Disable live speed adjustment where it has no benefit

Live speed adjustment is used for all live playback at the moment,
but has no user visible effect if the media is not played with low
latency. To avoid unnecessary adjustment during playback without
benefit, this change restricts the live speed adjustment to cases
where either the user requested a speed value in the MediaItem or the
media specifically defined a low-latency stream.

Issue: google/ExoPlayer#9329
PiperOrigin-RevId: 421514283

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/DefaultLivePlaybackSpeedControl.java

@@ -311,6 +311,10 @@ public void setLiveConfiguration(LiveConfiguration liveConfiguration) {
         liveConfiguration.maxPlaybackSpeed != C.RATE_UNSET
             ? liveConfiguration.maxPlaybackSpeed
             : fallbackMaxPlaybackSpeed;
+    if (minPlaybackSpeed == 1f && maxPlaybackSpeed == 1f) {
+      // Don't bother calculating adjustments if it's not possible to change the speed.
+      mediaConfigurationTargetLiveOffsetUs = C.TIME_UNSET;
+    }
     maybeResetTargetLiveOffsetUs();
   }
 

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/DefaultLivePlaybackSpeedControlTest.java

@@ -49,8 +49,8 @@ public void getTargetLiveOffsetUs_afterSetLiveConfiguration_returnsMediaLiveOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     assertThat(defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs()).isEqualTo(42_000);
@@ -66,8 +66,8 @@ public void getTargetLiveOffsetUs_afterSetLiveConfiguration_returnsMediaLiveOffs
             .setTargetOffsetMs(4321)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     assertThat(defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs()).isEqualTo(400_000);
@@ -83,8 +83,8 @@ public void getTargetLiveOffsetUs_afterSetLiveConfiguration_returnsMediaLiveOffs
             .setTargetOffsetMs(3)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     assertThat(defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs()).isEqualTo(5_000);
@@ -101,8 +101,8 @@ public void getTargetLiveOffsetUs_afterSetTargetLiveOffsetOverrideUs_returnsOver
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     long targetLiveOffsetUs = defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs();
@@ -122,8 +122,8 @@ public void getTargetLiveOffsetUs_afterSetTargetLiveOffsetOverrideUs_returnsOver
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     long targetLiveOffsetUs = defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs();
@@ -143,8 +143,8 @@ public void getTargetLiveOffsetUs_afterSetTargetLiveOffsetOverrideUs_returnsOver
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     long targetLiveOffsetUs = defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs();
@@ -164,6 +164,22 @@ public void getTargetLiveOffsetUs_afterSetTargetLiveOffsetOverrideUs_returnsOver
     assertThat(targetLiveOffsetUs).isEqualTo(C.TIME_UNSET);
   }
 
+  @Test
+  public void getTargetLiveOffsetUs_withUnitSpeed_returnsUnset() {
+    DefaultLivePlaybackSpeedControl defaultLivePlaybackSpeedControl =
+        new DefaultLivePlaybackSpeedControl.Builder().build();
+    defaultLivePlaybackSpeedControl.setLiveConfiguration(
+        new LiveConfiguration.Builder()
+            .setTargetOffsetMs(42)
+            .setMinPlaybackSpeed(1f)
+            .setMaxPlaybackSpeed(1f)
+            .build());
+
+    long targetLiveOffsetUs = defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs();
+
+    assertThat(targetLiveOffsetUs).isEqualTo(C.TIME_UNSET);
+  }
+
   @Test
   public void
       getTargetLiveOffsetUs_afterSetTargetLiveOffsetOverrideWithTimeUnset_returnsMediaLiveOffset() {
@@ -175,8 +191,8 @@ public void getTargetLiveOffsetUs_afterSetTargetLiveOffsetOverrideUs_returnsOver
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
     defaultLivePlaybackSpeedControl.setTargetLiveOffsetOverrideUs(C.TIME_UNSET);
 
