tsai
/
ImageSharp
mirror of https://github.com/SixLabors/ImageSharp
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Tidied up DCT code

pull/1761/head
Dmitry Pentin 5 years ago
parent
2f143bf9d3
commit
fb038aaf3c
3 changed files with 284 additions and 302 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 109
      src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs
  2. 230
      src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.Intrinsic.cs
  3. 247
      src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.cs

109
src/ImageSharp/Formats/Jpeg/Components/Block8x8F.cs
View File

@ -450,21 +450,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
a.V7R *= b.V7R; a.V7R *= b.V7R;
} }
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static Vector4 DivideRound(Vector4 dividend, Vector4 divisor)
{
var neg = new Vector4(-1);
var add = new Vector4(.5F);
// sign(dividend) = max(min(dividend, 1), -1)
Vector4 sign = Numerics.Clamp(dividend, neg, Vector4.One);
// AlmostRound(dividend/divisor) = dividend/divisor + 0.5*sign(dividend)
// TODO: This is wrong but I have no idea how to fix it without if-else operator
// sign here is a value in range [-1..1], it can be equal to -0.2 for example which is wrong
return (dividend / divisor) + (sign * add);
}
public void RoundInto(ref Block8x8 dest) public void RoundInto(ref Block8x8 dest)
{ {
for (int i = 0; i < Size; i++) for (int i = 0; i < Size; i++)
@ -562,6 +547,47 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
Unsafe.Add(ref dRef, 7) = bottom; Unsafe.Add(ref dRef, 7) = bottom;
} }
/// <summary>
/// Compares entire 8x8 block to a single scalar value.
/// </summary>
/// <param name="value">Value to compare to.</param>
public bool EqualsToScalar(int value)
{
#if SUPPORTS_RUNTIME_INTRINSICS
if (Avx2.IsSupported)
{
const int equalityMask = unchecked((int)0b1111_1111_1111_1111_1111_1111_1111_1111);
var targetVector = Vector256.Create(value);
ref Vector256<float> blockStride = ref this.V0;
for (int i = 0; i < RowCount; i++)
{
Vector256<int> areEqual = Avx2.CompareEqual(Avx.ConvertToVector256Int32WithTruncation(Unsafe.Add(ref this.V0, i)), targetVector);
if (Avx2.MoveMask(areEqual.AsByte()) != equalityMask)
{
return false;
}
}
return true;
}
#endif
{
ref float scalars = ref Unsafe.As<Block8x8F, float>(ref this);
for (int i = 0; i < Size; i++)
{
if ((int)Unsafe.Add(ref scalars, i) != value)
{
return false;
}
}
return true;
}
}
/// <inheritdoc /> /// <inheritdoc />
public bool Equals(Block8x8F other) public bool Equals(Block8x8F other)
=> this.V0L == other.V0L => this.V0L == other.V0L
@ -598,15 +624,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
return sb.ToString(); return sb.ToString();
} }
[MethodImpl(InliningOptions.ShortMethod)]
private static Vector<float> NormalizeAndRound(Vector<float> row, Vector<float> off, Vector<float> max)
{
row += off;
row = Vector.Max(row, Vector<float>.Zero);
row = Vector.Min(row, max);
return row.FastRound();
}
/// <summary> /// <summary>
/// Transpose the block inplace. /// Transpose the block inplace.
