mirror of
https://github.com/aaru-dps/Aaru.git
synced 2025-12-16 19:24:25 +00:00
REFACTOR: Fixed MOST name inconsistencies.
This commit is contained in:
@@ -67,21 +67,21 @@ namespace DiscImageChef.Checksums
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/* Primitive polynomials - see Lin & Costello, Error Control Coding Appendix A,
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* and Lee & Messerschmitt, Digital Communication p. 453.
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*/
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int[] Pp;
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int[] pp;
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/* index->polynomial form conversion table */
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int[] Alpha_to;
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int[] alpha_to;
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/* Polynomial->index form conversion table */
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int[] Index_of;
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int[] index_of;
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/* Generator polynomial g(x)
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* Degree of g(x) = 2*TT
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* has roots @**B0, @**(B0+1), ... ,@^(B0+2*TT-1)
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*/
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int[] Gg;
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int MM, KK, NN;
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int[] gg;
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int mm, kk, nn;
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/* No legal value in index form represents zero, so
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* we need a special value for this purpose
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*/
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int A0;
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int a0;
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bool initialized;
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/* Alpha exponent for the first root of the generator polynomial */
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const int B0 = 1;
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@@ -89,66 +89,66 @@ namespace DiscImageChef.Checksums
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/// <summary>
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/// Initializes the Reed-Solomon with RS(n,k) with GF(2^m)
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/// </summary>
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public void InitRS(int n, int k, int m)
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public void InitRs(int n, int k, int m)
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{
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switch(m)
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{
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case 2:
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Pp = new[] {1, 1, 1};
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pp = new[] {1, 1, 1};
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break;
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case 3:
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Pp = new[] {1, 1, 0, 1};
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pp = new[] {1, 1, 0, 1};
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break;
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case 4:
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Pp = new[] {1, 1, 0, 0, 1};
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pp = new[] {1, 1, 0, 0, 1};
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break;
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case 5:
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Pp = new[] {1, 0, 1, 0, 0, 1};
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pp = new[] {1, 0, 1, 0, 0, 1};
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break;
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case 6:
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Pp = new[] {1, 1, 0, 0, 0, 0, 1};
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pp = new[] {1, 1, 0, 0, 0, 0, 1};
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break;
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case 7:
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Pp = new[] {1, 0, 0, 1, 0, 0, 0, 1};
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pp = new[] {1, 0, 0, 1, 0, 0, 0, 1};
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break;
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case 8:
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Pp = new[] {1, 0, 1, 1, 1, 0, 0, 0, 1};
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pp = new[] {1, 0, 1, 1, 1, 0, 0, 0, 1};
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break;
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case 9:
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Pp = new[] {1, 0, 0, 0, 1, 0, 0, 0, 0, 1};
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pp = new[] {1, 0, 0, 0, 1, 0, 0, 0, 0, 1};
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break;
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case 10:
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Pp = new[] {1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1};
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pp = new[] {1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1};
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break;
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case 11:
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Pp = new[] {1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1};
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pp = new[] {1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1};
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break;
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case 12:
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Pp = new[] {1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1};
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pp = new[] {1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1};
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break;
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case 13:
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Pp = new[] {1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1};
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pp = new[] {1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1};
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break;
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case 14:
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Pp = new[] {1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1};
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pp = new[] {1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1};
