This Intra 16x16 prediction mode operates, depending on whether the neighbouring samples are marked as "available for intra_16x16 prediction", as follows: Rec. ITU-T H.264 (01/2012) If all neighbouring samples p[ X, -1 ], with X = 0..15, and p[ (-1,y], with y = 0..15, are marked as "available for Intra_16x16 prediction", the prediction for all luma samples in the macroblock is given by: (8-118) Otherwise, if any of the neighbouring samples pl X, -1], with X = 0..15, are marked as "not available for Intra_16x16 prediction" and all of the neighbouring samples p[ -1, y ], with y = 0..15, are marked as "available for atra_16x16 prediction", the prediction for all luma samples in the macroblock is given by: X, X, y = 0..15 (8-119) Otherwise, if any of the neighbouring samples p[ -1, y ], with y = 0..15, are marked as "not available for Intra_16x16 prediction" and all of the neighbouring samples p[ X, -1], with X = 0..15, are marked as "available for 16x16 prediction", the prediction for all luma samples in the macroblock is given by: 0..15 (8-120) Otherwise (some of the neighbouring samples p[ X, -1], with X = 0..15, and some of the neighbouring samples p[-1,y ], with y = 0..15, are marked as "not available for Intra_16x16 prediction"), the prediction for all luma samples in the macroblock is given by: redL[x,y]=(1<<(BitDepthy-1)),with - X, y = 0..15 (8-121) 8.3.3.4 Specification of Intra_16x16_Plane prediction mode This Intra_16x16 prediction mode shall be used only when the samples p[ X, -1] with X = -1..15 and -1, y ] with y = 0..15 are marked as "available for Intra_16x16 prediction". The values of the prediction samples predL[ X, y ], with X, y = 0..15, are derived by = 0..15, (8-122) where a =16*(p[-1,15]+p[15,-1]) (8-123) ==(5*H+32)>> (8-124) c=(5*V+32)>>( (8-125) and H and V are specified as (8-126) (8-127) 8.3.4 Intra prediction process for chroma samples This process is invoked for I and SI macroblock types. It specifies how the Intra prediction chroma samples for the current macroblock are derived. Inputs t