1 files changed, 68 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/entropy_coder_test.cc b/third_party/jpeg-xl/lib/jxl/entropy_coder_test.cc
new file mode 100644
index 0000000000..9dbeb137af
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/entropy_coder_test.cc
@@ -0,0 +1,68 @@
+// 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.
+
+// TODO(deymo): Move these tests to dec_ans.h and common.h
+
+#include <stdint.h>
+
+#include "lib/jxl/base/random.h"
+#include "lib/jxl/common.h"
+#include "lib/jxl/dec_ans.h"
+#include "lib/jxl/testing.h"
+
+namespace jxl {
+namespace {
+
+TEST(EntropyCoderTest, PackUnpack) {
+  for (int32_t i = -31; i < 32; ++i) {
+    uint32_t packed = PackSigned(i);
+    EXPECT_LT(packed, 63u);
+    int32_t unpacked = UnpackSigned(packed);
+    EXPECT_EQ(i, unpacked);
+  }
+}
+
+struct DummyBitReader {
+  uint32_t nbits, bits;
+  void Consume(uint32_t nbits) {}
+  uint32_t PeekBits(uint32_t n) {
+    EXPECT_EQ(n, nbits);
+    return bits;
+  }
+};
+
+void HybridUintRoundtrip(HybridUintConfig config, size_t limit = 1 << 24) {
+  Rng rng(0);
+  constexpr size_t kNumIntegers = 1 << 20;
+  std::vector<uint32_t> integers(kNumIntegers);
+  std::vector<uint32_t> token(kNumIntegers);
+  std::vector<uint32_t> nbits(kNumIntegers);
+  std::vector<uint32_t> bits(kNumIntegers);
+  for (size_t i = 0; i < kNumIntegers; i++) {
+    integers[i] = rng.UniformU(0, limit + 1);
+    config.Encode(integers[i], &token[i], &nbits[i], &bits[i]);
+  }
+  for (size_t i = 0; i < kNumIntegers; i++) {
+    DummyBitReader br{nbits[i], bits[i]};
+    EXPECT_EQ(integers[i],
+              ANSSymbolReader::ReadHybridUintConfig(config, token[i], &br));
+  }
+}
+
+TEST(HybridUintTest, Test000) {
+  HybridUintRoundtrip(HybridUintConfig{0, 0, 0});
+}
+TEST(HybridUintTest, Test411) {
+  HybridUintRoundtrip(HybridUintConfig{4, 1, 1});
+}
+TEST(HybridUintTest, Test420) {
+  HybridUintRoundtrip(HybridUintConfig{4, 2, 0});
+}
+TEST(HybridUintTest, Test421) {
+  HybridUintRoundtrip(HybridUintConfig{4, 2, 1}, 256);
+}
+
+}  // namespace
+}  // namespace jxl