Question

我在Asp.Net MVC 5框架的顶部使用c＃编写了一个应用程序。

我的目标是拨打第三方服务以下载wave文件。然后我想将此文件转换为mp3。最后，我想将mp3文件作为（byte []）返回，以允许用户直接从内存中下载。

以下是我的代码最终会如何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"); 
}

但是我遇到了ConvertToMp3方法的问题。

我正在使用NAudio库来转换文件转换。这是我到目前为止的代码

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);
    }
}

上述方法转换文件。但是这种方法将波形文件写入桌面，将其转换为mp3然后删除波形文件。此外，此方法将mp3文件写入桌面，而不是返回byte[]内容。

如何在不必写入桌面的情况下将文件转换为内存？另外，如何将mp3文件转换为byte[]？

Answer 1

也许是这样的。

注意：完全没有经过测试，我只是看了看来源。

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(); } } }

<强>异步

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(); } } }

如何在内存中将wav文件转换为mp3？

1 个答案: