Audio Signal Processing GUI developement using Qt, How to?

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 desi开发者_开发问答gn 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