Encode PBYTE and save as a jpg

Question

I am trying to make an encoder using WIC and replace the old encoder of an application. I could manage to decode and encode using file, but I need to to do that to the bitmap data which is in PBYTE type. I referred msdn and try to use stream still don't
understand how could i do that.
Can anyone show me the steps should i follow.
this is how i tried to do it:
PBYTE pBitmap, // coming as a parameter 
/* Create Com imaging factory */
if (SUCCEEDED(hr))
/* instance with a helper */
hr = CoCreateInstance(
CLSID_WICImagingFactory,
NULL,
CLSCTX_INPROC_SERVER,
IID_PPV_ARGS(&piFactory)
if (SUCCEEDED(hr))
hr = piFactory->CreateStream(&piStream);
if (SUCCEEDED(hr))
DWORD imageFileSize = lHeight * DIBWidthByte;
hr = piStream->InitializeFromMemory(
reinterpret_cast<BYTE*>(pDst),
imageFileSize);
// Create a decoder for the stream. and this gives error (component not found)
if (SUCCEEDED(hr)){
hr = piFactory->CreateDecoderFromStream(
piStream, // The stream to use to create the decoder
NULL, // Do not prefer a particular vendor
WICDecodeMetadataCacheOnLoad, // Cache metadata when needed
&piDecoder); // Pointer to the decoder
From here i was intended to do encoding part as i did using a file. still failed to create a decoder. (or can I just skip the decoding part sins I have image data as PBYTE) 
sorry if I bein silly. Pleas help.

Answer 1

I right click and choose save image