get api libs from bower

dashboard-ui/bower_components/hls.js/src/demux/id3.js

@@ -0,0 +1,123 @@
+/**
+ * ID3 parser
+ */
+import {logger} from '../utils/logger';
+//import Hex from '../utils/hex';
+
+ class ID3 {
+
+  constructor(data) {
+    this._hasTimeStamp = false;
+    var offset = 0, byte1,byte2,byte3,byte4,tagSize,endPos,header,len;
+      do {
+        header = this.readUTF(data,offset,3);
+        offset+=3;
+          // first check for ID3 header
+          if (header === 'ID3') {
+              // skip 24 bits
+              offset += 3;
+              // retrieve tag(s) length
+              byte1 = data[offset++] & 0x7f;
+              byte2 = data[offset++] & 0x7f;
+              byte3 = data[offset++] & 0x7f;
+              byte4 = data[offset++] & 0x7f;
+              tagSize = (byte1 << 21) + (byte2 << 14) + (byte3 << 7) + byte4;
+              endPos = offset + tagSize;
+              //logger.log(`ID3 tag found, size/end: ${tagSize}/${endPos}`);
+
+              // read ID3 tags
+              this._parseID3Frames(data, offset,endPos);
+              offset = endPos;
+          } else if (header === '3DI') {
+              // http://id3.org/id3v2.4.0-structure chapter 3.4.   ID3v2 footer
+              offset += 7;
+                  logger.log(`3DI footer found, end: ${offset}`);
+          } else {
+              offset -= 3;
+              len = offset;
+                  if (len) {
+                      //logger.log(`ID3 len: ${len}`);
+                      if (!this.hasTimeStamp) {
+                          logger.warn('ID3 tag found, but no timestamp');
+                      }
+                      this._length = len;
+                  }
+              return;
+          }
+      } while (true);
+  }
+
+  readUTF(data,start,len) {
+
+    var result = '',offset = start, end = start + len;
+    do {
+      result += String.fromCharCode(data[offset++]);
+    } while(offset < end);
+    return result;
+  }
+
+  _parseID3Frames(data,offset,endPos) {
+    var tagId,tagLen,tagStart,tagFlags,timestamp;
+    while(offset + 8 <= endPos) {
+      tagId = this.readUTF(data,offset,4);
+      offset +=4;
+
+      tagLen = data[offset++] << 24 +
+                data[offset++] << 16 +
+                data[offset++] << 8 +
+                data[offset++];
+
+      tagFlags = data[offset++] << 8 +
+                  data[offset++];
+
+      tagStart = offset;
+      //logger.log("ID3 tag id:" + tagId);
+      switch(tagId) {
+        case 'PRIV':
+            //logger.log('parse frame:' + Hex.hexDump(data.subarray(offset,endPos)));
+            // owner should be "com.apple.streaming.transportStreamTimestamp"
+            if (this.readUTF(data,offset,44) === 'com.apple.streaming.transportStreamTimestamp') {
+                offset+=44;
+                // smelling even better ! we found the right descriptor
+                // skip null character (string end) + 3 first bytes
+                offset+= 4;
+
+                // timestamp is 33 bit expressed as a big-endian eight-octet number, with the upper 31 bits set to zero.
+                var pts33Bit  = data[offset++] & 0x1;
+                this._hasTimeStamp = true;
+
+                timestamp = ((data[offset++] << 23) +
+                             (data[offset++] << 15) +
+                             (data[offset++] <<  7) +
+                             data[offset++]) /45;
+
+                if (pts33Bit) {
+                    timestamp   += 47721858.84; // 2^32 / 90
+                }
+                timestamp = Math.round(timestamp);
+                logger.trace(`ID3 timestamp found: ${timestamp}`);
+                this._timeStamp = timestamp;
+            }
+            break;
+        default:
+            break;
+      }
+    }
+  }
+
+  get hasTimeStamp() {
+    return this._hasTimeStamp;
+  }
+
+  get timeStamp() {
+    return this._timeStamp;
+  }
+
+  get length() {
+    return this._length;
+  }
+
+}
+
+export default ID3;
+