/// </summary> /// </summary>
@ -650,45 +667,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
} }
} }
/// <summary> [MethodImpl(InliningOptions.ShortMethod)]
/// Compares entire 8x8 block to a single scalar value. private static Vector<float> NormalizeAndRound(Vector<float> row, Vector<float> off, Vector<float> max)
/// </summary>
/// <param name="value">Value to compare to.</param>
public bool EqualsToScalar(int value)
{ {
#if SUPPORTS_RUNTIME_INTRINSICS row += off;
if (Avx2.IsSupported) row = Vector.Max(row, Vector<float>.Zero);
{ row = Vector.Min(row, max);
const int equalityMask = unchecked((int)0b1111_1111_1111_1111_1111_1111_1111_1111); return row.FastRound();
var targetVector = Vector256.Create(value);
ref Vector256<float> blockStride = ref this.V0;
for (int i = 0; i < RowCount; i++)
{
Vector256<int> areEqual = Avx2.CompareEqual(Avx.ConvertToVector256Int32WithTruncation(Unsafe.Add(ref this.V0, i)), targetVector);
if (Avx2.MoveMask(areEqual.AsByte()) != equalityMask)
{
return false;
}
}
return true;
}
#endif
{
ref float scalars = ref Unsafe.As<Block8x8F, float>(ref this);
for (int i = 0; i < Size; i++)
{
if ((int)Unsafe.Add(ref scalars, i) != value)
{
return false;
}
}
return true;
}
} }
} }
} }

230
src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.Intrinsic.cs
View File

@ -14,6 +14,30 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
{ {
internal static partial class FastFloatingPointDCT internal static partial class FastFloatingPointDCT
{ {
#pragma warning disable SA1310, SA1311, IDE1006 // naming rules violation warnings
private static readonly Vector256<float> mm256_F_0_7071 = Vector256.Create(0.707106781f);
private static readonly Vector256<float> mm256_F_0_3826 = Vector256.Create(0.382683433f);
private static readonly Vector256<float> mm256_F_0_5411 = Vector256.Create(0.541196100f);
private static readonly Vector256<float> mm256_F_1_3065 = Vector256.Create(1.306562965f);
private static readonly Vector128<float> mm128_F_0_7071 = Vector128.Create(0.707106781f);
private static readonly Vector128<float> mm128_F_0_3826 = Vector128.Create(0.382683433f);
private static readonly Vector128<float> mm128_F_0_5411 = Vector128.Create(0.541196100f);
private static readonly Vector128<float> mm128_F_1_3065 = Vector128.Create(1.306562965f);
private static readonly Vector256<float> mm256_F_1_1758 = Vector256.Create(1.175876f);
private static readonly Vector256<float> mm256_F_n1_9615 = Vector256.Create(-1.961570560f);
private static readonly Vector256<float> mm256_F_n0_3901 = Vector256.Create(-0.390180644f);
private static readonly Vector256<float> mm256_F_n0_8999 = Vector256.Create(-0.899976223f);
private static readonly Vector256<float> mm256_F_n2_5629 = Vector256.Create(-2.562915447f);
private static readonly Vector256<float> mm256_F_0_2986 = Vector256.Create(0.298631336f);
private static readonly Vector256<float> mm256_F_2_0531 = Vector256.Create(2.053119869f);
private static readonly Vector256<float> mm256_F_3_0727 = Vector256.Create(3.072711026f);
private static readonly Vector256<float> mm256_F_1_5013 = Vector256.Create(1.501321110f);
private static readonly Vector256<float> mm256_F_n1_8477 = Vector256.Create(-1.847759065f);
private static readonly Vector256<float> mm256_F_0_7653 = Vector256.Create(0.765366865f);
#pragma warning restore SA1310, SA1311, IDE1006
/// <summary> /// <summary>
/// Gets reciprocal coefficients for jpeg quantization tables calculation. /// Gets reciprocal coefficients for jpeg quantization tables calculation.
/// </summary> /// </summary>
@ -50,18 +74,6 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
0.45306373f, 0.32664075f, 0.34675997f, 0.38529903f, 0.45306373f, 0.5766407f, 0.8371526f, 1.642134f, 0.45306373f, 0.32664075f, 0.34675997f, 0.38529903f, 0.45306373f, 0.5766407f, 0.8371526f, 1.642134f,
}; };
#pragma warning disable SA1310, SA1311, IDE1006 // naming rules violation warnings
private static readonly Vector256<float> mm256_F_0_7071 = Vector256.Create(0.707106781f);
private static readonly Vector256<float> mm256_F_0_3826 = Vector256.Create(0.382683433f);
private static readonly Vector256<float> mm256_F_0_5411 = Vector256.Create(0.541196100f);
private static readonly Vector256<float> mm256_F_1_3065 = Vector256.Create(1.306562965f);
private static readonly Vector128<float> mm128_F_0_7071 = Vector128.Create(0.707106781f);
private static readonly Vector128<float> mm128_F_0_3826 = Vector128.Create(0.382683433f);
private static readonly Vector128<float> mm128_F_0_5411 = Vector128.Create(0.541196100f);
private static readonly Vector128<float> mm128_F_1_3065 = Vector128.Create(1.306562965f);
#pragma warning restore SA1310, SA1311, IDE1006
/// <summary> /// <summary>
/// Apply floating point FDCT inplace using simd operations. /// Apply floating point FDCT inplace using simd operations.
