Encoding is the process of converting audio data into a form that can be stored in a target format or codec, for example creating MP3, AAC, or FLAC from a PCM WAV. It is part of bouncing in a DAW, exporting from an audio conversion tool, and outputting from video editing software. The settings you encode with affect file size, compatibility, and changes to the sound.
Encoding and decoding
Encoding turns audio into coded data suited to storage and transmission; decoding reads that data back into a state you can play or edit. Playing an MP3 or AAC involves decoding. A codec is the name for the mechanism that handles both.
What you set
When exporting you choose the container, codec, sample rate, bit depth, channel count, and, where relevant, the bitrate. The items to check differ between putting PCM into WAV or AIFF and putting AAC into M4A. Check the destination’s specification first.
Lossless versus lossy
When you encode to a lossless format such as FLAC, decoding returns you to the original PCM data. With lossy compression such as MP3, AAC, and Opus, some information is discarded to reduce size. It is important not to re-encode lossy formats repeatedly, and to create each target format from the original PCM.
Relationship to bouncing
Bouncing in a DAW turns the result of your mix, effects, and automation into an audio file. Encoding happens at that point according to whether you choose WAV, MP3, AAC, and so on. When external hardware or real-time processing is involved, check which export method your DAW requires.
Check the converted file
Once encoding is finished, check the start, the end, the level, any silence, and the format in a different player. With lossy compression in particular, listen to the converted result before deciding. To keep the original WAV and create files for different purposes, use the audio format converter.
