feat: Add support for AC-3 and EC-3 audio in DVB streams (shaka-proje…

…ct#5484)

lib/util/ts_parser.js

@@ -225,7 +225,36 @@ shaka.util.TsParser = class {
     offset += 12 + programInfoLength;
     while (offset < tableEnd) {
       const pid = ((data[offset + 1] & 0x1f) << 8) | data[offset + 2];
+      const esInfoLength = ((data[offset + 3] & 0x0f) << 8) | data[offset + 4];
       switch (data[offset]) {
+        case 0x06:
+          // stream_type 6 can mean a lot of different things in case of DVB.
+          // We need to look at the descriptors. Right now, we're only
+          // interested in AC-3 and EC-3 audio, so we do the descriptor parsing
+          // only when we don't have an audio PID yet.
+          if (result.audio == -1 && esInfoLength > 0) {
+            let parsePos = offset + 5;
+            let remaining = esInfoLength;
+            while (remaining > 2) {
+              const descriptorId = data[parsePos];
+              switch (descriptorId) {
+                // DVB Descriptor for AC-3
+                case 0x6a:
+                  result.audio = pid;
+                  result.audioCodec = 'ac3';
+                  break;
+                // DVB Descriptor for EC-3
+                case 0x7a:
+                  result.audio = pid;
+                  result.audioCodec = 'ec3';
+                  break;
+              }
+              const descriptorLen = data[parsePos + 1] + 2;
+              parsePos += descriptorLen;
+              remaining -= descriptorLen;
+            }
+          }
+          break;
         // SAMPLE-AES AAC
         case 0xcf:
           break;
@@ -289,7 +318,7 @@ shaka.util.TsParser = class {
       }
       // move to the next table entry
       // skip past the elementary stream descriptors, if present
-      offset += (((data[offset + 3] & 0x0f) << 8) | data[offset + 4]) + 5;
+      offset += esInfoLength + 5;
     }
     return result;
   }