rework header encode/decode

src/decoders/rttrp.ts

@@ -12,37 +12,35 @@ export default (bytes: Uint8Array): RTTrPHeader => {
   let isLittleEndian = false;
   const intHeader = view.getUint16(dataOffset, isLittleEndian);
   dataOffset += 2;
-  const fltHeader = view.getUint16(dataOffset, isLittleEndian);
+  const floatHeader = view.getUint16(dataOffset, isLittleEndian);
   dataOffset += 2;
-  if (intHeader === 0x4154) {
-    isLittleEndian = false;
-  }
   const version = view.getUint16(dataOffset, isLittleEndian);
   dataOffset += 2;
   if (version !== 0x0002) {
     throw new Error('Only version 2 of the RTTrP header is currently supported');
   }
-  const pID = view.getUint32(dataOffset, isLittleEndian);
+  if (intHeader === 0x5441) {
+    isLittleEndian = true;
+  }
+  const packetID = view.getUint32(dataOffset, isLittleEndian);
   dataOffset += 4;
 
-  const pForm = view.getUint8(dataOffset);
+  const packetFormat = view.getUint8(dataOffset);
   dataOffset += 1;
-  const pktSize = view.getUint16(dataOffset, isLittleEndian);
+  const size = view.getUint16(dataOffset, isLittleEndian);
   dataOffset += 2;
   const context = view.getUint32(dataOffset, isLittleEndian);
   dataOffset += 4;
-  const numMods = view.getUint8(dataOffset);
+  const subModuleCount = view.getUint8(dataOffset);
   dataOffset += 1;
-  const data = bytes.slice(dataOffset);
   return {
     intHeader,
-    fltHeader,
+    floatHeader,
     version,
-    pID,
-    pForm,
-    pktSize,
+    packetID,
+    packetFormat,
+    size,
     context,
-    numMods,
-    data,
+    subModuleCount,
   };
 };

src/encoders/rttrp-header.ts

@@ -0,0 +1,45 @@
+const HEADER_SIZE = 18;
+
+export default (
+  floatSignature: number,
+  version: number,
+  packetID: number,
+  packetFormat: number,
+  context: number,
+  subModules: Uint8Array[],
+  isLittleEndian: boolean = false
+): Uint8Array => {
+  if (version !== 2) {
+    throw new Error('Only version 2 of the RTTrP header is currently supported');
+  }
+  const bytes = new Uint8Array(HEADER_SIZE);
+
+  let totalPacketSize = bytes.byteLength;
+  subModules.forEach((subModule) => {
+    totalPacketSize += subModule.length;
+  });
+
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+  let dataOffset = 0;
+
+  view.setUint16(dataOffset, 0x4154, isLittleEndian);
+  dataOffset += 2;
+  view.setUint16(dataOffset, floatSignature, isLittleEndian);
+  dataOffset += 2;
+  view.setUint16(dataOffset, version);
+  dataOffset += 2;
+
+  view.setUint32(dataOffset, packetID, isLittleEndian);
+  dataOffset += 4;
+
+  view.setUint8(dataOffset, packetFormat);
+  dataOffset += 1;
+  view.setUint16(dataOffset, totalPacketSize, isLittleEndian);
+  dataOffset += 2;
+  view.setUint32(dataOffset, context, isLittleEndian);
+  dataOffset += 4;
+  view.setUint8(dataOffset, subModules.length);
+  dataOffset += 1;
+
+  return bytes;
+};

src/encoders/rttrp.ts

@@ -1,37 +0,0 @@
-import { RTTrPHeader } from '../models';
-
-export default (header: RTTrPHeader): Uint8Array => {
-  if (header.version !== 2) {
-    throw new Error('Only version 2 of the RTTrP header is currently supported');
-  }
-  const bytes = new Uint8Array(18 + header.data.length);
-  bytes.set(header.data, 18);
-
-  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
-  let dataOffset = 0;
-
-  let isLittleEndian = false;
-  view.setUint16(dataOffset, header.intHeader, isLittleEndian);
-  dataOffset += 2;
-  view.setUint16(dataOffset, header.fltHeader, isLittleEndian);
-  dataOffset += 2;
-  if (header.intHeader === 0x4154) {
-    isLittleEndian = false;
-  }
-  view.setUint16(dataOffset, header.version, isLittleEndian);
-  dataOffset += 2;
-
-  view.setUint32(dataOffset, header.pID, isLittleEndian);
-  dataOffset += 4;
-
-  view.setUint8(dataOffset, header.pForm);
-  dataOffset += 1;
-  view.setUint16(dataOffset, header.pktSize, isLittleEndian);
-  dataOffset += 2;
-  view.setUint32(dataOffset, header.context, isLittleEndian);
-  dataOffset += 4;
-  view.setUint8(dataOffset, header.numMods);
-  dataOffset += 1;
-
-  return bytes;
-};

src/models.ts

@@ -1,11 +1,11 @@
 export type RTTrPHeader = {
-  intHeader: number;
-  fltHeader: number;
+  intHeader?: number;
+  floatHeader: number;
   version: number;
-  pID: number;
-  pForm: number;
-  pktSize: number;
+  packetID: number;
+  packetFormat: number;
+  size: number;
   context: number;
-  numMods: number;
-  data: Uint8Array;
+  subModuleCount: number;
+};
 };