Broadcast extension for AppRTCMobile on iOS

This provides an environment for testing out using WebRTC from an iOS
extension. It implements a ReplayKit broadcast extension for live
streaming games and screensharing.

The extension is only supported on iOS 11+ and is guarded by a build
flag.

Bug: webrtc:9335
Change-Id: Id218d6c73ef7599f5953c5a1e0e62e5d0dc4f10b
Reviewed-on: https://webrtc-review.googlesource.com/80000
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23504}

examples/BUILD.gn

@@ -245,6 +245,8 @@ if (is_ios || (is_mac && target_cpu != "x86")) {
       "objc/AppRTCMobile/ARDBitrateTracker.m",
       "objc/AppRTCMobile/ARDCaptureController.h",
       "objc/AppRTCMobile/ARDCaptureController.m",
+      "objc/AppRTCMobile/ARDExternalSampleCapturer.h",
+      "objc/AppRTCMobile/ARDExternalSampleCapturer.m",
       "objc/AppRTCMobile/ARDJoinResponse+Internal.h",
       "objc/AppRTCMobile/ARDJoinResponse.h",
       "objc/AppRTCMobile/ARDJoinResponse.m",
@@ -297,6 +299,7 @@ if (is_ios || (is_mac && target_cpu != "x86")) {
         "../sdk:peerconnectionfactory_base_objc",
         "../sdk:videocapture_objc",
         "../sdk:videocodec_objc",
+        "../sdk:videoframebuffer_objc",
         "../sdk:videosource_objc",
       ]
     }
@@ -365,11 +368,91 @@ if (is_ios || (is_mac && target_cpu != "x86")) {
         "../sdk:framework_objc",
       ]
 
+      if (rtc_apprtcmobile_broadcast_extension) {
+        deps += [
+          ":AppRTCMobileBroadcastSetupUI_extension_bundle",
+          ":AppRTCMobileBroadcastUpload_extension_bundle",
+        ]
+      }
+
       if (target_cpu == "x86") {
         deps += [ "//testing/iossim:iossim" ]
       }
     }
 
+    if (rtc_apprtcmobile_broadcast_extension) {
+      bundle_data("AppRTCMobileBroadcastUpload_extension_bundle") {
+        testonly = true
+        public_deps = [
+          ":AppRTCMobileBroadcastUpload",
+        ]
+        sources = [
+          "$root_out_dir/AppRTCMobileBroadcastUpload.appex",
+        ]
+        outputs = [
+          "{{bundle_plugins_dir}}/{{source_file_part}}",
+        ]
+      }
+
+      bundle_data("AppRTCMobileBroadcastSetupUI_extension_bundle") {
+        testonly = true
+        public_deps = [
+          ":AppRTCMobileBroadcastSetupUI",
+        ]
+        sources = [
+          "$root_out_dir/AppRTCMobileBroadcastSetupUI.appex",
+        ]
+        outputs = [
+          "{{bundle_plugins_dir}}/{{source_file_part}}",
+        ]
+      }
+
+      rtc_static_library("AppRTCMobileBroadcastUpload_lib") {
+        check_includes = false
+        testonly = true
+        sources = [
+          "objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSampleHandler.h",
+          "objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSampleHandler.m",
+        ]
+
+        deps = [
+          ":AppRTCMobile_ios_frameworks",
+          ":apprtc_signaling",
+          "../sdk:framework_objc",
+        ]
+
+        libs = [ "ReplayKit.framework" ]
+      }
+
+      ios_appex_bundle("AppRTCMobileBroadcastUpload") {
+        testonly = true
+        configs += [ "..:common_config" ]
+        public_configs = [ "..:common_inherited_config" ]
+
+        info_plist = "objc/AppRTCMobile/ios/broadcast_extension/BroadcastUploadInfo.plist"
+
+        deps = [
+          ":AppRTCMobileBroadcastUpload_lib",
+          "../sdk:framework_objc",
+        ]
+      }
+
+      ios_appex_bundle("AppRTCMobileBroadcastSetupUI") {
+        sources = [
+          "objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSetupViewController.h",
+          "objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSetupViewController.m",
+        ]
+
+        info_plist = "objc/AppRTCMobile/ios/broadcast_extension/BroadcastSetupUIInfo.plist"
+
+        libs = [ "ReplayKit.framework" ]
+
+        deps = [
+          ":AppRTCMobile_ios_bundle_data",
+        ]
+      }
+    }
+
     bundle_data("AppRTCMobile_ios_frameworks") {
       deps = [
         "../sdk:framework_objc+link",

