internal static void FDCT2D_llm(
Span <float> s,
Span <float> d,
Span <float> temp,
bool downscaleBy8 = false,
bool subtract128FromSource = false)
{
Span <float> sWorker = subtract128FromSource ? s.AddScalarToAllValues(-128f) : s;
for (int j = 0; j < 8; j++)
{
FDCT1Dllm_32f(sWorker.Slice(j * 8), temp.Slice(j * 8));
}
Transpose8x8(temp, d);
for (int j = 0; j < 8; j++)
{
FDCT1Dllm_32f(d.Slice(j * 8), temp.Slice(j * 8));
}
Transpose8x8(temp, d);
if (downscaleBy8)
{
for (int j = 0; j < 64; j++)
{
d[j] *= 0.125f;
}
}
}
public void ForwardThenInverse(int seed, int startAt)
{
Span <int> original = Create8x8RandomIntData(-200, 200, seed);
Span <int> block = original.AddScalarToAllValues(128);
ReferenceImplementations.StandardIntegerDCT.Subtract128_TransformFDCT_Upscale8_Inplace(block);
for (int i = 0; i < 64; i++)
{
block[i] /= 8;
}
ReferenceImplementations.StandardIntegerDCT.TransformIDCTInplace(block);
for (int i = startAt; i < 64; i++)
{
float expected = original[i];
float actual = block[i];
Assert.Equal(expected, actual, new ApproximateFloatComparer(3f));
}
}