我在做这样一件事情：通过某种方式得到像素数据（OpenGLES的glReadPixels方法或其它方式），然后创建CVPixelBuffer，写入视频。但是，我在5c、5s和6上测试后发现，6的视频中的图像出现变形，另外两个正常……
有谁知道怎么解决吗？
如图：
其中一种转换方式的代码如下：
CGSize viewSize=self.glView.bounds.size;
NSInteger myDataLength = viewSize.width * viewSize.height * 4;
// allocate array and read pixels into it.
GLubyte *buffer = (GLubyte *) malloc(myDataLength);
glReadPixels(0, 0, viewSize.width, viewSize.height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
// gl renders "upside down" so swap top to bottom into new array.
// there's gotta be a better way, but this works.
GLubyte *buffer2 = (GLubyte *) malloc(myDataLength);
for(int y = 0; y < viewSize.height; y++)
{
for(int x = 0; x < viewSize.width* 4; x++)
{
buffer2[(int)((viewSize.height-1 - y) * viewSize.width * 4 + x)] = buffer[(int)(y * 4 * viewSize.width + x)];
}
}
free(buffer);
// make data provider with data.
CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer2, myDataLength, NULL);
// prep the ingredients
int bitsPerComponent = 8;
int bitsPerPixel = 32;
int bytesPerRow = 4 * viewSize.width;
CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
// make the cgimage
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
CGImageRef imageRef = CGImageCreate(viewSize.width , viewSize.height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);
// UIImage *photo = [UIImage imageWithCGImage:imageRef];
int width = CGImageGetWidth(imageRef);
int height = CGImageGetHeight(imageRef);
CVPixelBufferRef pixelBuffer = NULL;
CVReturn status = CVPixelBufferPoolCreatePixelBuffer(NULL, _recorder.pixelBufferAdaptor.pixelBufferPool, &pixelBuffer);
NSAssert((status == kCVReturnSuccess && pixelBuffer != NULL), @"create pixel buffer failed.");
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pixelBuffer);
NSParameterAssert(pxdata != NULL);//CGContextRef
CGContextRef context = CGBitmapContextCreate(pxdata,
width,
height,
CGImageGetBitsPerComponent(imageRef),
CGImageGetBytesPerRow(imageRef),
colorSpaceRef,
kCGImageAlphaPremultipliedLast);
NSParameterAssert(context);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
CGColorSpaceRelease(colorSpaceRef);
CGContextRelease(context);
CGImageRelease(imageRef);
free(buffer2);
// CIImage *image = [CIImage imageWithCVPixelBuffer:pixelBuffer];
// record
// ......
CVPixelBufferRelease(pixelBuffer);
