6 min read
Convert MOV to WAV without touching the original quality
A MOV from an Alexa, a C300 or an iPhone already contains uncompressed audio. Getting it out as WAV should not change a single sample.
MOV is a container, not a codec. A QuickTime file from a cinema camera usually carries video in ProRes and audio in linear PCM, which is exactly what lives inside a WAV file. Extracting it is a repackaging job, not a conversion, and it should be bit for bit identical to what the camera wrote.
Why most converters degrade the audio
General purpose converters normalise everything to a house standard, typically 44.1 kHz 16 bit stereo. A camera recording at 48 kHz 24 bit then gets resampled and truncated for no reason, and a 96 kHz sound department file loses half its bandwidth on the way through.
- Resampling from 48 kHz to 44.1 kHz breaks frame accurate sync with the picture.
- Truncating 24 bit to 16 bit costs headroom on quiet dialogue.
- Forcing stereo folds a four channel camera master down and loses the isolated tracks.
The correct extraction
Read the audio stream parameters from the container first, then write a WAV with exactly those parameters. If the MOV says 48 kHz 24 bit four channels, the WAV should say 48 kHz 24 bit four channels. Only convert afterwards, deliberately, when a delivery spec asks for it.
Camera masters versus sound department files
Camera audio is a reference track in most narrative work: the scratch that lets an assistant sync to the real recorder files. It is still worth extracting cleanly, because it carries the slate clap and often the only continuous coverage of a take.
Doing it in the browser
The extractor on this site reads the MOV header, reports the native sample rate and bit depth it found, and writes a WAV at those values by default. The file never leaves your machine, which matters when the rushes are under embargo.