Add API to get the format from the file extension

This will allow to use the file extension in DefaultExtractorsFactory.

PiperOrigin-RevId: 314296640

library/common/src/main/java/com/google/android/exoplayer2/util/FilenameUtil.java

+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * 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.android.exoplayer2.util;
+
+import androidx.annotation.IntDef;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/** Filename related utility methods. */
+public final class FilenameUtil {
+
+  /**
+   * File formats. One of {@link #FILE_FORMAT_UNKNOWN}, {@link #FILE_FORMAT_AC3}, {@link
+   * #FILE_FORMAT_AC4}, {@link #FILE_FORMAT_ADTS}, {@link #FILE_FORMAT_AMR}, {@link
+   * #FILE_FORMAT_FLAC}, {@link #FILE_FORMAT_FLV}, {@link #FILE_FORMAT_MATROSKA}, {@link
+   * #FILE_FORMAT_MP3}, {@link #FILE_FORMAT_MP4}, {@link #FILE_FORMAT_OGG}, {@link #FILE_FORMAT_PS},
+   * {@link #FILE_FORMAT_TS}, {@link #FILE_FORMAT_WAV} and {@link #FILE_FORMAT_WEBVTT}.
+   */
+  @Documented
+  @Retention(RetentionPolicy.SOURCE)
+  @IntDef({
+    FILE_FORMAT_UNKNOWN,
+    FILE_FORMAT_AC3,
+    FILE_FORMAT_AC4,
+    FILE_FORMAT_ADTS,
+    FILE_FORMAT_AMR,
+    FILE_FORMAT_FLAC,
+    FILE_FORMAT_FLV,
+    FILE_FORMAT_MATROSKA,
+    FILE_FORMAT_MP3,
+    FILE_FORMAT_MP4,
+    FILE_FORMAT_OGG,
+    FILE_FORMAT_PS,
+    FILE_FORMAT_TS,
+    FILE_FORMAT_WAV,
+    FILE_FORMAT_WEBVTT
+  })
+  public @interface FileFormat {}
+  /** Unknown file format. */
+  public static final int FILE_FORMAT_UNKNOWN = -1;
+  /** File format for AC-3 and E-AC-3. */
+  public static final int FILE_FORMAT_AC3 = 0;
+  /** File format for AC-4. */
+  public static final int FILE_FORMAT_AC4 = 1;
+  /** File format for ADTS. */
+  public static final int FILE_FORMAT_ADTS = 2;
+  /** File format for AMR. */
+  public static final int FILE_FORMAT_AMR = 3;
+  /** File format for FLAC. */
+  public static final int FILE_FORMAT_FLAC = 4;
+  /** File format for FLV. */
+  public static final int FILE_FORMAT_FLV = 5;
+  /** File format for Matroska and WebM. */
+  public static final int FILE_FORMAT_MATROSKA = 6;
+  /** File format for MP3. */
+  public static final int FILE_FORMAT_MP3 = 7;
+  /** File format for MP4. */
+  public static final int FILE_FORMAT_MP4 = 8;
+  /** File format for Ogg. */
+  public static final int FILE_FORMAT_OGG = 9;
+  /** File format for MPEG-PS. */
+  public static final int FILE_FORMAT_PS = 10;
+  /** File format for MPEG-TS. */
+  public static final int FILE_FORMAT_TS = 11;
+  /** File format for WAV. */
+  public static final int FILE_FORMAT_WAV = 12;
+  /** File format for WebVTT. */
+  public static final int FILE_FORMAT_WEBVTT = 13;
+
+  private static final String FILE_EXTENSION_AC3 = ".ac3";
+  private static final String FILE_EXTENSION_EC3 = ".ec3";
+  private static final String FILE_EXTENSION_AC4 = ".ac4";
+  private static final String FILE_EXTENSION_ADTS = ".adts";
+  private static final String FILE_EXTENSION_AAC = ".aac";
+  private static final String FILE_EXTENSION_AMR = ".amr";
+  private static final String FILE_EXTENSION_FLAC = ".flac";
+  private static final String FILE_EXTENSION_FLV = ".flv";
+  private static final String FILE_EXTENSION_PREFIX_MK = ".mk";
+  private static final String FILE_EXTENSION_WEBM = ".webm";
+  private static final String FILE_EXTENSION_PREFIX_OG = ".og";
+  private static final String FILE_EXTENSION_OPUS = ".opus";
+  private static final String FILE_EXTENSION_MP3 = ".mp3";
+  private static final String FILE_EXTENSION_MP4 = ".mp4";
+  private static final String FILE_EXTENSION_PREFIX_M4 = ".m4";
