MP3 to WAV via ffmpeg.exe in AzureFunctions, for PowerApps and Flow

• PowerApps Microphone control records MP3 files
• Cognitive Speech to Text wants to turn WAV files into JSON
• Even with Flow, we can’t convert the audio file formats.
• We need an Azure Function to gluethis one step
• After a bit of research, it looks like FFMPEG, a popular free utility can be used to do the conversion