examples/objc/AppRTCMobile/ARDAppClient.h

@@ -23,6 +23,7 @@ typedef NS_ENUM(NSInteger, ARDAppClientState) {
 
 @class ARDAppClient;
 @class ARDSettingsModel;
+@class ARDExternalSampleCapturer;
 @class RTCMediaConstraints;
 @class RTCCameraVideoCapturer;
 @class RTCFileVideoCapturer;
@@ -56,6 +57,9 @@ typedef NS_ENUM(NSInteger, ARDAppClientState) {
 - (void)appClient:(ARDAppClient *)client
 didCreateLocalFileCapturer:(RTCFileVideoCapturer *)fileCapturer;
 
+- (void)appClient:(ARDAppClient *)client
+    didCreateLocalExternalSampleCapturer:(ARDExternalSampleCapturer *)externalSampleCapturer;
+
 @end
 
 // Handles connections to the AppRTC server for a given room. Methods on this
@@ -67,6 +71,8 @@ didCreateLocalFileCapturer:(RTCFileVideoCapturer *)fileCapturer;
 @property(nonatomic, assign) BOOL shouldGetStats;
 @property(nonatomic, readonly) ARDAppClientState state;
 @property(nonatomic, weak) id<ARDAppClientDelegate> delegate;
+@property(nonatomic, assign, getter=isBroadcast) BOOL broadcast;
+
 // Convenience constructor since all expected use cases will need a delegate
 // in order to receive remote tracks.
 - (instancetype)initWithDelegate:(id<ARDAppClientDelegate>)delegate;

examples/objc/AppRTCMobile/ARDAppClient.m

@@ -28,6 +28,7 @@
 #import "WebRTC/RTCVideoTrack.h"
 
 #import "ARDAppEngineClient.h"
+#import "ARDExternalSampleCapturer.h"
 #import "ARDJoinResponse.h"
 #import "ARDMessageResponse.h"
 #import "ARDSettingsModel.h"
@@ -128,6 +129,7 @@ static int const kKbpsMultiplier = 1000;
 @synthesize defaultPeerConnectionConstraints =
     _defaultPeerConnectionConstraints;
 @synthesize isLoopback = _isLoopback;
+@synthesize broadcast = _broadcast;
 
 - (instancetype)init {
   return [self initWithDelegate:nil];
@@ -237,8 +239,7 @@ static int const kKbpsMultiplier = 1000;
   [_turnClient requestServersWithCompletionHandler:^(NSArray *turnServers,
                                                      NSError *error) {
     if (error) {
-      RTCLogError("Error retrieving TURN servers: %@",
+      RTCLogError(@"Error retrieving TURN servers: %@", error.localizedDescription);
-                  error.localizedDescription);
     }
     ARDAppClient *strongSelf = weakSelf;
     [strongSelf.iceServers addObjectsFromArray:turnServers];
@@ -713,9 +714,14 @@ static int const kKbpsMultiplier = 1000;
   RTCVideoSource *source = [_factory videoSource];
 
 #if !TARGET_IPHONE_SIMULATOR
-  RTCCameraVideoCapturer *capturer = [[RTCCameraVideoCapturer alloc] initWithDelegate:source];
+  if (self.isBroadcast) {
-  [_delegate appClient:self didCreateLocalCapturer:capturer];
+    ARDExternalSampleCapturer *capturer =
-
+        [[ARDExternalSampleCapturer alloc] initWithDelegate:source];
+    [_delegate appClient:self didCreateLocalExternalSampleCapturer:capturer];
+  } else {
+    RTCCameraVideoCapturer *capturer = [[RTCCameraVideoCapturer alloc] initWithDelegate:source];
+    [_delegate appClient:self didCreateLocalCapturer:capturer];
+  }
 #else
 #if defined(__IPHONE_11_0) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_11_0)
   if (@available(iOS 10, *)) {

examples/objc/AppRTCMobile/ARDExternalSampleCapturer.h

@@ -0,0 +1,18 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import <WebRTC/RTCVideoCapturer.h>
+
+@protocol ARDExternalSampleDelegate <NSObject>
+- (void)didCaptureSampleBuffer:(CMSampleBufferRef)sampleBuffer;
+@end
+
+@interface ARDExternalSampleCapturer : RTCVideoCapturer <ARDExternalSampleDelegate>
+@end

