Reland of Split iOS sdk in to separate targets (patchset #1 id:1 of https://codereview.webrtc.org/2890513002/ )

Reason for revert:
Fixing downstream breakages

Original issue's description:
> Revert of Split iOS sdk in to separate targets (patchset #13 id:280001 of https://codereview.webrtc.org/2862543002/ )
>
> Reason for revert:
> Breaking downstream projects.
>
> Original issue's description:
> > Split iOS sdk in to separate targets
> >
> > This CL splits the iOS sdk into separate static libraries for video,
> > audio, ui, common, and peerconnection-related code. This will in the
> > future make it easier to compile WebRTC without unneeded components.
> >
> > BUG=webrtc:4867
> >
> > Review-Url: https://codereview.webrtc.org/2862543002
> > Cr-Commit-Position: refs/heads/master@{#18166}
> > Committed: 52c83fe710
>
> TBR=magjed@webrtc.org,denicija@webrtc.org,tkchin@webrtc.org,henrika@webrtc.org,kthelgason@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:4867
>
> Review-Url: https://codereview.webrtc.org/2890513002
> Cr-Commit-Position: refs/heads/master@{#18170}
> Committed: 9756238084

TBR=magjed@webrtc.org,denicija@webrtc.org,tkchin@webrtc.org,henrika@webrtc.org,charujain@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:4867

Review-Url: https://codereview.webrtc.org/2890733003
Cr-Commit-Position: refs/heads/master@{#18174}

webrtc/sdk/objc/Framework/Classes/UI/RTCCameraPreviewView.m

@@ -0,0 +1,75 @@
+/*
+ *  Copyright 2015 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/RTCCameraPreviewView.h"
+
+#import <AVFoundation/AVFoundation.h>
+#import <UIKit/UIKit.h>
+
+#import "RTCDispatcher+Private.h"
+
+@implementation RTCCameraPreviewView
+
+@synthesize captureSession = _captureSession;
+
++ (Class)layerClass {
+  return [AVCaptureVideoPreviewLayer class];
+}
+
+- (void)setCaptureSession:(AVCaptureSession *)captureSession {
+  if (_captureSession == captureSession) {
+    return;
+  }
+  _captureSession = captureSession;
+  AVCaptureVideoPreviewLayer *previewLayer = [self previewLayer];
+  [RTCDispatcher dispatchAsyncOnType:RTCDispatcherTypeCaptureSession
+                               block:^{
+    previewLayer.session = captureSession;
+  }];
+}
+
+- (void)layoutSubviews {
+  [super layoutSubviews];
+
+  // Update the video orientation based on the device orientation.
+  [self setCorrectVideoOrientation];
+}
+
+- (void)setCorrectVideoOrientation {
+  // Get current device orientation.
+  UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
+  AVCaptureVideoPreviewLayer *previewLayer = [self previewLayer];
+
+  // First check if we are allowed to set the video orientation.
+  if (previewLayer.connection.isVideoOrientationSupported) {
+    // Set the video orientation based on device orientation.
+    if (deviceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationPortraitUpsideDown;
+    } else if (deviceOrientation == UIInterfaceOrientationLandscapeRight) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationLandscapeRight;
+    } else if (deviceOrientation == UIInterfaceOrientationLandscapeLeft) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationLandscapeLeft;
+    } else {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationPortrait;
+    }
+  }
+}
+
+#pragma mark - Private
+
+- (AVCaptureVideoPreviewLayer *)previewLayer {
+  return (AVCaptureVideoPreviewLayer *)self.layer;
+}
+
+@end

