ओपनजीएल शायद जाने का रास्ता है। हालांकि, बनावट के बजाए ऑफस्क्रीन फ्रेमबफर को प्रस्तुत करने के लिए यह थोड़ा और अधिक कुशल हो सकता है।
एक नमूना बफर से एक बनावट निकालने के लिए:
// Note the caller is responsible for calling glDeleteTextures on the return value.
- (GLuint)textureFromSampleBuffer:(CMSampleBufferRef)sampleBuffer {
GLuint texture = 0;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
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);
CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
int width = CVPixelBufferGetWidth(pixelBuffer);
int height = CVPixelBufferGetHeight(pixelBuffer);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, CVPixelBufferGetBaseAddress(pixelBuffer));
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
return texture;
}
ओपन के माध्यम से बनावट संसाधन के लिए, आप तो कुछ इस तरह कर सकता है:
// This function exists to free the malloced data when the CGDataProviderRef is
// eventually freed.
void dataProviderFreeData(void *info, const void *data, size_t size){
free((void *)data);
}
// Returns an autoreleased CGImageRef.
- (CGImageRef)processTexture:(GLuint)texture width:(int)width height:(int)height {
CGImageRef newImage = NULL;
// Set up framebuffer and renderbuffer.
GLuint framebuffer;
glGenFramebuffers(1, &framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
GLuint colorRenderbuffer;
glGenRenderbuffers(1, &colorRenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, width, height);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderbuffer);
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE) {
NSLog(@"Failed to create OpenGL frame buffer: %x", status);
} else {
glViewport(0, 0, width, height);
glClearColor(0.0,0.0,0.0,1.0);
glClear(GL_COLOR_BUFFER_BIT);
// Do whatever is necessary to actually draw the texture to the framebuffer
[self renderTextureToCurrentFrameBuffer:texture];
// Read the pixels out of the framebuffer
void *data = malloc(width * height * 4);
glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
// Convert the data to a CGImageRef. Note that CGDataProviderRef takes
// ownership of our malloced data buffer, and the CGImageRef internally
// retains the CGDataProviderRef. Hence the callback above, to free the data
// buffer when the provider is finally released.
CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, data, width * height * 4, dataProviderFreeData);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
newImage = CGImageCreate(width, height, 8, 32, width*4, colorspace, kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast, dataProvider, NULL, true, kCGRenderingIntentDefault);
CFRelease(dataProvider);
CGColorSpaceRelease(colorspace);
// Autorelease the CGImageRef
newImage = (CGImageRef)[NSMakeCollectable(newImage) autorelease];
}
// Clean up the framebuffer and renderbuffer.
glDeleteRenderbuffers(1, &colorRenderbuffer);
glDeleteFramebuffers(1, &framebuffer);
return newImage;
}