Use new RTCCameraVideoCapturer in AppRTCMobile.

webrtc/examples/objc/AppRTCMobile/ARDAppClient.m

 /*
  *  Copyright 2014 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 "ARDAppClient+Internal.h"
 
 #import "WebRTC/RTCAVFoundationVideoSource.h"
 #import "WebRTC/RTCAudioTrack.h"
+#import "WebRTC/RTCCameraVideoCapturer.h"
 #import "WebRTC/RTCConfiguration.h"
 #import "WebRTC/RTCFileLogger.h"
 #import "WebRTC/RTCIceServer.h"
 #import "WebRTC/RTCLogging.h"
 #import "WebRTC/RTCMediaConstraints.h"
 #import "WebRTC/RTCMediaStream.h"
 #import "WebRTC/RTCPeerConnectionFactory.h"
 #import "WebRTC/RTCRtpSender.h"
 #import "WebRTC/RTCTracing.h"
+#import "WebRTC/RTCVideoTrack.h"
 
 #import "ARDAppEngineClient.h"
 #import "ARDJoinResponse.h"
 #import "ARDMessageResponse.h"
 #import "ARDSDPUtils.h"
 #import "ARDSettingsModel.h"
 #import "ARDSignalingMessage.h"
 #import "ARDTURNClient+Internal.h"
 #import "ARDUtilities.h"
 #import "ARDWebSocketChannel.h"
@@ skipping 59 matching lines @@
 - (void)timerDidFire:(NSTimer *)timer {
   _timerHandler();
 }
 
 @end
 
 @implementation ARDAppClient {
   RTCFileLogger *_fileLogger;
   ARDTimerProxy *_statsTimer;
   ARDSettingsModel *_settings;
+  RTCCameraVideoCapturer *_capturer;
+  RTCVideoTrack *_localVideoTrack;
+  BOOL _usingFrontCamera;
 }
 
 @synthesize shouldGetStats = _shouldGetStats;
 @synthesize state = _state;
 @synthesize delegate = _delegate;
 @synthesize roomServerClient = _roomServerClient;
 @synthesize channel = _channel;
 @synthesize loopbackChannel = _loopbackChannel;
 @synthesize turnClient = _turnClient;
 @synthesize peerConnection = _peerConnection;
@@ skipping 180 matching lines @@
   }
   if (_channel) {
     if (_channel.state == kARDSignalingChannelStateRegistered) {
       // Tell the other client we're hanging up.
       ARDByeMessage *byeMessage = [[ARDByeMessage alloc] init];
       [_channel sendMessage:byeMessage];
     }
     // Disconnect from collider.
     _channel = nil;
   }
+  if (_capturer) {
+    [_capturer stopCapture];
+    _capturer = nil;
+  }
   _clientId = nil;
   _roomId = nil;
   _isInitiator = NO;
   _hasReceivedSdp = NO;
   _messageQueue = [NSMutableArray array];
+  _localVideoTrack = nil;
 #if defined(WEBRTC_IOS)
   [_factory stopAecDump];
   [_peerConnection stopRtcEventLog];
 #endif
   _peerConnection = nil;
   self.state = kARDAppClientStateDisconnected;
 #if defined(WEBRTC_IOS)
   if (kARDAppClientEnableTracing) {
     RTCStopInternalCapture();
   }
 #endif
 }
 
+- (void)switchCamera {
+  _usingFrontCamera = !_usingFrontCamera;
+  [self startCapture];
+}
+
 #pragma mark - ARDSignalingChannelDelegate
 
 - (void)channel:(id<ARDSignalingChannel>)channel
     didReceiveMessage:(ARDSignalingMessage *)message {
   switch (message.type) {
     case kARDSignalingMessageTypeOffer:
     case kARDSignalingMessageTypeAnswer:
       // Offers and answers must be processed before any other message, so we
       // place them at the front of the queue.
       _hasReceivedSdp = YES;
@@ skipping 328 matching lines @@
     }];
   } else {
     [_channel sendMessage:message];
   }
 }
 
