public static void FDCT8x4_LeftPart(ref JpegBlock8x8F s, ref JpegBlock8x8F d)
{
Vector4 c0 = s.V0L;
Vector4 c1 = s.V7L;
Vector4 t0 = c0 + c1;
Vector4 t7 = c0 - c1;
c1 = s.V6L;
c0 = s.V1L;
Vector4 t1 = c0 + c1;
Vector4 t6 = c0 - c1;
c1 = s.V5L;
c0 = s.V2L;
Vector4 t2 = c0 + c1;
Vector4 t5 = c0 - c1;
c0 = s.V3L;
c1 = s.V4L;
Vector4 t3 = c0 + c1;
Vector4 t4 = c0 - c1;
c0 = t0 + t3;
Vector4 c3 = t0 - t3;
c1 = t1 + t2;
Vector4 c2 = t1 - t2;
d.V0L = c0 + c1;
d.V4L = c0 - c1;
float w0 = 0.541196f;
float w1 = 1.306563f;
d.V2L = (w0 * c2) + (w1 * c3);
d.V6L = (w0 * c3) - (w1 * c2);
w0 = 1.175876f;
w1 = 0.785695f;
c3 = (w0 * t4) + (w1 * t7);
c0 = (w0 * t7) - (w1 * t4);
w0 = 1.387040f;
w1 = 0.275899f;
c2 = (w0 * t5) + (w1 * t6);
c1 = (w0 * t6) - (w1 * t5);
d.V3L = c0 - c2;
d.V5L = c3 - c1;
float invsqrt2 = 0.707107f;
c0 = (c0 + c2) * invsqrt2;
c3 = (c3 + c1) * invsqrt2;
d.V1L = c0 + c3;
d.V7L = c0 - c3;
}
public static void FDCT8x4_RightPart(ref JpegBlock8x8F s, ref JpegBlock8x8F d)
{
Vector4 c0 = s.V0R;
Vector4 c1 = s.V7R;
Vector4 t0 = c0 + c1;
Vector4 t7 = c0 - c1;
c1 = s.V6R;
c0 = s.V1R;
Vector4 t1 = c0 + c1;
Vector4 t6 = c0 - c1;
c1 = s.V5R;
c0 = s.V2R;
Vector4 t2 = c0 + c1;
Vector4 t5 = c0 - c1;
c0 = s.V3R;
c1 = s.V4R;
Vector4 t3 = c0 + c1;
Vector4 t4 = c0 - c1;
c0 = t0 + t3;
Vector4 c3 = t0 - t3;
c1 = t1 + t2;
Vector4 c2 = t1 - t2;
d.V0R = c0 + c1;
d.V4R = c0 - c1;
float w0 = 0.541196f;
float w1 = 1.306563f;
d.V2R = (w0 * c2) + (w1 * c3);
d.V6R = (w0 * c3) - (w1 * c2);
w0 = 1.175876f;
w1 = 0.785695f;
c3 = (w0 * t4) + (w1 * t7);
c0 = (w0 * t7) - (w1 * t4);
w0 = 1.387040f;
w1 = 0.275899f;
c2 = (w0 * t5) + (w1 * t6);
c1 = (w0 * t6) - (w1 * t5);
d.V3R = c0 - c2;
d.V5R = c3 - c1;
c0 = (c0 + c2) * InvSqrt2;
c3 = (c3 + c1) * InvSqrt2;
d.V1R = c0 + c3;
d.V7R = c0 - c3;
}
public static void IDCT8x4_LeftPart(ref JpegBlock8x8F s, ref JpegBlock8x8F d)
{
Vector4 my1 = s.V1L;
Vector4 my7 = s.V7L;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3L;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5L;
Vector4 mz1 = my3 + my5;
Vector4 mz3 = my1 + my5;
Vector4 mz4 = (mz0 + mz1) * C_1_175876;
mz2 = (mz2 * C_1_961571) + mz4;
mz3 = (mz3 * C_0_390181) + mz4;
mz0 = mz0 * C_0_899976;
mz1 = mz1 * C_2_562915;
Vector4 mb3 = (my7 * C_0_298631) + mz0 + mz2;
Vector4 mb2 = (my5 * C_2_053120) + mz1 + mz3;
Vector4 mb1 = (my3 * C_3_072711) + mz1 + mz2;
Vector4 mb0 = (my1 * C_1_501321) + mz0 + mz3;
Vector4 my2 = s.V2L;
Vector4 my6 = s.V6L;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0L;
Vector4 my4 = s.V4L;
mz0 = my0 + my4;
mz1 = my0 - my4;
mz2 = mz4 + (my6 * C_1_847759);
mz3 = mz4 + (my2 * C_0_765367);
my0 = mz0 + mz3;
my3 = mz0 - mz3;
my1 = mz1 + mz2;
my2 = mz1 - mz2;
d.V0L = my0 + mb0;
d.V7L = my0 - mb0;
d.V1L = my1 + mb1;
d.V6L = my1 - mb1;
d.V2L = my2 + mb2;
d.V5L = my2 - mb2;
d.V3L = my3 + mb3;
d.V4L = my3 - mb3;
}
public static void TransformIDCT(ref JpegBlock8x8F src, ref JpegBlock8x8F dest, ref JpegBlock8x8F temp)
{
// TODO: Transpose is a bottleneck now. We need full AVX support to optimize it:
// https://github.com/dotnet/corefx/issues/22940
src.TransposeInto(ref temp);
IDCT8x4_LeftPart(ref temp, ref dest);
IDCT8x4_RightPart(ref temp, ref dest);
dest.TransposeInto(ref temp);
IDCT8x4_LeftPart(ref temp, ref dest);
IDCT8x4_RightPart(ref temp, ref dest);
// TODO: What if we leave the blocks in a scaled-by-x8 state until final color packing?
dest.MultiplyInplace(C_0_125);
}
public static void TransformFDCT(
ref JpegBlock8x8F src,
ref JpegBlock8x8F dest,
ref JpegBlock8x8F temp)
{
src.TransposeInto(ref temp);
FDCT8x4_LeftPart(ref temp, ref dest);
FDCT8x4_RightPart(ref temp, ref dest);
dest.TransposeInto(ref temp);
FDCT8x4_LeftPart(ref temp, ref dest);
FDCT8x4_RightPart(ref temp, ref dest);
dest.MultiplyInplace(C_0_125);
}
public static void TransformFDCT(
ref JpegBlock8x8F src,
ref JpegBlock8x8F dest,
ref JpegBlock8x8F temp,
bool offsetSourceByNeg128)
{
src.TransposeInto(ref temp);
if (offsetSourceByNeg128)
{
temp.AddToAllInplace(new Vector4(-128));
}
FDCT8x4_LeftPart(ref temp, ref dest);
FDCT8x4_RightPart(ref temp, ref dest);
dest.TransposeInto(ref temp);
FDCT8x4_LeftPart(ref temp, ref dest);
FDCT8x4_RightPart(ref temp, ref dest);
dest.MultiplyInplace(C_0_125);
}
internal void CopyTo(ref JpegBlock8x8F block)
{
ref short srcRef = ref _data[0];
