Clean up Util.inferContentType methods

This fixes some small niggles:
1. `inferContentType(String)` is documented to take a path, but in the
   tests we're passing full URIs.
2. A `String` parameter is usually a path, but also a MIME type or an
   extension. In the new methods, the meaning of a `String` parameter
   is always clear from the name of the method.
3. `inferContentType(String)` is always passed an extension in
   'production' code (which has to be manually prefixed with a dot).
4. `inferContentType(Uri, @Nullable String)` always ignores the Uri if
   the String is non-null. IMO this logic is clearer to a reader if it's
   just in-lined at the call-site.

These methods are used from the demo apps, so will be part of the stable
API.

PiperOrigin-RevId: 444826053

demos/gl/src/main/java/com/google/android/exoplayer2/gldemo/MainActivity.java

@@ -20,6 +20,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
+import android.text.TextUtils;
 import android.widget.FrameLayout;
 import android.widget.Toast;
 import androidx.annotation.Nullable;
@@ -156,7 +157,12 @@ public final class MainActivity extends Activity {
 
     DataSource.Factory dataSourceFactory = new DefaultDataSource.Factory(this);
     MediaSource mediaSource;
-    @C.ContentType int type = Util.inferContentType(uri, intent.getStringExtra(EXTENSION_EXTRA));
+    @Nullable String fileExtension = intent.getStringExtra(EXTENSION_EXTRA);
+    @C.ContentType
+    int type =
+        TextUtils.isEmpty(fileExtension)
+            ? Util.inferContentType(uri)
+            : Util.inferContentTypeForExtension(fileExtension);
     if (type == C.TYPE_DASH) {
       mediaSource =
           new DashMediaSource.Factory(dataSourceFactory)

demos/main/src/main/java/com/google/android/exoplayer2/demo/SampleChooserActivity.java

@@ -27,6 +27,7 @@ import android.content.res.AssetManager;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
+import android.text.TextUtils;
 import android.util.JsonReader;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -440,7 +441,10 @@ public class SampleChooserActivity extends AppCompatActivity
       } else {
         @Nullable
         String adaptiveMimeType =
-            Util.getAdaptiveMimeTypeForContentType(Util.inferContentType(uri, extension));
+            Util.getAdaptiveMimeTypeForContentType(
+                TextUtils.isEmpty(extension)
+                    ? Util.inferContentType(uri)
+                    : Util.inferContentTypeForExtension(extension));
         mediaItem
             .setUri(uri)
             .setMediaMetadata(new MediaMetadata.Builder().setTitle(title).build())

demos/surface/src/main/java/com/google/android/exoplayer2/surfacedemo/MainActivity.java

@@ -19,6 +19,7 @@ import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
+import android.text.TextUtils;
 import android.view.Surface;
 import android.view.SurfaceControl;
 import android.view.SurfaceHolder;
@@ -201,7 +202,12 @@ public final class MainActivity extends Activity {
 
     DataSource.Factory dataSourceFactory = new DefaultDataSource.Factory(this);
     MediaSource mediaSource;
-    @C.ContentType int type = Util.inferContentType(uri, intent.getStringExtra(EXTENSION_EXTRA));
+    @Nullable String fileExtension = intent.getStringExtra(EXTENSION_EXTRA);
+    @C.ContentType
+    int type =
+        TextUtils.isEmpty(fileExtension)
+            ? Util.inferContentType(uri)
+            : Util.inferContentTypeForExtension(fileExtension);
     if (type == C.TYPE_DASH) {
       mediaSource =
           new DashMediaSource.Factory(dataSourceFactory)

