Why podcast mix engineers demux interview MP4 to WAV before they touch EQ, not just drag the camera file into the session
Listeners ultimately hear AAC or another lossy codec in the podcatcher, yet inside the DAW you still want predictable linear PCM: equalization, de-essing, room control, and loudness normalization all rewrite the waveform repeatedly. Search clusters like "MP4 to WAV podcast," "AAC to PCM mastering," "true peak WAV," and "interview stem WAV" show that editors are worried about stacking implicit lossy decodes on top of the camera's AAC. MP4 also locks audio to a video clock; importing the native container can surface sample-rate and frame-alignment edge cases you do not want to debug on a ship date. Demuxing to a session-matched WAV makes it easier to spot-check against a proxy edit and to document what generation the file is. Be transparent about bytes: uncompressed PCM is far larger than MP3, so email attachments and LTE tether drops are the wrong handoff path; use object storage, ticketing, and checksum-linked archives instead. Licensed sting beds, applause, and guest dialog still share one stereo mix — WAV is not stem separation. Dynamic-ad-insertion hosts also need clearly labeled master WAV versus shelf AAC so you never overwrite half a back catalog six months later when you patch one episode.
Podcast path: from interview MP4 to mix-ready WAV without bloating the browser tab
- In your NLE, cut preroll, long silence, and anything not cleared for air, confirm the session rate is 48 kHz or 44.1 kHz, then export a short MP4 instead of uploading an uncut two-hour camera dump.
- In the browser tool, export WAV at the same sample depth your DAW session expects and label the folder with notes such as "includes room tone" so mastering does not apply an aggressive voice-only preset by mistake.
- Import the WAV, run integrated loudness and limiting per episode, encode the RSS build, upload a private preview chapter, and link MP4 plus WAV masters in your asset manager with matching checksums.