From 408b4449ff75e29a9bda7adc1b530b993fc47814 Mon Sep 17 00:00:00 2001
From: tonihei <tonihei@google.com>
Date: Tue, 28 Feb 2023 11:15:05 +0000
Subject: [PATCH] Ensure getPlaybackHeadPosition isn't called if not needed

Once the value returned from AudioTimestampPoller advances, we
only need getPlaybackHeadPosition to sample sync params and
verify the returned timestamp. Both of these happen less often
and we can avoid calling getPlaybackHeadPosition if we don't
actually need it.

PiperOrigin-RevId: 512882170
---
 .../audio/AudioTrackPositionTracker.java          | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioTrackPositionTracker.java b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioTrackPositionTracker.java
index 98b6202060..414cf24d40 100644
--- a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioTrackPositionTracker.java
+++ b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioTrackPositionTracker.java
@@ -451,13 +451,13 @@ import java.lang.reflect.Method;
   }
 
   private void maybeSampleSyncParams() {
-    long playbackPositionUs = getPlaybackHeadPositionUs();
-    if (playbackPositionUs == 0) {
-      // The AudioTrack hasn't output anything yet.
-      return;
-    }
     long systemTimeUs = System.nanoTime() / 1000;
     if (systemTimeUs - lastPlayheadSampleTimeUs >= MIN_PLAYHEAD_OFFSET_SAMPLE_INTERVAL_US) {
+      long playbackPositionUs = getPlaybackHeadPositionUs();
+      if (playbackPositionUs == 0) {
+        // The AudioTrack hasn't output anything yet.
+        return;
+      }
       // Take a new sample and update the smoothed offset between the system clock and the playhead.
       playheadOffsets[nextPlayheadOffsetIndex] =
           Util.getPlayoutDurationForMediaDuration(playbackPositionUs, audioTrackPlaybackSpeed)
@@ -479,11 +479,11 @@ import java.lang.reflect.Method;
       return;
     }
 
-    maybePollAndCheckTimestamp(systemTimeUs, playbackPositionUs);
+    maybePollAndCheckTimestamp(systemTimeUs);
     maybeUpdateLatency(systemTimeUs);
   }
 
-  private void maybePollAndCheckTimestamp(long systemTimeUs, long playbackPositionUs) {
+  private void maybePollAndCheckTimestamp(long systemTimeUs) {
     AudioTimestampPoller audioTimestampPoller = checkNotNull(this.audioTimestampPoller);
     if (!audioTimestampPoller.maybePollTimestamp(systemTimeUs)) {
       return;
@@ -492,6 +492,7 @@ import java.lang.reflect.Method;
     // Check the timestamp and accept/reject it.
     long audioTimestampSystemTimeUs = audioTimestampPoller.getTimestampSystemTimeUs();
     long audioTimestampPositionFrames = audioTimestampPoller.getTimestampPositionFrames();
+    long playbackPositionUs = getPlaybackHeadPositionUs();
     if (Math.abs(audioTimestampSystemTimeUs - systemTimeUs) > MAX_AUDIO_TIMESTAMP_OFFSET_US) {
       listener.onSystemTimeUsMismatch(
           audioTimestampPositionFrames,