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如何在内存中将wav文件转换成mp3?

lamemp3 file-conversion naudio mp3 c#

3

Junior · 技术社区 · 7 年前

我有一个应用程序是在ASP.NETMVC5框架之上用C编写的。

我的目标是打电话给第三方服务下载一个wave文件。然后我想把这个文件转换成MP3。最后,我想将mp3文件返回为(byte[]),以允许用户直接从内存中下载。

下面是我的代码的结尾,它允许用户从内存中下载转换后的文件

public ActionResult Download(int? id)
{

    // Download and convert the file
    // the variable "someUri" is generated based on the provided id value
    byte[] filedata = ConvertToMp3(someUri);

    var cd = new System.Net.Mime.ContentDisposition
    {
        FileName = "filename.mp3",
        Inline = true,
    };

    Response.AppendHeader("Content-Disposition", cd.ToString());

    return File(filedata, "audio/mpeg"); 
}

但我对 ConvertToMp3 方法。

我在用 NAudio 用于转换文件转换的库。这是我的密码

public void ConvertToMp3(Uri uri)
{
    using (var client = new WebClient())
    {
        byte[] file = client.DownloadData(uri);
        string wavFileFullName = GetFullDirectory() + "filename.wav";
        string mp3FileFullName = GetFullDirectory() + "filename.mp3";
        WaveFormat target = new WaveFormat(8000, 16, 1);
        using (WaveStream stream = new WaveFileReader(new MemoryStream(file)))
        using (WaveFormatConversionStream str = new WaveFormatConversionStream(target, stream))
        {
            WaveFileWriter.CreateWaveFile(wavFileFullName, str);

            using (var reader = new WaveFileReader(wavFileFullName))
            using (var writer = new LameMP3FileWriter(mp3FileFullName, reader.WaveFormat, bitRate))
            {
                reader.CopyTo(writer);
            }
        }
        File.Delete(wavFileFullName);
    }
}

上面的方法转换文件。但是这种方法将wave文件写入桌面,将其转换为mp3,然后删除wave文件。此外,此方法将MP3文件写入桌面,而不是返回 byte[] 内容。

如何在不必向桌面写入的情况下转换内存中的文件?另外,我如何将MP3文件转换为 字节[] ?

1 回复 | 直到 7 年前

1

2

Junior 7 年前

也许是这样的。

注释 :完全未经测试,我只是查看了源代码。

同步

public byte[] ConvertToMp3(Uri uri)
{
   using (var client = new WebClient())
   {
      var file = client.DownloadData(uri);
      var target = new WaveFormat(8000, 16, 1);
      using (var outPutStream = new MemoryStream())
      using (var waveStream = new WaveFileReader(new MemoryStream(file)))
      using (var conversionStream = new WaveFormatConversionStream(target, waveStream))
      using (var writer = new LameMP3FileWriter(outPutStream, conversionStream.WaveFormat, 32, null))
      {
         conversionStream.CopyTo(writer);

         return outPutStream.ToArray();
      }
   }
}

异步的

public async Task<byte[]> ConvertToMp3Async(Uri uri)
{
   using (var client = new WebClient())
   {
      var file = await client.DownloadDataTaskAsync(uri);
      var target = new WaveFormat(8000, 16, 1);
      using (var outPutStream = new MemoryStream())
      using (var waveStream = new WaveFileReader(new MemoryStream(file)))
      using (var conversionStream = new WaveFormatConversionStream(target, waveStream))
      using (var writer = new LameMP3FileWriter(outPutStream, conversionStream.WaveFormat, 32, null))
      {
          await conversionStream.CopyToAsync(writer);

          return outPutStream.ToArray();
      }
   }
}