Create an abstract LoudnessCalculatorFactory.

  - Implement a simple version which just copies user loudness.
  - In the future this will be used to configure a module which actually measures loudness for a Mix Presentation OBU.

PiperOrigin-RevId: 628083616

iamf/cli/BUILD

@@ -333,6 +333,16 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "loudness_calculator_factory",
+    srcs = ["loudness_calculator_factory.cc"],
+    hdrs = ["loudness_calculator_factory.h"],
+    deps = [
+        ":loudness_calculator",
+        "//iamf/obu:mix_presentation",
+    ],
+)
+
 cc_library(
     name = "mix_presentation_finalizer",
     srcs = ["mix_presentation_finalizer.cc"],

iamf/cli/loudness_calculator.h

@@ -64,7 +64,8 @@ class LoudnessCalculatorUserProvidedLoudness : public LoudnessCalculatorBase {
    *
    * \param user_provided_loudness User provided loudness to echo back.
    */
-  LoudnessCalculatorUserProvidedLoudness(LoudnessInfo user_provided_loudness)
+  LoudnessCalculatorUserProvidedLoudness(
+      const LoudnessInfo& user_provided_loudness)
       : user_provided_loudness_(user_provided_loudness) {}
 
   /*\!brief Destructor. */

iamf/cli/loudness_calculator_factory.cc

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2024, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 3-Clause Clear License
+ * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
+ * License was not distributed with this source code in the LICENSE file, you
+ * can obtain it at www.aomedia.org/license/software-license/bsd-3-c-c. If the
+ * Alliance for Open Media Patent License 1.0 was not distributed with this
+ * source code in the PATENTS file, you can obtain it at
+ * www.aomedia.org/license/patent.
+ */
+#include "iamf/cli/loudness_calculator_factory.h"
+
+#include <cstdint>
+#include <memory>
+
+#include "iamf/cli/loudness_calculator.h"
+#include "iamf/obu/mix_presentation.h"
+
+namespace iamf_tools {
+
+LoudnessCalculatorFactoryBase::~LoudnessCalculatorFactoryBase() {}
+
+std::unique_ptr<LoudnessCalculatorBase>
+LoudnessCalculatorFactoryUserProvidedLoudness::CreateLoudnessCalculator(
+    const MixPresentationLayout& layout, int32_t, int32_t) const {
+  return std::make_unique<LoudnessCalculatorUserProvidedLoudness>(
+      layout.loudness);
+}
+
+}  // namespace iamf_tools

iamf/cli/loudness_calculator_factory.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2024, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 3-Clause Clear License
+ * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
+ * License was not distributed with this source code in the LICENSE file, you
+ * can obtain it at www.aomedia.org/license/software-license/bsd-3-c-c. If the
+ * Alliance for Open Media Patent License 1.0 was not distributed with this
+ * source code in the PATENTS file, you can obtain it at
+ * www.aomedia.org/license/patent.
+ */
+#ifndef CLI_LOUDNESS_CALCULATOR_FACTORY_H_
+#define CLI_LOUDNESS_CALCULATOR_FACTORY_H_
+
+#include <cstdint>
+#include <memory>
+
+#include "iamf/cli/loudness_calculator.h"
+#include "iamf/obu/mix_presentation.h"
+
+namespace iamf_tools {
+
+/*\!brief Abstract class to create loudness calculators.
+ *
+ * This class will be used when calculating the loudness of a mix presentation
+ * layout. The mix presentation finalizer will take in a factory (or factories)
+ * and use them to create a loudness calculator for each stream. By taking in a
+ * factory the finalizer can be agnostic to the type of loudness calculator
+ * being used which may depend on implementation details, or it may depend on
+ * the specific layouts.
+ */
+class LoudnessCalculatorFactoryBase {
+ public:
+  /*\!brief Creates a loudness calculator.
+   *
+   * \param layout Layout to measure loudness on.
+   * \param rendered_sample_rate Sample rate of the rendered audio.
+   * \param rendered_bit_depth Bit-depth of the rendered audio.
+   * \return Unique pointer to a loudness calculator.
+   */
+  virtual std::unique_ptr<LoudnessCalculatorBase> CreateLoudnessCalculator(
+      const MixPresentationLayout& layout, int32_t rendered_sample_rate,
+      int32_t rendered_bit_depth) const = 0;
+
+  /*\!brief Destructor. */
+  virtual ~LoudnessCalculatorFactoryBase() = 0;
+};
+
+// TODO(b/302273947): Use this class to measure loudness when finalizing mix
+//                    presentations.
+/*\!brief Factory which always provides a fallback loudness calculator. */
+class LoudnessCalculatorFactoryUserProvidedLoudness
+    : public LoudnessCalculatorFactoryBase {
+ public:
+  /*\!brief Creates a fallback loudness calculator.
+   *
+   * \param layout Layout to use when echoing loudness back.
+   * \param rendered_sample_rate Sample rate of the rendered audio to ignore.
+   * \param rendered_bit_depth Bit-depth of the rendered audio to ignore.
+   * \return Unique pointer to a loudness calculator.
+   */
+  std::unique_ptr<LoudnessCalculatorBase> CreateLoudnessCalculator(
+      const MixPresentationLayout& layout, int32_t /*rendered_sample_rate*/,
+      int32_t /*rendered_bit_depth*/) const override;
+
+  /*\!brief Destructor. */
+  ~LoudnessCalculatorFactoryUserProvidedLoudness() override = default;
+};
+
+}  // namespace iamf_tools
+
+#endif  // CLI_LOUDNESS_CALCULATOR_H_

