Base64 decoding is the reverse process of converting Base64 encoded ASCII text back to the original binary form. In this article we will see how to convert Base64 encoded audio data in formats like wav or mp3 back to the original binary wav/mp3 file.
In fact, you can use the below methods to convert any base64 encoded data back to its binary format.
Step 1: Save the base64 encoded data into a text file
Copy ONLY the base64 data into text file and save it. Let us call the text file mybase64.txt
Please note that you should not copy any other encoding information like the example below. But only the actual Base64 content that is present after the below encoding information.
Step 2: Convert Base 64 text to Binary File
Convert Base64 text to Binary File in Ubuntu or any Linux Platform
Use the below command base64 with the -d option to decode the base64 content back to binary content in Ubuntu or any other Linux distribution.
base64 mybase64.txt -d > myaudio.wav
Convert Base64 text to Binary File in Windows Platform
Use the windows command line tool Base64.exe with the -d option to decode the base64 content back to binary content in Windows Platform.
Base64.exe -d mybase64.txt > myaudio.wav
Convert Base64 text to Binary File in Mac OS X Platform
Use the command line tool base64 with the –decode option to decode the base64 content back to binary content in Apple Mac OS X.
base64 --decode mybase64.txt > myaudio.wav
Fix Base64 Decode Error
If you receive any error message while converting base64 to binary format, then first make sure you have copied ONLY the bas64 code and not any encoding information like data/audio etc.
Next, if you copied the base64 code from a HTML encoding, then most probably you have “=” of the base64 encoding replaced by its HTML equivalent “%3D”. You can see the %3D if present, at the end of the base64 text.