protected override bool DoIntraPrediction(YuvFrameBuffer codedFrameBuffer, int[][] mpCb, int[][] mpCr)
{
var maxW = Macroblock.MbChromaWidth;
var maxH = Macroblock.MbChromaHeight;
if (!access.IsLeftAvailable(maxH)) return false;
var p = new Point();
// predC[ x, y ] = p[ -1, y ],
// with x = 0..MbWidthC - 1 and y = 0..MbHeightC - 1
for (var i = 0; i < maxH; i++)
{
access.GetNeighbour(-1, i, maxW, maxH, p);
for (var j = 0; j < maxW; j++)
{
mpCb[i][j] = codedFrameBuffer.GetCb8Bit(p.X, p.Y);
mpCr[i][j] = codedFrameBuffer.GetCr8Bit(p.X, p.Y);
}
}
return true;
}
protected override bool DoIntraPrediction(YuvFrameBuffer codedFrameBuffer, int[][] mpCb, int[][] mpCr)
{
var p = new Point();
var maxW = Macroblock.MbChromaWidth;
var maxH = Macroblock.MbChromaHeight;
var upAvail = access.IsUpAvailable(maxW);
var leftAvail = access.IsLeftAvailable(maxH);
// For each chroma block of 4x4 samples indexed by
// chroma4x4BlkIdx = 0..( 1 << ( ChromaArrayType + 1 ) ) – 1
for (var chroma4X4BlkIdx = 0; chroma4X4BlkIdx < 4; chroma4X4BlkIdx++)
{
var predCb = 0;
var predCr = 0;
var sumUpCb = 0;
var sumUpCr = 0;
var sumLeftCb = 0;
var sumLeftCr = 0;
var xO = PosX(chroma4X4BlkIdx);
var yO = PosY(chroma4X4BlkIdx);
// sum(x' = 0 to 3) { p[x' + xO, -1] }
if (upAvail)
{
for (var i = 0; i < ChromaBlkWidth; i++)
{
access.GetNeighbour(i, -1, maxW, maxH, p);
sumUpCb += codedFrameBuffer.GetCb8Bit(p.X + xO, p.Y);
sumUpCr += codedFrameBuffer.GetCr8Bit(p.X + xO, p.Y);
}
}
// sum(y' = 0 to 3) { p[-1, y' + yO] }
if (leftAvail)
{
for (var i = 0; i < ChromaBlkHeight; i++)
{
access.GetNeighbour(-1, i, maxW, maxH, p);
sumLeftCb += codedFrameBuffer.GetCb8Bit(p.X, p.Y + yO);
sumLeftCr += codedFrameBuffer.GetCr8Bit(p.X, p.Y + yO);
}
}
// TOP-LEFT and BOTTOM-RIGHT
if (((xO == 0) && (yO == 0)) || ((xO > 0) && (yO > 0)))
{
if (upAvail && leftAvail)
{
// predC[x+xO, y+yO] = (sumUp + sumLeft + 4) >> 3
predCb = (sumUpCb + sumLeftCb + 4) >> 3;
predCr = (sumUpCr + sumLeftCr + 4) >> 3;
}
else if (leftAvail)
{
// predC[x+xO, y+yO] = (sumLeft + 2) >> 2
predCb = (sumLeftCb + 2) >> 2;
predCr = (sumLeftCr + 2) >> 2;
}
else if (upAvail)
{
// predC[x+xO, y+yO] = (sumUp + 2) >> 2
predCb = (sumUpCb + 2) >> 2;
predCr = (sumUpCr + 2) >> 2;
}
else
{
// predC[x+xO, y+yO] = (1 << ( BitDepthC – 1 ))
predCb = 1 << (bitDepthC - 1);
predCr = 1 << (bitDepthC - 1);
}
} // TOP-RIGHT
else if ((xO > 0) && (yO == 0))
{
if (upAvail)
{
// predC[x+xO, y+yO] = (sumUp + 2) >> 2
predCb = (sumUpCb + 2) >> 2;
predCr = (sumUpCr + 2) >> 2;
}
else if (leftAvail)
{
// predC[x+xO, y+yO] = (sumLeft + 2) >> 2
predCb = (sumLeftCb + 2) >> 2;
predCr = (sumLeftCr + 2) >> 2;
}
else
{
// predC[x+xO, y+yO] = (1 << ( BitDepthC – 1 ))
predCb = 1 << (bitDepthC - 1);
predCr = 1 << (bitDepthC - 1);
}
} // BOTTOM-LEFT
else if ((xO == 0) && (yO > 0))
{
if (leftAvail)
{
// predC[x+xO, y+yO] = (sumLeft + 2) >> 2
predCb = (sumLeftCb + 2) >> 2;
predCr = (sumLeftCr + 2) >> 2;
}
else if (upAvail)
{
// predC[x+xO, y+yO] = (sumUp + 2) >> 2
predCb = (sumUpCb + 2) >> 2;
predCr = (sumUpCr + 2) >> 2;
}
else
{
// predC[x+xO, y+yO] = (1 << ( BitDepthC – 1 ))