webrtc/sdk/objc/Framework/Classes/UI/RTCEAGLVideoView.m

@@ -0,0 +1,297 @@
+/*
+ *  Copyright 2015 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/RTCEAGLVideoView.h"
+
+#import <GLKit/GLKit.h>
+
+#import "RTCShader+Private.h"
+#import "WebRTC/RTCLogging.h"
+#import "WebRTC/RTCVideoFrame.h"
+
+// RTCDisplayLinkTimer wraps a CADisplayLink and is set to fire every two screen
+// refreshes, which should be 30fps. We wrap the display link in order to avoid
+// a retain cycle since CADisplayLink takes a strong reference onto its target.
+// The timer is paused by default.
+@interface RTCDisplayLinkTimer : NSObject
+
+@property(nonatomic) BOOL isPaused;
+
+- (instancetype)initWithTimerHandler:(void (^)(void))timerHandler;
+- (void)invalidate;
+
+@end
+
+@implementation RTCDisplayLinkTimer {
+  CADisplayLink *_displayLink;
+  void (^_timerHandler)(void);
+}
+
+- (instancetype)initWithTimerHandler:(void (^)(void))timerHandler {
+  NSParameterAssert(timerHandler);
+  if (self = [super init]) {
+    _timerHandler = timerHandler;
+    _displayLink =
+        [CADisplayLink displayLinkWithTarget:self
+                                    selector:@selector(displayLinkDidFire:)];
+    _displayLink.paused = YES;
+    // Set to half of screen refresh, which should be 30fps.
+    [_displayLink setFrameInterval:2];
+    [_displayLink addToRunLoop:[NSRunLoop currentRunLoop]
+                       forMode:NSRunLoopCommonModes];
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [self invalidate];
+}
+
+- (BOOL)isPaused {
+  return _displayLink.paused;
+}
+
+- (void)setIsPaused:(BOOL)isPaused {
+  _displayLink.paused = isPaused;
+}
+
+- (void)invalidate {
+  [_displayLink invalidate];
+}
+
+- (void)displayLinkDidFire:(CADisplayLink *)displayLink {
+  _timerHandler();
+}
+
+@end
+
+// RTCEAGLVideoView wraps a GLKView which is setup with
+// enableSetNeedsDisplay = NO for the purpose of gaining control of
+// exactly when to call -[GLKView display]. This need for extra
+// control is required to avoid triggering method calls on GLKView
+// that results in attempting to bind the underlying render buffer
+// when the drawable size would be empty which would result in the
+// error GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT. -[GLKView display] is
+// the method that will trigger the binding of the render
+// buffer. Because the standard behaviour of -[UIView setNeedsDisplay]
+// is disabled for the reasons above, the RTCEAGLVideoView maintains
+// its own |isDirty| flag.
+
+@interface RTCEAGLVideoView () <GLKViewDelegate>
+// |videoFrame| is set when we receive a frame from a worker thread and is read
+// from the display link callback so atomicity is required.
+@property(atomic, strong) RTCVideoFrame *videoFrame;
+@property(nonatomic, readonly) GLKView *glkView;
+@end
+
+@implementation RTCEAGLVideoView {
+  RTCDisplayLinkTimer *_timer;
+  EAGLContext *_glContext;
+  // This flag should only be set and read on the main thread (e.g. by
+  // setNeedsDisplay)
+  BOOL _isDirty;
+  id<RTCShader> _i420Shader;
+  id<RTCShader> _nv12Shader;
+  RTCVideoFrame *_lastDrawnFrame;
+}
+
+@synthesize delegate = _delegate;
+@synthesize videoFrame = _videoFrame;
+@synthesize glkView = _glkView;
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  if (self = [super initWithFrame:frame]) {
+    [self configure];
+  }
+  return self;
+}
+
+- (instancetype)initWithCoder:(NSCoder *)aDecoder {
+  if (self = [super initWithCoder:aDecoder]) {
+    [self configure];
+  }
+  return self;
+}
+
+- (void)configure {
+  EAGLContext *glContext =
+    [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3];
+  if (!glContext) {
+    glContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
+  }
+  _glContext = glContext;
+
+  // GLKView manages a framebuffer for us.
+  _glkView = [[GLKView alloc] initWithFrame:CGRectZero
+                                    context:_glContext];
+  _glkView.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
+  _glkView.drawableDepthFormat = GLKViewDrawableDepthFormatNone;
+  _glkView.drawableStencilFormat = GLKViewDrawableStencilFormatNone;
+  _glkView.drawableMultisample = GLKViewDrawableMultisampleNone;
+  _glkView.delegate = self;
+  _glkView.layer.masksToBounds = YES;
+  _glkView.enableSetNeedsDisplay = NO;
+  [self addSubview:_glkView];
+
+  // Listen to application state in order to clean up OpenGL before app goes
+  // away.