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break;
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case 15:
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Pp = new[] {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
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pp = new[] {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
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break;
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case 16:
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Pp = new[] {1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1};
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pp = new[] {1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1};
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break;
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default: throw new ArgumentOutOfRangeException(nameof(m), "m must be between 2 and 16 inclusive");
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}
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MM = m;
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KK = k;
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NN = n;
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A0 = n;
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Alpha_to = new int[n + 1];
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Index_of = new int[n + 1];
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mm = m;
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kk = k;
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nn = n;
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a0 = n;
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alpha_to = new int[n + 1];
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index_of = new int[n + 1];
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Gg = new int[NN - KK + 1];
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gg = new int[nn - kk + 1];
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generate_gf();
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gen_poly();
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@@ -156,35 +156,35 @@ namespace DiscImageChef.Checksums
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initialized = true;
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}
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int modnn(int x)
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int Modnn(int x)
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{
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while(x >= NN)
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while(x >= nn)
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{
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x -= NN;
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x = (x >> MM) + (x & NN);
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x -= nn;
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x = (x >> mm) + (x & nn);
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}
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return x;
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}
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static int min(int a, int b)
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static int Min(int a, int b)
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{
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return ((a) < (b) ? (a) : (b));
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}
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static void CLEAR(ref int[] a, int n)
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static void Clear(ref int[] a, int n)
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{
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int ci;
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for(ci = (n) - 1; ci >= 0; ci--) (a)[ci] = 0;
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}
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static void COPY(ref int[] a, ref int[] b, int n)
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static void Copy(ref int[] a, ref int[] b, int n)
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{
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int ci;
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for(ci = (n) - 1; ci >= 0; ci--) (a)[ci] = (b)[ci];
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}
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static void COPYDOWN(ref int[] a, ref int[] b, int n)
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static void Copydown(ref int[] a, ref int[] b, int n)
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{
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int ci;
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for(ci = (n) - 1; ci >= 0; ci--) (a)[ci] = (b)[ci];
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@@ -225,32 +225,32 @@ namespace DiscImageChef.Checksums
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int i, mask;
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mask = 1;
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Alpha_to[MM] = 0;
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for(i = 0; i < MM; i++)
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alpha_to[mm] = 0;
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for(i = 0; i < mm; i++)
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{
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Alpha_to[i] = mask;
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Index_of[Alpha_to[i]] = i;
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alpha_to[i] = mask;
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index_of[alpha_to[i]] = i;
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/* If Pp[i] == 1 then, term @^i occurs in poly-repr of @^MM */
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if(Pp[i] != 0) Alpha_to[MM] ^= mask; /* Bit-wise EXOR operation */
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if(pp[i] != 0) alpha_to[mm] ^= mask; /* Bit-wise EXOR operation */
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mask <<= 1; /* single left-shift */
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}
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Index_of[Alpha_to[MM]] = MM;
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index_of[alpha_to[mm]] = mm;
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/*
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* Have obtained poly-repr of @^MM. Poly-repr of @^(i+1) is given by
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* poly-repr of @^i shifted left one-bit and accounting for any @^MM
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* term that may occur when poly-repr of @^i is shifted.
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*/
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mask >>= 1;
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for(i = MM + 1; i < NN; i++)
