Developing On Windows

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Revision as of 16:12, 22 November 2013 by Edgar (talk | contribs) (use Visual C++ Express (VC++) where appropriate)
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It can help to work in stages. It's probably not advisable to try to do all the steps on this page in one session.

Visual Studio Express and Microsoft SDK

Install Microsoft's Visual Studio or its free Visual C++ Express version. As of November 2013 Audacity only supports the 2008 version but there is an experimental 2012 project as well.

To develop in C/C++ for Windows you need a second download from Microsoft:

Don't forget to do a 'Windows Update' for any recent changes.

With VC++ set up you can write 'hello world' and similar small programs just to check things out, or use some of the examples that Microsoft provides. There is a Microsoft Forum for Visual C++ Express where you can get help with the program if you need it.

What about Visual Studio 2010? Or 64-bit?

It is strongly recommended that you use Visual Studio or VC++ Express 2008. The (free) VC++ 2008 Express version is just fine for building Audacity. The core developers have no intention of moving to VS2010 due to bugs in early VC++ 2010 Express versions that are not present in VC++ 2008 Express. If you're still keen to try:

  • As at April 2011, 3 projects in the solution will not build in VS 2010. wxWidgets steps must be followed closely and built targeting 32-bit, as must Audacity. Portaudio-v19, mod-script-pipe and of course Audacity will not build due to a number of MS compiler errors. Taglib would not build either, but is not currently in use in Audacity and no longer included in the solution file.
  • Several people have had a go at building Audacity with VS 2010.
    • Andreas Micheler has succeeded, after making some mods to the code.
    • Ed Musgrove has succeeded, also after various mods. See this Forum topic for details.
    If you are adventurous, you're encouraged to contact either person and post consolidated tips/experience here.

    It's a good idea to FIRST build with 2008 before attempting anything with 2010. Also check Bug 178 for the current known status of building in VS 2010.

  • VS 2010 apparently cannot build binaries that run on Windows 2000, XP RTM or Windows XP Service Pack 1. We still support those platforms. See this stackoverflow discussion.
  • Audacity is currently a 32-bit only application. It compiles fine on 64-bit versions of Windows using VS 2008, but is some way from being offered as a 64-bit application. A 32-bit limitation has been fixed for release in 2.0.6 that prevented loading projects where a clip contained 2^31 samples or more. However at least some other problems remain with such clips for example, incorrect display in Selection Toolbar.

    Making Audacity 64-bit ready requires a comprehensive review of Audacity, not just fixing the many errors flagged by the compiler. It's a large task, and not currently a priority.

Visual Studio 2012

There is some optimism about moving to Visual Studio 2012. Audacity already builds using Visual Studio Express 2012 and Widgets 2.8.12 as of November 2013, using win\audacity-vs2012.sln in the Audacity sources.

To avoid crashes in the built Audacity executable It is necessary to rebuild wxWidgets using VS2012 and to remove the following lines from src\msw\windows.cpp in the current Widgets sources we use (as per this widgets commit):

#if !defined __WXWINCE__ && !defined NEED_PBT_H
#include <pbt.h>

"Update 1" for VS2012 in November 2012 reintroduced some support for builds that work on Windows XP but installation of VS2012 requires Windows 7 or Windows 8.

Ed Musgrove has made modifications to Audacity code to build it with VC++ 2012 Express and wxWidgets 3.0:

Download wxWidgets

Next get a recent version of wxWidgets. If you want to work with cutting edge code in Audacity, use wxWidgets 2.8.12 (the version officially supported by Audacity as at December 2011). Follow the instructions in the wxWidgets documentation to get some of the wxWidgets samples to compile. For in-depth reference there is a 700-page book: Cross-Platform GUI Programming with wxWidgets which is also available as a PDF download. Time spent reading the documentation and trying things out is time well spent. There is one detail in setting up wxWidgets which is very important. It's setting up the $(WXWIN) environment variable. It's not set by the installer. It must be set correctly to your wxWidgets directory if you're to compile Audacity.

wxWidgets can be compiled in many different modes, such as Unicode and ANSI, debug and release, library or dll. If you want to work with the latest Audacity code, make sure that amongst the versions of wxWidgets that you compile is the DLL Unicode Debug version.

Don't try moving on further until you have at least one sample wxWidgets program compiled and running!

