From a2de68ac670570437b0c2f29419ecc5e69fad875 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Mon, 9 May 2022 14:42:51 -0400
Subject: [PATCH 01/11] Fix PERIOD_FLATTENING_FAILED error when periods have a
 compatible codec but different base sample types.

---
 lib/dash/dash_parser.js   |  4 +--
 lib/util/mime_utils.js    | 21 +++++++++++++
 lib/util/periods.js       |  8 ++---
 lib/util/stream_utils.js  |  4 +--
 test/util/periods_unit.js | 66 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 95 insertions(+), 8 deletions(-)

diff --git a/lib/dash/dash_parser.js b/lib/dash/dash_parser.js
index 5ea78abd57..c6898e75cc 100644
--- a/lib/dash/dash_parser.js
+++ b/lib/dash/dash_parser.js
@@ -765,8 +765,8 @@ shaka.dash.DashParser = class {
             // currently support that.  Just choose one.
             // TODO: https://github.com/shaka-project/shaka-player/issues/1528
             stream.trickModeVideo = trickModeSet.streams.find((trickStream) =>
-              shaka.util.MimeUtils.getCodecBase(stream.codecs) ==
-              shaka.util.MimeUtils.getCodecBase(trickStream.codecs));
+              shaka.util.MimeUtils.getNormalizedCodec(stream.codecs) ==
+              shaka.util.MimeUtils.getNormalizedCodec(trickStream.codecs));
           }
         }
       }
diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 8183e50448..8fa58a5a32 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -96,6 +96,27 @@ shaka.util.MimeUtils = class {
     return codecs.split(',');
   }
 
+  /**
+   * Get the codec from a codec string, ignoring differences in base sample types declared in the fourCC.
+   *
+   * @param {string} codecString
+   * @return {string}
+   */
+  static getNormalizedCodec(codecString) {
+    switch (shaka.util.MimeUtils.getCodecBase(codecString)) {
+      case 'avc1':
+      case 'avc3':
+        return 'avc';
+      case 'hvc1':
+      case 'hev1':
+        return 'hevc';
+      case 'dvh1':
+      case 'dvhe':
+        return 'dovi';
+    }
+    return codecString;
+  }
+
   /**
    * Get the base codec from a codec string.
    *
diff --git a/lib/util/periods.js b/lib/util/periods.js
index 9f41b98162..5917fae321 100644
--- a/lib/util/periods.js
+++ b/lib/util/periods.js
@@ -573,8 +573,8 @@ shaka.util.PeriodCombiner = class {
         // TODO(#1528): Consider changing this when we support codec switching.
         const hasCodec = outputStreams.some((s) => {
           return s.mimeType == stream.mimeType &&
-                shaka.util.MimeUtils.getCodecBase(s.codecs) ==
-                    shaka.util.MimeUtils.getCodecBase(stream.codecs);
+                shaka.util.MimeUtils.getNormalizedCodec(s.codecs) ==
+                    shaka.util.MimeUtils.getNormalizedCodec(stream.codecs);
         });
         if (!hasCodec) {
           continue;
@@ -1050,10 +1050,10 @@ shaka.util.PeriodCombiner = class {
    * @private
    */
   static areAVStreamsCompatible_(outputStream, candidate) {
-    const getCodecBase = (codecs) => shaka.util.MimeUtils.getCodecBase(codecs);
+    const getNormalizedCodec = (codecs) => shaka.util.MimeUtils.getNormalizedCodec(codecs);
     // Check MIME type and codecs, which should always be the same.
     if (candidate.mimeType != outputStream.mimeType ||
-        getCodecBase(candidate.codecs) != getCodecBase(outputStream.codecs)) {
+        getNormalizedCodec(candidate.codecs) != getNormalizedCodec(outputStream.codecs)) {
       return false;
     }
 
