# Preprocessing reference

The ONNX model starts at a normalized mono spectrogram tensor with shape `[1, 1, 128, 256]`. It
does not accept raw audio.

The Python files under [`upstream/`](upstream/) are an unchanged copy of BatDetect2's complete
`src/batdetect2/preprocess` package at revision
`9e2697458d3b3b03c30ccd7e49ed5409c8ac330d`. [View the same pinned directory upstream](https://github.com/macaodha/batdetect2/tree/9e2697458d3b3b03c30ccd7e49ed5409c8ac330d/src/batdetect2/preprocess).

These files depend on the rest of the BatDetect2 package. Use `scripts/fetch-upstream.sh` to
retrieve the complete pinned checkout, or the locked environment in `environment/` when
rebuilding the export. The reference copy remains subject to CC BY-NC 4.0.