From b1956113f5601b0cc6ac525d3918a0dfa8d240af Mon Sep 17 00:00:00 2001
From: Sven Gothel <sgothel@jausoft.com>
Date: Sun, 15 Oct 2023 07:06:53 +0200
Subject: Bug 1472: Enhance GLMediaPlayer AV Sync: Utilize SCR aware audio PTS
 used as master-clock, enabling proper AV sync w/ untouched audio

We can finally utilize the added pass through audio PTS, see commits
- GlueGen 52725b4c6525487f93407f529dc0a758b387a4fc
- JOAL 12029f1ec1d8afa576e1ac61655f318cc37c1d16

This enables us to use the audio PTS as the master-clock and adjust video to the untouched audio.

In case no audio is selected/playing or audio is muted,
we sync merely on the system-clock (SCR) w/o audio.

AV granularity is 22ms, however, since the ALAudioSink PTS may be a little late,
it renders even a slightly better sync in case of too early audio (d_apts < 0).

Since video frames are sync'ed to audio, the resync procedure may result
in a hysteresis swinging into sync. This might be notable at start
and when resumed audio or after seek.

We leave the audio frames untouched to reduce processing burden
and allow non-disrupted listening.

Passed AV sync tests
- Five-minute-sync-test.mp4
- Audio-Video-Sync-Test-Calibration-23.98fps-24fps.mp4
- Audio-Video-Sync-Test-2.mkv
---
 .../com/jogamp/opengl/util/av/GLMediaPlayer.java   | 29 ++++++++++++++++------
 1 file changed, 22 insertions(+), 7 deletions(-)

(limited to 'src/jogl/classes/com/jogamp/opengl/util/av/GLMediaPlayer.java')

diff --git a/src/jogl/classes/com/jogamp/opengl/util/av/GLMediaPlayer.java b/src/jogl/classes/com/jogamp/opengl/util/av/GLMediaPlayer.java
index 3e4d589f3..e3ef27303 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/av/GLMediaPlayer.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/av/GLMediaPlayer.java
@@ -137,10 +137,10 @@ import com.jogamp.opengl.util.texture.TextureSequence;
  * <p>
  * The class follows a passive A/V synchronization pattern.
  * Audio is being untouched, while {@link #getNextTexture(GL)} delivers a new video frame
- * only, if its timestamp is less than {@link #MAXIMUM_VIDEO_ASYNC} ahead of <i>time</i>.
- * If its timestamp is more than {@link #MAXIMUM_VIDEO_ASYNC} ahead of <i>time</i>,
+ * only, if its timestamp is less than {@link #MAX_VIDEO_ASYNC} ahead of <i>time</i>.
+ * If its timestamp is more than {@link #MAX_VIDEO_ASYNC} ahead of <i>time</i>,
  * the previous frame is returned.
- * If its timestamp is more than {@link #MAXIMUM_VIDEO_ASYNC} after <i>time</i>,
+ * If its timestamp is more than {@link #MAX_VIDEO_ASYNC} after <i>time</i>,
  * the frame is dropped and the next frame is being fetched.
  * </p>
  * <p>
@@ -253,7 +253,8 @@ public interface GLMediaPlayer extends TextureSequence {
     public static final String CameraPropRate = "rate";
 
     /** Maximum video frame async of {@value} milliseconds. */
-    public static final int MAXIMUM_VIDEO_ASYNC = 22;
+    public static final int MAX_VIDEO_ASYNC = 22;
+    public static final int MIN_VIDEO_ASYNC = 11;
 
     /**
      * A StreamException encapsulates a caught exception in the decoder thread, a.k.a <i>StreamWorker</i>,
@@ -612,12 +613,22 @@ public interface GLMediaPlayer extends TextureSequence {
     public int getPresentedFrameCount();
 
     /**
-     * @return current video presentation timestamp (PTS) in milliseconds of {@link #getLastTexture()}
+     * Returns current video presentation timestamp (PTS) in milliseconds of {@link #getLastTexture()}
+     * <p>
+     * The relative millisecond PTS since start of the presentation stored in integer
+     * covers a time span of 2'147'483'647 ms (see {@link Integer#MAX_VALUE}
+     * or 2'147'483 seconds or 24.855 days.
+     * </p>
      **/
     public int getVideoPTS();
 
     /**
-     * @return current audio presentation timestamp (PTS) in milliseconds.
+     * Returns current audio presentation timestamp (PTS) in milliseconds.
+     * <p>
+     * The relative millisecond PTS since start of the presentation stored in integer
+     * covers a time span of 2'147'483'647 ms (see {@link Integer#MAX_VALUE}
+     * or 2'147'483 seconds or 24.855 days.
+     * </p>
      **/
     public int getAudioPTS();
 
@@ -679,7 +690,11 @@ public interface GLMediaPlayer extends TextureSequence {
     public int getAudioFrames();
 
     /**
-     * @return total duration of stream in msec.
+     * Return total duration of stream in msec.
+     * <p>
+     * The duration stored in integer covers 2'147'483'647 ms (see {@link Integer#MAX_VALUE}
+     * or 2'147'483 seconds or 24.855 days.
+     * </p>
      */
     public int getDuration();
 
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