小编lei*_*rge的帖子

我正在尝试按照此答案访问内在矩阵。

通过运行下面的命令，我获得了一个 48 字节的AnyObject，并进一步将其转换为CFData。

let camData = CMGetAttachment(sampleBuffer, kCMSampleBufferAttachmentKey_CameraIntrinsicMatrix, nil)

但是，我检查了sampleBuffer的输出CMSampleBuffer.h：

/*! @constant   kCMSampleBufferAttachmentKey_CameraIntrinsicMatrix
     @abstract  Indicates the 3x3 camera intrinsic matrix applied to the current sample buffer.
     @discussion Camera intrinsic matrix is a CFData containing a matrix_float3x3, which is column-major.
        ....
 */
CM_EXPORT const CFStringRef kCMSampleBufferAttachmentKey_CameraIntrinsicMatrix  // CFData (matrix_float3x3) __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_11_0);

matrix_float3x3我应该如何访问from中的值CFData？