@@ -196,8 +212,8 @@ public void getTargetLiveOffsetUs_afterNotifyRebuffer_returnsIncreasedTargetOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     long targetLiveOffsetBeforeUs = defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs();
@@ -219,8 +235,8 @@ public void getTargetLiveOffsetUs_afterRepeatedNotifyRebuffer_returnsMaxLiveOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     List<Long> targetOffsetsUs = new ArrayList<>();
@@ -245,8 +261,8 @@ public void getTargetLiveOffsetUs_afterRepeatedNotifyRebuffer_returnsMaxLiveOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     defaultLivePlaybackSpeedControl.notifyRebuffer();
@@ -267,8 +283,8 @@ public void getTargetLiveOffsetUs_afterRepeatedNotifyRebuffer_returnsMaxLiveOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     defaultLivePlaybackSpeedControl.notifyRebuffer();
@@ -290,8 +306,8 @@ public void getTargetLiveOffsetUs_afterRepeatedNotifyRebuffer_returnsMaxLiveOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     long targetLiveOffsetBeforeUs = defaultLivePlaybackSpeedControl.getTargetLiveOffsetUs();
@@ -322,8 +338,8 @@ public void getTargetLiveOffsetUs_afterRepeatedNotifyRebuffer_returnsMaxLiveOffs
             .setTargetOffsetMs(42)
             .setMinOffsetMs(5)
             .setMaxOffsetMs(400)
-            .setMinPlaybackSpeed(1f)
-            .setMaxPlaybackSpeed(1f)
+            .setMinPlaybackSpeed(0.95f)
+            .setMaxPlaybackSpeed(1.05f)
             .build());
 
     defaultLivePlaybackSpeedControl.notifyRebuffer();

libraries/exoplayer_dash/src/main/java/androidx/media3/exoplayer/dash/DashMediaSource.java

@@ -802,7 +802,7 @@ private void processManifest(boolean scheduleRefresh) {
           nowUnixTimeUs
               - Util.msToUs(manifest.availabilityStartTimeMs)
               - windowStartTimeInManifestUs;
-      updateMediaItemLiveConfiguration(nowInWindowUs, windowDurationUs);
+      updateLiveConfiguration(nowInWindowUs, windowDurationUs);
       windowStartUnixTimeMs =
           manifest.availabilityStartTimeMs + Util.usToMs(windowStartTimeInManifestUs);
       windowDefaultPositionUs = nowInWindowUs - Util.msToUs(liveConfiguration.targetOffsetMs);
@@ -861,7 +861,7 @@ private void processManifest(boolean scheduleRefresh) {
     }
   }
 
-  private void updateMediaItemLiveConfiguration(long nowInWindowUs, long windowDurationUs) {
+  private void updateLiveConfiguration(long nowInWindowUs, long windowDurationUs) {
     // Default maximum offset: start of window.
     long maxPossibleLiveOffsetMs = usToMs(nowInWindowUs);
     long maxLiveOffsetMs = maxPossibleLiveOffsetMs;
@@ -936,6 +936,16 @@ private void updateMediaItemLiveConfiguration(long nowInWindowUs, long windowDur
     } else if (manifest.serviceDescription != null) {
       maxPlaybackSpeed = manifest.serviceDescription.maxPlaybackSpeed;
     }
+    if (minPlaybackSpeed == C.RATE_UNSET
+        && maxPlaybackSpeed == C.RATE_UNSET
+        && (manifest.serviceDescription == null
+            || manifest.serviceDescription.targetOffsetMs == C.TIME_UNSET)) {
+      // Force unit speed (instead of automatic adjustment with fallback speeds) if there are no
+      // specific speed limits defined by the media item or the manifest, and the manifest contains
+      // no low-latency target offset either.
+      minPlaybackSpeed = 1f;
+      maxPlaybackSpeed = 1f;
+    }
     liveConfiguration =
         new MediaItem.LiveConfiguration.Builder()
             .setTargetOffsetMs(targetOffsetMs)

libraries/exoplayer_dash/src/test/java/androidx/media3/exoplayer/dash/DashMediaSourceTest.java

@@ -22,6 +22,7 @@
 import android.net.Uri;
 import androidx.media3.common.C;
 import androidx.media3.common.MediaItem;
+import androidx.media3.common.MediaItem.LiveConfiguration;
 import androidx.media3.common.ParserException;
 import androidx.media3.common.Timeline;
 import androidx.media3.common.Timeline.Window;
@@ -140,7 +141,7 @@ public void factorySetFallbackTargetLiveOffsetMs_doesNotChangeMediaItem() {
   }
 