diff --git a/lib/util/stream_utils.js b/lib/util/stream_utils.js
index ed69233032..8016463951 100644
--- a/lib/util/stream_utils.js
+++ b/lib/util/stream_utils.js
@@ -283,12 +283,12 @@ shaka.util.StreamUtils = class {
     // both be considered the same codec: avc1.42c01e, avc1.4d401f
     let baseVideoCodec = '';
     if (variant.video) {
-      baseVideoCodec = shaka.util.MimeUtils.getCodecBase(variant.video.codecs);
+      baseVideoCodec = shaka.util.MimeUtils.getNormalizedCodec(variant.video.codecs);
     }
 
     let baseAudioCodec = '';
     if (variant.audio) {
-      baseAudioCodec = shaka.util.MimeUtils.getCodecBase(variant.audio.codecs);
+      baseAudioCodec = shaka.util.MimeUtils.getNormalizedCodec(variant.audio.codecs);
     }
 
     return baseVideoCodec + '-' + baseAudioCodec;
diff --git a/test/util/periods_unit.js b/test/util/periods_unit.js
index 87115a70e4..383dd2e53f 100644
--- a/test/util/periods_unit.js
+++ b/test/util/periods_unit.js
@@ -996,6 +996,72 @@ describe('PeriodCombiner', () => {
     expect(audio2.originalId).toBe('2,4');
   });
 
+  it('Matches streams with related codecs', async () => {
+    const stream1 = makeVideoStream(1080);
+    stream1.originalId = '1';
+    stream1.bandwidth = 120000;
+    stream1.codecs = 'hvc1.1.4.L126.B0';
+
+    const stream2 = makeVideoStream(1080);
+    stream2.originalId = '2';
+    stream2.bandwidth = 120000;
+    stream2.codecs = 'hev1.2.4.L123.B0';
+
+    const stream3 = makeVideoStream(1080);
+    stream3.originalId = '3';
+    stream3.bandwidth = 120000;
+    stream3.codecs = 'dvhe.05.01';
+
+    const stream4 = makeVideoStream(1080);
+    stream4.originalId = '4';
+    stream4.bandwidth = 120000;
+    stream4.codecs = 'dvh1.05.01';
+
+    const stream5 = makeVideoStream(1080);
+    stream5.originalId = '5';
+    stream5.bandwidth = 120000;
+    stream5.codecs = 'avc1.42001f';
+
+    const stream6 = makeVideoStream(1080);
+    stream6.originalId = '6';
+    stream6.bandwidth = 120000;
+    stream6.codecs = 'avc3.42001f';
+
+    /** @type {!Array.<shaka.util.PeriodCombiner.Period>} */
+    const periods = [
+      {
+        id: '0',
+        videoStreams: [
+          stream1,stream3,stream5,
+        ],
+        audioStreams: [],
+        textStreams: [],
+        imageStreams: [],
+      },
+      {
+        id: '1',
+        videoStreams: [
+          stream2,stream4,stream6,
+        ],
+        audioStreams: [],
+        textStreams: [],
+        imageStreams: [],
+      },
+    ];
+
+    await combiner.combinePeriods(periods, /* isDynamic= */ true);
+    const variants = combiner.getVariants();
+    expect(variants.length).toBe(3);
+    // We can use the originalId field to see what each track is composed of.
+    const video1 = variants[0].video;
+    expect(video1.originalId).toBe('1,2');
+
+    const video2 = variants[1].video;
+    expect(video2.originalId).toBe('3,4');
+
+    const video3 = variants[2].video;
+    expect(video3.originalId).toBe('5,6');
+  });
 
   it('Matches streams with most roles in common', async () => {
     const makeAudioStreamWithRoles = (roles) => {

From a9458311110d35afb739b2b75fa7092f76b5bda4 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Mon, 9 May 2022 15:38:17 -0400
Subject: [PATCH 02/11] Fix lint issues.