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for(i = mm + 1; i < nn; i++)
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{
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if(Alpha_to[i - 1] >= mask) Alpha_to[i] = Alpha_to[MM] ^ ((Alpha_to[i - 1] ^ mask) << 1);
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else Alpha_to[i] = Alpha_to[i - 1] << 1;
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Index_of[Alpha_to[i]] = i;
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if(alpha_to[i - 1] >= mask) alpha_to[i] = alpha_to[mm] ^ ((alpha_to[i - 1] ^ mask) << 1);
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else alpha_to[i] = alpha_to[i - 1] << 1;
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index_of[alpha_to[i]] = i;
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}
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Index_of[0] = A0;
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Alpha_to[NN] = 0;
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index_of[0] = a0;
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alpha_to[nn] = 0;
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}
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/*
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@@ -270,23 +270,23 @@ namespace DiscImageChef.Checksums
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{
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int i, j;
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Gg[0] = Alpha_to[B0];
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Gg[1] = 1; /* g(x) = (X+@**B0) initially */
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for(i = 2; i <= NN - KK; i++)
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gg[0] = alpha_to[B0];
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gg[1] = 1; /* g(x) = (X+@**B0) initially */
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for(i = 2; i <= nn - kk; i++)
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{
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Gg[i] = 1;
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gg[i] = 1;
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/*
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* Below multiply (Gg[0]+Gg[1]*x + ... +Gg[i]x^i) by
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* (@**(B0+i-1) + x)
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*/
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for(j = i - 1; j > 0; j--)
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if(Gg[j] != 0) Gg[j] = Gg[j - 1] ^ Alpha_to[modnn((Index_of[Gg[j]]) + B0 + i - 1)];
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else Gg[j] = Gg[j - 1];
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if(gg[j] != 0) gg[j] = gg[j - 1] ^ alpha_to[Modnn((index_of[gg[j]]) + B0 + i - 1)];
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else gg[j] = gg[j - 1];
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/* Gg[0] can never be zero */
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Gg[0] = Alpha_to[modnn((Index_of[Gg[0]]) + B0 + i - 1)];
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gg[0] = alpha_to[Modnn((index_of[gg[0]]) + B0 + i - 1)];
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}
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/* convert Gg[] to index form for quicker encoding */
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for(i = 0; i <= NN - KK; i++) Gg[i] = Index_of[Gg[i]];
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for(i = 0; i <= nn - kk; i++) gg[i] = index_of[gg[i]];
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}
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/*
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@@ -309,28 +309,28 @@ namespace DiscImageChef.Checksums
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{
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int i, j;
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int feedback;
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bb = new int[NN - KK];
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bb = new int[nn - kk];
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CLEAR(ref bb, NN - KK);
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for(i = KK - 1; i >= 0; i--)
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Clear(ref bb, nn - kk);
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for(i = kk - 1; i >= 0; i--)
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{
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if(MM != 8) { if(data[i] > NN) return -1; /* Illegal symbol */ }
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if(mm != 8) { if(data[i] > nn) return -1; /* Illegal symbol */ }
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feedback = Index_of[data[i] ^ bb[NN - KK - 1]];
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if(feedback != A0)
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feedback = index_of[data[i] ^ bb[nn - kk - 1]];
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if(feedback != a0)
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{
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/* feedback term is non-zero */
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for(j = NN - KK - 1; j > 0; j--)
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if(Gg[j] != A0) bb[j] = bb[j - 1] ^ Alpha_to[modnn(Gg[j] + feedback)];
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for(j = nn - kk - 1; j > 0; j--)
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if(gg[j] != a0) bb[j] = bb[j - 1] ^ alpha_to[Modnn(gg[j] + feedback)];
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else bb[j] = bb[j - 1];
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bb[0] = Alpha_to[modnn(Gg[0] + feedback)];
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bb[0] = alpha_to[Modnn(gg[0] + feedback)];
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}
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else
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{
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/* feedback term is zero. encoder becomes a
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* single-byte shifter */
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for(j = NN - KK - 1; j > 0; j--) bb[j] = bb[j - 1];
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for(j = nn - kk - 1; j > 0; j--) bb[j] = bb[j - 1];
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bb[0] = 0;
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}
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@@ -360,52 +360,52 @@ namespace DiscImageChef.Checksums
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/// </summary>
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/// <returns>Returns corrected symbols, -1 if illegal or uncorrectable</returns>
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/// <param name="data">Data symbols.</param>
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/// <param name="eras_pos">Position of erasures.</param>