 - (RTCRtpSender *)createVideoSender {
   RTCRtpSender *sender =
       [_peerConnection senderWithKind:kRTCMediaStreamTrackKindVideo
                              streamId:kARDMediaStreamId];
-  RTCVideoTrack *track = [self createLocalVideoTrack];
-  if (track) {
-    sender.track = track;
-    [_delegate appClient:self didReceiveLocalVideoTrack:track];
+  _localVideoTrack = [self createLocalVideoTrack];
+  if (_localVideoTrack) {
+    sender.track = _localVideoTrack;
+    [_delegate appClient:self didReceiveLocalVideoTrack:_localVideoTrack];
   }
+  [_delegate appClient:self didReceiveLocalVideoTrack:_localVideoTrack];

[daniela-webrtc, 2017/04/03 10:16:50]

Not sure if we should invoke the delegate with nil here to indicate the
localTrack was not created. If there is such need it's better to have additional
callback like `appClientFailedToCreateLocalVideoTrack` or adjust the existing
method to included error parameter.

[sakal, 2017/04/04 09:18:23]

Oops, this was added by accident.

 
   return sender;
 }
 
 - (void)setMaxBitrateForPeerConnectionVideoSender {
   for (RTCRtpSender *sender in _peerConnection.senders) {
     if (sender.track != nil) {
       if ([sender.track.kind isEqualToString:kARDVideoTrackKind]) {
         [self setMaxBitrate:[_settings currentMaxBitrateSettingFromStore] forVideoSender:sender];
       }
@@ skipping 18 matching lines @@
   RTCAudioSource *source = [_factory audioSourceWithConstraints:constraints];
   RTCAudioTrack *track = [_factory audioTrackWithSource:source
                                                 trackId:kARDAudioTrackId];
   RTCRtpSender *sender =
       [_peerConnection senderWithKind:kRTCMediaStreamTrackKindAudio
                              streamId:kARDMediaStreamId];
   sender.track = track;
   return sender;
 }
 
+- (void)startCapture {

[daniela-webrtc, 2017/04/03 10:16:50]

This should be exposed in the interface. Also, it signature can be changed to:
`startCaptureWithDevice:` That way you can ditch the _usingFrontCamera ivar and
move the responsibility of capturing device elsewhere (as it should be since
AppDelegate becomes quite cluttered otherwise).

[sakal, 2017/04/04 09:18:23]

Moved to CaptureController as discussed.

+  AVCaptureDevicePosition position =
+      _usingFrontCamera ? AVCaptureDevicePositionFront : AVCaptureDevicePositionBack;
+  AVCaptureDevice *device = [self findDeviceForPosition:position];
+  AVCaptureDeviceFormat *format = [self selectFormatForDevice:device];
+  int fps = [self selectFpsForFormat:format];
+
+  [_capturer startCaptureWithDevice:device format:format fps:fps];
+}
+
+- (AVCaptureDevice *)findDeviceForPosition:(AVCaptureDevicePosition)position {
+  NSArray<AVCaptureDevice *> *captureDevices = [RTCCameraVideoCapturer captureDevices];
+  for (AVCaptureDevice *device in captureDevices) {
+    if (device.position == position) {
+      return device;
+    }
+  }
+  return captureDevices[0];
+}
+
+- (AVCaptureDeviceFormat *)selectFormatForDevice:(AVCaptureDevice *)device {
+  NSArray<AVCaptureDeviceFormat *> *formats =
+      [RTCCameraVideoCapturer supportedFormatsForDevice:device];
+  int targetWidth = [_settings currentVideoResolutionWidthFromStore];
+  int targetHeight = [_settings currentVideoResolutionHeightFromStore];
+  AVCaptureDeviceFormat *selectedFormat;

[daniela-webrtc, 2017/04/03 10:16:50]

Preferably explicitly set pointers to nil.

[sakal, 2017/04/04 09:18:23]

Done.