+  private static final String FILE_EXTENSION_PREFIX_MP4 = ".mp4";
+  private static final String FILE_EXTENSION_PREFIX_CMF = ".cmf";
+  private static final String FILE_EXTENSION_PS = ".ps";
+  private static final String FILE_EXTENSION_MPEG = ".mpeg";
+  private static final String FILE_EXTENSION_MPG = ".mpg";
+  private static final String FILE_EXTENSION_M2P = ".m2p";
+  private static final String FILE_EXTENSION_TS = ".ts";
+  private static final String FILE_EXTENSION_PREFIX_TS = ".ts";
+  private static final String FILE_EXTENSION_WAV = ".wav";
+  private static final String FILE_EXTENSION_WAVE = ".wave";
+  private static final String FILE_EXTENSION_VTT = ".vtt";
+  private static final String FILE_EXTENSION_WEBVTT = ".webvtt";
+
+  private FilenameUtil() {}
+
+  /**
+   * Returns the {@link FileFormat} corresponding to the extension of the provided {@code filename}.
+   */
+  @FileFormat
+  public static int getFormatFromExtension(String filename) {
+    if (filename.endsWith(FILE_EXTENSION_AC3) || filename.endsWith(FILE_EXTENSION_EC3)) {
+      return FILE_FORMAT_AC3;
+    } else if (filename.endsWith(FILE_EXTENSION_AC4)) {
+      return FILE_FORMAT_AC4;
+    } else if (filename.endsWith(FILE_EXTENSION_ADTS) || filename.endsWith(FILE_EXTENSION_AAC)) {
+      return FILE_FORMAT_ADTS;
+    } else if (filename.endsWith(FILE_EXTENSION_AMR)) {
+      return FILE_FORMAT_AMR;
+    } else if (filename.endsWith(FILE_EXTENSION_FLAC)) {
+      return FILE_FORMAT_FLAC;
+    } else if (filename.endsWith(FILE_EXTENSION_FLV)) {
+      return FILE_FORMAT_FLV;
+    } else if (filename.startsWith(
+            FILE_EXTENSION_PREFIX_MK,
+            /* toffset= */ filename.length() - (FILE_EXTENSION_PREFIX_MK.length() + 1))
+        || filename.endsWith(FILE_EXTENSION_WEBM)) {
+      return FILE_FORMAT_MATROSKA;
+    } else if (filename.endsWith(FILE_EXTENSION_MP3)) {
+      return FILE_FORMAT_MP3;
+    } else if (filename.endsWith(FILE_EXTENSION_MP4)
+        || filename.startsWith(
+            FILE_EXTENSION_PREFIX_M4,
+            /* toffset= */ filename.length() - (FILE_EXTENSION_PREFIX_M4.length() + 1))
+        || filename.startsWith(
+            FILE_EXTENSION_PREFIX_MP4,
+            /* toffset= */ filename.length() - (FILE_EXTENSION_PREFIX_MP4.length() + 1))
+        || filename.startsWith(
+            FILE_EXTENSION_PREFIX_CMF,
+            /* toffset= */ filename.length() - (FILE_EXTENSION_PREFIX_CMF.length() + 1))) {
+      return FILE_FORMAT_MP4;
+    } else if (filename.startsWith(
+            FILE_EXTENSION_PREFIX_OG,
+            /* toffset= */ filename.length() - (FILE_EXTENSION_PREFIX_OG.length() + 1))
+        || filename.endsWith(FILE_EXTENSION_OPUS)) {
+      return FILE_FORMAT_OGG;
+    } else if (filename.endsWith(FILE_EXTENSION_PS)
+        || filename.endsWith(FILE_EXTENSION_MPEG)
+        || filename.endsWith(FILE_EXTENSION_MPG)
+        || filename.endsWith(FILE_EXTENSION_M2P)) {
+      return FILE_FORMAT_PS;
+    } else if (filename.endsWith(FILE_EXTENSION_TS)
+        || filename.startsWith(
+            FILE_EXTENSION_PREFIX_TS,
+            /* toffset= */ filename.length() - (FILE_EXTENSION_PREFIX_TS.length() + 1))) {
+      return FILE_FORMAT_TS;
+    } else if (filename.endsWith(FILE_EXTENSION_WAV) || filename.endsWith(FILE_EXTENSION_WAVE)) {
+      return FILE_FORMAT_WAV;
+    } else if (filename.endsWith(FILE_EXTENSION_VTT) || filename.endsWith(FILE_EXTENSION_WEBVTT)) {
+      return FILE_FORMAT_WEBVTT;
+    } else {
+      return FILE_FORMAT_UNKNOWN;
+    }
+  }
+}

