inputPackets = new HashMap<>();
+ inputPackets.put(TEXT_IN_STREAM_NAME, runner.getPacketCreator().createString(inputText));
+ return (LanguageDetectorResult) runner.process(inputPackets);
+ }
+
+ /** Closes and cleans up the {@link LanguageDetector}. */
+ @Override
+ public void close() {
+ runner.close();
+ }
+
+ /** Options for setting up a {@link LanguageDetector}. */
+ @AutoValue
+ public abstract static class LanguageDetectorOptions extends TaskOptions {
+
+ /** Builder for {@link LanguageDetectorOptions}. */
+ @AutoValue.Builder
+ public abstract static class Builder {
+ /** Sets the base options for the text classifier task. */
+ public abstract Builder setBaseOptions(BaseOptions value);
+
+ /**
+ * Sets the optional locale to use for display names specified through the TFLite Model
+ * Metadata, if any.
+ */
+ public abstract Builder setDisplayNamesLocale(String locale);
+
+ /**
+ * Sets the optional maximum number of top-scored classification results to return.
+ *
+ * If not set, all available results are returned. If set, must be > 0.
+ */
+ public abstract Builder setMaxResults(Integer maxResults);
+
+ /**
+ * Sets the optional score threshold. Results with score below this value are rejected.
+ *
+ *
Overrides the score threshold specified in the TFLite Model Metadata, if any.
+ */
+ public abstract Builder setScoreThreshold(Float scoreThreshold);
+
+ /**
+ * Sets the optional allowlist of category names.
+ *
+ *
If non-empty, detection results whose category name is not in this set will be filtered
+ * out. Duplicate or unknown category names are ignored. Mutually exclusive with {@code
+ * categoryDenylist}.
+ */
+ public abstract Builder setCategoryAllowlist(List categoryAllowlist);
+
+ /**
+ * Sets the optional denylist of category names.
+ *
+ * If non-empty, detection results whose category name is in this set will be filtered out.
+ * Duplicate or unknown category names are ignored. Mutually exclusive with {@code
+ * categoryAllowlist}.
+ */
+ public abstract Builder setCategoryDenylist(List categoryDenylist);
+
+ abstract LanguageDetectorOptions autoBuild();
+
+ /**
+ * Validates and builds the {@link LanguageDetectorOptions} instance.
+ *
+ * @throws IllegalArgumentException if any of the set options are invalid.
+ */
+ public final LanguageDetectorOptions build() {
+ LanguageDetectorOptions options = autoBuild();
+ if (options.maxResults().isPresent() && options.maxResults().get() <= 0) {
+ throw new IllegalArgumentException("If specified, maxResults must be > 0.");
+ }
+ if (!options.categoryAllowlist().isEmpty() && !options.categoryDenylist().isEmpty()) {
+ throw new IllegalArgumentException(
+ "Category allowlist and denylist are mutually exclusive.");
+ }
+ return options;
+ }
+ }
+
+ abstract BaseOptions baseOptions();
+
+ abstract Optional displayNamesLocale();
+
+ abstract Optional maxResults();
+
+ abstract Optional scoreThreshold();
+
+ // For backwards-compatibility reasons in OSS we want to avoid dependencies on libraries like
+ // Guava, so we don't use ImmutableList.
+ @SuppressWarnings("AutoValueImmutableFields")
+ abstract List categoryAllowlist();
+
+ @SuppressWarnings("AutoValueImmutableFields")
+ abstract List categoryDenylist();
+
+ @SuppressWarnings("AutoValueImmutableFields")
+ public static Builder builder() {
+ return new AutoValue_LanguageDetector_LanguageDetectorOptions.Builder()
+ .setCategoryAllowlist(Collections.emptyList())
+ .setCategoryDenylist(Collections.emptyList());
+ }
+
+ /**
+ * Converts a {@link LanguageDetectorOptions} to a {@link CalculatorOptions} protobuf message.
