BWE allocation strategy allows controlling of bitrate allocation with WEBRTC external logic.

This CL implements the main logic and IOS appRTC integration.

Unit tests and Android appRTC will be in separate CL.

Bug: webrtc:8243
Change-Id: If8e5195294046a47316e9fade1b0dfec211155e1
Reviewed-on: https://webrtc-review.googlesource.com/4860
Commit-Queue: Alex Narest <alexnarest@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20329}

examples/objc/AppRTCMobile/ARDAppClient.m

@@ -25,6 +25,7 @@
 #import "WebRTC/RTCVideoTrack.h"
 
 #import "ARDAppEngineClient.h"
+#import "ARDBitrateAllocationStrategy.h"
 #import "ARDJoinResponse.h"
 #import "ARDMessageResponse.h"
 #import "ARDSettingsModel.h"
@@ -50,6 +51,7 @@ static NSString * const kARDMediaStreamId = @"ARDAMS";
 static NSString * const kARDAudioTrackId = @"ARDAMSa0";
 static NSString * const kARDVideoTrackId = @"ARDAMSv0";
 static NSString * const kARDVideoTrackKind = @"video";
+static uint32_t const kSufficientAudioBitrate = 16000;
 
 // TODO(tkchin): Add these as UI options.
 static BOOL const kARDAppClientEnableTracing = NO;
@@ -104,6 +106,7 @@ static int const kKbpsMultiplier = 1000;
   ARDTimerProxy *_statsTimer;
   ARDSettingsModel *_settings;
   RTCVideoTrack *_localVideoTrack;
+  ARDBitrateAllocationStrategy *_bitrateAllocationStrategy;
 }
 
 @synthesize shouldGetStats = _shouldGetStats;
@@ -306,12 +309,14 @@ static int const kKbpsMultiplier = 1000;
   _hasReceivedSdp = NO;
   _messageQueue = [NSMutableArray array];
   _localVideoTrack = nil;
+
 #if defined(WEBRTC_IOS)
   [_factory stopAecDump];
   [_peerConnection stopRtcEventLog];
 #endif
   [_peerConnection close];
   _peerConnection = nil;
+  _bitrateAllocationStrategy = nil;
   self.state = kARDAppClientStateDisconnected;
 #if defined(WEBRTC_IOS)
   if (kARDAppClientEnableTracing) {
@@ -533,8 +538,14 @@ static int const kKbpsMultiplier = 1000;
   _peerConnection = [_factory peerConnectionWithConfiguration:config
                                                   constraints:constraints
                                                      delegate:self];
+  _bitrateAllocationStrategy = [ARDBitrateAllocationStrategy
+      createAudioPriorityBitrateAllocationStrategyForPeerConnection:_peerConnection
+                                                     withAudioTrack:kARDAudioTrackId
+                                             sufficientAudioBitrate:kSufficientAudioBitrate];
+
   // Create AV senders.
   [self createMediaSenders];
+
   if (_isInitiator) {
     // Send offer.
     __weak ARDAppClient *weakSelf = self;

examples/objc/AppRTCMobile/ARDBitrateAllocationStrategy.h

@@ -0,0 +1,23 @@
+/*
+ *  Copyright 2017 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 <Foundation/Foundation.h>
+#import "WebRTC/RTCPeerConnection.h"
+
+@interface ARDBitrateAllocationStrategy : NSObject
+
++ (ARDBitrateAllocationStrategy*)
+    createAudioPriorityBitrateAllocationStrategyForPeerConnection:(RTCPeerConnection*)peerConnection
+                                                   withAudioTrack:(NSString*)audioTrackID
+                                           sufficientAudioBitrate:(uint32_t)sufficientAudioBitrate;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+@end

examples/objc/AppRTCMobile/ARDBitrateAllocationStrategy.mm

@@ -0,0 +1,40 @@
+/*
+ *  Copyright 2017 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 "ARDBitrateAllocationStrategy.h"
+#import "WebRTC/RTCBitrateAllocationStrategy.h"
+
+#include "rtc_base/bitrateallocationstrategy.h"
+
+@implementation ARDBitrateAllocationStrategy
+
++ (ARDBitrateAllocationStrategy*)
+    createAudioPriorityBitrateAllocationStrategyForPeerConnection:(RTCPeerConnection*)peerConnection
+                                                   withAudioTrack:(NSString*)audioTrackID
+                                           sufficientAudioBitrate:(uint32_t)sufficientAudioBitrate {
+  return [[ARDBitrateAllocationStrategy alloc] initWithPeerCoonnection:peerConnection
+                                                        withAudioTrack:audioTrackID
+                                                sufficientAudioBitrate:sufficientAudioBitrate];
+}
+
+- (instancetype)initWithPeerCoonnection:(RTCPeerConnection*)peerConnection
+                         withAudioTrack:(NSString*)audioTrackID
+                 sufficientAudioBitrate:(uint32_t)sufficientAudioBitrate {
+  if (self = [super init]) {
+    [peerConnection
+        setBitrateAllocationStrategy:[[RTCBitrateAllocationStrategy alloc]
+                                         initWith:new rtc::AudioPriorityBitrateAllocationStrategy(
+                                                      std::string(audioTrackID.UTF8String),
+                                                      sufficientAudioBitrate)]];
+  }
+  return self;
+}
+
+@end

examples/objc/AppRTCMobile/ios/ARDAppDelegate.m

@@ -26,7 +26,8 @@
 - (BOOL)application:(UIApplication *)application
     didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
   NSDictionary *fieldTrials = @{
-    kRTCFieldTrialH264HighProfileKey: kRTCFieldTrialEnabledValue,
+    kRTCFieldTrialH264HighProfileKey : kRTCFieldTrialEnabledValue,
+    kRTCFieldTrialAudioSendSideBweKey : kRTCFieldTrialEnabledValue
   };
   RTCInitFieldTrialDictionary(fieldTrials);
   RTCInitializeSSL();