1 files changed, 81 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/quantizer_test.cc b/third_party/jpeg-xl/lib/jxl/quantizer_test.cc
new file mode 100644
index 0000000000..f9cf2c838e
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/quantizer_test.cc
@@ -0,0 +1,81 @@
+// 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/quantizer.h"
+
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/common.h"
+#include "lib/jxl/dec_bit_reader.h"
+#include "lib/jxl/enc_fields.h"
+#include "lib/jxl/image_ops.h"
+#include "lib/jxl/image_test_utils.h"
+#include "lib/jxl/testing.h"
+
+namespace jxl {
+namespace {
+
+void TestEquivalence(int qxsize, int qysize, const Quantizer& quantizer1,
+                     const Quantizer& quantizer2) {
+  ASSERT_NEAR(quantizer1.inv_quant_dc(), quantizer2.inv_quant_dc(), 1e-7);
+}
+
+TEST(QuantizerTest, QuantizerParams) {
+  for (uint32_t i = 1; i < 10000; ++i) {
+    QuantizerParams p;
+    p.global_scale = i;
+    size_t extension_bits = 0, total_bits = 0;
+    EXPECT_TRUE(Bundle::CanEncode(p, &extension_bits, &total_bits));
+    EXPECT_EQ(0u, extension_bits);
+    EXPECT_GE(total_bits, 4u);
+  }
+}
+
+TEST(QuantizerTest, BitStreamRoundtripSameQuant) {
+  const int qxsize = 8;
+  const int qysize = 8;
+  DequantMatrices dequant;
+  Quantizer quantizer1(&dequant);
+  ImageI raw_quant_field(qxsize, qysize);
+  quantizer1.SetQuant(0.17f, 0.17f, &raw_quant_field);
+  BitWriter writer;
+  QuantizerParams params = quantizer1.GetParams();
+  EXPECT_TRUE(WriteQuantizerParams(params, &writer, 0, nullptr));
+  writer.ZeroPadToByte();
+  const size_t bits_written = writer.BitsWritten();
+  Quantizer quantizer2(&dequant);
+  BitReader reader(writer.GetSpan());
+  EXPECT_TRUE(quantizer2.Decode(&reader));
+  EXPECT_TRUE(reader.JumpToByteBoundary());
+  EXPECT_EQ(reader.TotalBitsConsumed(), bits_written);
+  EXPECT_TRUE(reader.Close());
+  TestEquivalence(qxsize, qysize, quantizer1, quantizer2);
+}
+
+TEST(QuantizerTest, BitStreamRoundtripRandomQuant) {
+  const int qxsize = 8;
+  const int qysize = 8;
+  DequantMatrices dequant;
+  Quantizer quantizer1(&dequant);
+  ImageI raw_quant_field(qxsize, qysize);
+  quantizer1.SetQuant(0.17f, 0.17f, &raw_quant_field);
+  float quant_dc = 0.17f;
+  ImageF qf(qxsize, qysize);
+  RandomFillImage(&qf, 0.0f, 1.0f);
+  quantizer1.SetQuantField(quant_dc, qf, &raw_quant_field);
+  BitWriter writer;
+  QuantizerParams params = quantizer1.GetParams();
+  EXPECT_TRUE(WriteQuantizerParams(params, &writer, 0, nullptr));
+  writer.ZeroPadToByte();
+  const size_t bits_written = writer.BitsWritten();
+  Quantizer quantizer2(&dequant);
+  BitReader reader(writer.GetSpan());
+  EXPECT_TRUE(quantizer2.Decode(&reader));
+  EXPECT_TRUE(reader.JumpToByteBoundary());
+  EXPECT_EQ(reader.TotalBitsConsumed(), bits_written);
+  EXPECT_TRUE(reader.Close());
+  TestEquivalence(qxsize, qysize, quantizer1, quantizer2);
+}
+}  // namespace
+}  // namespace jxl