iamf/cli/mix_presentation_finalizer.cc

@@ -118,6 +118,8 @@ MeasureLoudnessOrFallbackToUserLoudnessMixPresentationFinalizer::Finalize(
             << "provided values.";
 
   // TODO(b/332567539): Use `RendererFactory` to render certain layouts.
+  // TODO(b/302273947): Once layouts are rendered and mixed then use a
+  //                    `LoudnessCalculatorFactory` to measure loudness.
   int metadata_index = 0;
   for (auto& mix_presentation_obu : mix_presentation_obus) {
     for (int sub_mix_index = 0;

iamf/cli/tests/BUILD

@@ -245,6 +245,20 @@ cc_test(
     ],
 )
 
+cc_test(
+    name = "loudness_calculator_factory_test",
+    srcs = ["loudness_calculator_factory_test.cc"],
+    deps = [
+        "//iamf/cli:loudness_calculator_factory",
+        "//iamf/cli/proto:obu_header_cc_proto",
+        "//iamf/cli/proto:parameter_data_cc_proto",
+        "//iamf/cli/proto:temporal_delimiter_cc_proto",
+        "//iamf/cli/proto:user_metadata_cc_proto",
+        "//iamf/obu:mix_presentation",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 cc_test(
     name = "loudness_calculator_test",
     srcs = ["loudness_calculator_test.cc"],

iamf/cli/tests/loudness_calculator_factory_test.cc

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2024, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 3-Clause Clear License
+ * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
+ * License was not distributed with this source code in the LICENSE file, you
+ * can obtain it at www.aomedia.org/license/software-license/bsd-3-c-c. If the
+ * Alliance for Open Media Patent License 1.0 was not distributed with this
+ * source code in the PATENTS file, you can obtain it at
+ * www.aomedia.org/license/patent.
+ */
+#include "iamf/cli/loudness_calculator_factory.h"
+
+#include <cstdint>
+
+#include "gtest/gtest.h"
+#include "iamf/cli/proto/obu_header.pb.h"
+#include "iamf/cli/proto/parameter_data.pb.h"
+#include "iamf/cli/proto/temporal_delimiter.pb.h"
+#include "iamf/cli/proto/user_metadata.pb.h"
+#include "iamf/obu/mix_presentation.h"
+
+namespace iamf_tools {
+namespace {
+
+constexpr int32_t kUnusedRenderedSampleRate = 0;
+constexpr int32_t kUnusedRenderedBitDepth = 0;
+
+TEST(CreatePrimaryLoudnessCalculator, NeverReturnsNull) {
+  const LoudnessCalculatorFactoryUserProvidedLoudness factory;
+  const MixPresentationLayout layout = {};
+
+  EXPECT_NE(factory.CreateLoudnessCalculator(layout, kUnusedRenderedSampleRate,
+                                             kUnusedRenderedBitDepth),
+            nullptr);
+}
+
+}  // namespace
+}  // namespace iamf_tools