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/// <param name="no_eras">Number of erasures.</param>
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public int eras_dec_rs(ref int[] data, out int[] eras_pos, int no_eras)
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/// <param name="erasPos">Position of erasures.</param>
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/// <param name="noEras">Number of erasures.</param>
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public int eras_dec_rs(ref int[] data, out int[] erasPos, int noEras)
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{
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if(initialized)
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{
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eras_pos = new int[NN - KK];
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int deg_lambda, el, deg_omega;
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erasPos = new int[nn - kk];
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int degLambda, el, degOmega;
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int i, j, r;
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int u, q, tmp, num1, num2, den, discr_r;
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int[] recd = new int[NN];
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int[] lambda = new int[NN - KK + 1]; /* Err+Eras Locator poly */
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int[] s = new int[NN - KK + 1]; /* syndrome poly */
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int[] b = new int[NN - KK + 1];
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int[] t = new int[NN - KK + 1];
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int[] omega = new int[NN - KK + 1];
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int[] root = new int[NN - KK];
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int[] reg = new int[NN - KK + 1];
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int[] loc = new int[NN - KK];
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int syn_error, count;
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int u, q, tmp, num1, num2, den, discrR;
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int[] recd = new int[nn];
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int[] lambda = new int[nn - kk + 1]; /* Err+Eras Locator poly */
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int[] s = new int[nn - kk + 1]; /* syndrome poly */
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int[] b = new int[nn - kk + 1];
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int[] t = new int[nn - kk + 1];
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int[] omega = new int[nn - kk + 1];
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int[] root = new int[nn - kk];
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int[] reg = new int[nn - kk + 1];
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int[] loc = new int[nn - kk];
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int synError, count;
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/* data[] is in polynomial form, copy and convert to index form */
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for(i = NN - 1; i >= 0; i--)
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for(i = nn - 1; i >= 0; i--)
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{
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if(MM != 8) { if(data[i] > NN) return -1; /* Illegal symbol */ }
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if(mm != 8) { if(data[i] > nn) return -1; /* Illegal symbol */ }
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recd[i] = Index_of[data[i]];
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recd[i] = index_of[data[i]];
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}
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/* first form the syndromes; i.e., evaluate recd(x) at roots of g(x)
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* namely @**(B0+i), i = 0, ... ,(NN-KK-1)
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*/
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syn_error = 0;
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for(i = 1; i <= NN - KK; i++)
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synError = 0;
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for(i = 1; i <= nn - kk; i++)
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{
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tmp = 0;
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for(j = 0; j < NN; j++)
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if(recd[j] != A0) /* recd[j] in index form */
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tmp ^= Alpha_to[modnn(recd[j] + (B0 + i - 1) * j)];
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for(j = 0; j < nn; j++)
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if(recd[j] != a0) /* recd[j] in index form */
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tmp ^= alpha_to[Modnn(recd[j] + (B0 + i - 1) * j)];
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syn_error |= tmp; /* set flag if non-zero syndrome =>
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synError |= tmp; /* set flag if non-zero syndrome =>
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* error */
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/* store syndrome in index form */
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s[i] = Index_of[tmp];
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s[i] = index_of[tmp];
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}
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if(syn_error == 0)
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if(synError == 0)
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{
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/*
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* if syndrome is zero, data[] is a codeword and there are no
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@@ -414,35 +414,35 @@ namespace DiscImageChef.Checksums
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return 0;
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}
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CLEAR(ref lambda, NN - KK);
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Clear(ref lambda, nn - kk);
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lambda[0] = 1;
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if(no_eras > 0)
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if(noEras > 0)
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{
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/* Init lambda to be the erasure locator polynomial */
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lambda[1] = Alpha_to[eras_pos[0]];
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for(i = 1; i < no_eras; i++)
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lambda[1] = alpha_to[erasPos[0]];