+ */
+ @Override
+ public CalculatorOptions convertToCalculatorOptionsProto() {
+ BaseOptionsProto.BaseOptions.Builder baseOptionsBuilder =
+ BaseOptionsProto.BaseOptions.newBuilder();
+ baseOptionsBuilder.mergeFrom(convertBaseOptionsToProto(baseOptions()));
+ ClassifierOptionsProto.ClassifierOptions.Builder classifierOptionsBuilder =
+ ClassifierOptionsProto.ClassifierOptions.newBuilder();
+ displayNamesLocale().ifPresent(classifierOptionsBuilder::setDisplayNamesLocale);
+ maxResults().ifPresent(classifierOptionsBuilder::setMaxResults);
+ scoreThreshold().ifPresent(classifierOptionsBuilder::setScoreThreshold);
+ if (!categoryAllowlist().isEmpty()) {
+ classifierOptionsBuilder.addAllCategoryAllowlist(categoryAllowlist());
+ }
+ if (!categoryDenylist().isEmpty()) {
+ classifierOptionsBuilder.addAllCategoryDenylist(categoryDenylist());
+ }
+ TextClassifierGraphOptionsProto.TextClassifierGraphOptions taskOptions =
+ TextClassifierGraphOptionsProto.TextClassifierGraphOptions.newBuilder()
+ .setBaseOptions(baseOptionsBuilder)
+ .setClassifierOptions(classifierOptionsBuilder)
+ .build();
+ return CalculatorOptions.newBuilder()
+ .setExtension(TextClassifierGraphOptionsProto.TextClassifierGraphOptions.ext, taskOptions)
+ .build();
+ }
+ }
+}
diff --git a/mediapipe/tasks/java/com/google/mediapipe/tasks/text/languagedetector/LanguageDetectorResult.java b/mediapipe/tasks/java/com/google/mediapipe/tasks/text/languagedetector/LanguageDetectorResult.java
new file mode 100644
index 00000000..10b8dac4
--- /dev/null
+++ b/mediapipe/tasks/java/com/google/mediapipe/tasks/text/languagedetector/LanguageDetectorResult.java
@@ -0,0 +1,72 @@
+// Copyright 2023 The MediaPipe Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.mediapipe.tasks.text.languagedetector;
+
+import com.google.auto.value.AutoValue;
+import com.google.mediapipe.tasks.components.containers.Category;
+import com.google.mediapipe.tasks.components.containers.ClassificationResult;
+import com.google.mediapipe.tasks.components.containers.Classifications;
+import com.google.mediapipe.tasks.components.containers.proto.ClassificationsProto;
+import com.google.mediapipe.tasks.core.TaskResult;
+import java.util.ArrayList;
+import java.util.List;
+
+/** Represents the prediction results generated by {@link LanguageDetector}. */
+@AutoValue
+public abstract class LanguageDetectorResult implements TaskResult {
+
+ /**
+ * Creates an {@link LanguageDetectorResult} instance.
+ *
+ * @param classificationResult the {@link ClassificationResult} object containing one set of
+ * results per classifier head.
+ * @param timestampMs a timestamp for this result.
+ */
+ static LanguageDetectorResult create(
+ ClassificationResult classificationResult, long timestampMs) {
+ if (classificationResult.classifications().size() != 1) {
+ throw new IllegalArgumentException(
+ "Expected 1 classification head, got " + classificationResult.classifications().size());
+ }
+ Classifications classifications = classificationResult.classifications().get(0);
+ List languagePredictions = new ArrayList<>();
+ for (Category category : classifications.categories()) {
+ languagePredictions.add(LanguagePrediction.create(category.categoryName(), category.score()));
+ }
+
+ return new AutoValue_LanguageDetectorResult(languagePredictions, timestampMs);
+ }
+
+ /**
+ * Creates an {@link LanguageDetectorResult} instance from a {@link
+ * ClassificationsProto.ClassificationResult} protobuf message.
+ *
+ * @param proto the {@link ClassificationsProto.ClassificationResult} protobuf message to convert.
+ * @param timestampMs a timestamp for this result.
+ */
+ static LanguageDetectorResult createFromProto(
+ ClassificationsProto.ClassificationResult proto, long timestampMs) {
+ return create(ClassificationResult.createFromProto(proto), timestampMs);
+ }
+
+ /** A list of predictions from the LanguageDetector. */
+ // For backwards-compatibility reasons in OSS we want to avoid dependencies on libraries like
+ // Guava, so we don't use ImmutableList.
+ @SuppressWarnings("AutoValueImmutableFields")
+ public abstract List languagesAndScores();
+
+ @Override
+ public abstract long timestampMs();
+}
diff --git a/mediapipe/tasks/java/com/google/mediapipe/tasks/text/languagedetector/LanguagePrediction.java b/mediapipe/tasks/java/com/google/mediapipe/tasks/text/languagedetector/LanguagePrediction.java
new file mode 100644
index 00000000..e2e4321a
--- /dev/null
+++ b/mediapipe/tasks/java/com/google/mediapipe/tasks/text/languagedetector/LanguagePrediction.java
@@ -0,0 +1,38 @@
+// Copyright 2023 The MediaPipe Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.mediapipe.tasks.text.languagedetector;
+
+import com.google.auto.value.AutoValue;
+
+/** A language code and its probability. Used as part of the output of {@link LanguageDetector}. */
+@AutoValue
+public abstract class LanguagePrediction {
+ /**
+ * Creates a {@link LanguageDetectorPrediction} instance.
+ *
+ * @param languageCode An i18n language / locale code, e.g. "en" for English, "uz" for Uzbek,
+ * "ja"-Latn for Japanese (romaji).
+ * @param probability The probability for the prediction.
