matlab supported features).
Python
Due to the PyAudio module, realtime audio I/O and DSP is more possible using Python! I would recommend Python if you are just starting out for sure since it's a nice introduction into any programming language and can help with teaching the fundamentals of DSP before attempting lower level languages.
Here's where you can get started with real-time non-blocking audio I/O in Python with PyAudio. To plot your data you can use a library such as matplotlib (designed similar to Matlab's easy plotting functionality).
For your FFT there are multiple libraries out there but I'd start with the Scipy / Numpy one.
C
One of the classic (and sometimes) most daunting programming language. With no objects (unless you want to make them yourself) or other high level abstractions, C is one of the few languages that still feels like you're building a lot from the ground up (which personally I like).
To get started with audio, I'd look at, in my opinion, the most widely used cross-platform audio I/O library; portaudio. This will let you access the soundcard data inputs and outputs in realtime on Mac, Linux & Windows.
Once you get this up and running an FFT I would use to get started would be the KissFFT just because of it's pure simplicity to use. If you want to plot the data, I would maybe look at gnuplot, but this is'nt a very pretty route in terms of development.
If you are very new to programming I would not recommend this unless you really want to get stuck in.
C++
Both KissFFT and portaudio will also compile with C++ code, but here are a couple of higher level alternatives.
One of my favourites is the JUCE framework / development environment. It has built in cross-platform audio I/O and already has a custom FFT function as part of the framework. You can build custom VSTs for your music DAW if you want to as well. It also comes with 'easy' (if you know C++) access to graphics windows with higher level access to openGL, so you could get fancy when plotting your data in real-time. If i remember correctly, one of the Demo projects on first installation is a real-time FFT plot you can compile and see the input from your laptop mic. JUCE is free for personal use, but comes with a small license fee as an indie developer.
Otherwise another one that comes to mind is the QT C++ library/framework for UI design (mainly). This is a cross platform easy to use GUI designer, that also has high level classes for obtaining audio input from a Mac/Win/Linux mic. Here is just one example I came across using QT's multimedia classes and FFTReal to plot a realtime FFT spectrum.
Summary
I've suggested a lot of options, but also missed out a few other people may recommend like languages such as R, C#, Java, Rust etc... and there are so many suggestions it's impossible to cover them all but I think this should be enough to get started. If it were me in terms of experience:
Complete Beginner to Programming: Max MSP
Novice / Knows their way around a little bit: Python (with PyAudio)
Programmed in other languages maybe looking to gain more programming skills : C++ with JUCE
Any of these languages you pick will be good in future reference for software positions and many companies / researchers use them to prototype / develop realtime audio processing software.
This is just my opinion but hopefully this gets you well along your way!
in case i have a source code and an api to generate windows executable version, is there any possibility or any easy approach to convert it into something that can be executed across Linux /mac or Solaris platforms?
If your code is in a .NET language, there are online and offline translators that can convert the code to Java.
This is just language translation, and doesn't convert the API calls, but it would be a first step in the process.
Another way to handle the problem would be to choose a cloud-based web service or bridge solution. If you have a significant amount of program logic, exposing APIs in this way would allow you to maintain much of the code in its existing language, while making it invocable on other platforms.
So I'm looking to build an application that will be able to record the users screen and stream it at the same time. I would like the application to run on both Windows and OSX. I don't have a high level of programming experience in any language, just basic understanding in C, C++, JS, (funny how each class you take in college wants a different language). I'm also pretty well versed in HTML and CSS but that is kind of irrelevant for this topic.
I've been looking around and it looks like the best solution is going to be writing the core of the program in one language, and then developing the Interface side for each platform differently, using appropriate languages and bindings for the different platforms (Objective-C and Cocoa for OSX and so forth).
I'm open to all suggestions, this project doesn't have a deadline or anything, I'm really just intending it as a learning experience. I've never done anything with video capture and streaming before, so I'm looking for suggestions as to which road to go down language-wise for this project.
Thanks in advance :)
the simplest solution that comes to my mind is to use VLC.
this is obviously not a "language" but an application, but it supports screen-capture and streaming on all of your target platforms (and more).
if this is not an option (e.g. because you don't want a separate application), you could use VLC's C-api for acquiring screen capture and use whatever you like for streaming.
if you want to only rely on native functionality, i would use C/C++ for the application and write the OSX part in ObjC/ObjC++ and Cocoa.
Hello I need to load NSKeyedArchiver classes to C++/CLI counterparts. Is there any way to get internal format of NSKeyedArchiver?
Another option is to rewrite whole saving and opening code into pure C++ for both Mac and Windows.
Thanks a lot.
So your constraints seem to be:
Something easy to parse on both Windows and Mac.
3D modeling data, so the format needs to be efficient
If you want something quick and dirty, go with a binary plist (and possibly gzip it). You could also try Google's protocol buffers but I have no experience with that. There are also a couple open source implementations of Foundation out there -- Cocotron might be most useful for you.
If you're not serializing anything Objective-C specific then just use XML property lists.
I have a C library, which I build as a shared object for Linux and a DLL for Windows with MinGW32. The API depends on a couple of data files (statistical models) which I'd really like to roll in with the SO/DLL so that deployment is just one file.
It looks like I can achieve this for Windows with a "resource file" compiled with windres, but then I've got to write a bunch of resource-handling code for Windows, and I'm still stuck with the files on Linux.
Is there a way to achieve the same functionality on Linux?
Even better, is there a portable solution?
It's actually quite simple on Linux and other ELF systems: http://www.linuxjournal.com/content/embedding-file-executable-aka-hello-world-version-5967
OS X has bundles, so you just build your library as a framework and put the file in the bundle.
Two potential solutions:
Phong Vo's sfio library, which is part of the AT&T Advanced Software Technology toolset, is a wonderful replacement for C stdio.h, and it will allow you to open either files or memory blocks using a single API. So you can easily convert your existing files to C initialized data to include in your DLL or SO file.
This is a good cross-platform solution, but the penalty is that the learning curve to get started is pretty high. They don't make it easy to figure out how stuff works or to take one part of their toolset and split it out for use independent of the other parts. But the good news is that if you want to adopt their U/Win system for running Unix codes on windows (all part of the same toolset), you can create DLLs and SOs using the same system.
For this kind of problem I often fall back on Lua; I can stored Lua data either in external files or within C as initialized data. This is great for distributing everything in one .so file; I do this for my students.
Again the downside is that you have to master and incorporate a new technology.
In my own work I use Lua over the AT&T stuff for these reasons:
Lua has a much smaller footprint and is designed to play well with others; with AST you really have do adopt their way of doing things.
The learning curve with Lua is much less steep; you can be productive very quickly.
Lua is dead easy to install and it's easy to get information about it. AST has its own quirky installation process shared by nobody else in the world; it's often hard to make the installation work; and it's harder to get information about it.
Using Lua has a lot of other payoffs, so the effort spent learning Lua and learning how to incorporate Lua into C codes is easy to amortize over multiple projects.