Merge pull request #3 from PRX/feat/configure_pad_bytes

Configure pad bytes

Author: kookster

dist/wavefile.js

@@ -446,6 +446,12 @@ WaveFile.prototype._PMX = {
  * @type {string}
  */
 WaveFile.prototype.bitDepth = "";
+/**
+ * Whether to apply a pad byte or not
+ * Defaults to 'true'
+ * @type {boolean}
+ */
+WaveFile.prototype.padBytes = true;
 
 /**
  * Return the samples packed in a Float64Array.

externs/wavefile.js

@@ -101,6 +101,12 @@ declare module wavefile {
      * @type {!Object<string, *>}
      */
     _PMX: object;
+    /**
+     * Whether to apply a pad byte or not
+     * Defaults to 'true'
+     * @type {boolean}
+     */
+     padBytes: boolean;
 
     /**
      * @param {Uint8Array=} [wavBuffer=null] A wave file buffer.

index.d.ts

@@ -72,6 +72,12 @@ export class RIFFFile {
      * @protected
      */
     this.supported_containers = ['RIFF', 'RIFX'];
+    /**
+     * Whether to apply a pad byte or not
+     * Defaults to 'true'
+     * @type {boolean}
+     */
+    this.padBytes = true;
   }
 
   /**
@@ -167,7 +173,9 @@ export class RIFFFile {
     while(i <= buffer.length - 8) {
       chunks.push(this.getSubChunkIndex_(buffer, i));
       i += 8 + chunks[chunks.length - 1].chunkSize;
-      i = i % 2 ? i + 1 : i;
+      if (this.padBytes) {
+        i = i % 2 ? i + 1 : i;
+      }
     }
     return chunks;
   }
@@ -191,8 +199,10 @@ export class RIFFFile {
       chunk.subChunks = this.getSubChunksIndex_(buffer);
     } else {
       /** @type {number} */
-      let realChunkSize = chunk.chunkSize % 2 ?
-        chunk.chunkSize + 1 : chunk.chunkSize;
+      let realChunkSize = chunk.chunkSize;
+      if (this.padBytes) {
+        realChunkSize = realChunkSize % 2 ? realChunkSize + 1 : realChunkSize;
+      }
       this.head = index + 8 + realChunkSize;
       chunk.chunkData = {
         start: index + 8,

lib/riff-file.js

@@ -619,8 +619,10 @@ export class WaveFileParser extends WaveFileReader {
    * @private
    */
   enforceByteLen_(bytes) {
-    if (bytes.length % 2) {
-      bytes.push(0);
+    if (this.padBytes) {
+      if (bytes.length % 2) {
+        bytes.push(0);
+      }
     }
   }
 }

lib/wavefile-parser.js

@@ -14,6 +14,36 @@ function cl(str) {
   return str.replace(/\0+$/, "");
 }
 
+describe("Write file without pad bytes", function() {
+  let wav = new WaveFile(fs.readFileSync(path + "cc_0101.wav"));
+  wav.cart.tagText = "1";
+  wav.padBytes = false;
+  fs.writeFileSync(path + "out/cc_0101_nopad.wav", wav.toBuffer());
+  fs.stat(path + "out/cc_0101_nopad.wav", (error, stats) => {
+    if (error) {
+      throw error;
+    }
+    else {
+      assert.equal(stats.size, 806911);
+    }
+  });
+  assert.equal(wav.cart.chunkSize, 2049);
+
+  wav = new WaveFile(fs.readFileSync(path + "cc_0101.wav"));
+  wav.cart.tagText = "1";
+  wav.padBytes = true;
+  fs.writeFileSync(path + "out/cc_0101_yespad.wav", wav.toBuffer());
+  fs.stat(path + "out/cc_0101_yespad.wav", (error, stats) => {
+    if (error) {
+      throw error;
+    }
+    else {
+      assert.equal(stats.size, 806912);
+    }
+  });
+  assert.equal(wav.cart.chunkSize, 2049);
+});
+
 describe("Read and write cart chunk PCM wav file", function() {
   let wav = new WaveFile(fs.readFileSync(path + "cc_0101.wav"));
   fs.writeFileSync(path + "out/cc_0101.wav", wav.toBuffer());