+  NSNotificationCenter *notificationCenter =
+    [NSNotificationCenter defaultCenter];
+  [notificationCenter addObserver:self
+                         selector:@selector(willResignActive)
+                             name:UIApplicationWillResignActiveNotification
+                           object:nil];
+  [notificationCenter addObserver:self
+                         selector:@selector(didBecomeActive)
+                             name:UIApplicationDidBecomeActiveNotification
+                           object:nil];
+
+  // Frames are received on a separate thread, so we poll for current frame
+  // using a refresh rate proportional to screen refresh frequency. This
+  // occurs on the main thread.
+  __weak RTCEAGLVideoView *weakSelf = self;
+  _timer = [[RTCDisplayLinkTimer alloc] initWithTimerHandler:^{
+      RTCEAGLVideoView *strongSelf = weakSelf;
+      [strongSelf displayLinkTimerDidFire];
+    }];
+  [self setupGL];
+}
+
+- (void)dealloc {
+  [[NSNotificationCenter defaultCenter] removeObserver:self];
+  UIApplicationState appState =
+      [UIApplication sharedApplication].applicationState;
+  if (appState == UIApplicationStateActive) {
+    [self teardownGL];
+  }
+  [_timer invalidate];
+  if (_glContext && [EAGLContext currentContext] == _glContext) {
+    [EAGLContext setCurrentContext:nil];
+  }
+}
+
+#pragma mark - UIView
+
+- (void)setNeedsDisplay {
+  [super setNeedsDisplay];
+  _isDirty = YES;
+}
+
+- (void)setNeedsDisplayInRect:(CGRect)rect {
+  [super setNeedsDisplayInRect:rect];
+  _isDirty = YES;
+}
+
+- (void)layoutSubviews {
+  [super layoutSubviews];
+  _glkView.frame = self.bounds;
+}
+
+#pragma mark - GLKViewDelegate
+
+// This method is called when the GLKView's content is dirty and needs to be
+// redrawn. This occurs on main thread.
+- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect {
+  // The renderer will draw the frame to the framebuffer corresponding to the
+  // one used by |view|.
+  RTCVideoFrame *frame = self.videoFrame;
+  if (!frame || frame == _lastDrawnFrame) {
+    return;
+  }
+  [self ensureGLContext];
+  glClear(GL_COLOR_BUFFER_BIT);
+  id<RTCShader> shader = nil;
+  if (frame.nativeHandle) {
+    if (!_nv12Shader) {
+      _nv12Shader = [[RTCNativeNV12Shader alloc] initWithContext:_glContext];
+    }
+    shader = _nv12Shader;
+  } else {
+    if (!_i420Shader) {
+      _i420Shader = [[RTCI420Shader alloc] initWithContext:_glContext];
+    }
+    shader = _i420Shader;
+  }
+  if (shader && [shader drawFrame:frame]) {
+    _lastDrawnFrame = frame;
+  } else {
+    RTCLog(@"Failed to draw frame.");
+  }
+}
+
+#pragma mark - RTCVideoRenderer
+
+// These methods may be called on non-main thread.
+- (void)setSize:(CGSize)size {
+  __weak RTCEAGLVideoView *weakSelf = self;
+  dispatch_async(dispatch_get_main_queue(), ^{
+    RTCEAGLVideoView *strongSelf = weakSelf;
+    [strongSelf.delegate videoView:strongSelf didChangeVideoSize:size];
+  });
+}
+
+- (void)renderFrame:(RTCVideoFrame *)frame {
+  self.videoFrame = frame;
+}
+
+#pragma mark - Private
+
+- (void)displayLinkTimerDidFire {
+  // Don't render unless video frame have changed or the view content
+  // has explicitly been marked dirty.
+  if (!_isDirty && _lastDrawnFrame == self.videoFrame) {
+    return;
+  }
+
+  // Always reset isDirty at this point, even if -[GLKView display]
+  // won't be called in the case the drawable size is empty.
+  _isDirty = NO;
+
+  // Only call -[GLKView display] if the drawable size is
+  // non-empty. Calling display will make the GLKView setup its
+  // render buffer if necessary, but that will fail with error
+  // GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT if size is empty.
+  if (self.bounds.size.width > 0 && self.bounds.size.height > 0) {
+    [_glkView display];
+  }
+}
+
+- (void)setupGL {
+  self.videoFrame = nil;
+  [self ensureGLContext];
+  glDisable(GL_DITHER);
+  _timer.isPaused = NO;
+}
+
+- (void)teardownGL {
+  self.videoFrame = nil;
+  _timer.isPaused = YES;
+  [_glkView deleteDrawable];
+  [self ensureGLContext];
+  _i420Shader = nil;
+  _nv12Shader = nil;
+}
+
+- (void)didBecomeActive {
+  [self setupGL];
+}
+
+- (void)willResignActive {
+  [self teardownGL];
+}
+
+- (void)ensureGLContext {
+  NSAssert(_glContext, @"context shouldn't be nil");
+  if ([EAGLContext currentContext] != _glContext) {
+    [EAGLContext setCurrentContext:_glContext];
+  }
+}
+
+@end