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for(i = 1; i < noEras; i++)
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{
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u = eras_pos[i];
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u = erasPos[i];
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for(j = i + 1; j > 0; j--)
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{
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tmp = Index_of[lambda[j - 1]];
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if(tmp != A0) lambda[j] ^= Alpha_to[modnn(u + tmp)];
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tmp = index_of[lambda[j - 1]];
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if(tmp != a0) lambda[j] ^= alpha_to[Modnn(u + tmp)];
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}
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}
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#if DEBUG
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/* find roots of the erasure location polynomial */
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for(i = 1; i <= no_eras; i++) reg[i] = Index_of[lambda[i]];
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for(i = 1; i <= noEras; i++) reg[i] = index_of[lambda[i]];
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count = 0;
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for(i = 1; i <= NN; i++)
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for(i = 1; i <= nn; i++)
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{
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q = 1;
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for(j = 1; j <= no_eras; j++)
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if(reg[j] != A0)
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for(j = 1; j <= noEras; j++)
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if(reg[j] != a0)
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{
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reg[j] = modnn(reg[j] + j);
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q ^= Alpha_to[reg[j]];
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reg[j] = Modnn(reg[j] + j);
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q ^= alpha_to[reg[j]];
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}
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if(q == 0)
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@@ -451,12 +451,12 @@ namespace DiscImageChef.Checksums
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* number indices
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*/
|
||||
root[count] = i;
|
||||
loc[count] = NN - i;
|
||||
loc[count] = nn - i;
|
||||
count++;
|
||||
}
|
||||
}
|
||||
|
||||
if(count != no_eras)
|
||||
if(count != noEras)
|
||||
{
|
||||
DicConsole.DebugWriteLine("Reed Solomon", "\n lambda(x) is WRONG\n");
|
||||
return -1;
|
||||
@@ -470,95 +470,95 @@ namespace DiscImageChef.Checksums
|
||||
#endif
|
||||
}
|
||||
|
||||
for(i = 0; i < NN - KK + 1; i++) b[i] = Index_of[lambda[i]];
|
||||
for(i = 0; i < nn - kk + 1; i++) b[i] = index_of[lambda[i]];
|
||||
|
||||
/*
|
||||
* Begin Berlekamp-Massey algorithm to determine error+erasure
|
||||
* locator polynomial
|
||||
*/
|
||||
r = no_eras;
|
||||
el = no_eras;
|
||||
while(++r <= NN - KK)
|
||||
r = noEras;
|
||||
el = noEras;
|
||||
while(++r <= nn - kk)
|
||||
{
|
||||
/* r is the step number */
|
||||
/* Compute discrepancy at the r-th step in poly-form */
|
||||
discr_r = 0;
|
||||
discrR = 0;
|
||||
for(i = 0; i < r; i++)
|
||||
{
|
||||
if((lambda[i] != 0) && (s[r - i] != A0))
|
||||
if((lambda[i] != 0) && (s[r - i] != a0))
|
||||
{
|
||||
discr_r ^= Alpha_to[modnn(Index_of[lambda[i]] + s[r - i])];
|
||||
discrR ^= alpha_to[Modnn(index_of[lambda[i]] + s[r - i])];
|
||||
}
|
||||
}
|
||||
|
||||
discr_r = Index_of[discr_r]; /* Index form */
|
||||
if(discr_r == A0)
|
||||
discrR = index_of[discrR]; /* Index form */
|
||||
if(discrR == a0)
|
||||
{
|
||||
/* 2 lines below: B(x) <-- x*B(x) */
|
||||
COPYDOWN(ref b, ref b, NN - KK);
|
||||
b[0] = A0;
|
||||
Copydown(ref b, ref b, nn - kk);
|
||||
b[0] = a0;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* 7 lines below: T(x) <-- lambda(x) - discr_r*x*b(x) */
|
||||
t[0] = lambda[0];
|
||||
for(i = 0; i < NN - KK; i++)
|
||||
for(i = 0; i < nn - kk; i++)
|
||||
{
|
||||
if(b[i] != A0) t[i + 1] = lambda[i + 1] ^ Alpha_to[modnn(discr_r + b[i])];
|
||||
if(b[i] != a0) t[i + 1] = lambda[i + 1] ^ alpha_to[Modnn(discrR + b[i])];
|
||||
else t[i + 1] = lambda[i + 1];
|
||||
}
|
||||
|
||||
if(2 * el <= r + no_eras - 1)
|
||||
if(2 * el <= r + noEras - 1)
|
||||
{
|
||||
el = r + no_eras - el;
|
||||
el = r + noEras - el;
|
||||
/*
|
||||
* 2 lines below: B(x) <-- inv(discr_r) *
|
||||
* lambda(x)
|
||||
*/
|
||||
for(i = 0; i <= NN - KK; i++)
|
||||
b[i] = (lambda[i] == 0) ? A0 : modnn(Index_of[lambda[i]] - discr_r + NN);
|
||||
for(i = 0; i <= nn - kk; i++)
|
||||
b[i] = (lambda[i] == 0) ? a0 : Modnn(index_of[lambda[i]] - discrR + nn);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* 2 lines below: B(x) <-- x*B(x) */
|
||||
COPYDOWN(ref b, ref b, NN - KK);
|
||||
b[0] = A0;
|
||||
Copydown(ref b, ref b, nn - kk);
|
||||
b[0] = a0;
|
||||
}
|
||||
|
||||
COPY(ref lambda, ref t, NN - KK + 1);
|
||||
Copy(ref lambda, ref t, nn - kk + 1);
|
||||
}
|
||||
}
|
||||
|
||||
/* Convert lambda to index form and compute deg(lambda(x)) */
|
||||
deg_lambda = 0;
|
||||
for(i = 0; i < NN - KK + 1; i++)
|
||||
degLambda = 0;
|
||||
for(i = 0; i < nn - kk + 1; i++)
|
||||
{
|
||||
lambda[i] = Index_of[lambda[i]];
|
||||
if(lambda[i] != A0) deg_lambda = i;
|
||||
lambda[i] = index_of[lambda[i]];
|
||||
if(lambda[i] != a0) degLambda = i;
|
||||
}
|
||||
/*
|
||||
* Find roots of the error+erasure locator polynomial. By Chien
|
||||
* Search
|
||||
*/
|
||||
int temp = reg[0];
|
||||
COPY(ref reg, ref lambda, NN - KK);
|
||||
Copy(ref reg, ref lambda, nn - kk);
|
||||
reg[0] = temp;
|
||||
count = 0; /* Number of roots of lambda(x) */
|
||||
for(i = 1; i <= NN; i++)
|
||||
for(i = 1; i <= nn; i++)
|
||||
{
|
||||
q = 1;
|
||||
for(j = deg_lambda; j > 0; j--)
|
||||
if(reg[j] != A0)
|
||||
for(j = degLambda; j > 0; j--)
|
||||
if(reg[j] != a0)
|
||||
{
|
||||
reg[j] = modnn(reg[j] + j);
|
||||
q ^= Alpha_to[reg[j]];
|
||||
reg[j] = Modnn(reg[j] + j);
|
||||
q ^= alpha_to[reg[j]];
|
||||
}
|
||||
|
||||
if(q == 0)
|
||||
{
|
||||
/* store root (index-form) and error location number */
|
||||
root[count] = i;
|
||||
loc[count] = NN - i;
|
||||
loc[count] = nn - i;
|
||||
count++;
|
||||
}
|
||||
}
|
||||
@@ -570,7 +570,7 @@ namespace DiscImageChef.Checksums
|
||||
DicConsole.DebugWriteLine("Reed Solomon", "\n");
|
||||
#endif
|
||||
|
||||
if(deg_lambda != count)
|
||||
if(degLambda != count)
|
||||
{
|
||||
/*
|
||||
* deg(lambda) unequal to number of roots => uncorrectable
|
||||
@@ -582,21 +582,21 @@ namespace DiscImageChef.Checksums
|
||||
* Compute err+eras evaluator poly omega(x) = s(x)*lambda(x) (modulo
|
||||
* x**(NN-KK)). in index form. Also find deg(omega).
