>

Convert Audio Formats with FFmpeg (M4A→MP3, MP3→WAV)

Transcode any audio file between MP3, M4A/AAC, WAV, FLAC and more from the command line.

WindowsaudioconversionffmpegLow risk
Run ffmpeg -i voice.m4a -c:a libmp3lame -q:a 2 voice.mp3 — FFmpeg reads the input format and picks the encoder from the output extension.

01Command

Command
$ ffmpeg -i voice.m4a -c:a libmp3lame -q:a 2 voice.mp3

02What it does

FFmpeg auto-detects the input format and chooses the output encoder from the file extension, so the same pattern converts M4A to MP3, MP3 to WAV (just omit the encoder: ffmpeg -i song.mp3 song.wav), or anything to AAC with -c:a aac -b:a 192k. The wiki's -q:a scale controls MP3 quality, with 2 being a good music setting. Converting a lossy format (MP3) to a lossless one (WAV) only makes a bigger file, never better sound.

03Risk

RiskLow risk
RequirementsFFmpeg is not preinstalled on Windows — install it first with: winget install --id Gyan.FFmpeg
!Warning: Converting lossy to lossless inflates the file size without recovering quality lost at the first encoding.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

  • MP3 Encoding Guide
    FFmpeg Trac Wiki · community · 2026-09-17
    Evidence: Documents libmp3lame encoding with -q:a VBR quality values for converting other formats to MP3.
  • AAC Encoding Guide
    FFmpeg Trac Wiki · community · 2026-09-17
    Evidence: Documents the native aac encoder and libfdk_aac for producing M4A/AAC files, including -b:a bitrate guidance.

Last verified: 2026-09-18 · Category: Media