/// <summary>
/// Run the Inverse DCT method on all of the block data
/// </summary>
public void IdctData()
{
foreach (float[][][] t in scanData)
{
for (int v = 0; v < factorV; v++)
{
for (int h = 0; h < factorH; h++)
{
float[] toDecode = t[h][v];
ZigZag.UnZigZag(toDecode, unZZ);
byte[][] decoded = scanDecodedBufferPool.GetNext();
switch (JpegConstants.SelectedIdct)
{
case IdctImplementation.Naive:
dct.DoIDCT_Naive(unZZ, decoded);
break;
case IdctImplementation.AAN:
dct.DoIDCT_AAN(unZZ, quantizationTable, decoded);
break;
case IdctImplementation.NVidia:
dct.DoIDCT_NVidia(unZZ, decoded);
break;
}
scanDecoded.Add(decoded);
}
}
}
}
public void IDCTPerformanceTest()
{
var source = new float[]
{
560, -196, -150, -80, 0, 0, 0, 0,
-210, -60, -35, 0, 0, 0, 0, 0,
-140, -32, -40, 0, 0, 0, 0, 0,
-70, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
const int iterations = 100000;
const int runs = 5;
var naivePerf = new PerformanceMonitor("Naive", runs);
var nvidiaPerf = new PerformanceMonitor("NVidia", runs);
var dct = new DCT(20);
var naive = new byte[8][];
var nvidia = new byte[8][];
for (int i = 0; i < 8; i++)
{
naive[i] = new byte[8];
nvidia[i] = new byte[8];
}
for (int run = 0; run < runs; run++)
{
naivePerf.Start();
for (int i = 0; i < iterations; i++)
{
dct.DoIDCT_Naive(source, naive);
}
naivePerf.Stop();
nvidiaPerf.Start();
for (int i = 0; i < iterations; i++)
{
dct.DoIDCT_NVidia(source, nvidia);
}
nvidiaPerf.Stop();
}
Assert.IsTrue(nvidiaPerf.AverageCompletionTimeInMs < naivePerf.AverageCompletionTimeInMs,
"The NVidia IDCT took {0:0.00} ms, while the naive IDCT took {1:0.00}", nvidiaPerf.AverageCompletionTimeInMs, naivePerf.AverageCompletionTimeInMs);
}
public void IDCTComparisonTest()
{
const int maxVariance = 1;
var source = new float[]
{
560, -196, -150, -80, 0, 0, 0, 0,
-210, -60, -35, 0, 0, 0, 0, 0,
-140, -32, -40, 0, 0, 0, 0, 0,
-70, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
var dct = new DCT(20);
var naive = new byte[8][];
var nvidia = new byte[8][];
for (int i = 0; i < 8; i++)
{
naive[i] = new byte[8];
nvidia[i] = new byte[8];
}
dct.DoIDCT_Naive(source, naive);
dct.DoIDCT_NVidia(source, nvidia);
for (int i = 0; i < 8; i++)
{
for (int j = 0; j < 8; j++)
{
int diff = Math.Abs(naive[i][j] - nvidia[i][j]);
// Debug.WriteLine("diff={0}", diff);
Assert.IsTrue(diff <= maxVariance);
}
}
}