|
||||
*/
|
||||
deg_omega = 0;
|
||||
for(i = 0; i < NN - KK; i++)
|
||||
degOmega = 0;
|
||||
for(i = 0; i < nn - kk; i++)
|
||||
{
|
||||
tmp = 0;
|
||||
j = (deg_lambda < i) ? deg_lambda : i;
|
||||
j = (degLambda < i) ? degLambda : i;
|
||||
for(; j >= 0; j--)
|
||||
{
|
||||
if((s[i + 1 - j] != A0) && (lambda[j] != A0)) tmp ^= Alpha_to[modnn(s[i + 1 - j] + lambda[j])];
|
||||
if((s[i + 1 - j] != a0) && (lambda[j] != a0)) tmp ^= alpha_to[Modnn(s[i + 1 - j] + lambda[j])];
|
||||
}
|
||||
|
||||
if(tmp != 0) deg_omega = i;
|
||||
omega[i] = Index_of[tmp];
|
||||
if(tmp != 0) degOmega = i;
|
||||
omega[i] = index_of[tmp];
|
||||
}
|
||||
|
||||
omega[NN - KK] = A0;
|
||||
omega[nn - kk] = a0;
|
||||
|
||||
/*
|
||||
* Compute error values in poly-form. num1 = omega(inv(X(l))), num2 =
|
||||
@@ -605,18 +605,18 @@ namespace DiscImageChef.Checksums
|
||||
for(j = count - 1; j >= 0; j--)
|
||||
{
|
||||
num1 = 0;
|
||||
for(i = deg_omega; i >= 0; i--)
|
||||
for(i = degOmega; i >= 0; i--)
|
||||
{
|
||||
if(omega[i] != A0) num1 ^= Alpha_to[modnn(omega[i] + i * root[j])];
|
||||
if(omega[i] != a0) num1 ^= alpha_to[Modnn(omega[i] + i * root[j])];
|
||||
}
|
||||
|
||||
num2 = Alpha_to[modnn(root[j] * (B0 - 1) + NN)];
|
||||
num2 = alpha_to[Modnn(root[j] * (B0 - 1) + nn)];
|
||||
den = 0;
|
||||
|
||||
/* lambda[i+1] for i even is the formal derivative lambda_pr of lambda[i] */
|
||||
for(i = min(deg_lambda, NN - KK - 1) & ~1; i >= 0; i -= 2)
|
||||
for(i = Min(degLambda, nn - kk - 1) & ~1; i >= 0; i -= 2)
|
||||
{
|
||||
if(lambda[i + 1] != A0) den ^= Alpha_to[modnn(lambda[i + 1] + i * root[j])];
|
||||
if(lambda[i + 1] != a0) den ^= alpha_to[Modnn(lambda[i + 1] + i * root[j])];
|
||||
}
|
||||
|
||||
if(den == 0)
|
||||
@@ -627,7 +627,7 @@ namespace DiscImageChef.Checksums
|
||||
/* Apply error to data */
|
||||
if(num1 != 0)
|
||||
{
|
||||
data[loc[j]] ^= Alpha_to[modnn(Index_of[num1] + Index_of[num2] + NN - Index_of[den])];
|
||||
data[loc[j]] ^= alpha_to[Modnn(index_of[num1] + index_of[num2] + nn - index_of[den])];
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user