---
 lib/util/mime_utils.js    | 3 ++-
 lib/util/periods.js       | 5 +++--
 lib/util/stream_utils.js  | 6 ++++--
 test/util/periods_unit.js | 4 ++--
 4 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 8fa58a5a32..2acfcc0eb0 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -97,7 +97,8 @@ shaka.util.MimeUtils = class {
   }
 
   /**
-   * Get the codec from a codec string, ignoring differences in base sample types declared in the fourCC.
+   * Get the codec from a codec string, ignoring differences in base sample
+   * types declared in the fourCC.
    *
    * @param {string} codecString
    * @return {string}
diff --git a/lib/util/periods.js b/lib/util/periods.js
index 5917fae321..6b8e580b7b 100644
--- a/lib/util/periods.js
+++ b/lib/util/periods.js
@@ -1050,10 +1050,11 @@ shaka.util.PeriodCombiner = class {
    * @private
    */
   static areAVStreamsCompatible_(outputStream, candidate) {
-    const getNormalizedCodec = (codecs) => shaka.util.MimeUtils.getNormalizedCodec(codecs);
+    const getCodec = (codecs) =>
+      shaka.util.MimeUtils.getNormalizedCodec(codecs);
     // Check MIME type and codecs, which should always be the same.
     if (candidate.mimeType != outputStream.mimeType ||
-        getNormalizedCodec(candidate.codecs) != getNormalizedCodec(outputStream.codecs)) {
+        getCodec(candidate.codecs) != getCodec(outputStream.codecs)) {
       return false;
     }
 
diff --git a/lib/util/stream_utils.js b/lib/util/stream_utils.js
index 8016463951..410482bb60 100644
--- a/lib/util/stream_utils.js
+++ b/lib/util/stream_utils.js
@@ -283,12 +283,14 @@ shaka.util.StreamUtils = class {
     // both be considered the same codec: avc1.42c01e, avc1.4d401f
     let baseVideoCodec = '';
     if (variant.video) {
-      baseVideoCodec = shaka.util.MimeUtils.getNormalizedCodec(variant.video.codecs);
+      baseVideoCodec =
+        shaka.util.MimeUtils.getNormalizedCodec(variant.video.codecs);
     }
 
     let baseAudioCodec = '';
     if (variant.audio) {
-      baseAudioCodec = shaka.util.MimeUtils.getNormalizedCodec(variant.audio.codecs);
+      baseAudioCodec =
+        shaka.util.MimeUtils.getNormalizedCodec(variant.audio.codecs);
     }
 
     return baseVideoCodec + '-' + baseAudioCodec;
diff --git a/test/util/periods_unit.js b/test/util/periods_unit.js
index 383dd2e53f..e28f11f1ed 100644
--- a/test/util/periods_unit.js
+++ b/test/util/periods_unit.js
@@ -1032,7 +1032,7 @@ describe('PeriodCombiner', () => {
       {
         id: '0',
         videoStreams: [
-          stream1,stream3,stream5,
+          stream1, stream3, stream5,
         ],
         audioStreams: [],
         textStreams: [],
@@ -1041,7 +1041,7 @@ describe('PeriodCombiner', () => {
       {
         id: '1',
         videoStreams: [
-          stream2,stream4,stream6,
+          stream2, stream4, stream6,
         ],
         audioStreams: [],
         textStreams: [],

From ccb2c6902a8ccff0e1330a39a84b4d1114288b49 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Mon, 9 May 2022 16:07:45 -0400
Subject: [PATCH 03/11] Add description for the returned codec names.

---
 lib/util/mime_utils.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 2acfcc0eb0..3773fb3672 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -107,13 +107,13 @@ shaka.util.MimeUtils = class {
     switch (shaka.util.MimeUtils.getCodecBase(codecString)) {
       case 'avc1':
       case 'avc3':
-        return 'avc';
+        return 'avc';  // H264
       case 'hvc1':
       case 'hev1':
-        return 'hevc';
+        return 'hevc'; // H265
       case 'dvh1':
       case 'dvhe':
-        return 'dovi';
+        return 'dovi'; // Dolby Vision
     }
     return codecString;
   }

From 786105a21815f924447be2c5ae8caeb6906f971e Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Mon, 9 May 2022 17:08:55 -0400
Subject: [PATCH 04/11] Fix default case.

