Can i convert WEBM to MP3?

Hello,

Can i convert from audio/webm to mp3 ?

I am trying like this:

const originFile = 'myAudio.webm'
const dstFile= 'myAudio.mp3'

const testData = new Uint8Array(fs.readFileSync(`./${originFile}`))
const result = ffmpeg({
          MEMFS: [{ name: originFile, data: testData }],
          arguments: [ '-i', originFile, '-vn', '-ab', '128k', '-ar', '44100', '-y', dstFile ],
        })

const out = result.MEMFS[0]
fs.writeFileSync(`./${dstFile}`, Buffer(out.data))

And receiving this kind of result:

ffmpeg version n4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with emcc (Emscripten gcc/clang-like replacement) 1.39.11
  configuration: --cc=emcc --ranlib=emranlib --enable-cross-compile --target-os=none --arch=x86 --disable-runtime-cpudetect --disable-asm --disable-fast-unaligned --disable-pthreads --disable-w32threads --disable-os2threads --disable-debug --disable-stripping --disable-safe-bitstream-reader --disable-all --enable-ffmpeg --enable-avcodec --enable-avformat --enable-avfilter --enable-swresample --enable-swscale --disable-network --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vdpau --enable-decoder=vp8 --enable-decoder=h264 --enable-decoder=vorbis --enable-decoder=opus --enable-decoder=mp3 --enable-decoder=aac --enable-decoder=pcm_s16le --enable-decoder=mjpeg --enable-decoder=png --enable-demuxer=matroska --enable-demuxer=ogg --enable-demuxer=mov --enable-demuxer=mp3 --enable-demuxer=wav --enable-demuxer=image2 --enable-demuxer=concat --enable-protocol=file --enable-filter=aresample --enable-filter=scale --enable-filter=crop --enable-filter=overlay --enable-filter=hstack --enable-filter=vstack --disable-bzlib --disable-iconv --disable-libxcb --disable-lzma --disable-sdl2 --disable-securetransport --disable-xlib --enable-zlib --enable-encoder=libvpx_vp8 --enable-encoder=libopus --enable-muxer=webm --enable-muxer=ogg --enable-muxer=null --enable-libopus --enable-libvpx --extra-cflags='-s USE_ZLIB=1 -I../libvpx/dist/include' --extra-ldflags=-L../libvpx/dist/lib
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
[opus @ 0x6a9ef0] Warning: not compiled with thread support, using thread emulation
Input #0, matroska,webm, from 'myAudio.webm':
  Metadata:
    encoder         : Chrome
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0(eng): Audio: opus, 48000 Hz, mono, fltp (default)
[NULL @ 0x6aaa00] Unable to find a suitable output format for 'myAudio.mp3'
myAudio.mp3: Invalid argument

// TypeError: Cannot read property 'data' of undefined

Kagami / ffmpeg.js

Can i convert WEBM to MP3? #159