ess in clause 6.4.7 with chroma4x4BlkIdx as the input and the output being assigned to (xO, yO). Depending on the values of xO and yO, the following applies: If xO, yO ) is equal to ( 0, 0 ) or xO and yO are greater than 0, the values of the prediction samples predc[x + y + ] with X, y=0..3 are derived as follows: If all samples p[x+x0,-1],with X = 0..3, and p[ -1, y +yO ], with y=0..3, are marked as "available for Intra chroma prediction", the values of the prediction samples predc[ x x x O, y + yO with X, y = 0..3, are derived as: y=0..3. (8-132) Otherwise, if any samples p[ X + x0,-1], with X = 0..3, are marked as "not available for Intra chroma prediction" and all samples p[-1,y+yO], with y=0..3, are marked as "available for Intra chroma prediction", the values of the prediction samples predcl xO, y + yO ], with X, y = 0..3, are derived as: =0..3. (8-133) Otherwise, if any samples p[ -1, y +yO], with y=0..3, are marked as "not available for Intra chroma prediction" and all samples p[x+x0,-1], with x=0..3, are marked as "available for Intra chroma prediction", the values of the prediction samples predcl xO, y + yO ], with X, y = 0..3, are derived as: y=0..3. (8-134) Otherwise (some samples p[ X + xO, -1], with X = 0..3, and some samples p[ -1, y +yO ], with y=0..3, = are marked as "not available for Intra chroma prediction"), the values of the prediction samples predc[ xO, y + yO with X, y = 0..3, are derived as: predc[x+xO,y+yO]=(1<<(BitDepthc-1)),withx, y = 0..3. (8-135) Otherwise, if xO is greater than 0 and yO is equal to 0, the values of the prediction samples predc[ + xO, y + yO ] with X, y=0..3 are derived as follows: If all samples p[ X + xO, -1], with X = 0..3, are marked as "available for Intra chroma prediction", the values of the prediction samples predc[ x + xO, y + yO ], with X, y = 0..3, are derived as: Rec. ITU-T H.264 (01/2012) y=0..3. (8-136) Otherwise, if all samples p[ -1, y +yO ], with y = 0..3, are marked as "available for Intra chroma prediction", the values of the prediction samples pre