Duration readers: Return TIME_UNSET rather than a negative value

This typically happens if there's a discontinuity in the stream.
It's better to say we don't know, than it is to return a negative
position.

Issue: #8346
#exofixit
#minor-release
PiperOrigin-RevId: 395224088

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ts/PsDurationReader.java

@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.extractor.PositionHolder;
+import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.TimestampAdjuster;
 import com.google.android.exoplayer2.util.Util;
@@ -41,6 +42,8 @@ import java.io.IOException;
  */
 /* package */ final class PsDurationReader {
 
+  private static final String TAG = "PsDurationReader";
+
   private static final int TIMESTAMP_SEARCH_BYTES = 20_000;
 
   private final TimestampAdjuster scrTimestampAdjuster;
@@ -102,6 +105,10 @@ import java.io.IOException;
     long minScrPositionUs = scrTimestampAdjuster.adjustTsTimestamp(firstScrValue);
     long maxScrPositionUs = scrTimestampAdjuster.adjustTsTimestamp(lastScrValue);
     durationUs = maxScrPositionUs - minScrPositionUs;
+    if (durationUs < 0) {
+      Log.w(TAG, "Invalid duration: " + durationUs + ". Using TIME_UNSET instead.");
+      durationUs = C.TIME_UNSET;
+    }
     return finishReadDuration(input);
   }
 

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ts/TsDurationReader.java

@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.extractor.PositionHolder;
+import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.TimestampAdjuster;
 import com.google.android.exoplayer2.util.Util;
@@ -38,6 +39,8 @@ import java.io.IOException;
  */
 /* package */ final class TsDurationReader {
 
+  private static final String TAG = "TsDurationReader";
+
   private final int timestampSearchBytes;
   private final TimestampAdjuster pcrTimestampAdjuster;
   private final ParsableByteArray packetBuffer;
@@ -98,6 +101,10 @@ import java.io.IOException;
     long minPcrPositionUs = pcrTimestampAdjuster.adjustTsTimestamp(firstPcrValue);
     long maxPcrPositionUs = pcrTimestampAdjuster.adjustTsTimestamp(lastPcrValue);
     durationUs = maxPcrPositionUs - minPcrPositionUs;
+    if (durationUs < 0) {
+      Log.w(TAG, "Invalid duration: " + durationUs + ". Using TIME_UNSET instead.");
+      durationUs = C.TIME_UNSET;
+    }
     return finishReadDuration(input);
   }