   @Test
-  public void prepare_withoutLiveConfiguration_withoutMediaItemLiveProperties_usesDefaultFallback()
+  public void prepare_withoutLiveConfiguration_withoutMediaItemLiveConfiguration_usesUnitSpeed()
       throws InterruptedException {
     DashMediaSource mediaSource =
         new DashMediaSource.Factory(
@@ -154,26 +155,79 @@ public void prepare_withoutLiveConfiguration_withoutMediaItemLiveProperties_uses
         .isEqualTo(DashMediaSource.DEFAULT_FALLBACK_TARGET_LIVE_OFFSET_MS);
     assertThat(liveConfiguration.minOffsetMs).isEqualTo(0L);
     assertThat(liveConfiguration.maxOffsetMs).isEqualTo(58_000L);
-    assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
-    assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
+    assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(1f);
+    assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(1f);
+  }
+
+  @Test
+  public void prepare_withoutLiveConfiguration_withOnlyMediaItemTargetOffset_usesUnitSpeed()
+      throws InterruptedException {
+    DashMediaSource mediaSource =
+        new DashMediaSource.Factory(
+                () -> createSampleMpdDataSource(SAMPLE_MPD_LIVE_WITHOUT_LIVE_CONFIGURATION))
+            .createMediaSource(
+                new MediaItem.Builder()
+                    .setUri(Uri.EMPTY)
+                    .setLiveConfiguration(
+                        new LiveConfiguration.Builder().setTargetOffsetMs(10_000L).build())
+                    .build());
+
+    MediaItem.LiveConfiguration liveConfiguration =
+        prepareAndWaitForTimelineRefresh(mediaSource).liveConfiguration;
+
+    assertThat(liveConfiguration.targetOffsetMs).isEqualTo(10_000L);
+    assertThat(liveConfiguration.minOffsetMs).isEqualTo(0L);
+    assertThat(liveConfiguration.maxOffsetMs).isEqualTo(58_000L);
+    assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(1f);
+    assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(1f);
   }
 
   @Test
-  public void prepare_withoutLiveConfiguration_withoutMediaItemLiveProperties_usesFallback()
+  public void prepare_withoutLiveConfiguration_withMediaItemSpeedLimits_usesDefaultFallbackValues()
       throws InterruptedException {
+    DashMediaSource mediaSource =
+        new DashMediaSource.Factory(
+                () -> createSampleMpdDataSource(SAMPLE_MPD_LIVE_WITHOUT_LIVE_CONFIGURATION))
+            .createMediaSource(
+                new MediaItem.Builder()
+                    .setUri(Uri.EMPTY)
+                    .setLiveConfiguration(
+                        new LiveConfiguration.Builder().setMinPlaybackSpeed(0.95f).build())
+                    .build());
+
+    MediaItem.LiveConfiguration liveConfiguration =
+        prepareAndWaitForTimelineRefresh(mediaSource).liveConfiguration;
+
+    assertThat(liveConfiguration.targetOffsetMs)
+        .isEqualTo(DashMediaSource.DEFAULT_FALLBACK_TARGET_LIVE_OFFSET_MS);
+    assertThat(liveConfiguration.minOffsetMs).isEqualTo(0L);
+    assertThat(liveConfiguration.maxOffsetMs).isEqualTo(58_000L);
+    assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(0.95f);
+    assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
+  }
+
+  @Test
+  public void
+      prepare_withoutLiveConfiguration_withoutMediaItemTargetOffset_usesDefinedFallbackTargetOffset()
+          throws InterruptedException {
     DashMediaSource mediaSource =
         new DashMediaSource.Factory(
                 () -> createSampleMpdDataSource(SAMPLE_MPD_LIVE_WITHOUT_LIVE_CONFIGURATION))
             .setFallbackTargetLiveOffsetMs(1234L)
-            .createMediaSource(MediaItem.fromUri(Uri.EMPTY));
+            .createMediaSource(
+                new MediaItem.Builder()
+                    .setUri(Uri.EMPTY)
+                    .setLiveConfiguration(
+                        new LiveConfiguration.Builder().setMinPlaybackSpeed(0.95f).build())
+                    .build());
 
