1 files changed, 131 insertions, 0 deletions
diff --git a/dom/media/webrtc/tests/mochitests/parser_rtp.js b/dom/media/webrtc/tests/mochitests/parser_rtp.js
new file mode 100644
index 0000000000..2275c1f787
--- /dev/null
+++ b/dom/media/webrtc/tests/mochitests/parser_rtp.js
@@ -0,0 +1,131 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/*
+ * Parses an RTP packet
+ * @param buffer an ArrayBuffer that contains the packet
+ * @return { type: "rtp", header: {...}, payload: a DataView }
+ */
+var ParseRtpPacket = buffer => {
+  // DataView.getFooInt returns big endian numbers by default
+  let view = new DataView(buffer);
+
+  // Standard Header Fields
+  // https://tools.ietf.org/html/rfc3550#section-5.1
+  //  0                   1                   2                   3
+  //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |V=2|P|X|  CC   |M|     PT      |       sequence number         |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |                           timestamp                           |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |           synchronization source (SSRC) identifier            |
+  // +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+  // |            contributing source (CSRC) identifiers             |
+  // |                             ....                              |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+  let header = {};
+  let offset = 0;
+  // Note that incrementing the offset happens as close to reading the data as
+  // possible. This simplifies ensuring that the number of read bytes and the
+  // offset increment match. Data may be manipulated between when the offset is
+  // incremented and before the next read.
+  let byte = view.getUint8(offset);
+  offset++;
+  // Version            2 Bit
+  header.version = (0xc0 & byte) >> 6;
+  // Padding            1 Bit
+  header.padding = (0x30 & byte) >> 5;
+  // Extension          1 Bit
+  header.extensionsPresent = (0x10 & byte) >> 4 == 1;
+  // CSRC count         4 Bit
+  header.csrcCount = 0xf & byte;
+
+  byte = view.getUint8(offset);
+  offset++;
+  // Marker             1 Bit
+  header.marker = (0x80 & byte) >> 7;
+  // Payload Type       7 Bit
+  header.payloadType = 0x7f & byte;
+  // Sequence Number   16 Bit
+  header.sequenceNumber = view.getUint16(offset);
+  offset += 2;
+  // Timestamp         32 Bit
+  header.timestamp = view.getUint32(offset);
+  offset += 4;
+  // SSRC              32 Bit
+  header.ssrc = view.getUint32(offset);
+  offset += 4;
+
+  // CSRC              32 Bit
+  header.csrcs = [];
+  for (let c = 0; c < header.csrcCount; c++) {
+    header.csrcs.push(view.getUint32(offset));
+    offset += 4;
+  }
+
+  // Extensions
+  header.extensions = [];
+  header.extensionPaddingBytes = 0;
+  header.extensionsTotalLength = 0;
+  if (header.extensionsPresent) {
+    // https://tools.ietf.org/html/rfc3550#section-5.3.1
+    //  0                   1                   2                   3
+    //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |      defined by profile       |           length              |
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |                        header extension                       |
+    // |                             ....                              |
+    let addExtension = (id, len) =>
+      header.extensions.push({
+        id,
+        data: new DataView(buffer, offset, len),
+      });
+    let extensionId = view.getUint16(offset);
+    offset += 2;
+    // len is in 32 bit units, not bytes
+    header.extensionsTotalLength = view.getUint16(offset) * 4;
+    offset += 2;
+    // Check for https://tools.ietf.org/html/rfc5285
+    if (extensionId != 0xbede) {
+      // No rfc5285
+      addExtension(extensionId, header.extensionsTotalLength);
+      offset += header.extensionsTotalLength;
+    } else {
+      let expectedEnd = offset + header.extensionsTotalLength;
+      while (offset < expectedEnd) {
+        // We only support "one-byte" extension headers ATM
+        // https://tools.ietf.org/html/rfc5285#section-4.2
+        //  0
+        //  0 1 2 3 4 5 6 7
+        // +-+-+-+-+-+-+-+-+
+        // |  ID   |  len  |
+        // +-+-+-+-+-+-+-+-+
+        byte = view.getUint8(offset);
+        offset++;
+        // Check for padding which can occur between extensions or at the end
+        if (byte == 0) {
+          header.extensionPaddingBytes++;
+          continue;
+        }
+        let id = (byte & 0xf0) >> 4;
+        // Check for the FORBIDDEN id (15), dun dun dun
+        if (id == 15) {
+          // Ignore bytes until until the end of extensions
+          offset = expectedEnd;
+          break;
+        }
+        // the length of the extention is len + 1
+        let len = (byte & 0x0f) + 1;
+        addExtension(id, len);
+        offset += len;
+      }
+    }
+  }
+  return { type: "rtp", header, payload: new DataView(buffer, offset) };
+};