GPUImageFramebuffer类用于管理帧缓冲对象,负责帧缓冲对象的创建和销毁,读取帧缓冲内容
@property(readonly) CGSize size
- (id)initWithSize:(CGSize)framebufferSize; { GPUTextureOptions defaultTextureOptions; defaultTextureOptions.minFilter = GL_LINEAR; defaultTextureOptions.magFilter = GL_LINEAR; defaultTextureOptions.wrapS = GL_CLAMP_TO_EDGE; defaultTextureOptions.wrapT = GL_CLAMP_TO_EDGE; defaultTextureOptions.internalFormat = GL_RGBA; defaultTextureOptions.format = GL_BGRA; defaultTextureOptions.type = GL_UNSIGNED_BYTE; if (!(self = [self initWithSize:framebufferSize textureOptions:defaultTextureOptions onlyTexture:NO])) { return nil; } return self; }
- (id)initWithSize:(CGSize)framebufferSize textureOptions:(GPUTextureOptions)fboTextureOptions onlyTexture:(BOOL)onlyGenerateTexture; { if (!(self = [super init])) { return nil; } _textureOptions = fboTextureOptions; _size = framebufferSize; framebufferReferenceCount = 0; referenceCountingDisabled = NO; _missingFramebuffer = onlyGenerateTexture; if (_missingFramebuffer) { runSynchronouslyOnVideoProcessingQueue(^{ [GPUImageContext useImageProcessingContext]; [self generateTexture]; framebuffer = 0; }); } else { [self generateFramebuffer]; } return self; }
- (id)initWithSize:(CGSize)framebufferSize overriddenTexture:(GLuint)inputTexture; { if (!(self = [super init])) { return nil; } GPUTextureOptions defaultTextureOptions; defaultTextureOptions.minFilter = GL_LINEAR; defaultTextureOptions.magFilter = GL_LINEAR; defaultTextureOptions.wrapS = GL_CLAMP_TO_EDGE; defaultTextureOptions.wrapT = GL_CLAMP_TO_EDGE; defaultTextureOptions.internalFormat = GL_RGBA; defaultTextureOptions.format = GL_BGRA; defaultTextureOptions.type = GL_UNSIGNED_BYTE; _textureOptions = defaultTextureOptions; _size = framebufferSize; framebufferReferenceCount = 0; referenceCountingDisabled = YES; _texture = inputTexture; return self; }
- (void)activateFramebuffer; { glBindFramebuffer(GL_FRAMEBUFFER, framebuffer); glViewport(0, 0, (int)_size.width, (int)_size.height); }
- (void)lock; { if (referenceCountingDisabled) { return; } framebufferReferenceCount++; }
- (void)unlock; { if (referenceCountingDisabled) { return; } NSAssert(framebufferReferenceCount > 0, @"Tried to overrelease a framebuffer, did you forget to call -useNextFrameForImageCapture before using -imageFromCurrentFramebuffer?"); framebufferReferenceCount--; if (framebufferReferenceCount < 1) { [[GPUImageContext sharedFramebufferCache] returnFramebufferToCache:self]; } }
- (void)clearAllLocks; { framebufferReferenceCount = 0; }
- (void)disableReferenceCounting; { referenceCountingDisabled = YES; }
- (void)enableReferenceCounting; { referenceCountingDisabled = NO; }
- (CGImageRef)newCGImageFromFramebufferContents; { // a CGImage can only be created from a 'normal' color texture NSAssert(self.textureOptions.internalFormat == GL_RGBA, @"For conversion to a CGImage the output texture format for this filter must be GL_RGBA."); NSAssert(self.textureOptions.type == GL_UNSIGNED_BYTE, @"For conversion to a CGImage the type of the output texture of this filter must be GL_UNSIGNED_BYTE."); __block CGImageRef cgImageFromBytes; runSynchronouslyOnVideoProcessingQueue(^{ [GPUImageContext useImageProcessingContext]; NSUInteger totalBytesForImage = (int)_size.width * (int)_size.height * 4; // It appears that the width of a texture must be padded out to be a multiple of 8 (32 bytes) if reading from it using a texture cache GLubyte *rawImagePixels; CGDataProviderRef dataProvider = NULL; if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE NSUInteger paddedWidthOfImage = CVPixelBufferGetBytesPerRow(renderTarget) / 4.0; NSUInteger paddedBytesForImage = paddedWidthOfImage * (int)_size.height * 4; glFinish(); CFRetain(renderTarget); // I need to retain the pixel buffer here and release in the data source callback to prevent its bytes from being prematurely deallocated during a photo write operation [self lockForReading]; rawImagePixels = (GLubyte *)CVPixelBufferGetBaseAddress(renderTarget); dataProvider = CGDataProviderCreateWithData((__bridge_retained