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Last week I was reading the motion compensation part of the specification,
I noticed a few typos/bugs while reading. Here are the notes I made. I hope
this will help you improve the specification.
On page 77, section 8.5.5:
1) "specifies the process wt(i,j,x,y)" this should be "specifies the process spatial_wt(i,j,x,y)"
2) "ypos = x - (i * ybsep - yoffset)" this should be: "ypos = y - (i * ybsep - yoffset)"
3) "WH[xpos] = ... , max_x)" should be "WH[xpos] = ... , 0, max_x)" (one argument is missing)
4) In the definition of WV: "WH[ypos] = max_y" this should be: "WV[ypos] = max_y"
this is used on two lines
5) i == state[blocks_x] and j == state[blocks_y]
I think this should be blocks_x - 1 and blocks_y - 1. For example i start at 0, the
last block index is blocks_x - 1, if I am not mistaken.
On page 81, section 22.214.171.124:
6) For clipping you use "height(ref)" (this is done twice). This should be: "width(ref2)", if
I am not mistaken.
Using the specification and with the changes I proposed I was able to implement a functional decoder
that is slow and due to some bugs there are some minor visual problems. But now you know it is possible
to write a functional decoder using the CVS version of the specification :-).
Thanks a lot for writing such a good and detailed specification :-).
Thanks for the comments - and we're really glad you've done this project :-)