Fix flakiness in HlsPlaybackTest and DashPlaybackTest

The tests became more flaky after 76e4abe428, likely because playback
was able to start slightly earlier, exaggerating any existing race
conditions. Fix the flakiness by letting all tests with subtitle
parsing wait until all data is fully loaded before starting to play.

PiperOrigin-RevId: 693380656

libraries/exoplayer_dash/src/test/java/androidx/media3/exoplayer/dash/e2etest/DashPlaybackTest.java

@@ -94,8 +94,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/standalone-webvtt/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -132,6 +135,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/standalone-webvtt/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -169,6 +177,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/standalone-webvtt/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -204,8 +217,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/standalone-ttml/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -233,8 +249,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/webvtt-in-mp4/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -261,8 +280,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/ttml-in-mp4/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -299,6 +321,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/ttml-in-mp4/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -336,6 +363,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/ttml-in-mp4/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -378,8 +410,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/cea608/manifest.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -416,8 +451,11 @@ public final class DashPlaybackTest {
     trackSelector.setParameters(trackSelector.buildUponParameters().setPreferredTextLanguage("en"));
     player.setMediaItem(MediaItem.fromUri("asset:///media/dash/cea608/manifest.mpd"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -651,8 +689,11 @@ public final class DashPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/dash/multi-period-with-offset/sample.mpd"));
     player.prepare();
+    // Ensure media is fully buffered to avoid flakiness from loading second period too late.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 

libraries/exoplayer_hls/src/test/java/androidx/media3/exoplayer/hls/e2etest/HlsPlaybackTest.java

@@ -84,8 +84,11 @@ public final class HlsPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/hls/standalone-webvtt/multivariant_playlist.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -120,6 +123,11 @@ public final class HlsPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/hls/standalone-webvtt/multivariant_playlist.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -155,6 +163,11 @@ public final class HlsPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/hls/standalone-webvtt/multivariant_playlist.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -184,8 +197,11 @@ public final class HlsPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/hls/ttml-in-mp4/multivariant_playlist.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -219,6 +235,11 @@ public final class HlsPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/hls/ttml-in-mp4/multivariant_playlist.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -253,6 +274,11 @@ public final class HlsPlaybackTest {
     player.setMediaItem(
         MediaItem.fromUri("asset:///media/hls/ttml-in-mp4/multivariant_playlist.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player)
+        .ignoringNonFatalErrors()
+        .untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).ignoringNonFatalErrors().untilLoadingIs(false);
     player.play();
     run(player).ignoringNonFatalErrors().untilState(Player.STATE_ENDED);
     player.release();
@@ -291,8 +317,11 @@ public final class HlsPlaybackTest {
 
     player.setMediaItem(MediaItem.fromUri("asset:///media/hls/cea608/manifest.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();
 
@@ -325,8 +354,11 @@ public final class HlsPlaybackTest {
 
     player.setMediaItem(MediaItem.fromUri("asset:///media/hls/cea608/manifest.m3u8"));
     player.prepare();
+    // Ensure media is fully buffered so that the first subtitle is ready at the start of playback.
+    run(player).untilBackgroundThreadCondition(() -> player.getBufferedPercentage() == 100);
+    run(player).untilLoadingIs(false);
     player.play();
-    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    run(player).untilState(Player.STATE_ENDED);
     player.release();
     surface.release();