void*)self, rawImagePixels, paddedBytesForImage, dataProviderUnlockCallback); [[GPUImageContext sharedFramebufferCache] addFramebufferToActiveImageCaptureList:self]; // In case the framebuffer is swapped out on the filter, need to have a strong reference to it somewhere for it to hang on while the image is in existence #else #endif } else { [self activateFramebuffer]; rawImagePixels = (GLubyte *)malloc(totalBytesForImage); glReadPixels(0, 0, (int)_size.width, (int)_size.height, GL_RGBA, GL_UNSIGNED_BYTE, rawImagePixels); dataProvider = CGDataProviderCreateWithData(NULL, rawImagePixels, totalBytesForImage, dataProviderReleaseCallback); [self unlock]; // Don't need to keep this around anymore } CGColorSpaceRef defaultRGBColorSpace = CGColorSpaceCreateDeviceRGB(); if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE cgImageFromBytes = CGImageCreate((int)_size.width, (int)_size.height, 8, 32, CVPixelBufferGetBytesPerRow(renderTarget), defaultRGBColorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst, dataProvider, NULL, NO, kCGRenderingIntentDefault); #else #endif } else { cgImageFromBytes = CGImageCreate((int)_size.width, (int)_size.height, 8, 32, 4 * (int)_size.width, defaultRGBColorSpace, kCGBitmapByteOrderDefault | kCGImageAlphaLast, dataProvider, NULL, NO, kCGRenderingIntentDefault); } // Capture image with current device orientation CGDataProviderRelease(dataProvider); CGColorSpaceRelease(defaultRGBColorSpace); }); return cgImageFromBytes; }
- (void)restoreRenderTarget; { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE [self unlockAfterReading]; CFRelease(renderTarget); #else #endif }
- (void)lockForReading { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE if ([GPUImageContext supportsFastTextureUpload]) { if (readLockCount == 0) { CVPixelBufferLockBaseAddress(renderTarget, 0); } readLockCount++; } #endif }
- (void)unlockAfterReading { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE if ([GPUImageContext supportsFastTextureUpload]) { NSAssert(readLockCount > 0, @"Unbalanced call to -[GPUImageFramebuffer unlockAfterReading]"); readLockCount--; if (readLockCount == 0) { CVPixelBufferUnlockBaseAddress(renderTarget, 0); } } #endif }
- (NSUInteger)bytesPerRow; { if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE return CVPixelBufferGetBytesPerRow(renderTarget); #else return _size.width * 4; // TODO: do more with this on the non-texture-cache side #endif } else { return _size.width * 4; } }
- (GLubyte *)byteBuffer; { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE [self lockForReading]; GLubyte * bufferBytes = CVPixelBufferGetBaseAddress(renderTarget); [self unlockAfterReading]; return bufferBytes; #else return NULL; // TODO: do more with this on the non-texture-cache side #endif }
#import <Foundation/Foundation.h> #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE #import <OpenGLES/EAGL.h> #import <OpenGLES/ES2/gl.h> #import <OpenGLES/ES2/glext.h> #else #import <OpenGL/OpenGL.h> #import <OpenGL/gl.h> #endif #import <QuartzCore/QuartzCore.h> #import <CoreMedia/CoreMedia.h> typedef struct GPUTextureOptions { GLenum minFilter; GLenum magFilter; GLenum wrapS; GLenum wrapT; GLenum internalFormat; GLenum format; GLenum type; } GPUTextureOptions; @interface GPUImageFramebuffer : NSObject @property(readonly) CGSize size; @property(readonly) GPUTextureOptions textureOptions; @property(readonly) GLuint texture; @property(readonly) BOOL missingFramebuffer; // Initialization and teardown - (id)initWithSize:(CGSize)framebufferSize; - (id)initWithSize:(CGSize)framebufferSize textureOptions:(GPUTextureOptions)fboTextureOptions onlyTexture:(BOOL)onlyGenerateTexture; - (id)initWithSize:(CGSize)framebufferSize overriddenTexture:(GLuint)inputTexture; // Usage - (void)activateFramebuffer; // Reference counting - (void)lock; - (void)unlock; - (void)clearAllLocks; - (void)disableReferenceCounting; - (void)enableReferenceCounting; // Image capture - (CGImageRef)newCGImageFromFramebufferContents; - (void)restoreRenderTarget; // Raw data bytes - (void)lockForReading; - (void)unlockAfterReading; - (NSUInteger)bytesPerRow; - (GLubyte *)byteBuffer; @end View Code