---
 lib/util/mime_utils.js    |  5 +++--
 test/util/periods_unit.js | 19 ++++++++++++++++---
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 3773fb3672..6caea138d8 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -104,7 +104,8 @@ shaka.util.MimeUtils = class {
    * @return {string}
    */
   static getNormalizedCodec(codecString) {
-    switch (shaka.util.MimeUtils.getCodecBase(codecString)) {
+    const cb = shaka.util.MimeUtils.getCodecBase(codecString);
+    switch (cb) {
       case 'avc1':
       case 'avc3':
         return 'avc';  // H264
@@ -115,7 +116,7 @@ shaka.util.MimeUtils = class {
       case 'dvhe':
         return 'dovi'; // Dolby Vision
     }
-    return codecString;
+    return cb;
   }
 
   /**
diff --git a/test/util/periods_unit.js b/test/util/periods_unit.js
index e28f11f1ed..ad655ab941 100644
--- a/test/util/periods_unit.js
+++ b/test/util/periods_unit.js
@@ -1027,12 +1027,22 @@ describe('PeriodCombiner', () => {
     stream6.bandwidth = 120000;
     stream6.codecs = 'avc3.42001f';
 
+    const stream7 = makeVideoStream(1080);
+    stream7.originalId = '7';
+    stream7.bandwidth = 120000;
+    stream7.codecs = 'vp09.00.10.08';
+
+    const stream8 = makeVideoStream(1080);
+    stream8.originalId = '8';
+    stream8.bandwidth = 120000;
+    stream8.codecs = 'vp09.01.20.08.01';
+
     /** @type {!Array.<shaka.util.PeriodCombiner.Period>} */
     const periods = [
       {
         id: '0',
         videoStreams: [
-          stream1, stream3, stream5,
+          stream1, stream3, stream5, stream7,
         ],
         audioStreams: [],
         textStreams: [],
@@ -1041,7 +1051,7 @@ describe('PeriodCombiner', () => {
       {
         id: '1',
         videoStreams: [
-          stream2, stream4, stream6,
+          stream2, stream4, stream6, stream8,
         ],
         audioStreams: [],
         textStreams: [],
@@ -1051,7 +1061,7 @@ describe('PeriodCombiner', () => {
 
     await combiner.combinePeriods(periods, /* isDynamic= */ true);
     const variants = combiner.getVariants();
-    expect(variants.length).toBe(3);
+    expect(variants.length).toBe(4);
     // We can use the originalId field to see what each track is composed of.
     const video1 = variants[0].video;
     expect(video1.originalId).toBe('1,2');
@@ -1061,6 +1071,9 @@ describe('PeriodCombiner', () => {
 
     const video3 = variants[2].video;
     expect(video3.originalId).toBe('5,6');
+
+    const video4 = variants[3].video;
+    expect(video4.originalId).toBe('7,8');
   });
 
   it('Matches streams with most roles in common', async () => {

From 095f2f11055e6ed2f693c9b037006bbf07effa0b Mon Sep 17 00:00:00 2001
From: Joey Parrish <joeyparrish@users.noreply.github.com>
Date: Mon, 9 May 2022 14:20:40 -0700
Subject: [PATCH 05/11] Expand variable name for readability

---
 lib/util/mime_utils.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 6caea138d8..295d4199dc 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -104,8 +104,8 @@ shaka.util.MimeUtils = class {
    * @return {string}
    */
   static getNormalizedCodec(codecString) {
-    const cb = shaka.util.MimeUtils.getCodecBase(codecString);
-    switch (cb) {
+    const codecBase = shaka.util.MimeUtils.getCodecBase(codecString);
+    switch (codecBase) {
       case 'avc1':
       case 'avc3':
         return 'avc';  // H264
@@ -116,7 +116,7 @@ shaka.util.MimeUtils = class {
       case 'dvhe':
         return 'dovi'; // Dolby Vision
     }
-    return cb;
+    return codecBase;
   }
 
   /**

From ac6992cb5491005f2c6bdd046d169248cce6a394 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Tue, 10 May 2022 22:32:46 -0400
Subject: [PATCH 06/11] Update mime_utils to group similar codec independently
 of their codec string.

