mac-au: Add an AUv3 host as filter

plugins/CMakeLists.txt

@@ -49,6 +49,7 @@ add_obs_plugin(linux-jack PLATFORMS LINUX FREEBSD OPENBSD)
 add_obs_plugin(linux-pipewire PLATFORMS LINUX FREEBSD OPENBSD)
 add_obs_plugin(linux-pulseaudio PLATFORMS LINUX FREEBSD OPENBSD)
 add_obs_plugin(linux-v4l2 PLATFORMS LINUX FREEBSD OPENBSD)
+add_obs_plugin(mac-au PLATFORMS MACOS)
 add_obs_plugin(mac-avcapture PLATFORMS MACOS)
 add_obs_plugin(mac-capture PLATFORMS MACOS)
 add_obs_plugin(mac-syphon PLATFORMS MACOS)

plugins/mac-au/CMakeLists.txt

@@ -0,0 +1,36 @@
+cmake_minimum_required(VERSION 3.28...3.30)
+
+add_library(mac-au MODULE)
+add_library(OBS::au ALIAS mac-au)
+
+target_sources(
+  mac-au
+  PRIVATE mac-au.cpp mac-au.h mac-au-scan.mm mac-au-scan.h mac-au-plugin.mm mac-au-plugin.h plugin-main.cpp
+)
+
+target_link_libraries(
+  mac-au
+  PRIVATE
+    OBS::libobs
+    "$<LINK_LIBRARY:FRAMEWORK,AudioUnit.framework>"
+    "$<LINK_LIBRARY:FRAMEWORK,AudioToolbox.framework>"
+    "$<LINK_LIBRARY:FRAMEWORK,AVFoundation.framework>"
+    "$<LINK_LIBRARY:FRAMEWORK,Cocoa.framework>"
+    "$<LINK_LIBRARY:FRAMEWORK,CoreAudio.framework>"
+    "$<LINK_LIBRARY:FRAMEWORK,CoreAudioKit.framework>"
+    "$<LINK_LIBRARY:FRAMEWORK,CoreFoundation.framework>"
+)
+
+set_source_files_properties(mac-au-plugin.mm mac-au-scan.mm PROPERTIES COMPILE_FLAGS "-fobjc-arc")
+
+set_target_properties_obs(
+  mac-au
+  PROPERTIES FOLDER plugins
+             PREFIX ""
+             XCODE_ATTRIBUTE_CLANG_WARN_SUSPICIOUS_IMPLICIT_CONVERSION YES
+             XCODE_ATTRIBUTE_GCC_WARN_SHADOW YES
+)
+
+if(CMAKE_VERSION VERSION_LESS_EQUAL 3.25.0)
+  set_property(TARGET mac-au PROPERTY XCODE_LINK_BUILD_PHASE_MODE BUILT_ONLY)
+endif()

plugins/mac-au/data/locale/en-US.ini

@@ -0,0 +1,7 @@
+AU.Filter="AU host filter"
+AU.Plugin="AU Plugin"
+AU.Button="Open/Close AU Editor"
+AU.NOGUI="Warning: this AU has no GUI."
+AU.ERR="This AU failed to initialize.\nCheck the log for more info."
+AU.Select="Select an AU ..."
+AU.SidechainSource="Sidechain source"

plugins/mac-au/mac-au-plugin.h

@@ -0,0 +1,82 @@
+/*****************************************************************************
+Copyright (C) 2025 by pkv@obsproject.com
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*****************************************************************************/
+#pragma once
+#include "mac-au-scan.h"
+#include <stdint.h>
+#include <stdbool.h>
+
+#ifdef __OBJC__
+#import <AVFoundation/AVFoundation.h>
+#import <CoreAudioKit/CoreAudioKit.h>
+#import <Cocoa/Cocoa.h>
+#else
+typedef void AVAudioUnit;
+typedef void AUAudioUnit;
+typedef void AUViewControllerBase;
+typedef void NSWindow;
+#endif
+
+struct au_data;
+
+struct au_plugin {
+    char uid[32];
+    char name[64];
+    NSString *title;
+    char vendor[64];
+
+    OSType type;
+    OSType subtype;
+    OSType manufacturer;
+    bool is_v3;
+
+    AVAudioUnit *av_unit;
+    AUAudioUnit *au;
+    void *objc;
+
+    bool has_view;
+    bool editor_is_visible;
+
+    uint32_t max_frames;
+    double sample_rate;
+    uint32_t channels;
+    double sample_time;
+
+    int num_in_audio_buses;
+    int num_out_audio_buses;
+    int num_enabled_in_audio_buses;
+    int num_enabled_out_audio_buses;
+    int sidechain_num_channels;
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    struct au_plugin *au_plugin_create(const struct au_descriptor *desc, double sr, uint32_t frames, uint32_t channels);
+    void au_plugin_destroy(struct au_plugin *p);
+    void au_plugin_process(struct au_plugin *p, float *const *channels, float *const *sc_channels,
+                           bool sidechain_enabled, uint32_t num_frames, uint32_t num_channels);
+
+    CFDataRef au_plugin_save_state(struct au_plugin *p);
+    void au_plugin_load_state(struct au_plugin *p, CFDataRef data);
+
+    void au_plugin_show_editor(struct au_plugin *p);
+    void au_plugin_hide_editor(struct au_plugin *p);
+
+#ifdef __cplusplus
+}
+#endif