#import "GPUImageFramebuffer.h" #import "GPUImageOutput.h" @interface GPUImageFramebuffer() { GLuint framebuffer; #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE CVPixelBufferRef renderTarget; CVOpenGLESTextureRef renderTexture; NSUInteger readLockCount; #else #endif NSUInteger framebufferReferenceCount; BOOL referenceCountingDisabled; } - (void)generateFramebuffer; - (void)generateTexture; - (void)destroyFramebuffer; @end void dataProviderReleaseCallback (void *info, const void *data, size_t size); void dataProviderUnlockCallback (void *info, const void *data, size_t size); @implementation GPUImageFramebuffer @synthesize size = _size; @synthesize textureOptions = _textureOptions; @synthesize texture = _texture; @synthesize missingFramebuffer = _missingFramebuffer; #pragma mark - #pragma mark Initialization and teardown - (id)initWithSize:(CGSize)framebufferSize textureOptions:(GPUTextureOptions)fboTextureOptions onlyTexture:(BOOL)onlyGenerateTexture; { if (!(self = [super init])) { return nil; } _textureOptions = fboTextureOptions; _size = framebufferSize; framebufferReferenceCount = 0; referenceCountingDisabled = NO; _missingFramebuffer = onlyGenerateTexture; if (_missingFramebuffer) { runSynchronouslyOnVideoProcessingQueue(^{ [GPUImageContext useImageProcessingContext]; [self generateTexture]; framebuffer = 0; }); } else { [self generateFramebuffer]; } return self; } - (id)initWithSize:(CGSize)framebufferSize overriddenTexture:(GLuint)inputTexture; { if (!(self = [super init])) { return nil; } GPUTextureOptions defaultTextureOptions; defaultTextureOptions.minFilter = GL_LINEAR; defaultTextureOptions.magFilter = GL_LINEAR; defaultTextureOptions.wrapS = GL_CLAMP_TO_EDGE; defaultTextureOptions.wrapT = GL_CLAMP_TO_EDGE; defaultTextureOptions.internalFormat = GL_RGBA; defaultTextureOptions.format = GL_BGRA; defaultTextureOptions.type = GL_UNSIGNED_BYTE; _textureOptions = defaultTextureOptions; _size = framebufferSize; framebufferReferenceCount = 0; referenceCountingDisabled = YES; _texture = inputTexture; return self; } - (id)initWithSize:(CGSize)framebufferSize; { GPUTextureOptions defaultTextureOptions; defaultTextureOptions.minFilter = GL_LINEAR; defaultTextureOptions.magFilter = GL_LINEAR; defaultTextureOptions.wrapS = GL_CLAMP_TO_EDGE; defaultTextureOptions.wrapT = GL_CLAMP_TO_EDGE; defaultTextureOptions.internalFormat = GL_RGBA; defaultTextureOptions.format = GL_BGRA; defaultTextureOptions.type = GL_UNSIGNED_BYTE; if (!(self = [self initWithSize:framebufferSize textureOptions:defaultTextureOptions onlyTexture:NO])) { return nil; } return self; } - (void)dealloc { [self destroyFramebuffer]; } #pragma mark - #pragma mark Internal - (void)generateTexture; { glActiveTexture(GL_TEXTURE1); glGenTextures(1, &_texture); glBindTexture(GL_TEXTURE_2D, _texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _textureOptions.minFilter); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, _textureOptions.magFilter); // This is necessary for non-power-of-two textures glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, _textureOptions.wrapS); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, _textureOptions.wrapT); // TODO: Handle mipmaps } - (void)generateFramebuffer; { runSynchronouslyOnVideoProcessingQueue(^{ [GPUImageContext useImageProcessingContext]; glGenFramebuffers(1, &framebuffer); glBindFramebuffer(GL_FRAMEBUFFER, framebuffer); // By default, all framebuffers on iOS 5.0+ devices are backed by texture caches, using one shared cache if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE CVOpenGLESTextureCacheRef coreVideoTextureCache = [[GPUImageContext sharedImageProcessingContext] coreVideoTextureCache]; // Code originally sourced from http://allmybrain.com/2011/12/08/rendering-to-a-texture-with-ios-5-texture-cache-api/ CFDictionaryRef empty; // empty value for attr value. CFMutableDictionaryRef attrs; empty = CFDictionaryCreate(kCFAllocatorDefault, NULL, NULL, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); // our