/// </summary> /// </summary>
@ -205,6 +217,200 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
block.V1 = Avx.Add(z11, z4); block.V1 = Avx.Add(z11, z4);
block.V7 = Avx.Subtract(z11, z4); block.V7 = Avx.Subtract(z11, z4);
} }
/// <summary>
/// Performs 8x8 matrix Inverse Discrete Cosine Transform
/// </summary>
/// <param name="s">Source</param>
/// <param name="d">Destination</param>
public static void IDCT8x8(ref Block8x8F s, ref Block8x8F d)
{
#if SUPPORTS_RUNTIME_INTRINSICS
if (Avx.IsSupported)
{
IDCT8x8_Avx(ref s, ref d);
}
else
#endif
{
IDCT8x4_LeftPart(ref s, ref d);
IDCT8x4_RightPart(ref s, ref d);
}
}
/// <summary>
/// Do IDCT internal operations on the left part of the block. Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">Destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_LeftPart(ref Block8x8F s, ref Block8x8F 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;
}
/// <summary>
/// Do IDCT internal operations on the right part of the block.
/// Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">The destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_RightPart(ref Block8x8F s, ref Block8x8F d)
{
Vector4 my1 = s.V1R;
Vector4 my7 = s.V7R;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3R;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5R;
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.V2R;
Vector4 my6 = s.V6R;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0R;
Vector4 my4 = s.V4R;
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.V0R = my0 + mb0;
d.V7R = my0 - mb0;
d.V1R = my1 + mb1;
d.V6R = my1 - mb1;
d.V2R = my2 + mb2;
d.V5R = my2 - mb2;
d.V3R = my3 + mb3;
d.V4R = my3 - mb3;
}
/// <summary>
/// Combined operation of <see cref="IDCT8x4_LeftPart(ref Block8x8F, ref Block8x8F)"/> and <see cref="IDCT8x4_RightPart(ref Block8x8F, ref Block8x8F)"/>
/// using AVX commands.
/// </summary>
/// <param name="s">Source</param>
/// <param name="d">Destination</param>
public static void IDCT8x8_Avx(ref Block8x8F s, ref Block8x8F d)
{
#if SUPPORTS_RUNTIME_INTRINSICS
Debug.Assert(Avx.IsSupported, "AVX is required to execute this method");
Vector256<float> my1 = s.V1;
Vector256<float> my7 = s.V7;
Vector256<float> mz0 = Avx.Add(my1, my7);
Vector256<float> my3 = s.V3;
Vector256<float> mz2 = Avx.Add(my3, my7);
Vector256<float> my5 = s.V5;
Vector256<float> mz1 = Avx.Add(my3, my5);
Vector256<float> mz3 = Avx.Add(my1, my5);
Vector256<float> mz4 = Avx.Multiply(Avx.Add(mz0, mz1), mm256_F_1_1758);
mz2 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, mz2, mm256_F_n1_9615);
mz3 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, mz3, mm256_F_n0_3901);
mz0 = Avx.Multiply(mz0, mm256_F_n0_8999);
mz1 = Avx.Multiply(mz1, mm256_F_n2_5629);
Vector256<float> mb3 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz0, my7, mm256_F_0_2986), mz2);
Vector256<float> mb2 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz1, my5, mm256_F_2_0531), mz3);
Vector256<float> mb1 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz1, my3, mm256_F_3_0727), mz2);
Vector256<float> mb0 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz0, my1, mm256_F_1_5013), mz3);
Vector256<float> my2 = s.V2;
Vector256<float> my6 = s.V6;
mz4 = Avx.Multiply(Avx.Add(my2, my6), mm256_F_0_5411);
Vector256<float> my0 = s.V0;
Vector256<float> my4 = s.V4;
mz0 = Avx.Add(my0, my4);
mz1 = Avx.Subtract(my0, my4);
mz2 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, my6, mm256_F_n1_8477);
mz3 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, my2, mm256_F_0_7653);
