As I've already said in another thread, I'm working on a project related to real-time graphical programming for audio (something like Pure Data, Max/MSP, Reaktor).
I did a day of research on Internet, looking for a good (maintained, well documented and highly portable) C++ library for low level interaction with audio and MIDI, but I still can not make up my mind about a library.
I'm considering PortAudio+PortMIDI (PortMedia), but they lack of documentation (especially PortMIDI) and there is no official community, just a mail list (and I think forum communities are very important!), same (or worst) situation with RTAudio and RTMidi libraries.
I also give a try to:
STK, I dodn't like its file organization.
Juce, I think it does too much for me, I need only an easy hardware integration
OpenAL, I didn't understand its architecture, it relies on ASIO/ALSA/CoreAudio...? Can I access to MIDI port?
So... My question is: have you any experience with real-time audio/MIDI? Which library do you recommend me?
Thanks
I've used both PortAudio/PortMidi and Juce with great results on both. I'm in the process of switching a project over from PortMidi to Juce, because for my uses all that other app framework stuff ends up being incredibly useful (and in my experience, it's rock solid.). YMMV.
I've created a C++ audio library named "Crosstalk".
Crosstalk is a real-time C++ audio engine that allows you to create and route audio systems in real-time (Pretty much what your trying to achieve graphically), and it's really easy to use.
Here's an example of how to play an mp3 file:
XtSystem system;
XtMp3Decoder mp3Decoder;
XtAudioDevice audioDevice;
long md = system.addComponent(&mp3Decoder);
long ad = system.addComponent(&audioDevice);
system.connOutToIn(md,0,ad,0);
system.connOutToIn(md,1,ad,1);
mp3Decoder.loadFile("../05 Tchaikovski-Swan Lake-Scene.mp3");
mp3Decoder.play();
You can check out the API documentation and licensing details here:
http://www.adaptaudio.com/Crosstalk
EDIT (01-12-2012):
Crosstalk has been replaced by an open-source project called "DSPatch". DSPatch is essentially an upgraded version of the routing engine behind Crosstalk that is no longer limited to only audio processing. DSPatch allows you to create and route almost any type of process chain imaginable, and free for personal AND proprietary use :)
I would also recommend openFramworks: http://www.openframeworks.cc/ It is meant for all kinds of media, interaction, ... and it has a very easy to use/understand API, which is also pretty well documented. Just follow the link above and check it out.
Good luck, Audiodroid
In this tutorial series there's a post about reacting to MIDI data. It also covers other topics such as synthesis etc.
Related
I'm considering adding SNMP support to a simple daemon I wrote under linux. My daemon is written in C++ and Qt5.
I'm looking for an easy way to add this support. I found several MIB creation tools, the problem is writing the agent (or subagent). I'd rather not code this in C, would anyone know of q Qt library that helps out? I found mib2c which will create a skeleton in C (but I'd rather use C++ with Qt).
You can try using CIMPLE, which I've forked on github from it's original website. I've done some cleanup on github and I've attempted to contact the original authors, but they've never returned any of my emails which makes me wonder whether or not they intend to continue supporting the library.
Regardless, it does work and it plays fairly nicely with both Windows and Linux, which have very different styles of implementing SNMP agents. If you google around for "WBEM" you will find some other libraries as well. CIMPLE is the one we used at Fusion-io for SNMP support. It supported C++ fairly well and uses a code generator to handle lots of the boiler plate stuff that's really boring to write and not specific to your application.
I need to develop an application that can be run on both Windows and Mac OS X, is a application "monitor" that needs to display data in real time, connection over ethernet. I'm interested in the performance and graphics. I know very well the c++. can you help me in choosing a development tool?thank you
JUCE is not just about for Music industry. Its for all. I have used it in Music softwares, Image processing and only GUI applications too.
Its a well built library which supports all platform.
you need not to create different project files for the application. JUCE creates it for you.
And its pure C++.
I would say your two choices are Juce or Qt. Juce is geared toward audio and graphics, letting you get your hands on creating fast and powerful DSP algorithms. Although Juce's largest following is with developers making music software, it's fully capable of making general purpose applications with the same ease as Qt. Qt does have advantages resulting from it's greater adoption; you will find plenty of tutorials, books and courses on Qt but hardly much on Juce at the moment.
Hopefully that will change soon as Juce was bought out by ROLI and will likely have more resources soon.
So in Windows, you can use the PlaySound function to play an MP3 file in a C++ application. What would be some similar functions available for use in Mac OS X/Linux? I would also appreciate it if you could link to some sample Hello-World type programs demonstrating this.
You can just open("/dev/dsp") and write to it. That's as "native syscall" as you can get, I believe.
Concerning Audio: Linux != Mac, so I will answer both separately.
MacOS uses the core audio framework for low level audio. Building on that there are several higher level APIs. If you just want to play a sound file the AV Foundation Framework is most likely the way to go. Here you find an example to build a simple app for iOS, which can be ported to MacOS easily.
For Linux the whole situation is quite delicate. There exist many different frameworks and libraries and it very unclear which is low and which is high level, since some of them are emulating the others. Basically there is ALSA and OSS for low level audio. Both of them are crap. Jack is aiming to provide a framework for professional audio but it's not very portable (at least if you are interested in embedded devices). Most Linux OS currently are using PulseAudio as their audio server, which has also a simple API for just playing a single sound and a very difficult API for low level stuff. And then there is the gstreamer library, which is rather portable and has a half way descent API and is especially designed for playing audio & video files and streams, and so probably the way to go on linux.
I personally recommend to use PortAudio, which is a library that provides – as the name states – an audio framework which is portable across several operating systems and audio frameworks. PortAudio is also well designed and has a simple but flexible API.