library/common/src/test/java/com/google/android/exoplayer2/util/FilenameUtilTest.java

+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * 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.android.exoplayer2.util;
+
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_MATROSKA;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_MP3;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_UNKNOWN;
+import static com.google.android.exoplayer2.util.FilenameUtil.getFormatFromExtension;
+import static com.google.common.truth.Truth.assertThat;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Tests for {@link FilenameUtilTest}. */
+@RunWith(AndroidJUnit4.class)
+public class FilenameUtilTest {
+
+  @Test
+  public void getFormatFromExtension_withExtension_returnsExpectedFormat() {
+    assertThat(getFormatFromExtension("filename.mp3")).isEqualTo(FILE_FORMAT_MP3);
+  }
+
+  @Test
+  public void getFormatFromExtension_withExtensionPrefix_returnsExpectedFormat() {
+    assertThat(getFormatFromExtension("filename.mka")).isEqualTo(FILE_FORMAT_MATROSKA);
+  }
+
+  @Test
+  public void getFormatFromExtension_unknownExtension_returnsUnknownFormat() {
+    assertThat(getFormatFromExtension("filename.unknown")).isEqualTo(FILE_FORMAT_UNKNOWN);
+  }
+}

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/DefaultHlsExtractorFactory.java

@@ -15,6 +15,15 @@
  */
 package com.google.android.exoplayer2.source.hls;
 
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_AC3;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_AC4;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_ADTS;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_MP3;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_MP4;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_TS;
+import static com.google.android.exoplayer2.util.FilenameUtil.FILE_FORMAT_WEBVTT;
+import static com.google.android.exoplayer2.util.FilenameUtil.getFormatFromExtension;
+
 import android.net.Uri;
 import android.text.TextUtils;
 import androidx.annotation.Nullable;
@@ -30,6 +39,7 @@ import com.google.android.exoplayer2.extractor.ts.DefaultTsPayloadReaderFactory;
 import com.google.android.exoplayer2.extractor.ts.TsExtractor;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.android.exoplayer2.util.FilenameUtil;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.TimestampAdjuster;
 import java.io.EOFException;
@@ -43,20 +53,6 @@ import java.util.Map;
  */
 public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
 
-  public static final String AAC_FILE_EXTENSION = ".aac";
-  public static final String AC3_FILE_EXTENSION = ".ac3";
-  public static final String EC3_FILE_EXTENSION = ".ec3";
-  public static final String AC4_FILE_EXTENSION = ".ac4";
-  public static final String MP3_FILE_EXTENSION = ".mp3";
-  public static final String MP4_FILE_EXTENSION = ".mp4";
-  public static final String M4_FILE_EXTENSION_PREFIX = ".m4";
-  public static final String MP4_FILE_EXTENSION_PREFIX = ".mp4";
-  public static final String CMF_FILE_EXTENSION_PREFIX = ".cmf";
-  public static final String TS_FILE_EXTENSION = ".ts";
-  public static final String TS_FILE_EXTENSION_PREFIX = ".ts";
-  public static final String VTT_FILE_EXTENSION = ".vtt";
-  public static final String WEBVTT_FILE_EXTENSION = ".webvtt";
-
   @DefaultTsPayloadReaderFactory.Flags private final int payloadReaderFactoryFlags;
   private final boolean exposeCea608WhenMissingDeclarations;
 
