Convert audio to Whisper-compatible format
useful tips
// scenario
OpenAI Whisper expects 16 kHz mono audio. Pre-converting avoids internal resampling and reduces processing time.
// shell
$ ffmpeg -i input.mp4 -ar 16000 -ac 1 -c:a pcm_s16le output.wav$ ffmpeg -i audio.mp3 -ar 16000 -ac 1 -c:a pcm_s16le output.wav