empty IOSurface properties dictionary attrs = CFDictionaryCreateMutable(kCFAllocatorDefault, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); CFDictionarySetValue(attrs, kCVPixelBufferIOSurfacePropertiesKey, empty); CVReturn err = CVPixelBufferCreate(kCFAllocatorDefault, (int)_size.width, (int)_size.height, kCVPixelFormatType_32BGRA, attrs, &renderTarget); if (err) { NSLog(@"FBO size: %f, %f", _size.width, _size.height); NSAssert(NO, @"Error at CVPixelBufferCreate %d", err); } err = CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault, coreVideoTextureCache, renderTarget, NULL, // texture attributes GL_TEXTURE_2D, _textureOptions.internalFormat, // opengl format (int)_size.width, (int)_size.height, _textureOptions.format, // native iOS format _textureOptions.type, 0, &renderTexture); if (err) { NSAssert(NO, @"Error at CVOpenGLESTextureCacheCreateTextureFromImage %d", err); } CFRelease(attrs); CFRelease(empty); glBindTexture(CVOpenGLESTextureGetTarget(renderTexture), CVOpenGLESTextureGetName(renderTexture)); _texture = CVOpenGLESTextureGetName(renderTexture); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, _textureOptions.wrapS); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, _textureOptions.wrapT); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, CVOpenGLESTextureGetName(renderTexture), 0); #endif } else { [self generateTexture]; glBindTexture(GL_TEXTURE_2D, _texture); glTexImage2D(GL_TEXTURE_2D, 0, _textureOptions.internalFormat, (int)_size.width, (int)_size.height, 0, _textureOptions.format, _textureOptions.type, 0); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, _texture, 0); } #ifndef NS_BLOCK_ASSERTIONS GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER); NSAssert(status == GL_FRAMEBUFFER_COMPLETE, @"Incomplete filter FBO: %d", status); #endif glBindTexture(GL_TEXTURE_2D, 0); }); } - (void)destroyFramebuffer; { runSynchronouslyOnVideoProcessingQueue(^{ [GPUImageContext useImageProcessingContext]; if (framebuffer) { glDeleteFramebuffers(1, &framebuffer); framebuffer = 0; } if ([GPUImageContext supportsFastTextureUpload] && (!_missingFramebuffer)) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE if (renderTarget) { CFRelease(renderTarget); renderTarget = NULL; } if (renderTexture) { CFRelease(renderTexture); renderTexture = NULL; } #endif } else { glDeleteTextures(1, &_texture); } }); } #pragma mark - #pragma mark Usage - (void)activateFramebuffer; { glBindFramebuffer(GL_FRAMEBUFFER, framebuffer); glViewport(0, 0, (int)_size.width, (int)_size.height); } #pragma mark - #pragma mark Reference counting - (void)lock; { if (referenceCountingDisabled) { return; } framebufferReferenceCount++; } - (void)unlock; { if (referenceCountingDisabled) { return; } NSAssert(framebufferReferenceCount > 0, @"Tried to overrelease a framebuffer, did you forget to call -useNextFrameForImageCapture before using -imageFromCurrentFramebuffer?"); framebufferReferenceCount--; if (framebufferReferenceCount < 1) { [[GPUImageContext sharedFramebufferCache] returnFramebufferToCache:self]; } } - (void)clearAllLocks; { framebufferReferenceCount = 0; } - (void)disableReferenceCounting; { referenceCountingDisabled = YES; } - (void)enableReferenceCounting; { referenceCountingDisabled = NO; } #pragma mark - #pragma mark Image capture void dataProviderReleaseCallback (void *info, const void *data, size_t size) { free((void *)data); } void dataProviderUnlockCallback (void *info, const void *data, size_t size) { GPUImageFramebuffer *framebuffer = (__bridge_transfer GPUImageFramebuffer*)info; [framebuffer restoreRenderTarget]; [framebuffer unlock]; [[GPUImageContext sharedFramebufferCache] removeFramebufferFromActiveImageCaptureList:framebuffer]; } - (CGImageRef)newCGImageFromFramebufferContents; { // a CGImage can only be created from a 'normal' color texture NSAssert(self.textureOptions.internalFormat == GL_RGBA, @"For conversion to a CGImage the output texture format for this filter must be GL_RGBA."); NSAssert(self.textureOptions.type == GL_UNSIGNED_BYTE, @"For