Miscellaneous fixes to FragmentedMp4Extractor

ISSUE: #7308
PiperOrigin-RevId: 319747742

RELEASENOTES.md

@@ -203,7 +203,8 @@
         ([#6410](https://github.com/google/ExoPlayer/issues/6410)).
     *   Select first extractors based on the filename extension and the response
         headers mime type in `DefaultExtractorsFactory`.
-    *   Add support for partially fragmented MP4s.
+    *   Add support for partially fragmented MP4s
+        ([#7308](https://github.com/google/ExoPlayer/issues/7308)).
 *   Testing
     *   Add `TestExoPlayer`, a utility class with APIs to create
         `SimpleExoPlayer` instances with fake components for testing.

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java

@@ -1565,7 +1565,7 @@ public void updateDrmInitData(DrmInitData drmInitData) {
       output.format(format);
     }
 
-    /** Resets the current fragment, sample indices and {@code isInFragment} boolean. */
+    /** Resets the current fragment, sample indices and {@link #currentlyInFragment} boolean. */
     public void reset() {
       fragment.reset();
       currentSampleIndex = 0;

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/TrackFragment.java

@@ -89,8 +89,8 @@
    */
   public boolean sampleEncryptionDataNeedsFill;
   /**
-   * The absolute decode time of the start of the next fragment, excluding the samples outside
-   * fragments.
+   * The duration of all samples defined in fragments up to and including this one. Samples defined
+   * in the moov box are not included.
    */
   public long nextFragmentDecodeTime;