pipewire: initialize stream

meson.build

@@ -35,6 +35,7 @@ xkbcommon = dependency('xkbcommon')
 thread_dep = dependency('threads')
 cap_dep = dependency('libcap')
 sdl_dep = dependency('SDL2')
+pipewire_dep = dependency('libpipewire-0.3', required: get_option('pipewire'))
 
 wlroots_dep = dependency(
   'wlroots',
@@ -67,28 +68,39 @@ liftoff_dep = dependency(
   default_options: ['default_library=static'],
 )
 
+add_project_arguments(
+  '-DHAVE_PIPEWIRE=@0@'.format(pipewire_dep.found().to_int()),
+  language: 'cpp',
+)
+
 subdir('protocol')
 
+src = [
+  'src/steamcompmgr.cpp',
+  'src/main.cpp',
+  'src/wlserver.cpp',
+  'src/drm.cpp',
+  'src/cvt.cpp',
+  'src/sdlwindow.cpp',
+  'src/vblankmanager.cpp',
+  'src/rendervulkan.cpp',
+  'src/log.cpp',
+  spirv_shader,
+  gamescope_xwayland_proto_files,
+]
+
+if pipewire_dep.found()
+  src += 'src/pipewire.cpp'
+endif
+
 executable(
   'gamescope',
-  [
-    'src/steamcompmgr.cpp',
-    'src/main.cpp',
-    'src/wlserver.cpp',
-    'src/drm.cpp',
-    'src/cvt.cpp',
-    'src/sdlwindow.cpp',
-    'src/vblankmanager.cpp',
-    'src/rendervulkan.cpp',
-    'src/log.cpp',
-    spirv_shader,
-    gamescope_xwayland_proto_files,
-  ],
+  src,
   dependencies: [
     dep_x11, dep_xdamage, dep_xcomposite, dep_xrender, dep_xext, dep_xfixes,
     dep_xxf86vm, dep_xres, drm_dep, wayland_server, wayland_protos,
     xkbcommon, thread_dep, sdl_dep, wlroots_dep,
-    vulkan_dep, liftoff_dep, dep_xtst, cap_dep
+    vulkan_dep, liftoff_dep, dep_xtst, cap_dep, pipewire_dep,
   ],
   install: true,
 )

meson_options.txt

@@ -0,0 +1 @@
+option('pipewire', type: 'feature', description: 'Screen capture via PipeWire')

src/main.cpp

@@ -19,6 +19,10 @@
 #include "wlserver.hpp"
 #include "gpuvis_trace_utils.h"
 
+#if HAVE_PIPEWIRE
+#include "pipewire.hpp"
+#endif
+
 std::atomic< bool > g_bRun{true};
 
 int g_nNestedWidth = 0;
@@ -255,6 +259,13 @@ int main(int argc, char **argv)
 	setenv("DISPLAY", wlserver_get_nested_display_name(), 1);
 	setenv("GAMESCOPE_WAYLAND_DISPLAY", wlserver_get_wl_display_name(), 1);
 
+#if HAVE_PIPEWIRE
+	if ( !init_pipewire() )
+	{
+		fprintf( stderr, "Warning: failed to setup PipeWire, screen capture won't be available\n" );
+	}
+#endif
+
 	std::thread steamCompMgrThread( steamCompMgrThreadRun, argc, argv );
 	steamCompMgrThread.detach();
 