predCb = 1 << (bitDepthC - 1);
predCr = 1 << (bitDepthC - 1);
}
}
// store DC prediction
for (var j = yO; j < ChromaBlkHeight + yO; j++)
{
for (var i = xO; i < ChromaBlkWidth + xO; i++)
{
mpCb[j][i] = predCb;
mpCr[j][i] = predCr;
}
}
}
return true;
}
protected override bool DoIntraPrediction(YuvFrameBuffer codedFrameBuffer, int[][] mpCb, int[][] mpCr)
{
var maxW = Macroblock.MbChromaWidth;
var maxH = Macroblock.MbChromaHeight;
var upAvail = access.IsUpAvailable(maxW);
var leftAvail = access.IsLeftAvailable(maxH);
var leftUpAvail = access.IsLeftUpAvailable();
if (!upAvail || !leftAvail || !leftUpAvail)
return false;
// Note: used (chroma_block_width >> 1) instead of (xCF + 4)
// Note: used (chroma_block_height >> 1) instead of (yCF + 4)
var hCb = 0;
var vCb = 0;
var hCr = 0;
var vCr = 0;
var pUp = new Point();
var pLeft = new Point();
var pLeftUp = new Point();
access.GetNeighbour(0, -1, maxW, maxH, pUp);
access.GetNeighbour(-1, 0, maxW, maxH, pLeft);
access.GetNeighbour(-1, -1, maxW, maxH, pLeftUp);
// H = sum(x' = 0 to (3 + xCF)){ (x'+1) * (p[4 + xCF + x', -1] - p[2 + xCF -x', -1]) }
for (var i = 1; i <= (maxW >> 1); i++)
{
var x = i - 1; // x'
hCb += i*(codedFrameBuffer.GetCb8Bit(pUp.X + (maxW >> 1) + x, pUp.Y) - codedFrameBuffer.GetCb8Bit(pUp.X + (maxW >> 1) - 2 - x, pUp.Y));
hCr += i*(codedFrameBuffer.GetCr8Bit(pUp.X + (maxW >> 1) + x, pUp.Y) - codedFrameBuffer.GetCr8Bit(pUp.X + (maxW >> 1) - 2 - x, pUp.Y));
}
// V = sum(y' = 0 to (3 + yCF)){ (y'+1) * (p[-1, 4 + yCF + y'] - p[-1, 2 + yCF - y']) }
for (var i = 1; i <= (maxH >> 1); i++)
{
var y = i - 1; // y'
vCb += i*(codedFrameBuffer.GetCb8Bit(pLeft.X, pLeft.Y + (maxH >> 1) + y) - codedFrameBuffer.GetCb8Bit(pLeft.X, pLeft.Y + (maxH >> 1) - 2 - y));
vCr += i*(codedFrameBuffer.GetCr8Bit(pLeft.X, pLeft.Y + (maxH >> 1) + y) - codedFrameBuffer.GetCr8Bit(pLeft.X, pLeft.Y + (maxH >> 1) - 2 - y));
}
// a = 16 * ( p[ -1, MbHeightC - 1 ] + p[ MbWidthC - 1, -1 ] )
var aCb = 16*(codedFrameBuffer.GetCb8Bit(pLeft.X, pLeft.Y + maxH - 1) + codedFrameBuffer.GetCb8Bit(pUp.X + maxH - 1, pUp.Y));
var aCr = 16*(codedFrameBuffer.GetCr8Bit(pLeft.X, pLeft.Y + maxH - 1) + codedFrameBuffer.GetCr8Bit(pUp.X + maxH - 1, pUp.Y));
// b = ( ( 34 – 29 * ( ChromaArrayType == 3 ) ) * H + 32 ) >> 6
var bCb = ((maxW == 8 ? 17 : 5)*hCb + 2*maxW) >> (maxW == 8 ? 5 : 6);
var bCr = ((maxW == 8 ? 17 : 5)*hCr + 2*maxW) >> (maxW == 8 ? 5 : 6);
// c = ( ( 34 – 29 * ( ChromaArrayType != 1 ) ) * V + 32 ) >> 6
var cCb = ((maxH == 8 ? 17 : 5)*vCb + 2*maxH) >> (maxH == 8 ? 5 : 6);
var cCr = ((maxH == 8 ? 17 : 5)*vCr + 2*maxH) >> (maxH == 8 ? 5 : 6);
// predC[ x, y ] = Clip1C( ( a + b * ( x – 3 – xCF ) + c * ( y – 3 – yCF ) + 16 ) >> 5 ),
// with x = 0..MbWidthC - 1 and y = 0..MbHeightC - 1
for (var j = 0; j < maxH; j++)
{
for (var i = 0; i < maxW; i++)
{
var predCb = (aCb + (i - (maxW >> 1) + 1)*bCb + (j - (maxH >> 1) + 1)*cCb + 16) >> 5;
var predCr = (aCr + (i - (maxW >> 1) + 1)*bCr + (j - (maxH >> 1) + 1)*cCr + 16) >> 5;
mpCb[j][i] = MathHelper.Clip(maxImagePelValue, predCb);
mpCr[j][i] = MathHelper.Clip(maxImagePelValue, predCr);
}
}
return true;
}
