Spec text fix for primary transformation process (Clause 8.7.4.1)

[xinzhao]

In Draft 5 v10, Clause 8.7.4.1, the output, i.e., (nTbW)x(nTbH) array r[ x ][ y ], is not valued when nTbW is equal to 1. One possible fix is adding the following Step 4, which is described by bold texts.

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The (nTbW)x(nTbH) array r of residual samples is derived as follows:

1. When nTbH is greater than 1, each (vertical) column of scaled transform coefficients d[ x ][ y ] with x = 0..nonZeroW − 1, y = 0..nonZeroH − 1 is transformed to e[ x ][ y ] with x = 0..nonZeroW − 1, y = 0..nTbH − 1 by invoking the one-dimensional transformation process as specified in clause 8.7.4.4 for each column x = 0..nonZeroW − 1 with the height of the transform block nTbH, the non-zero height of the scaled transform coefficients nonZeroH, the list d[ x ][ y ] with y = 0..nonZeroH − 1 and the transform type variable trType set equal to trTypeVer as inputs, and the output is the list e[ x ][ y ] with y = 0..nTbH − 1.
2. When nTbH and nTbW are both greater than 1, the intermediate sample values g[ x ][ y ] with x = 0..nonZeroW − 1, y = 0..nTbH − 1 are derived as follows:

g[ x ][ y ] = Clip3( CoeffMin, CoeffMax, ( e[ x ][ y ] + 64 ) >> 7 ) (8 980)

3. When nTbW is greater than 1, each (horizontal) row of the resulting array g[ x ][ y ] with x = 0..nonZeroW − 1, y = 0..nTbH − 1 is transformed to r[ x ][ y ] with x = 0..nTbW − 1, y = 0..nTbH − 1 by invoking the one-dimensional transformation process as specified in clause 8.7.4.4 for each row y = 0..nTbH − 1 with the width of the transform block nTbW, the non-zero width of the resulting array g[ x ][ y ] nonZeroW, the list g[ x ][ y ] with x = 0..nonZeroW − 1 and the transform type variable trType set equal to trTypeHor as inputs, and the output is the list r[ x ][ y ] with x = 0..nTbW − 1.

4. When nTbW is equal to 1, r[ x ][ y ] is set equal to e[ x ][ y ] with x = 0..nTbW – 1, y = 0..nTbH – 1.
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[bbross]

Will be fixed in vD