MD                263 libavfilter/vf_curves.c     matrix[0][MD] = matrix[n - 1][MD] = 1;
MD                266 libavfilter/vf_curves.c         matrix[i][MD] = 2 * (h[i-1] + h[i]);
MD                272 libavfilter/vf_curves.c         double den = matrix[i][MD] - matrix[i][BD] * matrix[i-1][AD];