feat: Add AC-3 and EC-3 support in Mp4Generator

shaka-project · May 16, 2023 · 428a89b · 428a89b
1 parent 82e905b
commit 428a89b
Show file tree

Hide file tree

Showing 3 changed files with 42 additions and 0 deletions.
diff --git a/lib/mss/mss_parser.js b/lib/mss/mss_parser.js
@@ -632,6 +632,7 @@ shaka.mss.MssParser = class {
           timescale: stream.mssPrivateData.timescale,
           duration: stream.mssPrivateData.duration,
           videoNalus: videoNalus,
+          audioConfig: new Uint8Array([]),
           data: null, // Data is not necessary for init segement.
           stream: stream,
         };

diff --git a/lib/transmuxer/mp3_transmuxer.js b/lib/transmuxer/mp3_transmuxer.js
@@ -170,6 +170,7 @@ shaka.transmuxer.Mp3Transmuxer = class {
       timescale: sampleRate,
       duration: duration,
       videoNalus: [],
+      audioConfig: new Uint8Array([]),
       data: {
         sequenceNumber: this.frameIndex_,
         baseMediaDecodeTime: baseMediaDecodeTime,

diff --git a/lib/util/mp4_generator.js b/lib/util/mp4_generator.js
@@ -33,6 +33,9 @@ shaka.util.Mp4Generator = class {
     /** @private {!Array.<string>} */
     this.videoNalus_ = streamInfo.videoNalus;
 
+    /** @private {!Uint8Array} */
+    this.audioConfig_ = streamInfo.audioConfig;
+
     /** @private {number} */
     this.sequenceNumber_ = 0;
 
@@ -310,6 +313,10 @@ shaka.util.Mp4Generator = class {
         this.stream_.codecs.includes('mp3') ||
         this.stream_.codecs.includes('mp4a.40.34')) {
           bytes = this.mp3_();
+        } else if (this.stream_.codecs.includes('ac-3')) {
+          bytes = this.dac3_();
+        } else if (this.stream_.codecs.includes('ec-3')) {
+          bytes = this.dec3_();
         } else {
           bytes = this.mp4a_();
         }
@@ -471,6 +478,36 @@ shaka.util.Mp4Generator = class {
     return Mp4Generator.box('.mp3', this.audioStsd_());
   }
 
+  /**
+   * Generate a DAC3 box
+   *
+   * @return {!Uint8Array}
+   * @private
+   */
+  dac3_() {
+    const Mp4Generator = shaka.util.Mp4Generator;
+    let boxName = 'dac3';
+    if (this.stream_.encrypted) {
+      boxName = 'enca';
+    }
+    return Mp4Generator.box(boxName, this.audioStsd_(), this.audioConfig_);
+  }
+
+  /**
+   * Generate a DEC3 box
+   *
+   * @return {!Uint8Array}
+   * @private
+   */
+  dec3_() {
+    const Mp4Generator = shaka.util.Mp4Generator;
+    let boxName = 'dec3';
+    if (this.stream_.encrypted) {
+      boxName = 'enca';
+    }
+    return Mp4Generator.box(boxName, this.audioStsd_(), this.audioConfig_);
+  }
+
   /**
    * Generate a MP4A box
    *
@@ -1147,6 +1184,7 @@ shaka.util.Mp4Generator.DINF_ = new Uint8Array([]);
  *    timescale: number,
  *    duration: number,
  *    videoNalus: !Array.<string>,
+ *    audioConfig: !Uint8Array,
  *    data: ?shaka.util.Mp4Generator.Data,
  *    stream: !shaka.extern.Stream
  * }}
@@ -1157,6 +1195,8 @@ shaka.util.Mp4Generator.DINF_ = new Uint8Array([]);
  *   The Stream's duration.
  * @property {!Array.<string>} videoNalus
  *   The stream's video nalus.
+ * @property {!Uint8Array} audioConfig
+ *   The stream's audio config.
  * @property {?shaka.util.Mp4Generator.Data} data
  *   The stream's data.
  * @property {!shaka.extern.Stream} stream