library/common/src/main/java/com/google/android/exoplayer2/C.java

@@ -722,18 +722,15 @@ public final class C {
   @Target({FIELD, METHOD, PARAMETER, LOCAL_VARIABLE, TYPE_USE})
   @IntDef({TYPE_DASH, TYPE_SS, TYPE_HLS, TYPE_RTSP, TYPE_OTHER})
   public @interface ContentType {}
-  /** Value returned by {@link Util#inferContentType} for DASH manifests. */
+  /** Value representing a DASH manifest. */
   public static final int TYPE_DASH = 0;
-  /** Value returned by {@link Util#inferContentType} for Smooth Streaming manifests. */
+  /** Value representing a Smooth Streaming manifest. */
   public static final int TYPE_SS = 1;
-  /** Value returned by {@link Util#inferContentType} for HLS manifests. */
+  /** Value representing an HLS manifest. */
   public static final int TYPE_HLS = 2;
-  /** Value returned by {@link Util#inferContentType} for RTSP. */
+  /** Value representing an RTSP stream. */
   public static final int TYPE_RTSP = 3;
-  /**
+  /** Value representing files other than DASH, HLS or Smooth Streaming manifests, or RTSP URIs. */
-   * Value returned by {@link Util#inferContentType} for files other than DASH, HLS or Smooth
-   * Streaming manifests, or RTSP URIs.
-   */
   public static final int TYPE_OTHER = 4;
 
   /** A return value for methods where the end of an input was encountered. */

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

@@ -156,8 +156,9 @@ public final class Util {
               + "(T(([0-9]*)H)?(([0-9]*)M)?(([0-9.]*)S)?)?$");
   private static final Pattern ESCAPED_CHARACTER_PATTERN = Pattern.compile("%([A-Fa-f0-9]{2})");
 
-  // https://docs.microsoft.com/en-us/azure/media-services/previous/media-services-deliver-content-overview#URLs.
+  // https://docs.microsoft.com/en-us/azure/media-services/previous/media-services-deliver-content-overview#URLs
-  private static final Pattern ISM_URL_PATTERN = Pattern.compile(".*\\.isml?(?:/(manifest(.*))?)?");
+  private static final Pattern ISM_PATH_PATTERN =
+      Pattern.compile(".*\\.isml?(?:/(manifest(.*))?)?", Pattern.CASE_INSENSITIVE);
   private static final String ISM_HLS_FORMAT_EXTENSION = "format=m3u8-aapl";
   private static final String ISM_DASH_FORMAT_EXTENSION = "format=mpd-time-csf";
 
@@ -1818,16 +1819,14 @@ public final class Util {
   }
 
   /**
-   * Makes a best guess to infer the {@link ContentType} from a {@link Uri}.
+   * @deprecated Use {@link #inferContentTypeForExtension(String)} when {@code overrideExtension} is
-   *
+   *     non-empty, and {@link #inferContentType(Uri)} otherwise.
-   * @param uri The {@link Uri}.
-   * @param overrideExtension If not null, used to infer the type.
-   * @return The content type.
    */
+  @Deprecated
   public static @ContentType int inferContentType(Uri uri, @Nullable String overrideExtension) {
     return TextUtils.isEmpty(overrideExtension)
         ? inferContentType(uri)
-        : inferContentType("." + overrideExtension);
+        : inferContentTypeForExtension(overrideExtension);
   }
 
