使用 javascript 修剪音频文件（前 3 秒）

Question

我有一个问题，我可以修剪通过 javascript 录制的音频文件吗？就像我想修剪前 3 秒一样。我使用

p5.js

录制了音频文件，并使用

AudioContext()

将录制的文件与卡拉 OK 音频合并，我想修剪它，因为开始时有不愉快的声音。

Answer 1

您可能需要使用

AudioBuffer

 之类的工具将音频读入

AudioContext.decodeAudioData()，然后将

AudioBuffer

插入

AudioBufferSourceNode

。然后您可以使用

AudioBufferSourceNode.start()

的 offset 参数跳过前 3 秒并记录结果输出流。

示例代码：

var source = audioCtx.createBufferSource();
var dest = audioCtx.createMediaStreamDestination();
var mediaRecorder = new MediaRecorder(dest.stream);

var request = new XMLHttpRequest();
request.open('GET', 'your.ogg', true);
request.responseType = 'arraybuffer';

request.onload = function() {
  var audioData = request.response;
  audioCtx.decodeAudioData(
    audioData,
    function(buffer) {
      source.buffer = buffer;
      source.connect(dest);
      mediaRecorder.start();
      source.start(audioCtx.currentTime, 3);
      // etc...
    },
    function(e){ 
      console.log("Error with decoding audio data" + e.err);
    }
  );

}

request.send();

Answer 2

选择一个文件超过 40 秒来尝试一下：

<!DOCTYPE html>
<html>

<head>
  <title>Audio Trimmer</title>
</head>

<body>
  <input type="file" id="audioFile" accept="audio/*">
  <button onclick="trimAudio()">Trim Audio</button>

  <script>
    async function trimAudio() {
      const audioFileInput = document.getElementById('audioFile');
      const audioFile = audioFileInput.files[0];
      const startTime = 10; // Start time in seconds
      const endTime = 30; // End time in seconds

      if (audioFile) {
        try {
          const audioContext = new AudioContext();
          const fileBuffer = await audioFile.arrayBuffer();
          const audioBuffer = await audioContext.decodeAudioData(fileBuffer);

          // Trim the audio buffer
          const trimmedBuffer = trimAudioBuffer(audioBuffer, audioContext, startTime, endTime);

          // Create a Blob from the trimmed buffer
          const trimmedAudioBlob = await createBlobFromAudioBuffer(trimmedBuffer);

          // Create an <audio> element to play the trimmed audio
          const audioElement = document.createElement('audio');
          audioElement.controls = true;
          const audioUrl = URL.createObjectURL(trimmedAudioBlob);
          audioElement.src = audioUrl;

          document.body.appendChild(audioElement);
        } catch (error) {
          console.error('Error trimming audio:', error);
        }
      } else {
        console.error('Please select an audio file.');
      }
    }

    function trimAudioBuffer(buffer, audioContext, startTime, endTime) {
      const sampleRate = buffer.sampleRate;
      const startFrame = startTime * sampleRate;
      const endFrame = endTime * sampleRate;
      const duration = endTime - startTime;
      const channels = buffer.numberOfChannels;

      // Create a new AudioBuffer for the trimmed audio
      const trimmedBuffer = audioContext.createBuffer(
        channels,
        (endFrame - startFrame),
        sampleRate
      );

      for (let channel = 0; channel < channels; channel++) {
        const sourceData = buffer.getChannelData(channel).subarray(startFrame, endFrame);
        trimmedBuffer.getChannelData(channel).set(sourceData);
      }

      return trimmedBuffer;
    }

    function createBlobFromAudioBuffer(audioBuffer) {
      return new Promise((resolve) => {
        const audioContext = new(window.AudioContext || window.webkitAudioContext)();
        const audioBufferSource = audioContext.createBufferSource();
        audioBufferSource.buffer = audioBuffer;

        audioBufferSource.connect(audioContext.destination);

        audioBufferSource.onended = () => {
          const audioData = audioBuffer.getChannelData(0);
          const audioBlob = new Blob([audioData], {
            type: 'audio/wav'
          });
          resolve(audioBlob);
        };

        audioBufferSource.start();
        audioBufferSource.stop(audioContext.currentTime + audioBuffer.duration);
      });
    }
  </script>
</body>

</html>

使用 javascript 修剪音频文件（前 3 秒）

问题描述投票：0回答：2

2个回答

选择一个文件超过 40 秒来尝试一下：

最新问题

使用 javascript 修剪音频文件（前 3 秒）

问题描述 投票：0回答：2

2个回答

选择一个文件超过 40 秒来尝试一下：

最新问题

问题描述投票：0回答：2