webrtc/sdk/objc/Framework/Classes/UI/RTCNSGLVideoView.m

@@ -0,0 +1,173 @@
+/*
+ *  Copyright 2015 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>
+
+#if !TARGET_OS_IPHONE
+
+#import "WebRTC/RTCNSGLVideoView.h"
+
+#import <AppKit/NSOpenGL.h>
+#import <CoreVideo/CVDisplayLink.h>
+#import <OpenGL/gl3.h>
+
+#import "RTCShader+Private.h"
+#import "WebRTC/RTCLogging.h"
+#import "WebRTC/RTCVideoFrame.h"
+
+@interface RTCNSGLVideoView ()
+// |videoFrame| is set when we receive a frame from a worker thread and is read
+// from the display link callback so atomicity is required.
+@property(atomic, strong) RTCVideoFrame *videoFrame;
+@property(atomic, strong) id<RTCShader> i420Shader;
+
+- (void)drawFrame;
+@end
+
+static CVReturn OnDisplayLinkFired(CVDisplayLinkRef displayLink,
+                                   const CVTimeStamp *now,
+                                   const CVTimeStamp *outputTime,
+                                   CVOptionFlags flagsIn,
+                                   CVOptionFlags *flagsOut,
+                                   void *displayLinkContext) {
+  RTCNSGLVideoView *view = (__bridge RTCNSGLVideoView *)displayLinkContext;
+  [view drawFrame];
+  return kCVReturnSuccess;
+}
+
+@implementation RTCNSGLVideoView {
+  CVDisplayLinkRef _displayLink;
+  RTCVideoFrame *_lastDrawnFrame;
+}
+
+@synthesize delegate = _delegate;
+@synthesize videoFrame = _videoFrame;
+@synthesize i420Shader = _i420Shader;
+
+- (void)dealloc {
+  [self teardownDisplayLink];
+}
+
+- (void)drawRect:(NSRect)rect {
+  [self drawFrame];
+}
+
+- (void)reshape {
+  [super reshape];
+  NSRect frame = [self frame];
+  CGLLockContext([[self openGLContext] CGLContextObj]);
+  glViewport(0, 0, frame.size.width, frame.size.height);
+  CGLUnlockContext([[self openGLContext] CGLContextObj]);
+}
+
+- (void)lockFocus {
+  NSOpenGLContext *context = [self openGLContext];
+  [super lockFocus];
+  if ([context view] != self) {
+    [context setView:self];
+  }
+  [context makeCurrentContext];
+}
+
+- (void)prepareOpenGL {
+  [super prepareOpenGL];
+  [self ensureGLContext];
+  glDisable(GL_DITHER);
+  [self setupDisplayLink];
+}
+
+- (void)clearGLContext {
+  [self ensureGLContext];
+  self.i420Shader = nil;
+  [super clearGLContext];
+}
+
+#pragma mark - RTCVideoRenderer
+
+// These methods may be called on non-main thread.
+- (void)setSize:(CGSize)size {
+  dispatch_async(dispatch_get_main_queue(), ^{
+    [self.delegate videoView:self didChangeVideoSize:size];
+  });
+}
+
+- (void)renderFrame:(RTCVideoFrame *)frame {
+  self.videoFrame = frame;
+}
+
+#pragma mark - Private
+
+- (void)drawFrame {
+  RTCVideoFrame *frame = self.videoFrame;
+  if (!frame || frame == _lastDrawnFrame) {
+    return;
+  }
+  // This method may be called from CVDisplayLink callback which isn't on the
+  // main thread so we have to lock the GL context before drawing.
+  NSOpenGLContext *context = [self openGLContext];
+  CGLLockContext([context CGLContextObj]);
+
+  [self ensureGLContext];
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  // Rendering native CVPixelBuffer is not supported on OS X.
+  frame = [frame newI420VideoFrame];
+  if (!self.i420Shader) {
+    self.i420Shader = [[RTCI420Shader alloc] initWithContext:context];
+  }
+  if (self.i420Shader && [self.i420Shader drawFrame:frame]) {
+    [context flushBuffer];
+    _lastDrawnFrame = frame;
+  } else {
+    RTCLog(@"Failed to draw frame.");
+  }
+  CGLUnlockContext([context CGLContextObj]);
+}
+
+- (void)setupDisplayLink {
+  if (_displayLink) {
+    return;
+  }
+  // Synchronize buffer swaps with vertical refresh rate.
+  GLint swapInt = 1;
+  [[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
+
+  // Create display link.
+  CVDisplayLinkCreateWithActiveCGDisplays(&_displayLink);
+  CVDisplayLinkSetOutputCallback(_displayLink,
+                                 &OnDisplayLinkFired,
+                                 (__bridge void *)self);
+  // Set the display link for the current renderer.
+  CGLContextObj cglContext = [[self openGLContext] CGLContextObj];
+  CGLPixelFormatObj cglPixelFormat = [[self pixelFormat] CGLPixelFormatObj];
+  CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(
+      _displayLink, cglContext, cglPixelFormat);
+  CVDisplayLinkStart(_displayLink);
+}
+
+- (void)teardownDisplayLink {
+  if (!_displayLink) {
+    return;
+  }
+  CVDisplayLinkRelease(_displayLink);
+  _displayLink = NULL;
+}
+
+- (void)ensureGLContext {
+  NSOpenGLContext* context = [self openGLContext];
+  NSAssert(context, @"context shouldn't be nil");
+  if ([NSOpenGLContext currentContext] != context) {
+    [context makeCurrentContext];
+  }
+}
+
+@end
+
+#endif  // !TARGET_OS_IPHONE