   /**
@@ -1843,23 +1842,19 @@ public final class Util {
     }
 
     @Nullable String path = uri.getPath();
-    return path == null ? C.TYPE_OTHER : inferContentType(path);
+    if (path == null) {
-  }
+      return C.TYPE_OTHER;
-
-  /**
-   * Makes a best guess to infer the {@link ContentType} from a file name.
-   *
-   * @param fileName Name of the file. It can include the path of the file.
-   * @return The content type.
-   */
-  public static @ContentType int inferContentType(String fileName) {
-    fileName = Ascii.toLowerCase(fileName);
-    if (fileName.endsWith(".mpd")) {
-      return C.TYPE_DASH;
-    } else if (fileName.endsWith(".m3u8")) {
-      return C.TYPE_HLS;
     }
-    Matcher ismMatcher = ISM_URL_PATTERN.matcher(fileName);
+    int lastDotIndex = path.lastIndexOf('.');
+    if (lastDotIndex >= 0) {
+      @C.ContentType
+      int contentType = inferContentTypeForExtension(path.substring(lastDotIndex + 1));
+      if (contentType != C.TYPE_OTHER) {
+        return contentType;
+      }
+    }
+
+    Matcher ismMatcher = ISM_PATH_PATTERN.matcher(path);
     if (ismMatcher.matches()) {
       @Nullable String extensions = ismMatcher.group(2);
       if (extensions != null) {
@@ -1871,6 +1866,31 @@ public final class Util {
       }
       return C.TYPE_SS;
     }
+
+    return C.TYPE_OTHER;
+  }
+
+  /**
+   * @deprecated Use {@link Uri#parse(String)} and {@link #inferContentType(Uri)} for full file
+   *     paths or {@link #inferContentTypeForExtension(String)} for extensions.
+   */
+  @Deprecated
+  public static @ContentType int inferContentType(String fileName) {
+    return inferContentType(Uri.parse("file:///" + fileName));
+  }
+
+  /**
+   * Makes a best guess to infer the {@link ContentType} from a file extension.
+   *
+   * @param fileExtension The extension of the file (excluding the '.').
+   * @return The content type.
+   */
+  public static @ContentType int inferContentTypeForExtension(String fileExtension) {
+    if (Ascii.equalsIgnoreCase("mpd", fileExtension)) {
+      return C.TYPE_DASH;
+    } else if (Ascii.equalsIgnoreCase("m3u8", fileExtension)) {
+      return C.TYPE_HLS;
+    }
     return C.TYPE_OTHER;
   }
 
@@ -1933,7 +1953,7 @@ public final class Util {
     if (path == null) {
       return uri;
     }
-    Matcher ismMatcher = ISM_URL_PATTERN.matcher(Ascii.toLowerCase(path));
+    Matcher ismMatcher = ISM_PATH_PATTERN.matcher(path);
     if (ismMatcher.matches() && ismMatcher.group(1) == null) {
       // Add missing "Manifest" suffix.
       return Uri.withAppendedPath(uri, "Manifest");

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

@@ -103,50 +103,103 @@ public class UtilTest {
 
   @Test
   public void inferContentType_handlesHlsIsmUris() {
-    assertThat(Util.inferContentType("http://a.b/c.ism/manifest(format=m3u8-aapl)"))
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism/manifest(format=m3u8-aapl)")))
         .isEqualTo(C.TYPE_HLS);
-    assertThat(Util.inferContentType("http://a.b/c.ism/manifest(format=m3u8-aapl,quality=hd)"))
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("http://a.b/c.ism/manifest(format=m3u8-aapl,quality=hd)")))
         .isEqualTo(C.TYPE_HLS);
-    assertThat(Util.inferContentType("http://a.b/c.ism/manifest(quality=hd,format=m3u8-aapl)"))
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("http://a.b/c.ism/manifest(quality=hd,format=m3u8-aapl)")))
         .isEqualTo(C.TYPE_HLS);
   }
 
   @Test
   public void inferContentType_handlesHlsIsmV3Uris() {
-    assertThat(Util.inferContentType("http://a.b/c.ism/manifest(format=m3u8-aapl-v3)"))
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism/manifest(format=m3u8-aapl-v3)")))
         .isEqualTo(C.TYPE_HLS);
-    assertThat(Util.inferContentType("http://a.b/c.ism/manifest(format=m3u8-aapl-v3,quality=hd)"))
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("http://a.b/c.ism/manifest(format=m3u8-aapl-v3,quality=hd)")))
         .isEqualTo(C.TYPE_HLS);
-    assertThat(Util.inferContentType("http://a.b/c.ism/manifest(quality=hd,format=m3u8-aapl-v3)"))
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("http://a.b/c.ism/manifest(quality=hd,format=m3u8-aapl-v3)")))
         .isEqualTo(C.TYPE_HLS);
   }
 