@@ -196,39 +192,37 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
       Format format,
       @Nullable List<Format> muxedCaptionFormats,
       TimestampAdjuster timestampAdjuster) {
-    String lastPathSegment = uri.getLastPathSegment();
-    if (lastPathSegment == null) {
-      lastPathSegment = "";
-    }
-    if (MimeTypes.TEXT_VTT.equals(format.sampleMimeType)
-        || lastPathSegment.endsWith(WEBVTT_FILE_EXTENSION)
-        || lastPathSegment.endsWith(VTT_FILE_EXTENSION)) {
+    if (MimeTypes.TEXT_VTT.equals(format.sampleMimeType)) {
       return new WebvttExtractor(format.language, timestampAdjuster);
-    } else if (lastPathSegment.endsWith(AAC_FILE_EXTENSION)) {
-      return new AdtsExtractor();
-    } else if (lastPathSegment.endsWith(AC3_FILE_EXTENSION)
-        || lastPathSegment.endsWith(EC3_FILE_EXTENSION)) {
-      return new Ac3Extractor();
-    } else if (lastPathSegment.endsWith(AC4_FILE_EXTENSION)) {
-      return new Ac4Extractor();
-    } else if (lastPathSegment.endsWith(MP3_FILE_EXTENSION)) {
-      return new Mp3Extractor(/* flags= */ 0, /* forcedFirstSampleTimestampUs= */ 0);
-    } else if (lastPathSegment.endsWith(MP4_FILE_EXTENSION)
-        || lastPathSegment.startsWith(M4_FILE_EXTENSION_PREFIX, lastPathSegment.length() - 4)
-        || lastPathSegment.startsWith(MP4_FILE_EXTENSION_PREFIX, lastPathSegment.length() - 5)
-        || lastPathSegment.startsWith(CMF_FILE_EXTENSION_PREFIX, lastPathSegment.length() - 5)) {
-      return createFragmentedMp4Extractor(timestampAdjuster, format, muxedCaptionFormats);
-    } else if (lastPathSegment.endsWith(TS_FILE_EXTENSION)
-        || lastPathSegment.startsWith(TS_FILE_EXTENSION_PREFIX, lastPathSegment.length() - 4)) {
-      return createTsExtractor(
-          payloadReaderFactoryFlags,
-          exposeCea608WhenMissingDeclarations,
-          format,
-          muxedCaptionFormats,
-          timestampAdjuster);
-    } else {
+    }
+    String filename = uri.getLastPathSegment();
+    if (filename == null) {
       return null;
     }
+    @FilenameUtil.FileFormat int fileFormat = getFormatFromExtension(filename);
+    switch (fileFormat) {
+      case FILE_FORMAT_WEBVTT:
+        return new WebvttExtractor(format.language, timestampAdjuster);
+      case FILE_FORMAT_ADTS:
+        return new AdtsExtractor();
+      case FILE_FORMAT_AC3:
+        return new Ac3Extractor();
+      case FILE_FORMAT_AC4:
+        return new Ac4Extractor();
+      case FILE_FORMAT_MP3:
+        return new Mp3Extractor(/* flags= */ 0, /* forcedFirstSampleTimestampUs= */ 0);
+      case FILE_FORMAT_MP4:
+        return createFragmentedMp4Extractor(timestampAdjuster, format, muxedCaptionFormats);
+      case FILE_FORMAT_TS:
+        return createTsExtractor(
+            payloadReaderFactoryFlags,
+            exposeCea608WhenMissingDeclarations,
+            format,
+            muxedCaptionFormats,
+            timestampAdjuster);
+      default:
+        return null;
+    }
   }
 
   private static TsExtractor createTsExtractor(