3 * Copyright 2014, Google Inc.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
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16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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28 #if !defined(__has_feature) || !__has_feature(objc_arc)
29 #error "This file requires ARC support."
32 #import "RTCNSGLVideoView.h"
34 #import <CoreVideo/CVDisplayLink.h>
35 #import <OpenGL/gl3.h>
36 #import "RTCOpenGLVideoRenderer.h"
37 #import "RTCVideoRenderer.h"
39 @interface RTCNSGLVideoView () <RTCVideoRendererDelegate>
40 // |i420Frame| is set when we receive a frame from a worker thread and is read
41 // from the display link callback so atomicity is required.
42 @property(atomic, strong) RTCI420Frame* i420Frame;
43 @property(atomic, strong) RTCOpenGLVideoRenderer* glRenderer;
47 static CVReturn OnDisplayLinkFired(CVDisplayLinkRef displayLink,
48 const CVTimeStamp* now,
49 const CVTimeStamp* outputTime,
50 CVOptionFlags flagsIn,
51 CVOptionFlags* flagsOut,
52 void* displayLinkContext) {
53 RTCNSGLVideoView* view = (__bridge RTCNSGLVideoView*)displayLinkContext;
55 return kCVReturnSuccess;
58 @implementation RTCNSGLVideoView {
59 CVDisplayLinkRef _displayLink;
60 RTCVideoRenderer* _videoRenderer;
63 - (instancetype)initWithFrame:(NSRect)frame
64 pixelFormat:(NSOpenGLPixelFormat*)format {
65 if (self = [super initWithFrame:frame pixelFormat:format]) {
66 _videoRenderer = [[RTCVideoRenderer alloc] initWithDelegate:self];
72 [self teardownDisplayLink];
75 - (void)drawRect:(NSRect)rect {
81 NSRect frame = [self frame];
82 CGLLockContext([[self openGLContext] CGLContextObj]);
83 glViewport(0, 0, frame.size.width, frame.size.height);
84 CGLUnlockContext([[self openGLContext] CGLContextObj]);
88 NSOpenGLContext* context = [self openGLContext];
90 if ([context view] != self) {
91 [context setView:self];
93 [context makeCurrentContext];
96 - (void)prepareOpenGL {
97 [super prepareOpenGL];
98 if (!self.glRenderer) {
100 [[RTCOpenGLVideoRenderer alloc] initWithContext:[self openGLContext]];
102 [self.glRenderer setupGL];
103 [self setupDisplayLink];
106 - (void)clearGLContext {
107 [self.glRenderer teardownGL];
108 self.glRenderer = nil;
109 [super clearGLContext];
112 - (void)setVideoTrack:(RTCVideoTrack*)videoTrack {
113 if (_videoTrack == videoTrack) {
117 [_videoTrack removeRenderer:_videoRenderer];
118 CVDisplayLinkStop(_displayLink);
120 self.i420Frame = nil;
123 _videoTrack = videoTrack;
125 [_videoTrack addRenderer:_videoRenderer];
126 CVDisplayLinkStart(_displayLink);
130 #pragma mark - RTCVideoRendererDelegate
132 // These methods are called when the video track has frame information to
133 // provide. This occurs on non-main thread.
134 - (void)renderer:(RTCVideoRenderer*)renderer
135 didSetSize:(CGSize)size {
136 dispatch_async(dispatch_get_main_queue(), ^{
137 [self.delegate videoView:self didChangeVideoSize:size];
141 - (void)renderer:(RTCVideoRenderer*)renderer
142 didReceiveFrame:(RTCI420Frame*)frame {
143 self.i420Frame = frame;
146 #pragma mark - Private
149 RTCI420Frame* i420Frame = self.i420Frame;
150 if (self.glRenderer.lastDrawnFrame != i420Frame) {
151 // This method may be called from CVDisplayLink callback which isn't on the
152 // main thread so we have to lock the GL context before drawing.
153 CGLLockContext([[self openGLContext] CGLContextObj]);
154 [self.glRenderer drawFrame:i420Frame];
155 CGLUnlockContext([[self openGLContext] CGLContextObj]);
159 - (void)setupDisplayLink {
163 // Synchronize buffer swaps with vertical refresh rate.
165 [[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
167 // Create display link.
168 CVDisplayLinkCreateWithActiveCGDisplays(&_displayLink);
169 CVDisplayLinkSetOutputCallback(_displayLink,
171 (__bridge void*)self);
172 // Set the display link for the current renderer.
173 CGLContextObj cglContext = [[self openGLContext] CGLContextObj];
174 CGLPixelFormatObj cglPixelFormat = [[self pixelFormat] CGLPixelFormatObj];
175 CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(
176 _displayLink, cglContext, cglPixelFormat);
178 CVDisplayLinkStart(_displayLink);
182 - (void)teardownDisplayLink {
186 CVDisplayLinkRelease(_displayLink);