src/pipewire.cpp

@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <spa/param/video/format-utils.h>
+
+#include "main.hpp"
+#include "pipewire.hpp"
+
+static void stream_handle_state_changed(void *data, enum pw_stream_state old_stream_state, enum pw_stream_state stream_state, const char *error)
+{
+	struct pipewire_state *state = (struct pipewire_state *) data;
+
+	fprintf(stderr, "pipewire: stream state changed: %s\n", pw_stream_state_as_string(stream_state));
+
+	switch (stream_state) {
+	case PW_STREAM_STATE_PAUSED:
+		if (state->stream_node_id == SPA_ID_INVALID) {
+			state->stream_node_id = pw_stream_get_node_id(state->stream);
+		}
+		break;
+	case PW_STREAM_STATE_STREAMING:
+		break;
+	default:
+		break;
+	}
+}
+
+static const struct pw_stream_events stream_events = {
+	.version = PW_VERSION_STREAM_EVENTS,
+	.state_changed = stream_handle_state_changed,
+	//.param_changed = stream_handle_param_changed,
+	//.add_buffer = stream_handle_add_buffer,
+	//.remove_buffer = stream_handle_remove_buffer,
+};
+
+bool init_pipewire(void)
+{
+	pw_init(nullptr, nullptr);
+
+	struct pipewire_state state = { .stream_node_id = SPA_ID_INVALID };
+
+	state.loop = pw_loop_new(nullptr);
+	if (!state.loop) {
+		fprintf(stderr, "pipewire: pw_loop_new failed\n");
+		return false;
+	}
+
+	state.context = pw_context_new(state.loop, nullptr, 0);
+	if (!state.context) {
+		fprintf(stderr, "pipewire: pw_context_new failed\n");
+		return false;
+	}
+
+	state.core = pw_context_connect(state.context, nullptr, 0);
+	if (!state.core) {
+		fprintf(stderr, "pipewire: pw_context_connect failed\n");
+		return false;
+	}
+
+	state.stream = pw_stream_new(state.core, "gamescope",
+		pw_properties_new(
+			PW_KEY_MEDIA_CLASS, "Video/Source",
+			nullptr));
+	if (!state.stream) {
+		fprintf(stderr, "pipewire: pw_stream_new failed\n");
+		return false;
+	}
+
+	struct spa_hook stream_hook;
+	pw_stream_add_listener(state.stream, &stream_hook, &stream_events, &state);
+
+	struct spa_rectangle size = SPA_RECTANGLE(g_nOutputWidth, g_nOutputHeight);
+	struct spa_fraction framerate = SPA_FRACTION(0, 1);
+
+	uint8_t buf[1024];
+	struct spa_pod_builder builder = SPA_POD_BUILDER_INIT(buf, sizeof(buf));
+	const struct spa_pod *param = (const struct spa_pod *)spa_pod_builder_add_object(&builder,
+		SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
+		SPA_FORMAT_mediaType, SPA_POD_Id(SPA_MEDIA_TYPE_video),
+		SPA_FORMAT_mediaSubtype, SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
+		SPA_FORMAT_VIDEO_format, SPA_POD_Id(SPA_VIDEO_FORMAT_RGB),
+		SPA_FORMAT_VIDEO_size, SPA_POD_Rectangle(&size),
+		SPA_FORMAT_VIDEO_framerate, SPA_POD_Fraction(&framerate));
+
+	// TODO: PW_STREAM_FLAG_ALLOC_BUFFERS
+	enum pw_stream_flags flags = PW_STREAM_FLAG_DRIVER;
+	int ret = pw_stream_connect(state.stream, PW_DIRECTION_OUTPUT, PW_ID_ANY, flags, &param, 1);
+	if (ret != 0) {
+		fprintf(stderr, "pipewire: pw_stream_connect failed\n");
+		return false;
+	}
+
+	while (state.stream_node_id == SPA_ID_INVALID) {
+		int ret = pw_loop_iterate(state.loop, -1);
+		if (ret < 0) {
+			fprintf(stderr, "pipewire: pw_loop_iterate failed\n");
+			return false;
+		}
+	}
+
+	fprintf(stderr, "pipewire: stream available on node ID: %u\n", state.stream_node_id);
+
+	return true;
+}

src/pipewire.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <pipewire/pipewire.h>
+
+struct pipewire_state {
+	struct pw_loop *loop;
+	struct pw_context *context;
+	struct pw_core *core;
+	struct pw_stream *stream;
+	uint32_t stream_node_id;
+};
+
+bool init_pipewire(void);