In order to convert m4a to wav, we can use python pydub.
Converting m4a to wav using pydub in Python – Python Tutorial
However, if you can not install python pydub in your system, how to convert? In this tutorial, we will introduce you how to use ffmpeg to convert m4a to wav directly.
Preliminary
If you are using linux system, you can install ffmpeg offline as follows:
Install FFmpeg in Linux Offline: A Step Guide – Linux Tutorial
View audio information
In order to conver to m4a to wav correctly, we should know the sample rate, mono or stereo. We can use ffprobe to check them.
View Audio Sample Rate, Data Format PCM or ALAW Using ffprobe – Python Tutorial
Use ffmpeg to convert m4a to wav
We can use ffmpeg command to convert. Here is a command example:
ffmpeg -i m4a_file_name -ar sample_rate -ac channel_num -f wav wav_file_name
Here
sample_rate: the sample rate of wav_file_name, it can be 8000, 16000 et al.
channel_num: the channel num of wav_file_name, we often keep the channel num of m4a_file_name and wav_fle_name same
1–mono 2–stereo
Here is an example:
ffmpeg -i test.m4a -ar 8000 -ac 1 -f wav test.wav
Moreover, we also can use python subprocess to execute this command using python script. Here is the tutorial:
Implement Python subprocess.Popen(): Execute an External Command and Get Output