pipewire

Pipewire client library, statically linked, ported to the Zig build system.

Motivation

I want a static executable that can play audio and turn screen contents into a video feed. The pipewire library makes heavy use of dlopen internally, so this is nontrivial.

Strategy

This library builds pipewire with an alternate implementation of dlfcn.h (and some filesystem APIs) that look for data in a symbol table statically compiled with the executable, instead of loading the data at runtime.

For more information, see src/wrap.

This project follows the pristine tarball approach. No modifications are required to the upstream pipewire source.

Status

You can run the video-play example with zig build video-play to see the current webcam feed. This currently works without pipewire accessing the dynamic linker, but the example executable isn't fully static since it relies on SDL. I plan to port the example away from SDL so that this can be changed.

Only the pipewire plugins/modules required for this example are currently built. To use other parts of the pipewire API, you may need to add more symbols to src/wrap/dlfcn.zig and regenerate c.zig if additional pipewire headers are required.

Usage

First, add pipewire to your build.zig.zon:

zig fetch --save git+https://github.com/allyourcodebase/pipewire

Then, link it to you executable in build.zig

const pipewire = b.dependency("pipewire", .{
    .optimize = optimize,
    .target = target,
});

// For Zig projects, add the `pipewire` module.
my_zig_exe.root_module.addImport("pipewire", pipewire.module("pipewire"));

// For C projects, link the `pipewire-0.3` static library.
my_c_exe.linkLibrary(pipewire.artifact("pipewire-0.3"));

You can then access pipewire as you would normally from C, you can import the already translated headers from Zig. This is necessary for now as the headers can't yet be translated automatically, in the future you'll be able to use @cImport directly:

const pw = @import("pipewire").c;

pw.pw_init(0, null);
defer pw.pw_deinit();

// ...

See src/examples for more information.