Also fix issue in getCodecParts_.
---
 lib/util/mime_utils.js       | 52 +++++++++++++++++++++++++---------
 test/util/mime_utils_unit.js | 55 ++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+), 13 deletions(-)
 create mode 100644 test/util/mime_utils_unit.js

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');
+  });
+});

From bc06277a5ff16fac11ed5a93dbd3e2c16b653187 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Wed, 11 May 2022 10:22:23 -0400
Subject: [PATCH 07/11] Remove grouping for ac3,ec3,dtsx and dtsc

the codec string indicates a container difference which may be incompatible when switching from one to another.
---
 lib/util/mime_utils.js       | 10 +---------
 test/util/mime_utils_unit.js | 14 --------------
 2 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 898b15c0fe..f9e9dc1acc 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -98,7 +98,7 @@ shaka.util.MimeUtils = class {
 
   /**
    * Get the normalized codec from a codec string,
-   * ignoring multiple names of a same codec.
+   * grouping them as long as they are compatible.
    *
    * @param {string} codecString
    * @return {string}
@@ -124,14 +124,6 @@ shaka.util.MimeUtils = class {
         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
diff --git a/test/util/mime_utils_unit.js b/test/util/mime_utils_unit.js
index 447f62b62a..67c4a81c06 100644
--- a/test/util/mime_utils_unit.js
+++ b/test/util/mime_utils_unit.js
@@ -26,23 +26,9 @@ describe('MimeUtils', () => {
 
     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');
 

From 7172b30e33657c6c52d9e503b5e48cacdb29ea08 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Wed, 11 May 2022 22:56:58 -0400
Subject: [PATCH 08/11] Remove container distinction.

---
 lib/util/mime_utils.js       | 16 ++++++++++++----
 test/util/mime_utils_unit.js | 32 +++++++++++++++++++++++---------
 2 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index f9e9dc1acc..b1392f12ab 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -98,7 +98,7 @@ shaka.util.MimeUtils = class {
 
   /**
    * Get the normalized codec from a codec string,
-   * grouping them as long as they are compatible.
+   * indendently of their container.
    *
    * @param {string} codecString
    * @return {string}
@@ -112,7 +112,7 @@ shaka.util.MimeUtils = class {
       case base === 'mp4a' && profile === '66':
       case base === 'mp4a' && profile === '67':
       case base === 'mp4a' && profile === '68':
-        return 'mpeg2_aac';
+        return 'aac';
       case base === 'mp4a' && profile === '69':
       case base === 'mp4a' && profile === '6b':
         return 'mp3';
@@ -121,9 +121,17 @@ shaka.util.MimeUtils = class {
       case base === 'mp4a' && profile === '40.5':
       case base === 'mp4a' && profile === '40.05':
       case base === 'mp4a' && profile === '40.29':
-        return 'mpeg4_aac';
+        return 'aac';
       case base === 'mp4a' && profile === '40.42':
-        return 'mpeg4_xhe_aac'; // Extended HE-AAC
+        return '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
diff --git a/test/util/mime_utils_unit.js b/test/util/mime_utils_unit.js
index 67c4a81c06..61b7941189 100644
--- a/test/util/mime_utils_unit.js
+++ b/test/util/mime_utils_unit.js
@@ -9,22 +9,36 @@ describe('MimeUtils', () => {
     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('mp4a.66')).toBe('aac');
+    expect(getNormalizedCodec('mp4a.67')).toBe('aac');
+    expect(getNormalizedCodec('mp4a.68')).toBe('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.40.2')).toBe('aac');
+    expect(getNormalizedCodec('mp4a.40.02')).toBe('aac');
+    expect(getNormalizedCodec('mp4a.40.5')).toBe('aac');
+    expect(getNormalizedCodec('mp4a.40.05')).toBe('aac');
+    expect(getNormalizedCodec('mp4a.40.29')).toBe('aac');
 
-    expect(getNormalizedCodec('mp4a.40.42')).toBe('mpeg4_xhe_aac');
+    expect(getNormalizedCodec('mp4a.40.42')).toBe('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('dtsc')).toBe('dtsc');
+    expect(getNormalizedCodec('mp4a.a9')).toBe('dtsc');
+
+    expect(getNormalizedCodec('dtsx')).toBe('dtsx');
+    expect(getNormalizedCodec('mp4a.b2')).toBe('dtsx');
 
     expect(getNormalizedCodec('vp8')).toBe('vp8');
     expect(getNormalizedCodec('vp8.0')).toBe('vp8');

From 1f70352e264af7ab4fdfa05725b1d908e39615a5 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Wed, 11 May 2022 23:01:09 -0400
Subject: [PATCH 09/11] case-insensitivity tweak.

