Optimize AAC seeking except for xHE-AAC

In 2.11.2 to 2.11.5, we considered all AAC streams as consisting
only of sync samples. In 2.11.6+, we considered no AAC streams as
consisting of sync samples, because the property is not guaranteed
specifically for xHE-AAC. This will have caused a small regression
is seek speed for some types of media.

This change brings back the optimization for AAC, specifically
excluding only xHE-AAC (and cases where we don't know what type of
AAC we're dealing with).

PiperOrigin-RevId: 328950697

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

@@ -170,15 +170,16 @@ public final class MimeTypes {
   }
   }
 
 
   /**
   /**
-   * Returns true if it is known that all samples in a stream of the given MIME type are guaranteed
-   * to be sync samples (i.e., {@link C#BUFFER_FLAG_KEY_FRAME} is guaranteed to be set on every
-   * sample).
+   * Returns true if it is known that all samples in a stream of the given MIME type and codec are
+   * guaranteed to be sync samples (i.e., {@link C#BUFFER_FLAG_KEY_FRAME} is guaranteed to be set on
+   * every sample).
    *
    *
-   * @param mimeType A MIME type.
-   * @return True if it is known that all samples in a stream of the given MIME type are guaranteed
-   *     to be sync samples. False otherwise, including if {@code null} is passed.
+   * @param mimeType The MIME type of the stream.
+   * @param codec The RFC 6381 codec string of the stream, or {@code null} if unknown.
+   * @return Whether it is known that all samples in the stream are guaranteed to be sync samples.
    */
    */
-  public static boolean allSamplesAreSyncSamples(@Nullable String mimeType) {
+  public static boolean allSamplesAreSyncSamples(
+      @Nullable String mimeType, @Nullable String codec) {
     if (mimeType == null) {
     if (mimeType == null) {
       return false;
       return false;
     }
     }
@@ -198,6 +199,20 @@ public final class MimeTypes {
       case AUDIO_E_AC3:
       case AUDIO_E_AC3:
       case AUDIO_E_AC3_JOC:
       case AUDIO_E_AC3_JOC:
         return true;
         return true;
+      case AUDIO_AAC:
+        if (codec == null) {
+          return false;
+        }
+        @Nullable Mp4aObjectType objectType = getObjectTypeFromMp4aRFC6381CodecString(codec);
+        if (objectType == null) {
+          return false;
+        }
+        @C.Encoding
+        int encoding = AacUtil.getEncodingForAudioObjectType(objectType.audioObjectTypeIndication);
+        // xHE-AAC is an exception in which it's not true that all samples will be sync samples.
+        // Also return false for ENCODING_INVALID, which indicates we weren't able to parse the
+        // encoding from the codec string.
+        return encoding != C.ENCODING_INVALID && encoding != C.ENCODING_AAC_XHE;
       default:
       default:
         return false;
         return false;
     }
     }

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

@@ -15,6 +15,8 @@
  */
  */
 package com.google.android.exoplayer2.util;
 package com.google.android.exoplayer2.util;
 
 
+import static android.media.MediaCodecInfo.CodecProfileLevel.AACObjectHE;
+import static android.media.MediaCodecInfo.CodecProfileLevel.AACObjectXHE;
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertThat;
 
 
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
@@ -171,4 +173,17 @@ public final class MimeTypesTest {
     assertThat(objectType.objectTypeIndication).isEqualTo(expectedObjectTypeIndicator);
     assertThat(objectType.objectTypeIndication).isEqualTo(expectedObjectTypeIndicator);
     assertThat(objectType.audioObjectTypeIndication).isEqualTo(expectedAudioObjectTypeIndicator);
     assertThat(objectType.audioObjectTypeIndication).isEqualTo(expectedAudioObjectTypeIndicator);
   }
   }
+
+  @Test
+  public void allSamplesAreSyncSamples_forAac_usesCodec() {
+    assertThat(MimeTypes.allSamplesAreSyncSamples(MimeTypes.AUDIO_AAC, "mp4a.40." + AACObjectHE))
+        .isTrue();
+    assertThat(MimeTypes.allSamplesAreSyncSamples(MimeTypes.AUDIO_AAC, "mp4a.40." + AACObjectXHE))
+        .isFalse();
+    assertThat(MimeTypes.allSamplesAreSyncSamples(MimeTypes.AUDIO_AAC, "mp4a.40")).isFalse();
+    assertThat(MimeTypes.allSamplesAreSyncSamples(MimeTypes.AUDIO_AAC, "mp4a.40.")).isFalse();
+    assertThat(MimeTypes.allSamplesAreSyncSamples(MimeTypes.AUDIO_AAC, "invalid")).isFalse();
+    assertThat(MimeTypes.allSamplesAreSyncSamples(MimeTypes.AUDIO_AAC, /* codec= */ null))
+        .isFalse();
+  }
 }
 }

library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaPeriod.java

@@ -264,7 +264,8 @@ public final class ClippingMediaPeriod implements MediaPeriod, MediaPeriod.Callb
       for (TrackSelection trackSelection : selections) {
       for (TrackSelection trackSelection : selections) {
         if (trackSelection != null) {
         if (trackSelection != null) {
           Format selectedFormat = trackSelection.getSelectedFormat();
           Format selectedFormat = trackSelection.getSelectedFormat();
-          if (!MimeTypes.allSamplesAreSyncSamples(selectedFormat.sampleMimeType)) {
+          if (!MimeTypes.allSamplesAreSyncSamples(
+              selectedFormat.sampleMimeType, selectedFormat.codecs)) {
             return true;
             return true;
           }
           }
         }
         }

library/core/src/main/java/com/google/android/exoplayer2/source/SampleQueue.java

@@ -659,7 +659,7 @@ public class SampleQueue implements TrackOutput {
       upstreamFormat = format;
       upstreamFormat = format;
     }
     }
     upstreamAllSamplesAreSyncSamples =
     upstreamAllSamplesAreSyncSamples =
-        MimeTypes.allSamplesAreSyncSamples(upstreamFormat.sampleMimeType);
+        MimeTypes.allSamplesAreSyncSamples(upstreamFormat.sampleMimeType, upstreamFormat.codecs);
     loggedUnexpectedNonSyncSample = false;
     loggedUnexpectedNonSyncSample = false;
     return true;
     return true;
   }
   }