ability to specify bitrate setting in lamejs plugin (#214)

* add ability to specify bitrate setting in lamejs plugin
* allow overriding sampleRate in lamejs plugin
* allow to specify samplerate in libvorbis plugin

CHANGES.md

@@ -6,6 +6,7 @@ videojs-record changelog
 
 - Bump required version for videojs-wavesurfer to 2.2.1 for compatibility
   with video.js 6.7.x (#208)
+- Ability to specify bitrate setting in lamejs plugin (#213)
 
 
 2.1.1 - 2018/02/19

README.md

@@ -229,6 +229,7 @@ The available options for this plugin are:
 | `audioMimeType` | string | `'auto'` | The mime type for the audio recorder. Defaults to `auto` which will pick the best option available in the browser (e.g. either `audio/wav`, `audio/ogg` or `audio/webm`). A full list of supported mime-types in the Chrome browser is listed [here](https://cs.chromium.org/chromium/src/third_party/WebKit/LayoutTests/fast/mediarecorder/MediaRecorder-isTypeSupported.html).|
 | `audioBufferSize` | float | `4096` | The size of the audio buffer (in sample-frames per second). Legal values: 0, 256, 512, 1024, 2048, 4096, 8192 and 16384. |
 | `audioSampleRate` | float | `44100` | The audio sample rate (in sample-frames per second) at which the `AudioContext` handles audio. Legal values are in the range of 22050 to 96000. |
+| `audioBitRate` | float | `128` | The audio bitrate in kbps (only used in the lamejs plugin). |
 | `audioChannels` | float | `2` | Number of audio channels. Using a single channel results in a smaller filesize. |
 | `audioWorkerURL` | string | `''` | URL for the audio worker, for example: `/opus-recorder/build/encoderWorker.min.js`. Currently only used for opus-recorder and lamejs plugins. |
 | `animationFrameRate` | float | `200` | Frame rate for animated GIF (in frames per second). |

examples/plugins/audio-only-mp3.html

@@ -49,7 +49,9 @@
             maxLength: 20,
             debug: true,
             audioEngine: "lamejs",
-            audioWorkerURL: "../../node_modules/lamejs/worker-example/worker-realtime.js"
+            audioWorkerURL: "../../node_modules/lamejs/worker-example/worker-realtime.js",
+            audioSampleRate: 44100,
+            audioBitRate: 128
         }
     }
 }, function() {

examples/plugins/audio-only-ogg.html

@@ -49,7 +49,8 @@
             video: false,
             maxLength: 20,
             debug: true,
-            audioEngine: "libvorbis.js"
+            audioEngine: "libvorbis.js",
+            audioSampleRate: 32000
         }
     }
 }, function() {

src/js/defaults.js

@@ -59,6 +59,8 @@ const pluginDefaultOptions = {
     // An implementation must support sample-rates in at least
     // the range 22050 to 96000.
     audioSampleRate: 44100,
+    // The audio bitrate in kbps (only used in lamejs plugin).
+    audioBitRate: 128,
     // Allows you to record single-channel audio, which can reduce the
     // filesize.
     audioChannels: 2,

src/js/plugins/lamejs-plugin.js

@@ -19,18 +19,19 @@ class LamejsEngine extends RecordEngine {
         this.inputStream = stream;
         this.mediaType = mediaType;
         this.debug = debug;
+        this.audioType = 'audio/mp3';
 
         let config = {
             debug: this.debug,
-            sampleRate: this.sampleRate
+            sampleRate: this.sampleRate,
+            bitRate: this.bitRate
         };
 
         this.audioContext = new AudioContext();
         this.audioSourceNode = this.audioContext.createMediaStreamSource(
             this.inputStream);
         this.processor = this.audioContext.createScriptProcessor(
             16384, 1, 1);
-        config.sampleRate = this.audioContext.sampleRate;
 
         this.engine = new Worker(this.audioWorkerURL);
         this.engine.onmessage = this.onWorkerMessage.bind(this);
@@ -67,7 +68,7 @@ class LamejsEngine extends RecordEngine {
         switch (ev.data.cmd) {
             case 'end':
                 this.onStopRecording(new Blob(ev.data.buf,
-                    {type: 'audio/mp3'}));
+                    {type: this.audioType}));
                 break;
 
             case 'error':

src/js/plugins/libvorbis-plugin.js

@@ -22,7 +22,7 @@ class LibVorbisEngine extends RecordEngine {
 
         // setup libvorbis.js
         this.options = {
-            audioBitsPerSecond: 32000
+            audioBitsPerSecond: this.sampleRate
         };
     }
 

src/js/videojs.record.js

@@ -135,6 +135,7 @@ class Record extends Plugin {
         this.audioWorkerURL = recordOptions.audioWorkerURL;
         this.audioBufferSize = recordOptions.audioBufferSize;
         this.audioSampleRate = recordOptions.audioSampleRate;
+        this.audioBitRate = recordOptions.audioBitRate;
         this.audioChannels = recordOptions.audioChannels;
         this.audioMimeType = recordOptions.audioMimeType;
 
@@ -444,6 +445,7 @@ class Record extends Plugin {
             // audio settings
             this.engine.bufferSize = this.audioBufferSize;
             this.engine.sampleRate = this.audioSampleRate;
+            this.engine.bitRate = this.audioBitRate;
             this.engine.audioChannels = this.audioChannels;
             this.engine.audioWorkerURL = this.audioWorkerURL;