conversion to a CGImage the type of the output texture of this filter must be GL_UNSIGNED_BYTE."); __block CGImageRef cgImageFromBytes; runSynchronouslyOnVideoProcessingQueue(^{ [GPUImageContext useImageProcessingContext]; NSUInteger totalBytesForImage = (int)_size.width * (int)_size.height * 4; // It appears that the width of a texture must be padded out to be a multiple of 8 (32 bytes) if reading from it using a texture cache GLubyte *rawImagePixels; CGDataProviderRef dataProvider = NULL; if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE NSUInteger paddedWidthOfImage = CVPixelBufferGetBytesPerRow(renderTarget) / 4.0; NSUInteger paddedBytesForImage = paddedWidthOfImage * (int)_size.height * 4; glFinish(); CFRetain(renderTarget); // I need to retain the pixel buffer here and release in the data source callback to prevent its bytes from being prematurely deallocated during a photo write operation [self lockForReading]; rawImagePixels = (GLubyte *)CVPixelBufferGetBaseAddress(renderTarget); dataProvider = CGDataProviderCreateWithData((__bridge_retained void*)self, rawImagePixels, paddedBytesForImage, dataProviderUnlockCallback); [[GPUImageContext sharedFramebufferCache] addFramebufferToActiveImageCaptureList:self]; // In case the framebuffer is swapped out on the filter, need to have a strong reference to it somewhere for it to hang on while the image is in existence #else #endif } else { [self activateFramebuffer]; rawImagePixels = (GLubyte *)malloc(totalBytesForImage); glReadPixels(0, 0, (int)_size.width, (int)_size.height, GL_RGBA, GL_UNSIGNED_BYTE, rawImagePixels); dataProvider = CGDataProviderCreateWithData(NULL, rawImagePixels, totalBytesForImage, dataProviderReleaseCallback); [self unlock]; // Don't need to keep this around anymore } CGColorSpaceRef defaultRGBColorSpace = CGColorSpaceCreateDeviceRGB(); if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE cgImageFromBytes = CGImageCreate((int)_size.width, (int)_size.height, 8, 32, CVPixelBufferGetBytesPerRow(renderTarget), defaultRGBColorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst, dataProvider, NULL, NO, kCGRenderingIntentDefault); #else #endif } else { cgImageFromBytes = CGImageCreate((int)_size.width, (int)_size.height, 8, 32, 4 * (int)_size.width, defaultRGBColorSpace, kCGBitmapByteOrderDefault | kCGImageAlphaLast, dataProvider, NULL, NO, kCGRenderingIntentDefault); } // Capture image with current device orientation CGDataProviderRelease(dataProvider); CGColorSpaceRelease(defaultRGBColorSpace); }); return cgImageFromBytes; } - (void)restoreRenderTarget; { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE [self unlockAfterReading]; CFRelease(renderTarget); #else #endif } #pragma mark - #pragma mark Raw data bytes - (void)lockForReading { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE if ([GPUImageContext supportsFastTextureUpload]) { if (readLockCount == 0) { CVPixelBufferLockBaseAddress(renderTarget, 0); } readLockCount++; } #endif } - (void)unlockAfterReading { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE if ([GPUImageContext supportsFastTextureUpload]) { NSAssert(readLockCount > 0, @"Unbalanced call to -[GPUImageFramebuffer unlockAfterReading]"); readLockCount--; if (readLockCount == 0) { CVPixelBufferUnlockBaseAddress(renderTarget, 0); } } #endif } - (NSUInteger)bytesPerRow; { if ([GPUImageContext supportsFastTextureUpload]) { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE return CVPixelBufferGetBytesPerRow(renderTarget); #else return _size.width * 4; // TODO: do more with this on the non-texture-cache side #endif } else { return _size.width * 4; } } - (GLubyte *)byteBuffer; { #if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE [self lockForReading]; GLubyte * bufferBytes = CVPixelBufferGetBaseAddress(renderTarget); [self unlockAfterReading]; return bufferBytes; #else return NULL; // TODO: do more with this on the non-texture-cache side #endif } - (GLuint)texture; { // NSLog(@"Accessing texture: %d from FB: %@", _texture, self); return _texture; } @end View Code