WAV for an editing workflow
An editor may require WAV even when your recording arrived as M4A. Sound Flipper inspects the codec inside the container before resolving what can be preserved. The output may be considerably larger than the input.
What is preserved depends on the source
Supported 16/24-bit ALAC becomes matching integer WAV with exact sample preservation. AAC-LC and mapping-family-0 mono/stereo Opus become float32 WAV preserving the decoded signal; this cannot restore information already discarded by lossy encoding. AAC and ALAC retain the admitted source rate. Opus decoding uses 48 kHz, as the format requires.
Check the presented recording
M4A timing can exclude encoder priming and end padding. The qualified reader verifies the declared presentation, including the supported Opus pre-skip and terminal trim. A tested music-export layout can include one tx3g timed-subtitle track and recognized C2PA provenance, which conversion omits with a warning. Video, extra audio tracks and unsupported layouts remain refused.
Check playback and representation
Confirm that your target editor supports the output's integer or float representation. Keep the M4A until the WAV's beginning, end and duration are checked. Read M4A codecs explained and why a WAV container cannot restore lossy detail.