From 94fc582eef902e4b661c6539148b5caa854262bf Mon Sep 17 00:00:00 2001
From: Gennady Grishkovtsov <grishkovelli@gmail.com>
Date: Fri, 3 May 2019 01:17:56 +0300
Subject: [PATCH] Add WAV support

---
 README.md                              |  6 +--
 demo/app.vue                           |  2 +
 src/components/downloader.vue          |  3 +-
 src/components/recorder.vue            |  3 +-
 src/lib/{encoder.js => mp3-encoder.js} |  6 +--
 src/lib/recorder.js                    | 37 ++++++++++++---
 src/lib/wav-encoder.js                 | 65 ++++++++++++++++++++++++++
 src/mixins/uploader-props.js           |  1 +
 8 files changed, 109 insertions(+), 14 deletions(-)
 rename src/lib/{encoder.js => mp3-encoder.js} (93%)
 create mode 100644 src/lib/wav-encoder.js

diff --git a/README.md b/README.md
index b5baa36..bd3c864 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@
 - Records limit
 - A lot of callbacks
 - Individual an audio player
-- MP3 support
+- MP3/WAV support
 
 ### Tested in (desktop)
 
@@ -35,9 +35,10 @@ npm i vue-audio-recorder --save
 | attempts              | Number   | Number of recording attempts                                             |
 | headers               | Object   | HTTP headers                                                             |
 | time                  | Number   | Time limit for the record (minutes)                                      |
-| bit-rate              | Number   | Default: 128                                                             |
+| bit-rate              | Number   | Default: 128 (only for MP3)                                              |
 | sample-rate           | Number   | Default: 44100                                                           |
 | filename              | String   | Download/Upload filename                                                 |
+| format                | String   | WAV/MP3. Default: mp3                                                    |
 | upload-url            | String   | URL for uploading                                                        |
 | show-download-button  | Boolean  | If it is true show a download button. Default: true                      |
 | show-upload-button    | Boolean  | If it is true show an upload button. Default: true                       |
@@ -106,7 +107,6 @@ npm run build
 ## TODO
 
 - Clear record list
-- Return WAV format
 - Responsive design
 
 ## Authors
diff --git a/demo/app.vue b/demo/app.vue
index c6e84bd..024a577 100644
--- a/demo/app.vue
+++ b/demo/app.vue
@@ -11,6 +11,8 @@
 
     <audio-recorder v-if="showRecorder"
       upload-url="some url"
+      filename="ninja"
+      format="wav"
       :attempts="3"
       :time="2"
       :headers="headers"
diff --git a/src/components/downloader.vue b/src/components/downloader.vue
index 224123b..1ee0213 100644
--- a/src/components/downloader.vue
+++ b/src/components/downloader.vue
@@ -27,9 +27,10 @@
           return
         }
 
+        const type = this.record.blob.type.split('/')[1]
         const link = document.createElement('a')
         link.href = this.record.url
-        link.download = `${this.filename}.mp3`
+        link.download = `${this.filename}.${type}`
         link.click()
       }
     }
diff --git a/src/components/recorder.vue b/src/components/recorder.vue
index 32170e7..4622580 100644
--- a/src/components/recorder.vue
+++ b/src/components/recorder.vue
@@ -348,7 +348,8 @@
           pauseRecording  : this.pauseRecording,
           micFailed       : this.micFailed,
           bitRate         : this.bitRate,
-          sampleRate      : this.sampleRate
+          sampleRate      : this.sampleRate,
+          format          : this.format
         })
       }
     },
diff --git a/src/lib/encoder.js b/src/lib/mp3-encoder.js
similarity index 93%
rename from src/lib/encoder.js
rename to src/lib/mp3-encoder.js
index 944de62..fd390ba 100644
--- a/src/lib/encoder.js
+++ b/src/lib/mp3-encoder.js
@@ -27,9 +27,9 @@ export default class {
     this.dataBuffer = []
 
     return {
-      id    : Date.now(),
-      blob  : blob,
-      url   : URL.createObjectURL(blob)
+      id   : Date.now(),
+      blob : blob,
+      url  : URL.createObjectURL(blob)
     }
   }
 
diff --git a/src/lib/recorder.js b/src/lib/recorder.js
index 9101539..acd2c52 100644
--- a/src/lib/recorder.js
+++ b/src/lib/recorder.js
@@ -1,4 +1,5 @@
-import Encoder from './encoder'
+import Mp3Encoder from './mp3-encoder'
+import WavEncoder from './wav-encoder'
 import { convertTimeMMSS } from './utils'
 
 export default class {
@@ -7,8 +8,9 @@ export default class {
     this.pauseRecording  = options.pauseRecording
     this.afterRecording  = options.afterRecording
     this.micFailed       = options.micFailed
+    this.format          = options.format
 
-    this.lameOptions = {
+    this.encoderOptions = {
       bitRate    : options.bitRate,
       sampleRate : options.sampleRate
     }
@@ -22,6 +24,8 @@ export default class {
     this.duration = 0
     this.volume   = 0
 
