Color32[] to byte[] too slow (in c#)

Hi guys,

I have a live video captured from the web camera( done with WebCamTexture), and extracted the data in Color32[] format. Now I would like to convert it to byte[] (by reading the r,g,b value of each pixel one by one and storing it in byte[]), and pass the byte stream into a function defined in a dll file. However, the conversion is quite slow for a 1920*1080 sized video(more than 100ms per frame).
I would like to know:

1 why it is so slow converting from Color32[] to byte []? Is there a faster method?

2 When I pass Color32[] directly into the functions in the dll file, the time becomes even longer (more than 300ms per frame), why does that happen?

3 Are there any better solution to pass the captured video into the function defined in the dll file?

Thanks and wait for ur suggestions!

 

Thanks!
The followed question is, how to recover the image from the "byte* ptr" in "MyNativeFunction"? Especially, if "MyNativeFunction" is written in c++ and wrapped in a dll file, how to recover an image from "byte* ptr" ?

 

Thanks Tau, it realy works.
But there's still one problem:
I restore the image in the function using the following method:

int _DLLExport GetWebcamImg(byte* ImgIn)
{
cv::Mat opencvImage(1080,1920,CV_8UC4);
memcpy(opencvImage.data,ImgIn,1920*1080*4);
cv::cvtColor(opencvImage,opencvImage,CV_BGR2RGB);
}

but the image I obtained is the one that flipped horizontally, why is that please?