dify

dify/web/app/components/base/voice-input/utils.ts

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+import lamejs from 'lamejs'
+import MPEGMode from 'lamejs/src/js/MPEGMode'
+import Lame from 'lamejs/src/js/Lame'
+import BitStream from 'lamejs/src/js/BitStream'
+
+if (globalThis) {
+  (globalThis as any).MPEGMode = MPEGMode
+  ;(globalThis as any).Lame = Lame
+  ;(globalThis as any).BitStream = BitStream
+}
+
+export const convertToMp3 = (recorder: any) => {
+  const wav = lamejs.WavHeader.readHeader(recorder.getWAV())
+  const { channels, sampleRate } = wav
+  const mp3enc = new lamejs.Mp3Encoder(channels, sampleRate, 128)
+  const result = recorder.getChannelData()
+  const buffer: BlobPart[] = []
+
+  const leftData = result.left && new Int16Array(result.left.buffer, 0, result.left.byteLength / 2)
+  const rightData = result.right && new Int16Array(result.right.buffer, 0, result.right.byteLength / 2)
+  const remaining = leftData.length + (rightData ? rightData.length : 0)
+
+  const maxSamples = 1152
+  const toArrayBuffer = (bytes: Int8Array) => {
+    const arrayBuffer = new ArrayBuffer(bytes.length)
+    new Uint8Array(arrayBuffer).set(bytes)
+    return arrayBuffer
+  }
+
+  for (let i = 0; i < remaining; i += maxSamples) {
+    const left = leftData.subarray(i, i + maxSamples)
+    let right = null
+    let mp3buf = null
+
+    if (channels === 2) {
+      right = rightData.subarray(i, i + maxSamples)
+      mp3buf = mp3enc.encodeBuffer(left, right)
+    }
+    else {
+      mp3buf = mp3enc.encodeBuffer(left)
+    }
+
+    if (mp3buf.length > 0)
+      buffer.push(toArrayBuffer(mp3buf))
+  }
+
+  const enc = mp3enc.flush()
+
+  if (enc.length > 0)
+    buffer.push(toArrayBuffer(enc))
+
+  return new Blob(buffer, { type: 'audio/mp3' })
+}