+    this.wavSamples = []
+
     this._duration = 0
   }
 
@@ -44,8 +48,8 @@ export default class {
     this.isPause     = false
     this.isRecording = true
 
-    if (!this.lameEncoder) {
-      this.lameEncoder = new Encoder(this.lameOptions)
+    if (this._isMp3() && !this.lameEncoder) {
+      this.lameEncoder = new Mp3Encoder(this.encoderOptions)
     }
   }
 
@@ -55,7 +59,20 @@ export default class {
     this.processor.disconnect()
     this.context.close()
 
-    const record = this.lameEncoder.finish()
+    let record = null
+
+    if (this._isMp3()) {
+      record = this.lameEncoder.finish()
+    } else {
+      let wavEncoder = new WavEncoder({
+        bufferSize : this.bufferSize,
+        sampleRate : this.encoderOptions.sampleRate,
+        samples    : this.wavSamples
+      })
+      record = wavEncoder.finish()
+      this.wavSamples = []
+    }
+
     record.duration = convertTimeMMSS(this.duration)
     this.records.push(record)
 
@@ -98,7 +115,11 @@ export default class {
       const sample = ev.inputBuffer.getChannelData(0)
       let sum = 0.0
 
-      this.lameEncoder.encode(sample)
+      if (this._isMp3()) {
+        this.lameEncoder.encode(sample)
+      } else {
+        this.wavSamples.push(new Float32Array(sample))
+      }
 
       for (let i = 0; i < sample.length; ++i) {
         sum += sample[i] * sample[i]
@@ -115,4 +136,8 @@ export default class {
   _micError (error) {
     this.micFailed && this.micFailed(error)
   }
+
+  _isMp3 () {
+    return this.format.toLowerCase() === 'mp3'
+  }
 }
diff --git a/src/lib/wav-encoder.js b/src/lib/wav-encoder.js
new file mode 100644
index 0000000..f91fd4f
--- /dev/null
+++ b/src/lib/wav-encoder.js
@@ -0,0 +1,65 @@
+export default class {
+  constructor (options) {
+    this.bufferSize = options.bufferSize || 4096
+    this.sampleRate = options.sampleRate
+    this.samples    = options.samples
+  }
+
+  finish () {
+    this._joinSamples()
+
+    let buffer = new ArrayBuffer(44 + this.samples.length * 2)
+    let view   = new DataView(buffer)
+
+    this._writeString(view, 0, 'RIFF')                       // RIFF identifier
+    view.setUint32(4, 36 + this.samples.length * 2, true)    // RIFF chunk length
+    this._writeString(view, 8, 'WAVE')                       // RIFF type
+    this._writeString(view, 12, 'fmt ')                      // format chunk identifier
+    view.setUint32(16, 16, true)                             // format chunk length
+    view.setUint16(20, 1, true)                              // sample format (raw)
+    view.setUint16(22, 1, true)                              // channel count
+    view.setUint32(24, this.sampleRate, true)                // sample rate
+    view.setUint32(28, this.sampleRate * 4, true)            // byte rate (sample rate * block align)
+    view.setUint16(32, 4, true)                              // block align (channel count * bytes per sample)
+    view.setUint16(34, 16, true)                             // bits per sample
+    this._writeString(view, 36, 'data')                      // data chunk identifier
+    view.setUint32(40, this.samples.length * 2, true)        // data chunk length
+
+    this._floatTo16BitPCM(view, 44, this.samples)
+
+    const blob = new Blob([view], {type: 'audio/wav'})
+
+    return {
+      id   : Date.now(),
+      blob : blob,
+      url  : URL.createObjectURL(blob)
+    }
+  }
+
+  _floatTo16BitPCM (output, offset, input) {
+    for (let i = 0; i < input.length; i++, offset += 2) {
+      let s = Math.max(-1, Math.min(1, input[i]))
+      output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true)
+    }
+  }
+
+  _joinSamples () {
+    let recordLength  = this.samples.length * this.bufferSize
+    let joinedSamples = new Float64Array(recordLength)
+    let offset        = 0
+
+    for (let i = 0; i < this.samples.length; i++) {
+      let sample = this.samples[i]
+      joinedSamples.set(sample, offset)
+      offset += sample.length
+    }
+
+    this.samples = joinedSamples
+  }
+
+  _writeString (view, offset, string) {
+    for (let i = 0; i < string.length; i++) {
+      view.setUint8(offset + i, string.charCodeAt(i))
+    }
+  }
+}
diff --git a/src/mixins/uploader-props.js b/src/mixins/uploader-props.js
index 5da1fcf..9d411bc 100644
--- a/src/mixins/uploader-props.js
+++ b/src/mixins/uploader-props.js
@@ -1,6 +1,7 @@
 export default {
   props: {
     filename  : { type: String, default: 'record'   },
+    format    : { type: String, default: 'mp3'      },
     headers   : { type: Object, default: () => ({}) },
     uploadUrl : { type: String                      }
   }