Set up for SVN

For Windows, TortoiseSVN is possibly the easiest client to use to get the code from the repository. It adds extra right-click menu items to the Explorer file manager. These are used for synchronising your local copy of the files with the repository. Any user can read the files and that's all you need at this stage.

Once TortoiseSVN is installed, in Explorer, create a folder for the source, right-click on it and select 'SVN Checkout...' then paste

into the first box and hit 'OK'. Wait a bit and you should have the source (about 230MB, May 2010).

If you have problems checking out the code, please e-mail our feedback address so we can look into it.

Compiling wxWidgets and Audacity

In May 2008 we made significant changes so that we build Audacity modularly. In the past, Audacity was always built against a custom monolithic non-DLL build of wxWidgets. This let us use multi-threaded wxWidgets while having Audacity as a single executable. But now we want to use plug-in modules in Audacity, and the modules and Audacity must both link to wxWidgets. Unfortunately it is not possible to embed the wxWidgets dll's into Audacity and share them as static links. So, Audacity will ship with these dll's and link to them dynamically. On the other hand, DLL builds of wxWidgets are automatically multi-threaded, so we no longer need a custom wxWidgets build.

As from 30 October 2013 ( r12804), there are just two configurations of Audacity, both modular, both for Unicode use only (Audacity stopped releasing ANSI builds for Windows 98 and ME with the 2.0.1 Release). To build, first build the appropriate configuration of Widgets for your required build of Audacity:

Audacity configuration Purpose Required wxWidgets build
Release General Unicode-based use DLL Unicode Release
Debug Slower performance, debuggable, Unicode support DLL Unicode Debug

Prior to r12804 an additional two configurations were available for non-Unicode use. These were called "Release" (requiring to build wxWidgets DLL Release) and "Debug" (requiring to build wxWidgets "DLL Debug"). The Unicode-based configurations at that time were explicitly called "Unicode Release" and "Unicode Debug" respectively.

Build wxWidgets, set the environment variable, build Audacity

There are excellent instructions in the online compile.txt or abridged Wiki version for MSVC. Building Widgets is straightforward, but it's worth repeating that you need to exit Visual Studio and set the WXWIN environment variable before building Audacity.

Set the WXWIN environment variable to "C:\wxWidgets-2.8.12" assuming you installed wxWidgets 2.8.12 into its standard location of C:\. To do this:

  • Windows 2000 and later: Right-click over "My Computer", then follow any "Advanced" links to arrive at "System Properties". Click on "Advanced" then "Environment Variables". Add a user or system variable with name "WXWIN" and value "C:\wxWidgets-2.8.12" (without quotes).
  • Windows 98/ME: Edit AUTOEXEC.BAT to add a line "set WXWIN=C:\wxWidgets-2.8.12" (without quotes). It's safest to do this by running MSCONFIG, and click "New" on the "Autoexec.bat" tab.
Warning icon It is highly recommended to reboot the computer after setting WXWIN. It is definitely essential on Windows 98/ME, and in practice seems to be required on later versions of Windows too.

Common Compilation Errors

  • Setup.h not found:
    If when you try to compile Audacity you get errors about "Setup.h" not being found, that could mean:
    • a) You have not compiled wxWidgets in the right version for the version of Audacity you are trying to build (e.g. incorrect Unicode choice - You must select "DLL Unicode Debug" or "DLL Unicode Release" and NOT "DLL Universal Unicode Debug/Release") OR
    • b) Your $(WXWIN) environment variable is wrong. For it to take effect after a change you must restart Visual Studio or better, reboot.
    • c) Rarely, additional include directories need to be added to MSVC.
  • unistd.h not found:
    • Add "..\..\lib-src\libsamplerate\Win32" to INCLUDE path (C/C++->General->Additional Include Directories) for the project that fails to build with this error (usually - libid3tag).
  • wx*26ud.lib not found when building in Unicode_Debug configuration:
    • Change wx*26ud to wx*28ud for Audacity project (In Visual Studio: Project > Audacity Properties > expand Configuration Properties > Linker > Input > Additional Dependencies).
    • Make sure you built wxWidgets in Unicode Debug configuration.
    • This applies to all similar errors (with other configurations) - first check that dependencies has the right version, then check that these files exist at all.

Still can't build?