my0 = Avx.Add(mz0, mz3);
my3 = Avx.Subtract(mz0, mz3);
my1 = Avx.Add(mz1, mz2);
my2 = Avx.Subtract(mz1, mz2);
d.V0 = Avx.Add(my0, mb0);
d.V7 = Avx.Subtract(my0, mb0);
d.V1 = Avx.Add(my1, mb1);
d.V6 = Avx.Subtract(my1, mb1);
d.V2 = Avx.Add(my2, mb2);
d.V5 = Avx.Subtract(my2, mb2);
d.V3 = Avx.Add(my3, mb3);
d.V4 = Avx.Subtract(my3, mb3);
#endif
}
} }
} }
#endif #endif

247
src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.cs
View File

@ -43,216 +43,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
private const float C_0_765367 = 0.765366865f; private const float C_0_765367 = 0.765366865f;
private const float C_0_125 = 0.1250f; private const float C_0_125 = 0.1250f;
#if SUPPORTS_RUNTIME_INTRINSICS
private static readonly Vector256<float> C_V_0_5411 = Vector256.Create(0.541196f);
private static readonly Vector256<float> C_V_1_1758 = Vector256.Create(1.175876f);
private static readonly Vector256<float> C_V_n1_9615 = Vector256.Create(-1.961570560f);
private static readonly Vector256<float> C_V_n0_3901 = Vector256.Create(-0.390180644f);
private static readonly Vector256<float> C_V_n0_8999 = Vector256.Create(-0.899976223f);
private static readonly Vector256<float> C_V_n2_5629 = Vector256.Create(-2.562915447f);
private static readonly Vector256<float> C_V_0_2986 = Vector256.Create(0.298631336f);
private static readonly Vector256<float> C_V_2_0531 = Vector256.Create(2.053119869f);
private static readonly Vector256<float> C_V_3_0727 = Vector256.Create(3.072711026f);
private static readonly Vector256<float> C_V_1_5013 = Vector256.Create(1.501321110f);
private static readonly Vector256<float> C_V_n1_8477 = Vector256.Create(-1.847759065f);
private static readonly Vector256<float> C_V_0_7653 = Vector256.Create(0.765366865f);
#endif
#pragma warning restore SA1310 // FieldNamesMustNotContainUnderscore #pragma warning restore SA1310 // FieldNamesMustNotContainUnderscore
/// <summary>
/// Performs 8x8 matrix Inverse Discrete Cosine Transform
/// </summary>
/// <param name="s">Source</param>
/// <param name="d">Destination</param>
public static void IDCT8x8(ref Block8x8F s, ref Block8x8F d)
{
#if SUPPORTS_RUNTIME_INTRINSICS
if (Avx.IsSupported)
{
IDCT8x8_Avx(ref s, ref d);
}
else
#endif
{
IDCT8x4_LeftPart(ref s, ref d);
IDCT8x4_RightPart(ref s, ref d);
}
}
/// <summary>
/// Do IDCT internal operations on the left part of the block. Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">Destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_LeftPart(ref Block8x8F s, ref Block8x8F 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;
}
/// <summary>
/// Do IDCT internal operations on the right part of the block.
/// Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">The destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_RightPart(ref Block8x8F s, ref Block8x8F d)
{
Vector4 my1 = s.V1R;
Vector4 my7 = s.V7R;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3R;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5R;
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.V2R;
Vector4 my6 = s.V6R;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0R;
Vector4 my4 = s.V4R;
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.V0R = my0 + mb0;
d.V7R = my0 - mb0;
d.V1R = my1 + mb1;
d.V6R = my1 - mb1;
d.V2R = my2 + mb2;
d.V5R = my2 - mb2;
d.V3R = my3 + mb3;
d.V4R = my3 - mb3;
}
/// <summary>
/// Combined operation of <see cref="IDCT8x4_LeftPart(ref Block8x8F, ref Block8x8F)"/> and <see cref="IDCT8x4_RightPart(ref Block8x8F, ref Block8x8F)"/>
/// using AVX commands.
