diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 6caea138d8..898b15c0fe 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -97,26 +97,52 @@ shaka.util.MimeUtils = class {
   }
 
   /**
-   * Get the codec from a codec string, ignoring differences in base sample
-   * types declared in the fourCC.
+   * Get the normalized codec from a codec string,
+   * ignoring multiple names of a same codec.
    *
    * @param {string} codecString
    * @return {string}
    */
   static getNormalizedCodec(codecString) {
-    const cb = shaka.util.MimeUtils.getCodecBase(codecString);
-    switch (cb) {
-      case 'avc1':
-      case 'avc3':
-        return 'avc';  // H264
-      case 'hvc1':
-      case 'hev1':
+    const parts =
+      shaka.util.MimeUtils.getCodecParts_(codecString.toLowerCase());
+    const base = parts[0];
+    const profile = parts[1];
+    switch (true) {
+      case base === 'mp4a' && profile === '66':
+      case base === 'mp4a' && profile === '67':
+      case base === 'mp4a' && profile === '68':
+        return 'mpeg2_aac';
+      case base === 'mp4a' && profile === '69':
+      case base === 'mp4a' && profile === '6b':
+        return 'mp3';
+      case base === 'mp4a' && profile === '40.2':
+      case base === 'mp4a' && profile === '40.02':
+      case base === 'mp4a' && profile === '40.5':
+      case base === 'mp4a' && profile === '40.05':
+      case base === 'mp4a' && profile === '40.29':
+        return 'mpeg4_aac';
+      case base === 'mp4a' && profile === '40.42':
+        return 'mpeg4_xhe_aac'; // Extended HE-AAC
+      case base === 'mp4a' && profile === 'a5':
+        return 'ac-3'; // Dolby Digital
+      case base === 'mp4a' && profile === 'a6':
+        return 'ec-3'; // Dolby Digital Plus
+      case base === 'mp4a' && profile === 'b2':
+        return 'dtsx'; // DTS:X
+      case base === 'mp4a' && profile === 'a9':
+        return 'dtsc'; // DTS Digital Surround
+      case base === 'avc1':
+      case base === 'avc3':
+        return 'avc'; // H264
+      case base === 'hvc1':
+      case base === 'hev1':
         return 'hevc'; // H265
-      case 'dvh1':
-      case 'dvhe':
+      case base === 'dvh1':
+      case base === 'dvhe':
         return 'dovi'; // Dolby Vision
     }
-    return cb;
+    return base;
   }
 
   /**
@@ -175,7 +201,7 @@ shaka.util.MimeUtils = class {
 
     const base = parts[0];
 
-    parts.pop();
+    parts.shift();
     const profile = parts.join('.');
 
     // Make sure that we always return a "base" and "profile".
diff --git a/test/util/mime_utils_unit.js b/test/util/mime_utils_unit.js
new file mode 100644
index 0000000000..447f62b62a
--- /dev/null
+++ b/test/util/mime_utils_unit.js
@@ -0,0 +1,55 @@
+/*! @license
+ * Shaka Player
+ * Copyright 2016 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+describe('MimeUtils', () => {
+  const getNormalizedCodec = (codecs) =>
+    shaka.util.MimeUtils.getNormalizedCodec(codecs);
+
+  it('normalizes codecs', () => {
+    expect(getNormalizedCodec('mp4a.66')).toBe('mpeg2_aac');
+    expect(getNormalizedCodec('mp4a.67')).toBe('mpeg2_aac');
+    expect(getNormalizedCodec('mp4a.68')).toBe('mpeg2_aac');
+
+    expect(getNormalizedCodec('mp3')).toBe('mp3');
+    expect(getNormalizedCodec('mp4a.69')).toBe('mp3');
+    expect(getNormalizedCodec('mp4a.6B')).toBe('mp3');
+    expect(getNormalizedCodec('mp4a.6b')).toBe('mp3');
+
+    expect(getNormalizedCodec('mp4a.40.2')).toBe('mpeg4_aac');
+    expect(getNormalizedCodec('mp4a.40.02')).toBe('mpeg4_aac');
+    expect(getNormalizedCodec('mp4a.40.5')).toBe('mpeg4_aac');
+    expect(getNormalizedCodec('mp4a.40.05')).toBe('mpeg4_aac');
+    expect(getNormalizedCodec('mp4a.40.29')).toBe('mpeg4_aac');
+
+    expect(getNormalizedCodec('mp4a.40.42')).toBe('mpeg4_xhe_aac');
+
+    expect(getNormalizedCodec('ac-3')).toBe('ac-3');
+    expect(getNormalizedCodec('mp4a.a5')).toBe('ac-3');
+    expect(getNormalizedCodec('mp4a.A5')).toBe('ac-3');
+
+    expect(getNormalizedCodec('ec-3')).toBe('ec-3');
+    expect(getNormalizedCodec('mp4a.a6')).toBe('ec-3');
+    expect(getNormalizedCodec('mp4a.A6')).toBe('ec-3');
+
+    expect(getNormalizedCodec('vp8')).toBe('vp8');
+    expect(getNormalizedCodec('vp8.0')).toBe('vp8');
+
+    expect(getNormalizedCodec('dtsc')).toBe('dtsc');
+    expect(getNormalizedCodec('mp4a.a9')).toBe('dtsc');
+
+    expect(getNormalizedCodec('dtsx')).toBe('dtsx');
+    expect(getNormalizedCodec('mp4a.b2')).toBe('dtsx');
+
+    expect(getNormalizedCodec('avc1')).toBe('avc');
+    expect(getNormalizedCodec('avc3')).toBe('avc');
+
+    expect(getNormalizedCodec('hvc1')).toBe('hevc');
+    expect(getNormalizedCodec('hev1')).toBe('hevc');
+
+    expect(getNormalizedCodec('dvh1.05')).toBe('dovi');
+    expect(getNormalizedCodec('dvhe.05')).toBe('dovi');
+  });
+});