fix: Improve TsParse to avoid parsing errors (#5615)

shaka-project · Sep 7, 2023 · 5fa8b42 · 5fa8b42
1 parent 54eaf63
commit 5fa8b42
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Showing 2 changed files with 32 additions and 9 deletions.
diff --git a/lib/transmuxer/ts_transmuxer.js b/lib/transmuxer/ts_transmuxer.js
@@ -623,9 +623,7 @@ shaka.transmuxer.TsTransmuxer = class {
     let baseMediaDecodeTime = null;
 
     let nalus = [];
-    const videoData = tsParser.getVideoData().filter((pes) => {
-      return pes.pts != null && pes.dts != null;
-    });
+    const videoData = tsParser.getVideoData();
     for (let i = 0; i < videoData.length; i++) {
       const pes = videoData[i];
       let nextPes;
@@ -638,7 +636,7 @@ shaka.transmuxer.TsTransmuxer = class {
       if (!frame) {
         continue;
       }
-      if (baseMediaDecodeTime == null && pes.dts != null) {
+      if (baseMediaDecodeTime == null) {
         baseMediaDecodeTime = pes.dts;
       }
       let duration;

diff --git a/lib/util/ts_parser.js b/lib/util/ts_parser.js
@@ -362,6 +362,12 @@ shaka.util.TsParser = class {
       dts: null,
     };
 
+    // if PES parsed length is not zero and greater than total received length,
+    // stop parsing. PES might be truncated. minus 6 : PES header size
+    if (pes.packetLength && pes.packetLength > data.byteLength - 6) {
+      return null;
+    }
+
     // PES packets may be annotated with a PTS value, or a PTS value
     // and a DTS value. Determine what combination of values is
     // available to work with.
@@ -396,10 +402,15 @@ shaka.util.TsParser = class {
           (data[18] & 0xfe) / 2;
       }
     }
-    // the data section starts immediately after the PES header.
-    // pes_header_data_length specifies the number of header bytes
-    // that follow the last byte of the field.
-    pes.data = data.subarray(9 + data[8]);
+
+    const pesHdrLen = data[8];
+    // 9 bytes : 6 bytes for PES header + 3 bytes for PES extension
+    const payloadStartOffset = pesHdrLen + 9;
+    if (data.byteLength <= payloadStartOffset) {
+      return null;
+    }
+
+    pes.data = data.subarray(payloadStartOffset);
 
     return pes;
   }
@@ -474,6 +485,10 @@ shaka.util.TsParser = class {
         // previous Nalu and don't scan for more nalus.
         const startCodeSize = numZeros > 3 ? 3 : numZeros;
         const lastByteToKeep = i - startCodeSize;
+        // Optimization
+        if (lastByteToKeep == 0) {
+          break;
+        }
         infoOfLastNalu.data = shaka.util.Uint8ArrayUtils.concat(
             infoOfLastNalu.data, data.subarray(0, lastByteToKeep));
         infoOfLastNalu.fullData = shaka.util.Uint8ArrayUtils.concat(
@@ -603,11 +618,21 @@ shaka.util.TsParser = class {
    * @export
    */
   getVideoData() {
+    const Uint8ArrayUtils = shaka.util.Uint8ArrayUtils;
     const video = [];
     for (const videoData of this.videoData_) {
       const pes = this.parsePES_(videoData);
-      if (pes) {
+      if (pes && pes.pts != null && pes.dts != null) {
         video.push(pes);
+      } else if (video.length) {
+        const data = pes ? pes.data : videoData;
+        if (!data) {
+          continue;
+        }
+        const previousPes = video.pop();
+        previousPes.data =
+            Uint8ArrayUtils.concat(previousPes.data, data);
+        video.push(previousPes);
       }
     }
     return video;