Well, I'm not sure if current desktops have some more advanced services/libraries that play audio files, but if you really want to do some low-level OS audio output, start looking here. Maybe this is a little too low-level for your needs.
I have some basic effect algorithms (i.e chrous, LP filtering..) which I would like to build a GUI application to be able to use these algorithms.
For example I want to be able to open an audio file, process the audio file in some way with my algorithms and playback the processed file.
Later on I would like to, if possible be able to see the waveforms of the original file and the processed file in the GUI application. This is my objective now.
In the future I want to be able to create a user interface through which users can be able to use my own audio processing algorithms on files of their own.
Is it possible to design such a GUI with the Qt programming framework? If so, could someone point me in the right direction to get started? Right now I have the Qt SDK 1.1 beta running on Windows 7 OS and also using Qt creator. I would really appreciate some guidance.
Qt is a very powerful application framework, but do not expect any extra help with DSP tasks from it. It contains API for some basic and common tasks, like playing an audio/video file, working with audio devices, creating audio effects (search QAudio and Phonon in the Qt's help) etc. You can use some ready-to-use widgets and create your own multimedia player in a few moments.
But in the DSP you are -mostly, on your own. There is, for instance, only a limited audio file format support, so if you want to work with more formats than .wav and .aiff, use some specialized library. I recommend libsndfile (http://www.mega-nerd.com/libsndfile/) which is most powerful free audio file library available. And if you plan your effects to be more universal, use rather VST technology by Steinberg - today's audio plug-in standard, but it is relatively complicated, not suitable for beginners.
There is no built-in widget which can show a waveform, you have to create it yourself, but it is not much complicated. Qt has a really cool drawing functions, brushes, texts, gradients, transformations, antialiasing, even OpenGL wrapper - everything ready and very simple to use.
So the answer is definitely yes. I use Qt in my multimedia applications for three years and now I can't see how I could live without it (using VST GUI and Windows APIs before).
Sure its possible, QT is a framework for writing applications, you can write any application you want using it, you'll probably end up needing to write some custom controls. As an example, here's an Open source QT based application that does pretty much everything you are talking about and much more:
http://qtractor.sourceforge.net/qtractor-index.html
Coming from C++ & MFC background, is there any better (maintainability/customization) platform in developing application GUI ?
We are developing industrial applications (machine vision), where :
-Performance-critical (mostly image processing in CPU atm, but GPU is up next)
-Low level hardware interfacing (inhouse PCI device, frame grabber, motion card)
-Real-time data visualization (images / statistical graph)
-Future roadmap includes networkability for distributed processing and remote access.
Cross-platform will not be important for us since the system runs in controlled-environment (customer only cares whether the system runs and they got their output).
There are also concerns on migration cost (3rd party dependencies, training cost for developers and service personnel)
Edit
Clarification on the "image processing" mentioned above:
I'm referring to "picture" (2D information in matrix format) rather than graphic (commonly 3D vectorized). Currently we uses 3rd party imaging library (for spatial domain processing like segmentation, OCR/OCV, morphology, pattern match) and incorporate our result logic.
If you need performance-critical graphics processing, then C++/DirectX or C++/OpenGL are your best bets, hands down. C++/DirectX is arguably the more maintainable of the two.
That said... depending on the actual processing you're doing, you might consider moving portions of your UI to a more maintainable platform. The .NET framework / WPF can do some pretty amazing things, and with good implementation of patterns like MVVM and can be amazingly maintainable. Ditto the networking side; WCF abstracts a lot of common protocols away from the code, making for cleaner, more maintainable networking code. You can even write your translation layer between your unmanaged processing and your managed layer in C++/CLI.
That said, it's all very subjective. I can't tell enough from your bullet points to make a good judgement on whether or not you can offload some or even all of your processing to .NET/C#. It's worth considering, but my gut tells me that it's probably not your best bet.
As a fan of Qt I would be remiss not to mention it.
Although cross-platform is not one of your criteria, it is a nice bonus.
Qt also has good video hardware support through OpenGL (I'm not sure that it will help with capture hardware though).
It is open-source so you can get your hands as dirty as you like.
It is highly customizable.
It is actively developed and has a large community.
MFC programmers should not have much trouble coming up to speed.
You should also read through some of these questions and answers:
Good C++ GUI library for Windows
https://stackoverflow.com/questions/610/gui-programming-apis
What I had did before when developing a C++ scientific application is that, it will develop it completely under console based application. The console based application will able accept various type of command from user keyboard, and perform action accordingly. For example :
image_processor > load input.png
image_processor > save out.png
The good thing on this is, I can 100% in concentrating my algorithm design, without worry much on how to fit into the GUI framework. Either they are MFC or QT.
At the end of day, instead of taking input from keyboard input stream, I will just simply hook my console based application's STDIN, to the GUI application communication channel. My GUI application will then string based command, to talk and receive feedback from the console application.
Guess what I use to develop the GUI? Java Swing :)
I guess I am taking Unix people approach. See what Joel says :
Suppose you take a Unix programmer and a Windows programmer and give them each the task of creating the same end-user application. The Unix programmer will create a command-line or text-driven core and occasionally, as an afterthought, build a GUI which drives that core. This way the main operations of the application will be available to other programmers who can invoke the program on the command line and read the results as text. The Windows programmer will tend to start with a GUI, and occasionally, as an afterthought, add a scripting language which can automate the operation of the GUI interface.
I realize by taking Windows approach, you will end up with a more user friendly application. However, if your main concern is to get the sophisticated algorithm written well and GUI is the secondary, I would suggest that you go for Unix approach.