1 files changed, 21 insertions, 0 deletions
diff --git a/media/libjxl/src/lib/jxl/base/random.cc b/media/libjxl/src/lib/jxl/base/random.cc
new file mode 100644
index 0000000000..0fbe758068
--- /dev/null
+++ b/media/libjxl/src/lib/jxl/base/random.cc
@@ -0,0 +1,21 @@
+// 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/base/random.h"
+
+#include "lib/jxl/fast_math-inl.h"
+
+namespace jxl {
+
+Rng::GeometricDistribution::GeometricDistribution(float p)
+    : inv_log_1mp(1.0 / FastLog2f(1 - p)) {}
+
+uint32_t Rng::Geometric(const GeometricDistribution& dist) {
+  float f = UniformF(0, 1);
+  float log = FastLog2f(1 - f) * dist.inv_log_1mp;
+  return static_cast<uint32_t>(log);
+}
+
+}  // namespace jxl