1 files changed, 44 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/opsin_params.cc b/third_party/jpeg-xl/lib/jxl/opsin_params.cc
new file mode 100644
index 0000000000..ec3db4ee76
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/opsin_params.cc
@@ -0,0 +1,44 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/jxl/opsin_params.h"
+
+#include <stdlib.h>
+
+#include "lib/jxl/matrix_ops.h"
+
+namespace jxl {
+
+#define INVERSE_OPSIN_FROM_SPEC 1
+
+const float* GetOpsinAbsorbanceInverseMatrix() {
+#if INVERSE_OPSIN_FROM_SPEC
+  return DefaultInverseOpsinAbsorbanceMatrix();
+#else   // INVERSE_OPSIN_FROM_SPEC
+  // Compute the inverse opsin matrix from the forward matrix. Less precise
+  // than taking the values from the specification, but must be used if the
+  // forward transform is changed and the spec will require updating.
+  static const float* const kInverse = [] {
+    static float inverse[9];
+    for (int i = 0; i < 9; i++) {
+      inverse[i] = kOpsinAbsorbanceMatrix[i];
+    }
+    Inv3x3Matrix(inverse);
+    return inverse;
+  }();
+  return kInverse;
+#endif  // INVERSE_OPSIN_FROM_SPEC
+}
+
+void InitSIMDInverseMatrix(const float* JXL_RESTRICT inverse,
+                           float* JXL_RESTRICT simd_inverse,
+                           float intensity_target) {
+  for (size_t i = 0; i < 9; ++i) {
+    simd_inverse[4 * i] = simd_inverse[4 * i + 1] = simd_inverse[4 * i + 2] =
+        simd_inverse[4 * i + 3] = inverse[i] * (255.0f / intensity_target);
+  }
+}
+
+}  // namespace jxl