我正在iOS应用中录制实时视频.在另一个StackOverflow页面(
Link)上,我发现你可以使用vImage_Buffer来处理我的帧.
问题是我不知道如何从输出的vImage_buffer返回CVPixelBufferRef.
NSInteger cropX0 = 100,cropY0 = 100,cropHeight = 100,cropWidth = 100,outWidth = 480,outHeight = 480;
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer,0);
void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
vImage_Buffer inBuff;
inBuff.height = cropHeight;
inBuff.width = cropWidth;
inBuff.rowBytes = bytesPerRow;
int startpos = cropY0*bytesPerRow+4*cropX0;
inBuff.data = baseAddress+startpos;
unsigned char *outImg= (unsigned char*)malloc(4*outWidth*outHeight);
vImage_Buffer outBuff = {outImg,outHeight,outWidth,4*outWidth};
vImage_Error err = vImageScale_ARGB8888(&inBuff,&outBuff,NULL,0);
if (err != kvImageNoError) NSLog(@" error %ld",err);
现在我需要将outBuff转换为CVPixelBufferRef.
我假设我需要使用vImageBuffer_CopyToCVPixelBuffer,但我不确定如何.
我的第一次尝试失败了EXC_BAD_ACCESS：
CVPixelBufferUnlockBaseAddress(ImageBuffer的,0);
CVPixelBufferRef pixelBuffer;
CVPixelBufferCreate(kcfAllocatorSystemDefault,480,kCVPixelFormatType_32BGRA,&pixelBuffer);
CVPixelBufferLockBaseAddress( pixelBuffer,0 );
vImage_CGImageFormat format = {
.bitsPerComponent = 8,.bitsPerPixel = 32,.bitmapInfo = kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,//BGRX8888
.colorSpace = NULL,//sRGB
};
vImageBuffer_CopyToCVPixelBuffer(&outBuff,&format,pixelBuffer,kvImageNoFlags); // Here is the crash!
CVPixelBufferUnlockBaseAddress( pixelBuffer,0 );
任何的想法？
解决方法
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool : YES],kCVPixelBufferCGImageCompatibilityKey,[NSNumber numberWithBool : YES],kCVPixelBufferCGBitmapContextCompatibilityKey,[NSNumber numberWithInt : 480],kCVPixelBufferWidthKey,kCVPixelBufferHeightKey,nil];
status = CVPixelBufferCreateWithBytes(kcfAllocatorDefault,outImg,bytesPerRow,(__bridge CFDictionaryRef)options,&pixbuffer);
你应该生成一个像上面这样的新pixelBuffer.
