Waveform / stereo · audio
What does this recording look like?
This decodes the audio and draws each channel, then checks the stereo image: how alike the two channels are, how wide the picture is, whether a "stereo" file is really two copies of the same mono, and whether the waveform is centred or has drifted off zero. Each of those is a small tell about how the file was made.
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Decoding and drawing…
Reading a waveform
The waveform is amplitude over time: how far the signal swings from the centre line at each moment. A natural recording swings above and below zero symmetrically and centres on the line. A waveform that hugs one side, sits off-centre, or has hard flat tops has been processed: a DC offset pushes the whole trace up or down and points to a converter or editing fault, and flat tops mean clipping.
The stereo image
Two channels can be a true stereo field or just the same mono signal twice. Correlation
measures how alike the channels are: +1 is identical, 0 is fully independent,
and negative values mean they partly cancel, which collapses to nothing in mono. Width
is how much of the sound lives in the side (the difference between the channels) versus the middle. A
file that reports as stereo but is really dual mono (both channels bit-for-bit the same)
often started life as mono and was padded out to two channels.
What it tells you
These are shape and structure, not a verdict. A dual-mono "stereo" file, an off-centre waveform, or a stereo image that suddenly narrows partway through are each worth a closer look. Pair it with the loudness & clipping meter and the silence finder.