     MediaItem.LiveConfiguration liveConfiguration =
         prepareAndWaitForTimelineRefresh(mediaSource).liveConfiguration;
 
     assertThat(liveConfiguration.targetOffsetMs).isEqualTo(1234L);
     assertThat(liveConfiguration.minOffsetMs).isEqualTo(0L);
     assertThat(liveConfiguration.maxOffsetMs).isEqualTo(58_000L);
-    assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
+    assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(0.95f);
     assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
   }
 
@@ -213,7 +267,12 @@ public void prepare_withSuggestedPresentationDelayAndMinBufferTime_usesManifestV
                     createSampleMpdDataSource(
                         SAMPLE_MPD_LIVE_WITH_SUGGESTED_PRESENTATION_DELAY_2S_MIN_BUFFER_TIME_500MS))
             .setFallbackTargetLiveOffsetMs(1234L)
-            .createMediaSource(MediaItem.fromUri(Uri.EMPTY));
+            .createMediaSource(
+                new MediaItem.Builder()
+                    .setUri(Uri.EMPTY)
+                    .setLiveConfiguration(
+                        new LiveConfiguration.Builder().setMaxPlaybackSpeed(1.05f).build())
+                    .build());
 
     MediaItem.LiveConfiguration liveConfiguration =
         prepareAndWaitForTimelineRefresh(mediaSource).liveConfiguration;
@@ -222,7 +281,7 @@ public void prepare_withSuggestedPresentationDelayAndMinBufferTime_usesManifestV
     assertThat(liveConfiguration.minOffsetMs).isEqualTo(500L);
     assertThat(liveConfiguration.maxOffsetMs).isEqualTo(58_000L);
     assertThat(liveConfiguration.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
-    assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
+    assertThat(liveConfiguration.maxPlaybackSpeed).isEqualTo(1.05f);
   }
 
   @Test

libraries/exoplayer_hls/src/main/java/androidx/media3/exoplayer/hls/HlsMediaSource.java

@@ -25,6 +25,7 @@
 import androidx.annotation.VisibleForTesting;
 import androidx.media3.common.C;
 import androidx.media3.common.MediaItem;
+import androidx.media3.common.MediaItem.LiveConfiguration;
 import androidx.media3.common.MediaLibraryInfo;
 import androidx.media3.common.StreamKey;
 import androidx.media3.common.util.UnstableApi;
@@ -476,7 +477,7 @@ private SinglePeriodTimeline createTimelineForLive(
     targetLiveOffsetUs =
         Util.constrainValue(
             targetLiveOffsetUs, liveEdgeOffsetUs, playlist.durationUs + liveEdgeOffsetUs);
-    maybeUpdateLiveConfiguration(targetLiveOffsetUs);
+    updateLiveConfiguration(playlist, targetLiveOffsetUs);
     long windowDefaultStartPositionUs =
         getLiveWindowDefaultStartPositionUs(playlist, liveEdgeOffsetUs);
     boolean suppressPositionProjection =
@@ -566,12 +567,18 @@ private long getLiveWindowDefaultStartPositionUs(
     return segment.relativeStartTimeUs;
   }
 
-  private void maybeUpdateLiveConfiguration(long targetLiveOffsetUs) {
-    long targetLiveOffsetMs = Util.usToMs(targetLiveOffsetUs);
-    if (targetLiveOffsetMs != liveConfiguration.targetOffsetMs) {
-      liveConfiguration =
-          liveConfiguration.buildUpon().setTargetOffsetMs(targetLiveOffsetMs).build();
-    }
+  private void updateLiveConfiguration(HlsMediaPlaylist playlist, long targetLiveOffsetUs) {
+    boolean disableSpeedAdjustment =
+        mediaItem.liveConfiguration.minPlaybackSpeed == C.RATE_UNSET
+            && mediaItem.liveConfiguration.maxPlaybackSpeed == C.RATE_UNSET
+            && playlist.serverControl.holdBackUs == C.TIME_UNSET
+            && playlist.serverControl.partHoldBackUs == C.TIME_UNSET;
+    liveConfiguration =
+        new LiveConfiguration.Builder()
+            .setTargetOffsetMs(Util.usToMs(targetLiveOffsetUs))
+            .setMinPlaybackSpeed(disableSpeedAdjustment ? 1f : liveConfiguration.minPlaybackSpeed)
+            .setMaxPlaybackSpeed(disableSpeedAdjustment ? 1f : liveConfiguration.maxPlaybackSpeed)
+            .build();
   }
 
   /**