---
 lib/util/mime_utils.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index b1392f12ab..5b933e344f 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -105,9 +105,9 @@ shaka.util.MimeUtils = class {
    */
   static getNormalizedCodec(codecString) {
     const parts =
-      shaka.util.MimeUtils.getCodecParts_(codecString.toLowerCase());
+      shaka.util.MimeUtils.getCodecParts_(codecString);
     const base = parts[0];
-    const profile = parts[1];
+    const profile = parts[1].toLowerCase();
     switch (true) {
       case base === 'mp4a' && profile === '66':
       case base === 'mp4a' && profile === '67':

From 13b1e9b7783a5bfed92b946b2d2c026a82eb79a6 Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Wed, 11 May 2022 23:09:28 -0400
Subject: [PATCH 10/11] Group xhe_aac and aac.

---
 lib/util/mime_utils.js       | 11 +++++------
 test/util/mime_utils_unit.js |  3 +--
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 5b933e344f..ce5b9f8949 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -98,7 +98,7 @@ shaka.util.MimeUtils = class {
 
   /**
    * Get the normalized codec from a codec string,
-   * indendently of their container.
+   * independently of their container.
    *
    * @param {string} codecString
    * @return {string}
@@ -109,21 +109,20 @@ shaka.util.MimeUtils = class {
     const base = parts[0];
     const profile = parts[1].toLowerCase();
     switch (true) {
+      case base === 'mp4a' && profile === '69':
+      case base === 'mp4a' && profile === '6b':
+        return 'mp3';
       case base === 'mp4a' && profile === '66':
       case base === 'mp4a' && profile === '67':
       case base === 'mp4a' && profile === '68':
         return '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':
+      case base === 'mp4a' && profile === '40.42': // Extended HE-AAC
         return 'aac';
-      case base === 'mp4a' && profile === '40.42':
-        return 'xhe_aac'; // Extended HE-AAC
       case base === 'mp4a' && profile === 'a5':
         return 'ac-3'; // Dolby Digital
       case base === 'mp4a' && profile === 'a6':
diff --git a/test/util/mime_utils_unit.js b/test/util/mime_utils_unit.js
index 61b7941189..0364314ac1 100644
--- a/test/util/mime_utils_unit.js
+++ b/test/util/mime_utils_unit.js
@@ -23,8 +23,7 @@ describe('MimeUtils', () => {
     expect(getNormalizedCodec('mp4a.40.5')).toBe('aac');
     expect(getNormalizedCodec('mp4a.40.05')).toBe('aac');
     expect(getNormalizedCodec('mp4a.40.29')).toBe('aac');
-
-    expect(getNormalizedCodec('mp4a.40.42')).toBe('xhe_aac');
+    expect(getNormalizedCodec('mp4a.40.42')).toBe('aac');
 
     expect(getNormalizedCodec('ac-3')).toBe('ac-3');
     expect(getNormalizedCodec('mp4a.a5')).toBe('ac-3');

From c4f412e44da1010792e14cbf711fda79846528bd Mon Sep 17 00:00:00 2001
From: Gaetan Hervouet <gaetanhervouet@google.com>
Date: Wed, 11 May 2022 23:11:55 -0400
Subject: [PATCH 11/11] Remove unnecessary return

---
 lib/util/mime_utils.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index ce5b9f8949..1e0cf992d5 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -115,7 +115,6 @@ shaka.util.MimeUtils = class {
       case base === 'mp4a' && profile === '66':
       case base === 'mp4a' && profile === '67':
       case base === 'mp4a' && profile === '68':
-        return 'aac';
       case base === 'mp4a' && profile === '40.2':
       case base === 'mp4a' && profile === '40.02':
       case base === 'mp4a' && profile === '40.5':