Ok, I understand the Bayer pattern of RGBG. My question is just to be clear on how to read the dimensions.
By printing out:

raw2image(): imgdata.image[ 0 ][0 to 3] = | 2141 | 0 | 0 | 0
raw2image(): imgdata.image[ 1 ][0 to 3] = | 0 | 2098 | 0 | 0
raw2image(): imgdata.image[ 2 ][0 to 3] = | 2034 | 0 | 0 | 0
raw2image(): imgdata.image[ 3 ][0 to 3] = | 0 | 2084 | 0 | 0

Which dimension is going across the R G B G values. At first I thought it was [0 to 3] (2nd dimensions, "columns") which was giving the R G B G (which I abusively call the "channels"). Is that the other way round? Are they, in fact, in the 1st dimension (rows)? I'm often confused on the dimension when I see tables of pointers such as:
imgdata.image = (ushort (*)[4]) calloc(S.iwidth*S.iheight,sizeof(*imgdata.image));

You didn't say anything about the other question:

dcraw_processed(): imgdata.image[ 0 ][0 to 3] = | 1576 | 0 | 688 | 0

Is the row here the demosaiced RGB values of a given pixel (from left to right column) ?

Thanks