examples/objc/AppRTCMobile/ARDExternalSampleCapturer.m

@@ -0,0 +1,43 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "ARDExternalSampleCapturer.h"
+
+#import "WebRTC/RTCVideoFrameBuffer.h"
+
+@implementation ARDExternalSampleCapturer
+
+- (instancetype)initWithDelegate:(__weak id<RTCVideoCapturerDelegate>)delegate {
+  return [super initWithDelegate:delegate];
+}
+
+#pragma mark - ARDExternalSampleDelegate
+
+- (void)didCaptureSampleBuffer:(CMSampleBufferRef)sampleBuffer {
+  if (CMSampleBufferGetNumSamples(sampleBuffer) != 1 || !CMSampleBufferIsValid(sampleBuffer) ||
+      !CMSampleBufferDataIsReady(sampleBuffer)) {
+    return;
+  }
+
+  CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
+  if (pixelBuffer == nil) {
+    return;
+  }
+
+  RTCCVPixelBuffer *rtcPixelBuffer = [[RTCCVPixelBuffer alloc] initWithPixelBuffer:pixelBuffer];
+  int64_t timeStampNs =
+      CMTimeGetSeconds(CMSampleBufferGetPresentationTimeStamp(sampleBuffer)) * NSEC_PER_SEC;
+  RTCVideoFrame *videoFrame = [[RTCVideoFrame alloc] initWithBuffer:rtcPixelBuffer
+                                                           rotation:RTCVideoRotation_0
+                                                        timeStampNs:timeStampNs];
+  [self.delegate capturer:self didCaptureVideoFrame:videoFrame];
+}
+
+@end

examples/objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSampleHandler.h

@@ -0,0 +1,25 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import <ReplayKit/ReplayKit.h>
+
+#import "WebRTC/RTCLogging.h"
+
+#import "ARDAppClient.h"
+
+@protocol ARDExternalSampleDelegate;
+
+API_AVAILABLE(ios(10.0))
+@interface ARDBroadcastSampleHandler
+    : RPBroadcastSampleHandler<ARDAppClientDelegate>
+
+@property(nonatomic, strong) id<ARDExternalSampleDelegate> capturer;
+
+@end

