Ignore negative payload size in TS PesReader

Issue: #8005
PiperOrigin-RevId: 335625992

RELEASENOTES.md

@@ -44,6 +44,8 @@
     *   Add TS extractor parameter to configure the number of bytes in which
         to search for a timestamp to determine the duration and to seek.
         ([#7988](https://github.com/google/ExoPlayer/issues/7988)).
+    *   Ignore negative payload size in PES packets
+        ([#8005](https://github.com/google/ExoPlayer/issues/8005)).
 *   IMA extension:
     *   Fix position reporting after fetch errors
         ([#7956](https://github.com/google/ExoPlayer/issues/7956)).

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

@@ -97,11 +97,11 @@ public final class PesReader implements TsPayloadReader {
           Log.w(TAG, "Unexpected start indicator reading extended header");
           break;
         case STATE_READING_BODY:
-          // If payloadSize == -1 then the length of the previous packet was unspecified, and so
-          // we only know that it's finished now that we've seen the start of the next one. This
-          // is expected. If payloadSize != -1, then the length of the previous packet was known,
-          // but we didn't receive that amount of data. This is not expected.
-          if (payloadSize != -1) {
+          // If payloadSize is unset then the length of the previous packet was unspecified, and so
+          // we only know that it's finished now that we've seen the start of the next one. This is
+          // expected. If payloadSize is set, then the length of the previous packet was known, but
+          // we didn't receive that amount of data. This is not expected.
+          if (payloadSize != C.LENGTH_UNSET) {
             Log.w(TAG, "Unexpected start indicator: expected " + payloadSize + " more bytes");
           }
           // Either way, notify the reader that it has now finished.
@@ -136,13 +136,13 @@ public final class PesReader implements TsPayloadReader {
           break;
         case STATE_READING_BODY:
           readLength = data.bytesLeft();
-          int padding = payloadSize == -1 ? 0 : readLength - payloadSize;
+          int padding = payloadSize == C.LENGTH_UNSET ? 0 : readLength - payloadSize;
           if (padding > 0) {
             readLength -= padding;
             data.setLimit(data.getPosition() + readLength);
           }
           reader.consume(data);
-          if (payloadSize != -1) {
+          if (payloadSize != C.LENGTH_UNSET) {
             payloadSize -= readLength;
             if (payloadSize == 0) {
               reader.packetFinished();
@@ -191,7 +191,7 @@ public final class PesReader implements TsPayloadReader {
     int startCodePrefix = pesScratch.readBits(24);
     if (startCodePrefix != 0x000001) {
       Log.w(TAG, "Unexpected start code prefix: " + startCodePrefix);
-      payloadSize = -1;
+      payloadSize = C.LENGTH_UNSET;
       return false;
     }
 
@@ -208,10 +208,14 @@ public final class PesReader implements TsPayloadReader {
     extendedHeaderLength = pesScratch.readBits(8);
 
     if (packetLength == 0) {
-      payloadSize = -1;
+      payloadSize = C.LENGTH_UNSET;
     } else {
       payloadSize = packetLength + 6 /* packetLength does not include the first 6 bytes */
           - HEADER_SIZE - extendedHeaderLength;
+      if (payloadSize < 0) {
+        Log.w(TAG, "Found negative packet payload size: " + payloadSize);
+        payloadSize = C.LENGTH_UNSET;
+      }
     }
     return true;
   }