Can't convert from a BYTE buffer to a cv::Mat image - c++

Question

So i have a problem with converting a BYTE buffer to an image, (cv::Mat).
I am trying to read a real time video from a distant camera, and i got two elements, a pointer to the buffer and the buffer size, and i need to convert that to a cv::Mat image so that i can show it with cv::imshow. i tried to use:
cv::imdecode(cv::Mat(bufferSize,CV_8UC3,*buffer),cv::imread_color);
but it isn't working and i get this error:
error: (-215:Assertion failed) buf.checkVector(1, CV_8U) > 0 in function 'imdecode_'
when i try to convert directly without the imdecode function like this:
cv::Mat(bufferSize,CV_8UC3,*buffer)
i get an image but i can't show it so the programm just continue running without doing anything.
Can anyone help me please on how do we convert from BYTE buffer pointer to an cv::Mat image
EDIT:
Buffer is declared like this : BYTE *Buffer
the function where i get the buffer from is declared like this
void CALLBACK RealDataCallBackEx(LLONG lRealHandle, DWORD dwDataType, BYTE *pBuffer,DWORD dwBufSize, LONG param, LDWORD dwUser)
where:
lRealHandle : Real-time monitoring handle
dwDataType :
0 : Original data which is consistent with data saved by savedRealData
1 : Frame data.
2 : Yuv data.
3 : Pcm audio data.
pBuffer : Buffer for callback data. Data of different length will be called back according to different data type. The data are called back by frame for every type but type 0, and each time one frame is called back.
dwBufSize : Callback data length. The data buffers are diffreent for different types. The unit is BYTE
In my case i always get data type 0
This is how i try to decode then :
cv::Mat img = cv::imdecode(cv::Mat(dwBufSize,CV_8UC3,*pBuffer),cv::IMREAD_COLOR);
cv::Imshow("img",img);
my programm stops here, it continue running but it dosen't do anything after cuz i have put a std::cout here to check if it will pass this line of imshow or not but nothing happens
Thank you.