• набор кодеков, такой как K-Lite Codec Pack
• видеоредактор Virtual Dub
• AVISynth

@echo off
@rem © danx
set VD=VirtualDub.audio.
echo VirtualDub.Open(VirtualDub.params[0],"",0); > 1.jobs
echo %VD%SetSource(1); >> 1.jobs
echo %VD%SetMode(1); >> 1.jobs
echo %VD%SetInterleave(1,500,1,0,0); >> 1.jobs
echo %VD%SetClipMode(1,1); >> 1.jobs
echo %VD%SetConversion(44100,0,1,0,1); >> 1.jobs
echo %VD%SetVolume(); >> 1.jobs
echo %VD%SetCompression(); >> 1.jobs
echo %VD%EnableFilterGraph(0); >> 1.jobs
echo %VD%filters.Clear(); >> 1.jobs
echo VirtualDub.SaveWAV(VirtualDub.params[1]); >> 1.jobs
echo VirtualDub.Close(); >> 1.jobs
FOR %%i IN (*.*) do (
  if not exist %%~ni.wav (
    echo.
    echo Re-compressing %%i
    echo c = DirectShowSource^("%%i"^) > 3.avs
    echo AudioDub^(BlankClip^(length=c.FrameCount^), c^) >> 3.avs
    "C:\Program Files\VirtulDub\vdub.exe" /i 1.jobs 3.avs %%~ni.wav >nul
  )
)
del /q /s 3.avs >nul 2>&1
del /q /s 1.jobs >nul 2>&1