+ */
+ public static LanguagePrediction create(String languageCode, float probability) {
+ return new AutoValue_LanguagePrediction(languageCode, probability);
+ }
+
+ /** The i18n language / locale code for the prediction. */
+ public abstract String languageCode();
+
+ /** The probability for the prediction. */
+ public abstract float probability();
+}
diff --git a/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/AndroidManifest.xml b/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/AndroidManifest.xml
new file mode 100644
index 00000000..782fe8df
--- /dev/null
+++ b/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/AndroidManifest.xml
@@ -0,0 +1,24 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/BUILD b/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/BUILD
new file mode 100644
index 00000000..c1448676
--- /dev/null
+++ b/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/BUILD
@@ -0,0 +1,19 @@
+# Copyright 2023 The MediaPipe Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//mediapipe/tasks:internal"])
+
+licenses(["notice"])
+
+# TODO: Enable this in OSS
diff --git a/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/LanguageDetectorTest.java b/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/LanguageDetectorTest.java
new file mode 100644
index 00000000..fe6d28f4
--- /dev/null
+++ b/mediapipe/tasks/javatests/com/google/mediapipe/tasks/text/languagedetector/LanguageDetectorTest.java
@@ -0,0 +1,110 @@
+// Copyright 2023 The MediaPipe Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.mediapipe.tasks.text.languagedetector;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.mediapipe.framework.MediaPipeException;
+import com.google.mediapipe.tasks.core.BaseOptions;
+import com.google.mediapipe.tasks.core.TestUtils;
+import com.google.mediapipe.tasks.text.languagedetector.LanguageDetector.LanguageDetectorOptions;
+import java.util.Arrays;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Test for {@link LanguageDetector}/ */
+@RunWith(AndroidJUnit4.class)
+public class LanguageDetectorTest {
+ private static final String MODEL_FILE = "language_detector.tflite";
+
+ @Test
+ public void options_failsWithNegativeMaxResults() throws Exception {
+ IllegalArgumentException exception =
+ assertThrows(
+ IllegalArgumentException.class,
+ () ->
+ LanguageDetectorOptions.builder()
+ .setBaseOptions(BaseOptions.builder().setModelAssetPath(MODEL_FILE).build())
+ .setMaxResults(-1)
+ .build());
+ assertThat(exception).hasMessageThat().contains("If specified, maxResults must be > 0");
+ }
+
+ @Test
+ public void options_failsWithBothAllowlistAndDenylist() throws Exception {
+ IllegalArgumentException exception =
+ assertThrows(
+ IllegalArgumentException.class,
+ () ->
+ LanguageDetectorOptions.builder()
+ .setBaseOptions(BaseOptions.builder().setModelAssetPath(MODEL_FILE).build())
+ .setCategoryAllowlist(Arrays.asList("foo"))
+ .setCategoryDenylist(Arrays.asList("bar"))
+ .build());
+ assertThat(exception)
+ .hasMessageThat()
+ .contains("Category allowlist and denylist are mutually exclusive");
+ }
+
+ @Test
+ public void create_failsWithMissingModel() throws Exception {
+ String nonExistentFile = "/path/to/non/existent/file";
+ MediaPipeException exception =
+ assertThrows(
+ MediaPipeException.class,
+ () ->
+ LanguageDetector.createFromFile(
+ ApplicationProvider.getApplicationContext(), nonExistentFile));
+ assertThat(exception).hasMessageThat().contains(nonExistentFile);
+ }
+
+ @Test
+ public void detect_succeedsWithL2CModel() throws Exception {
+ LanguageDetector languageDetector =
+ LanguageDetector.createFromFile(ApplicationProvider.getApplicationContext(), MODEL_FILE);
+ LanguageDetectorResult enResult =
+ languageDetector.detect("To be, or not to be, that is the question");
+ assertThat(enResult.languagesAndScores().size()).isEqualTo(1);
+ assertThat(enResult.languagesAndScores().get(0))
+ .isEqualTo(LanguagePrediction.create("en", 0.9998559f));
+ LanguageDetectorResult frResult =
+ languageDetector.detect(
+ "Il y a beaucoup de bouches qui parlent et fort peu de têtes qui pensent.");
+ assertThat(frResult.languagesAndScores().size()).isEqualTo(1);
+ assertThat(frResult.languagesAndScores().get(0))
+ .isEqualTo(LanguagePrediction.create("fr", 0.9997813f));
+ LanguageDetectorResult ruResult = languageDetector.detect("это какой-то английский язык");
+ assertThat(ruResult.languagesAndScores().size()).isEqualTo(1);
+ assertThat(ruResult.languagesAndScores().get(0))
+ .isEqualTo(LanguagePrediction.create("ru", 0.9933616f));
+ }
+
+ @Test
+ public void detect_succeedsWithFileObject() throws Exception {
+ LanguageDetector languageDetector =
+ LanguageDetector.createFromFile(
+ ApplicationProvider.getApplicationContext(),
+ TestUtils.loadFile(ApplicationProvider.getApplicationContext(), MODEL_FILE));
+ LanguageDetectorResult mixedResult = languageDetector.detect("分久必合合久必分");
+ assertThat(mixedResult.languagesAndScores().size()).isEqualTo(2);
+ assertThat(mixedResult.languagesAndScores().get(0))
+ .isEqualTo(LanguagePrediction.create("zh", 0.50542367f));
+ assertThat(mixedResult.languagesAndScores().get(1))
+ .isEqualTo(LanguagePrediction.create("ja", 0.4816168f));
+ }
+}