How convert audio aiff to MP3 using Memory stream, NAudio and LameMP3

Question

I try to convert aiff audio file from IFormFile to MP3 and upload it to Azure Storage. I don't understand how works memory streams with NAudio... I don't want to copy file in a temp file but only using streams. Is it possible ?

using (var retMs = new MemoryStream())
{
   file.CopyTo(retMs);
   var fileBytes = retMs.ToArray();
   string s = Convert.ToBase64String(fileBytes);

    using (var ms = new MemoryStream(fileBytes))
    using (var reader = new AiffFileReader(ms))
    using (var writer = new LameMP3FileWriter(retMs, reader.WaveFormat, 128))
    {
       reader.CopyTo(writer);

       var result = await _blobService.UploadFileBlobAsync(
                              reader,
                              "audio/mpeg3",
                              "fr2.mp3");

       toReturn = result.AbsoluteUri; 
      }
                                
   }

Answer 1

I think the demo code below could be helpful for you.

using Azure.Storage.Blobs;
using NAudio.Lame;
using NAudio.Wave;
using System;
using System.IO;

namespace blobUpload
{
    class Program
    {
        static void Main(string[] args)
        {
            string containerName = "<container name>";
            string blobName = "test.mp3";
            string storageConnStr = "<storage account conn str>";

            var blobServiceClient = new BlobServiceClient(storageConnStr);
            var blobClient = blobServiceClient.GetBlobContainerClient(containerName).GetBlobClient(blobName);

            using (var retMs = new MemoryStream())
            {
                FileStream inputfileStream = new FileStream(@"<aiff file path>", FileMode.Open, FileAccess.Read);
                inputfileStream.CopyTo(retMs);
                var fileBytes = retMs.ToArray();
                
                var bytes = ConvertWavToMp3(fileBytes);

                blobClient.UploadAsync(new MemoryStream(bytes)).GetAwaiter().GetResult();

            }

        }

        public static byte[] ConvertWavToMp3(byte[] wavFile)
        {

            using (var retMs = new MemoryStream())
            using (var ms = new MemoryStream(wavFile))
            using (var rdr = new AiffFileReader(ms))
            using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 128))
            {
                rdr.CopyTo(wtr);
                return retMs.ToArray();
            }

       }
    }

Result :

I have tested on my side, this .MP3 file could be played perfectly.