examples/objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSampleHandler.m

@@ -0,0 +1,130 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "ARDBroadcastSampleHandler.h"
+
+#import <os/log.h>
+
+#import "ARDExternalSampleCapturer.h"
+#import "ARDSettingsModel.h"
+
+#import "WebRTC/RTCCallbackLogger.h"
+#import "WebRTC/RTCLogging.h"
+
+@implementation ARDBroadcastSampleHandler {
+  ARDAppClient *_client;
+  RTCCallbackLogger *_callbackLogger;
+}
+
+@synthesize capturer = _capturer;
+
+- (instancetype)init {
+  if (self = [super init]) {
+    _callbackLogger = [[RTCCallbackLogger alloc] init];
+    os_log_t rtc_os_log = os_log_create("com.google.AppRTCMobile", "RTCLog");
+    [_callbackLogger start:^(NSString *logMessage) {
+      os_log(rtc_os_log, "%{public}s", [logMessage cStringUsingEncoding:NSUTF8StringEncoding]);
+    }];
+  }
+  return self;
+}
+
+- (void)broadcastStartedWithSetupInfo:(NSDictionary<NSString *, NSObject *> *)setupInfo {
+  // User has requested to start the broadcast. Setup info from the UI extension can be supplied but
+  // optional.
+  ARDSettingsModel *settingsModel = [[ARDSettingsModel alloc] init];
+
+  _client = [[ARDAppClient alloc] initWithDelegate:self];
+  _client.broadcast = YES;
+
+  NSString *roomName = nil;
+  if (setupInfo[@"roomName"]) {
+    roomName = (NSString *)setupInfo[@"roomName"];
+  } else {
+    u_int32_t randomRoomSuffix = arc4random_uniform(1000);
+    roomName = [NSString stringWithFormat:@"broadcast_%d", randomRoomSuffix];
+  }
+  [_client connectToRoomWithId:roomName settings:settingsModel isLoopback:NO];
+  RTCLog(@"Broadcast started.");
+}
+
+- (void)broadcastPaused {
+  // User has requested to pause the broadcast. Samples will stop being delivered.
+}
+
+- (void)broadcastResumed {
+  // User has requested to resume the broadcast. Samples delivery will resume.
+}
+
+- (void)broadcastFinished {
+  // User has requested to finish the broadcast.
+  [_client disconnect];
+}
+
+- (void)processSampleBuffer:(CMSampleBufferRef)sampleBuffer
+                   withType:(RPSampleBufferType)sampleBufferType {
+  switch (sampleBufferType) {
+    case RPSampleBufferTypeVideo:
+      [self.capturer didCaptureSampleBuffer:sampleBuffer];
+      break;
+    case RPSampleBufferTypeAudioApp:
+      break;
+    case RPSampleBufferTypeAudioMic:
+      break;
+    default:
+      break;
+  }
+}
+
+#pragma mark - ARDAppClientDelegate
+
+- (void)appClient:(ARDAppClient *)client didChangeState:(ARDAppClientState)state {
+  switch (state) {
+    case kARDAppClientStateConnected:
+      RTCLog(@"Client connected.");
+      break;
+    case kARDAppClientStateConnecting:
+      RTCLog("Client connecting.");
+      break;
+    case kARDAppClientStateDisconnected:
+      RTCLog(@"Client disconnected.");
+      break;
+  }
+}
+
+- (void)appClient:(ARDAppClient *)client didChangeConnectionState:(RTCIceConnectionState)state {
+  RTCLog(@"ICE state changed: %ld", (long)state);
+}
+
+- (void)appClient:(ARDAppClient *)client
+    didCreateLocalCapturer:(RTCCameraVideoCapturer *)localCapturer {
+}
+
+- (void)appClient:(ARDAppClient *)client
+    didCreateLocalExternalSampleCapturer:(ARDExternalSampleCapturer *)externalSampleCapturer {
+  self.capturer = externalSampleCapturer;
+}
+
+- (void)appClient:(ARDAppClient *)client
+    didReceiveLocalVideoTrack:(RTCVideoTrack *)localVideoTrack {
+}
+
+- (void)appClient:(ARDAppClient *)client
+    didReceiveRemoteVideoTrack:(RTCVideoTrack *)remoteVideoTrack {
+}
+
+- (void)appClient:(ARDAppClient *)client didGetStats:(NSArray *)stats {
+}
+
+- (void)appClient:(ARDAppClient *)client didError:(NSError *)error {
+  RTCLog(@"Error: %@", error);
+}
+
+@end

examples/objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSetupViewController.h

@@ -0,0 +1,18 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import <ReplayKit/ReplayKit.h>
+#import <UIKit/UIKit.h>
+
+API_AVAILABLE(ios(11.0))
+@interface ARDBroadcastSetupViewController
+    : UIViewController<UITextFieldDelegate>
+
+@end

examples/objc/AppRTCMobile/ios/broadcast_extension/ARDBroadcastSetupViewController.m

@@ -0,0 +1,107 @@
+/*
+ *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "ARDBroadcastSetupViewController.h"
+
+@implementation ARDBroadcastSetupViewController {
+  UITextField *_roomNameField;
+}
+
+- (void)loadView {
+  UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
+  view.backgroundColor = [UIColor colorWithWhite:1.0 alpha:0.7];
+
+  UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Icon-180"]];
+  imageView.translatesAutoresizingMaskIntoConstraints = NO;
+  [view addSubview:imageView];
+
+  _roomNameField = [[UITextField alloc] initWithFrame:CGRectZero];
+  _roomNameField.borderStyle = UITextBorderStyleRoundedRect;
+  _roomNameField.font = [UIFont systemFontOfSize:14.0];
+  _roomNameField.translatesAutoresizingMaskIntoConstraints = NO;
+  _roomNameField.placeholder = @"Room name";
+  _roomNameField.returnKeyType = UIReturnKeyDone;
+  _roomNameField.delegate = self;
+  [view addSubview:_roomNameField];
+
+  UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeSystem];
+  doneButton.translatesAutoresizingMaskIntoConstraints = NO;
+  doneButton.titleLabel.font = [UIFont systemFontOfSize:20.0];
+  [doneButton setTitle:@"Done" forState:UIControlStateNormal];
+  [doneButton addTarget:self
+                 action:@selector(userDidFinishSetup)
+       forControlEvents:UIControlEventTouchUpInside];
+  [view addSubview:doneButton];
+
+  UIButton *cancelButton = [UIButton buttonWithType:UIButtonTypeSystem];
+  cancelButton.translatesAutoresizingMaskIntoConstraints = NO;
+  cancelButton.titleLabel.font = [UIFont systemFontOfSize:20.0];
+  [cancelButton setTitle:@"Cancel" forState:UIControlStateNormal];
+  [cancelButton addTarget:self
+                   action:@selector(userDidCancelSetup)
+         forControlEvents:UIControlEventTouchUpInside];
+  [view addSubview:cancelButton];
+
+  UILayoutGuide *margin = view.layoutMarginsGuide;
+  [imageView.widthAnchor constraintEqualToConstant:60.0].active = YES;
+  [imageView.heightAnchor constraintEqualToConstant:60.0].active = YES;
+  [imageView.topAnchor constraintEqualToAnchor:margin.topAnchor constant:20].active = YES;
+  [imageView.centerXAnchor constraintEqualToAnchor:view.centerXAnchor].active = YES;
+
+  [_roomNameField.leadingAnchor constraintEqualToAnchor:margin.leadingAnchor].active = YES;
+  [_roomNameField.topAnchor constraintEqualToAnchor:imageView.bottomAnchor constant:20].active =
+      YES;
+  [_roomNameField.trailingAnchor constraintEqualToAnchor:margin.trailingAnchor].active = YES;
+
+  [doneButton.leadingAnchor constraintEqualToAnchor:margin.leadingAnchor].active = YES;
+  [doneButton.bottomAnchor constraintEqualToAnchor:margin.bottomAnchor constant:-20].active = YES;
+
+  [cancelButton.trailingAnchor constraintEqualToAnchor:margin.trailingAnchor].active = YES;
+  [cancelButton.bottomAnchor constraintEqualToAnchor:margin.bottomAnchor constant:-20].active = YES;
+
+  UITapGestureRecognizer *tgr =
+      [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(didTap:)];
+  [view addGestureRecognizer:tgr];
+
+  self.view = view;
+}
+
+- (IBAction)didTap:(id)sender {
+  [self.view endEditing:YES];
+}
+
+- (void)userDidFinishSetup {
+  // URL of the resource where broadcast can be viewed that will be returned to the application
+  NSURL *broadcastURL = [NSURL
+      URLWithString:[NSString stringWithFormat:@"https://appr.tc/r/%@", _roomNameField.text]];
+
+  // Dictionary with setup information that will be provided to broadcast extension when broadcast
+  // is started
+  NSDictionary *setupInfo = @{@"roomName" : _roomNameField.text};
+
+  // Tell ReplayKit that the extension is finished setting up and can begin broadcasting
+  [self.extensionContext completeRequestWithBroadcastURL:broadcastURL setupInfo:setupInfo];
+}
+
+- (void)userDidCancelSetup {
+  // Tell ReplayKit that the extension was cancelled by the user
+  [self.extensionContext cancelRequestWithError:[NSError errorWithDomain:@"com.google.AppRTCMobile"
+                                                                    code:-1
+                                                                userInfo:nil]];
+}
+
+#pragma mark - UITextFieldDelegate
+
+- (BOOL)textFieldShouldReturn:(UITextField *)textField {
+  [self userDidFinishSetup];
+  return YES;
+}
+
+@end

examples/objc/AppRTCMobile/ios/broadcast_extension/BroadcastSetupUIInfo.plist

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleDisplayName</key>
+	<string>AppRTCMobile</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.google.AppRTCMobile.BroadcastSetupUI</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>XPC!</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionAttributes</key>
+		<dict>
+			<key>NSExtensionActivationRule</key>
+			<dict>
+				<key>NSExtensionActivationSupportsReplayKitStreaming</key>
+				<true/>
+			</dict>
+		</dict>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.broadcast-services-setupui</string>
+		<key>NSExtensionPrincipalClass</key>
+		<string>ARDBroadcastSetupViewController</string>
+	</dict>
+</dict>
+</plist>

examples/objc/AppRTCMobile/ios/broadcast_extension/BroadcastUploadInfo.plist

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleDisplayName</key>
+	<string>AppRTCMobile</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.google.AppRTCMobile.BroadcastUpload</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>XPC!</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.broadcast-services-upload</string>
+		<key>NSExtensionPrincipalClass</key>
+		<string>ARDBroadcastSampleHandler</string>
+		<key>RPBroadcastProcessMode</key>
+		<string>RPBroadcastProcessModeSampleBuffer</string>
+	</dict>
+</dict>
+</plist>

sdk/BUILD.gn

@@ -48,6 +48,12 @@ if (is_ios || is_mac) {
     ]
   }
 
+  config("used_from_extension") {
+    if (is_ios && rtc_apprtcmobile_broadcast_extension) {
+      cflags = [ "-fapplication-extension" ]
+    }
+  }
+
   rtc_static_library("common_objc") {
     sources = [
       "objc/Framework/Classes/Common/NSString+StdString.h",
@@ -71,7 +77,10 @@ if (is_ios || is_mac) {
       "../rtc_base:checks",
       "../rtc_base:rtc_base",
     ]
-    configs += [ "..:common_objc" ]
+    configs += [
+      "..:common_objc",
+      ":used_from_extension",
+    ]
 
     public_configs = [ ":common_config_objc" ]
 
@@ -176,7 +185,10 @@ if (is_ios || is_mac) {
           "objc/Framework/Headers/WebRTC/RTCAudioSession.h",
           "objc/Framework/Headers/WebRTC/RTCAudioSessionConfiguration.h",
         ]
-        configs += [ "..:common_objc" ]
+        configs += [
+          "..:common_objc",
+          ":used_from_extension",
+        ]
 
         public_configs = [ ":common_config_objc" ]
 
@@ -218,7 +230,10 @@ if (is_ios || is_mac) {
         "//third_party/libyuv",
       ]
 
-      configs += [ "..:common_objc" ]
+      configs += [
+        "..:common_objc",
+        ":used_from_extension",
+      ]
       if (!build_with_chromium && is_clang) {
         # Suppress warnings from the Chromium Clang plugin
         # (bugs.webrtc.org/163).
@@ -244,7 +259,10 @@ if (is_ios || is_mac) {
         "//rtc_base:rtc_base_approved",
         "//third_party/libyuv",
       ]
-      configs += [ "..:common_objc" ]
+      configs += [
+        "..:common_objc",
+        ":used_from_extension",
+      ]
     }
 
     rtc_static_library("video_objc") {
@@ -294,7 +312,10 @@ if (is_ios || is_mac) {
         "../rtc_base:rtc_base",
       ]
 
-      configs += [ "..:common_objc" ]
+      configs += [
+        "..:common_objc",
+        ":used_from_extension",
+      ]
       if (!build_with_chromium && is_clang) {
         # Suppress warnings from the Chromium Clang plugin
         # (bugs.webrtc.org/163).
@@ -629,7 +650,10 @@ if (is_ios || is_mac) {
         "objc/Framework/Headers/WebRTC/RTCMediaSource.h",
       ]
 
-      configs += [ "..:common_objc" ]
+      configs += [
+        "..:common_objc",
+        ":used_from_extension",
+      ]
       public_configs = [ ":common_config_objc" ]
 
       deps = [
@@ -734,7 +758,10 @@ if (is_ios || is_mac) {
         "objc/Framework/Headers/WebRTC/RTCVideoTrack.h",
       ]
 
-      configs += [ "..:common_objc" ]
+      configs += [
+        "..:common_objc",
+        ":used_from_extension",
+      ]
       public_configs = [ ":common_config_objc" ]
 
       if (!build_with_chromium && is_clang) {
@@ -1056,7 +1083,10 @@ if (is_ios || is_mac) {
           "GLKit.framework",
         ]
 
-        configs += [ "..:common_objc" ]
+        configs += [
+          "..:common_objc",
+          ":used_from_extension",
+        ]
 
         public_configs = [ ":common_config_objc" ]
 
@@ -1218,7 +1248,14 @@ if (is_ios || is_mac) {
         "objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm",
       ]
 