/// </summary>
/// <param name="s">Source</param>
/// <param name="d">Destination</param>
public static void IDCT8x8_Avx(ref Block8x8F s, ref Block8x8F d)
{
#if SUPPORTS_RUNTIME_INTRINSICS
Debug.Assert(Avx.IsSupported, "AVX is required to execute this method");
Vector256<float> my1 = s.V1;
Vector256<float> my7 = s.V7;
Vector256<float> mz0 = Avx.Add(my1, my7);
Vector256<float> my3 = s.V3;
Vector256<float> mz2 = Avx.Add(my3, my7);
Vector256<float> my5 = s.V5;
Vector256<float> mz1 = Avx.Add(my3, my5);
Vector256<float> mz3 = Avx.Add(my1, my5);
Vector256<float> mz4 = Avx.Multiply(Avx.Add(mz0, mz1), C_V_1_1758);
mz2 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, mz2, C_V_n1_9615);
mz3 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, mz3, C_V_n0_3901);
mz0 = Avx.Multiply(mz0, C_V_n0_8999);
mz1 = Avx.Multiply(mz1, C_V_n2_5629);
Vector256<float> mb3 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz0, my7, C_V_0_2986), mz2);
Vector256<float> mb2 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz1, my5, C_V_2_0531), mz3);
Vector256<float> mb1 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz1, my3, C_V_3_0727), mz2);
Vector256<float> mb0 = Avx.Add(SimdUtils.HwIntrinsics.MultiplyAdd(mz0, my1, C_V_1_5013), mz3);
Vector256<float> my2 = s.V2;
Vector256<float> my6 = s.V6;
mz4 = Avx.Multiply(Avx.Add(my2, my6), C_V_0_5411);
Vector256<float> my0 = s.V0;
Vector256<float> my4 = s.V4;
mz0 = Avx.Add(my0, my4);
mz1 = Avx.Subtract(my0, my4);
mz2 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, my6, C_V_n1_8477);
mz3 = SimdUtils.HwIntrinsics.MultiplyAdd(mz4, my2, C_V_0_7653);
my0 = Avx.Add(mz0, mz3);
my3 = Avx.Subtract(mz0, mz3);
my1 = Avx.Add(mz1, mz2);
my2 = Avx.Subtract(mz1, mz2);
d.V0 = Avx.Add(my0, mb0);
d.V7 = Avx.Subtract(my0, mb0);
d.V1 = Avx.Add(my1, mb1);
d.V6 = Avx.Subtract(my1, mb1);
d.V2 = Avx.Add(my2, mb2);
d.V5 = Avx.Subtract(my2, mb2);
d.V3 = Avx.Add(my3, mb3);
d.V4 = Avx.Subtract(my3, mb3);
#endif
}
/// <summary> /// <summary>
/// Apply floating point IDCT inplace. /// Apply floating point IDCT inplace.
@ -267,10 +58,28 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
temp.Transpose(); temp.Transpose();
IDCT8x8(ref temp, ref block); IDCT8x8(ref temp, ref block);
// TODO: What if we leave the blocks in a scaled-by-x8 state until final color packing? // TODO: This can be fused into quantization table step
block.MultiplyInPlace(C_0_125); block.MultiplyInPlace(C_0_125);
} }
/// <summary>
/// Apply 2D floating point FDCT inplace.
/// </summary>
/// <param name="block">Input matrix.</param>
public static void TransformFDCT(ref Block8x8F block)
{
#if SUPPORTS_RUNTIME_INTRINSICS
if (Avx.IsSupported || Sse.IsSupported)
{
ForwardTransformSimd(ref block);
}
else
#endif
{
ForwardTransformScalar(ref block);
}
}
/// <summary> /// <summary>
/// Apply 2D floating point FDCT inplace using scalar operations. /// Apply 2D floating point FDCT inplace using scalar operations.
/// </summary> /// </summary>
@ -380,23 +189,5 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
dataRef = ref Unsafe.Add(ref dataRef, 1); dataRef = ref Unsafe.Add(ref dataRef, 1);
} }
} }
/// <summary>
/// Apply 2D floating point FDCT inplace.
/// </summary>
/// <param name="block">Input matrix.</param>
public static void TransformFDCT(ref Block8x8F block)
{
#if SUPPORTS_RUNTIME_INTRINSICS
if (Avx.IsSupported || Sse.IsSupported)
{
ForwardTransformSimd(ref block);
}
else
#endif
{
ForwardTransformScalar(ref block);
}
}
} }
} }

Write Preview
Loading…
Cancel
Save