private static short[] GetFinalBuffer(int[] Buffer)
{
short[] Output = new short[Buffer.Length];
for (int Offset = 0; Offset < Buffer.Length; Offset++)
{
Output[Offset] = DspUtils.Saturate(Buffer[Offset]);
}
return(Output);
}
private unsafe static short[] GetFinalBuffer(int[] buffer)
{
short[] output = new short[buffer.Length];
int offset = 0;
// Perform Saturation using SSE2 if supported
if (Sse2.IsSupported)
{
fixed(int *inptr = buffer)
fixed(short *outptr = output)
{
for (; offset + 32 <= buffer.Length; offset += 32)
{
// Unroll the loop a little to ensure the CPU pipeline
// is always full.
Vector128 <int> block1A = Sse2.LoadVector128(inptr + offset + 0);
Vector128 <int> block1B = Sse2.LoadVector128(inptr + offset + 4);
Vector128 <int> block2A = Sse2.LoadVector128(inptr + offset + 8);
Vector128 <int> block2B = Sse2.LoadVector128(inptr + offset + 12);
Vector128 <int> block3A = Sse2.LoadVector128(inptr + offset + 16);
Vector128 <int> block3B = Sse2.LoadVector128(inptr + offset + 20);
Vector128 <int> block4A = Sse2.LoadVector128(inptr + offset + 24);
Vector128 <int> block4B = Sse2.LoadVector128(inptr + offset + 28);
Vector128 <short> output1 = Sse2.PackSignedSaturate(block1A, block1B);
Vector128 <short> output2 = Sse2.PackSignedSaturate(block2A, block2B);
Vector128 <short> output3 = Sse2.PackSignedSaturate(block3A, block3B);
Vector128 <short> output4 = Sse2.PackSignedSaturate(block4A, block4B);
Sse2.Store(outptr + offset + 0, output1);
Sse2.Store(outptr + offset + 8, output2);
Sse2.Store(outptr + offset + 16, output3);
Sse2.Store(outptr + offset + 24, output4);
}
}
}
// Process left overs
for (; offset < buffer.Length; offset++)
{
output[offset] = DspUtils.Saturate(buffer[offset]);
}
return(output);
}
public static int[] Decode(byte[] Buffer, AdpcmDecoderContext Context)
{
int Samples = GetSamplesCountFromSize(Buffer.Length);
int[] Pcm = new int[Samples * 2];
short History0 = Context.History0;
short History1 = Context.History1;
int InputOffset = 0;
int OutputOffset = 0;
while (InputOffset < Buffer.Length)
{
byte Header = Buffer[InputOffset++];
int Scale = 0x800 << (Header & 0xf);
int CoeffIndex = (Header >> 4) & 7;
short Coeff0 = Context.Coefficients[CoeffIndex * 2 + 0];
short Coeff1 = Context.Coefficients[CoeffIndex * 2 + 1];
int FrameSamples = SamplesPerFrame;
if (FrameSamples > Samples)
{
FrameSamples = Samples;
}
int Value = 0;
for (int SampleIndex = 0; SampleIndex < FrameSamples; SampleIndex++)
{
int Sample;
if ((SampleIndex & 1) == 0)
{
Value = Buffer[InputOffset++];
Sample = (Value << 24) >> 28;
}
else
{
Sample = (Value << 28) >> 28;
}
int Prediction = Coeff0 * History0 + Coeff1 * History1;
Sample = (Sample * Scale + Prediction + 0x400) >> 11;
short SaturatedSample = DspUtils.Saturate(Sample);
History1 = History0;
History0 = SaturatedSample;
Pcm[OutputOffset++] = SaturatedSample;
Pcm[OutputOffset++] = SaturatedSample;
}
Samples -= FrameSamples;
}
Context.History0 = History0;
Context.History1 = History1;
return(Pcm);
}