+  int currentDiff = INT_MAX;
+
+  for (AVCaptureDeviceFormat *format in formats) {
+    CMVideoDimensions dimension = CMVideoFormatDescriptionGetDimensions(format.formatDescription);
+    int diff = abs(targetWidth - dimension.width) + abs(targetHeight - dimension.height);
+    if (diff < currentDiff) {
+      selectedFormat = format;
+      currentDiff = diff;
+    }
+  }
+
+  NSAssert(selectedFormat != nil, @"No suitable capture format found.");
+  return selectedFormat;
+}
+
+- (int)selectFpsForFormat:(AVCaptureDeviceFormat *)format {
+  Float64 maxFramerate = 0;
+  for (AVFrameRateRange *fpsRange in format.videoSupportedFrameRateRanges) {
+    maxFramerate = fmax(maxFramerate, fpsRange.maxFrameRate);
+  }
+  return maxFramerate;
+}
+
 - (RTCVideoTrack *)createLocalVideoTrack {
   RTCVideoTrack* localVideoTrack = nil;
   // The iOS simulator doesn't provide any sort of camera capture
   // support or emulation (http://goo.gl/rHAnC1) so don't bother
   // trying to open a local stream.
 #if !TARGET_IPHONE_SIMULATOR
   if (!_isAudioOnly) {
-    RTCMediaConstraints *cameraConstraints =
-        [self cameraConstraints];
-    RTCAVFoundationVideoSource *source =
-        [_factory avFoundationVideoSourceWithConstraints:cameraConstraints];
+    RTCVideoSource *source = [_factory videoSource];
+    _capturer = [[RTCCameraVideoCapturer alloc] initWithDelegate:source];
+    [_delegate appClient:self didCreateLocalCapturer:_capturer];
+    _usingFrontCamera = true;
+    [self startCapture];

[daniela-webrtc, 2017/04/03 10:16:50]

[startCapture] should not be here but rather exposed in the interface of this
class so that it can be invoked when convenient (for instance in this case in
the delegate callback `appClient:didReceiveLocalVideoTrack:`.
Also, this way `createLocalVideoTrack`has a lot of side effects and does way
more than it's naming suggests.

[sakal, 2017/04/04 09:18:23]

Done.

     localVideoTrack =
         [_factory videoTrackWithSource:source
                                trackId:kARDVideoTrackId];
   }
 #endif
   return localVideoTrack;
 }
 
 #pragma mark - Collider methods
 
@@ skipping 24 matching lines @@
  - (RTCMediaConstraints *)defaultMediaAudioConstraints {
    NSString *valueLevelControl = _shouldUseLevelControl ?
        kRTCMediaConstraintsValueTrue : kRTCMediaConstraintsValueFalse;
    NSDictionary *mandatoryConstraints = @{ kRTCMediaConstraintsLevelControl : valueLevelControl };
    RTCMediaConstraints *constraints =
        [[RTCMediaConstraints alloc] initWithMandatoryConstraints:mandatoryConstraints
                                              optionalConstraints:nil];
    return constraints;
 }
 
-- (RTCMediaConstraints *)cameraConstraints {
-  RTCMediaConstraints *cameraConstraints = [[RTCMediaConstraints alloc]
-      initWithMandatoryConstraints:nil
-               optionalConstraints:[_settings currentMediaConstraintFromStoreAsRTCDictionary]];
-  return cameraConstraints;
-}
-
 - (RTCMediaConstraints *)defaultAnswerConstraints {
   return [self defaultOfferConstraints];
 }
 
 - (RTCMediaConstraints *)defaultOfferConstraints {
   NSDictionary *mandatoryConstraints = @{
     @"OfferToReceiveAudio" : @"true",
     @"OfferToReceiveVideo" : @"true"
   };
   RTCMediaConstraints* constraints =
@@ skipping 67 matching lines @@
                                          code:kARDAppClientErrorInvalidRoom
                                      userInfo:@{
         NSLocalizedDescriptionKey: @"Invalid room.",
       }];
       break;
   }
   return error;
 }
 
 @end