How to Build a Wma To Mp3 Converter

// Server-side: FFmpeg conversion
  import { exec } from 'child_process';

  function convertWMAtoMP3(inputPath, outputPath, options = {}) {
  const {
    bitrate = '192k',  // 128k, 192k, 256k, 320k
    sampleRate = 44100, // 44100 or 48000
    channels = 2        // 1 for mono, 2 for stereo
  } = options;

  const command = `ffmpeg -i "${inputPath}" -codec:a libmp3lame -b:a ${bitrate} -ar ${sampleRate} -ac ${channels} "${outputPath}"`;

  return new Promise((resolve, reject) => {
    exec(command, (error, stdout, stderr) => {
      if (error) reject(error);
      else resolve({ output: outputPath, stderr });
    });
  });
  }

  // Browser-side: FFmpeg WASM for client-side conversion
  async function convertInBrowser(wmaFile) {
  const { createFFmpeg, fetchFile } = FFmpeg;
  const ffmpeg = createFFmpeg({ log: false });
  await ffmpeg.load();

  ffmpeg.FS('writeFile', 'input.wma', await fetchFile(wmaFile));
  await ffmpeg.run(
    '-i', 'input.wma',
    '-codec:a', 'libmp3lame',
    '-b:a', '192k',
    '-ar', '44100',
    'output.mp3'
  );

  const data = ffmpeg.FS('readFile', 'output.mp3');
  return new Blob([data.buffer], { type: 'audio/mpeg' });
  }

  // Preserve metadata during conversion
  function convertWithMetadata(inputPath, outputPath, bitrate = '192k') {
  // -map_metadata 0 copies all metadata from input to output
  const command = `ffmpeg -i "${inputPath}" -codec:a libmp3lame -b:a ${bitrate} -map_metadata 0 -id3v2_version 3 "${outputPath}"`;
  return execPromise(command);
  }