-      configs += [ "..:common_objc" ]
+      configs += [
+        "..:common_objc",
+        ":used_from_extension",
+      ]
+
+      if (is_ios && rtc_apprtcmobile_broadcast_extension) {
+        defines = [ "RTC_APPRTCMOBILE_BROADCAST_EXTENSION" ]
+      }
 
       deps = [
         ":common_objc",

sdk/objc/Framework/Classes/Common/RTCUIApplicationStatusObserver.h

@@ -12,6 +12,7 @@
 
 #import <Foundation/Foundation.h>
 
+NS_EXTENSION_UNAVAILABLE_IOS("Application status not available in app extensions.")
 @interface RTCUIApplicationStatusObserver : NSObject
 
 + (instancetype)sharedInstance;

sdk/objc/Framework/Classes/VideoToolbox/RTCVideoDecoderH264.mm

@@ -78,7 +78,7 @@ void decompressionOutputCallback(void *decoderRef,
 
 - (instancetype)init {
   if (self = [super init]) {
-#if defined(WEBRTC_IOS)
+#if defined(WEBRTC_IOS) && !defined(RTC_APPRTCMOBILE_BROADCAST_EXTENSION)
     [RTCUIApplicationStatusObserver prepareForUse];
     _error = noErr;
 #endif
@@ -113,7 +113,7 @@ void decompressionOutputCallback(void *decoderRef,
     return WEBRTC_VIDEO_CODEC_ERROR;
   }
 
-#if defined(WEBRTC_IOS)
+#if defined(WEBRTC_IOS) && !defined(RTC_APPRTCMOBILE_BROADCAST_EXTENSION)
   if (![[RTCUIApplicationStatusObserver sharedInstance] isApplicationActive]) {
     // Ignore all decode requests when app isn't active. In this state, the
     // hardware decoder has been invalidated by the OS.

sdk/objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm

@@ -307,7 +307,7 @@ CFStringRef ExtractProfile(webrtc::SdpVideoFormat videoFormat) {
     RTC_LOG(LS_INFO) << "Using profile " << CFStringToString(_profile);
     RTC_CHECK([codecInfo.name isEqualToString:kRTCVideoCodecH264Name]);
 
-#if defined(WEBRTC_IOS)
+#if defined(WEBRTC_IOS) && !defined(RTC_APPRTCMOBILE_BROADCAST_EXTENSION)
     [RTCUIApplicationStatusObserver prepareForUse];
 #endif
   }
@@ -345,7 +345,7 @@ CFStringRef ExtractProfile(webrtc::SdpVideoFormat videoFormat) {
   if (!_callback || !_compressionSession) {
     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
   }
-#if defined(WEBRTC_IOS)
+#if defined(WEBRTC_IOS) && !defined(RTC_APPRTCMOBILE_BROADCAST_EXTENSION)
   if (![[RTCUIApplicationStatusObserver sharedInstance] isApplicationActive]) {
     // Ignore all encode requests when app isn't active. In this state, the
     // hardware encoder has been invalidated by the OS.

sdk/objc/Framework/Headers/WebRTC/RTCCameraVideoCapturer.h

@@ -19,6 +19,7 @@ NS_ASSUME_NONNULL_BEGIN
 RTC_EXPORT
 // Camera capture that implements RTCVideoCapturer. Delivers frames to a RTCVideoCapturerDelegate
 // (usually RTCVideoSource).
+NS_EXTENSION_UNAVAILABLE_IOS("Camera not available in app extensions.")
 @interface RTCCameraVideoCapturer : RTCVideoCapturer
 
 // Capture session that is used for capturing. Valid from initialization to dealloc.

sdk/objc/Framework/Headers/WebRTC/RTCEAGLVideoView.h

@@ -28,6 +28,7 @@ RTC_EXPORT
  * bounds using OpenGLES 2.0 or OpenGLES 3.0.
  */
 RTC_EXPORT
+NS_EXTENSION_UNAVAILABLE_IOS("Rendering not available in app extensions.")
 @interface RTCEAGLVideoView : UIView <RTCVideoRenderer>
 
 @property(nonatomic, weak) id<RTCVideoViewDelegate> delegate;

webrtc.gni

@@ -151,6 +151,12 @@ declare_args() {
 
   # Disable this to build without support for built-in software codecs.
   rtc_use_builtin_sw_codecs = true
+
+  if (is_ios) {
+    # Build broadcast extension in AppRTCMobile for iOS. This results in the
+    # binary only running on iOS 11+, which is why it is disabled by default.
+    rtc_apprtcmobile_broadcast_extension = false
+  }
 }
 
 if (!build_with_mozilla) {