Error in conv

After I updated to R28.4, conv reports some errors?

libv4l2_nvvidconv (0):(1670) (ERROR) : NvDdkVicConfigure Failed
libv4l2_nvvidconv (0):(1692) (ERROR) : NVVIDCONV ERROR 2

What is the reason? In R28.2, It’s OK!

And more info:
In R28.2,

TVMR: cbBeginSequence:1683 ColorSpace = NvColorSpace_YCbCr601

But In R28.4
TVMR: cbBeginSequence:1674 ColorSpace = NvColorSpace_YCbCr709_ER

Why the colorspace is changed?

In later release(s), we separate YUV420 in different color spaces(bt601, bt709, bt2020). Please call NvBufferTransform() instead of using NvVideoConverter.

Thank You!The error is fixed