ObjC: Split out NV12 texture uploading into separate class

webrtc/sdk/objc/Framework/Classes/RTCNV12TextureCache.m

+/*
+ *  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 "RTCNV12TextureCache.h"
+
+#import "WebRTC/RTCVideoFrame.h"
+
+@implementation RTCNV12TextureCache {
+  CVOpenGLESTextureCacheRef _textureCache;
+  CVOpenGLESTextureRef _yTextureRef;
+  CVOpenGLESTextureRef _uvTextureRef;
+}
+
+- (GLuint)yTexture {
+  return CVOpenGLESTextureGetName(_yTextureRef);
+}
+
+- (GLuint)uvTexture {
+  return CVOpenGLESTextureGetName(_uvTextureRef);
+}
+
+- (instancetype)initWithContext:(EAGLContext *)context {
+  if (self = [super init]) {
+    CVReturn ret = CVOpenGLESTextureCacheCreate(
+        kCFAllocatorDefault, NULL,
+#if COREVIDEO_USE_EAGLCONTEXT_CLASS_IN_API
+        context,
+#else
+        (__bridge void *)context,
+#endif
+        NULL, &_textureCache);
+    if (ret != kCVReturnSuccess) {
+      self = nil;
+    }
+  }
+  return self;
+}
+
+- (BOOL)loadTexture:(CVOpenGLESTextureRef *)textureOut
+        pixelBuffer:(CVPixelBufferRef)pixelBuffer
+         planeIndex:(int)planeIndex
+        pixelFormat:(GLenum)pixelFormat {
+  const int width = CVPixelBufferGetWidthOfPlane(pixelBuffer, planeIndex);
+  const int height = CVPixelBufferGetHeightOfPlane(pixelBuffer, planeIndex);
+
+  *textureOut = nil;

[sakal, 2017/04/26 13:31:56]

I think we should call CFRelease if textureOut is not already nil?

[magjed_webrtc, 2017/04/26 14:40:41]

Looks like it. Done.

+  CVReturn ret = CVOpenGLESTextureCacheCreateTextureFromImage(
+      kCFAllocatorDefault, _textureCache, pixelBuffer, NULL, GL_TEXTURE_2D, pixelFormat, width,
+      height, pixelFormat, GL_UNSIGNED_BYTE, planeIndex, textureOut);
+  if (ret != kCVReturnSuccess) {
+    CFRelease(*textureOut);
+    *textureOut = nil;
+    return NO;
+  }
+  NSAssert(CVOpenGLESTextureGetTarget(*textureOut) == GL_TEXTURE_2D,
+           @"Unexpected GLES texture target");
+  glBindTexture(GL_TEXTURE_2D, CVOpenGLESTextureGetName(*textureOut));
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+  return YES;
+}
+
+- (BOOL)uploadFrameToTextures:(RTCVideoFrame *)frame {
+  CVPixelBufferRef pixelBuffer = frame.nativeHandle;
+  NSParameterAssert(pixelBuffer);
+  return [self loadTexture:&_yTextureRef
+               pixelBuffer:pixelBuffer
+                planeIndex:0
+               pixelFormat:GL_LUMINANCE] &&
+         [self loadTexture:&_uvTextureRef
+               pixelBuffer:pixelBuffer
+                planeIndex:1
+               pixelFormat:GL_LUMINANCE_ALPHA];
+}
+
+- (void)releaseTextures {
+  if (_uvTextureRef) {
+    CFRelease(_uvTextureRef);
+    _uvTextureRef = nil;
+  }
+  if (_yTextureRef) {
+    CFRelease(_yTextureRef);
+    _yTextureRef = nil;
+  }
+}
+
+- (void)dealloc {
+  [self releaseTextures];
+  if (_textureCache) {
+    CFRelease(_textureCache);
+    _textureCache = nil;
+  }
+}
+
+@end
+