   @Test
   public void inferContentType_handlesDashIsmUris() {
-    assertThat(Util.inferContentType("http://a.b/c.isml/manifest(format=mpd-time-csf)"))
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.isml/manifest(format=mpd-time-csf)")))
         .isEqualTo(C.TYPE_DASH);
-    assertThat(Util.inferContentType("http://a.b/c.isml/manifest(format=mpd-time-csf,quality=hd)"))
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("http://a.b/c.isml/manifest(format=mpd-time-csf,quality=hd)")))
         .isEqualTo(C.TYPE_DASH);
-    assertThat(Util.inferContentType("http://a.b/c.isml/manifest(quality=hd,format=mpd-time-csf)"))
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("http://a.b/c.isml/manifest(quality=hd,format=mpd-time-csf)")))
         .isEqualTo(C.TYPE_DASH);
   }
 
   @Test
   public void inferContentType_handlesSmoothStreamingIsmUris() {
-    assertThat(Util.inferContentType("http://a.b/c.ism")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism"))).isEqualTo(C.TYPE_SS);
-    assertThat(Util.inferContentType("http://a.b/c.isml")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.isml"))).isEqualTo(C.TYPE_SS);
-    assertThat(Util.inferContentType("http://a.b/c.ism/")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism/"))).isEqualTo(C.TYPE_SS);
-    assertThat(Util.inferContentType("http://a.b/c.isml/")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.isml/"))).isEqualTo(C.TYPE_SS);
-    assertThat(Util.inferContentType("http://a.b/c.ism/Manifest")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism/Manifest"))).isEqualTo(C.TYPE_SS);
-    assertThat(Util.inferContentType("http://a.b/c.isml/manifest")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.isml/manifest"))).isEqualTo(C.TYPE_SS);
-    assertThat(Util.inferContentType("http://a.b/c.isml/manifest(filter=x)")).isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.isml/manifest(filter=x)")))
-    assertThat(Util.inferContentType("http://a.b/c.isml/manifest_hd")).isEqualTo(C.TYPE_SS);
+        .isEqualTo(C.TYPE_SS);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.isml/manifest_hd")))
+        .isEqualTo(C.TYPE_SS);
   }
 
   @Test
   public void inferContentType_handlesOtherIsmUris() {
-    assertThat(Util.inferContentType("http://a.b/c.ism/video.mp4")).isEqualTo(C.TYPE_OTHER);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism/video.mp4")))
-    assertThat(Util.inferContentType("http://a.b/c.ism/prefix-manifest")).isEqualTo(C.TYPE_OTHER);
+        .isEqualTo(C.TYPE_OTHER);
+    assertThat(Util.inferContentType(Uri.parse("http://a.b/c.ism/prefix-manifest")))
+        .isEqualTo(C.TYPE_OTHER);
+  }
+
+  /**
+   * Test that the deprecated {@link Util#inferContentType(String)} works when passed only a file
+   * extension and the leading dot.
+   */
+  @SuppressWarnings("deprecation")
+  @Test
+  public void inferContentType_extensionAsPath() {
+    assertThat(Util.inferContentType(".m3u8")).isEqualTo(C.TYPE_HLS);
+    assertThat(Util.inferContentType(".mpd")).isEqualTo(C.TYPE_DASH);
+    assertThat(Util.inferContentType(".mp4")).isEqualTo(C.TYPE_OTHER);
+  }
+
+  // Testing deprecated method.
+  @SuppressWarnings("deprecation")
+  @Test
+  public void inferContentType_extensionOverride() {
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("file:///path/to/something.mpd"), /* overrideExtension= */ null))
+        .isEqualTo(C.TYPE_DASH);
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("file:///path/to/something.mpd"), /* overrideExtension= */ ""))
+        .isEqualTo(C.TYPE_DASH);
+    assertThat(
+            Util.inferContentType(
+                Uri.parse("file:///path/to/something.mpd"), /* overrideExtension= */ "m3u8"))
+        .isEqualTo(C.TYPE_HLS);
+  }
+
+  @Test
+  public void inferContentTypeForExtension() {
+    assertThat(Util.inferContentTypeForExtension("m3u8")).isEqualTo(C.TYPE_HLS);
+    assertThat(Util.inferContentTypeForExtension("mpd")).isEqualTo(C.TYPE_DASH);
+    assertThat(Util.inferContentTypeForExtension("mp4")).isEqualTo(C.TYPE_OTHER);
   }
 
   @Test