Purpose

Spectrum STFT turns stereo audio into a stream of spectrum frames using a short-time Fourier transform. It is the entry point for working with sound in the frequency domain, whether for analysis or for spectral effects that run between STFT and Spectrum ISTFT.

TouchDesigner Use

Wire stereo audio into in and route out into a spectrum-aware operator, or into Spectrum ISTFT to return to audio. When pairing with Spectrum ISTFT for a round trip, set the same Windowsize, Hopsize, and Window on both so the reconstruction lines up.

Inputs And Outputs

• Input 0: in accepts stereo PCM. It is required.
• Output 0: out emits a stereo spectrum ring of complex frequency frames.

Main Controls

• Windowsize: analysis window in samples: 512, 1024, 2048, or 4096. Larger windows give finer frequency detail with slower time response.
• Hopsize: how far the window advances between frames, as a fraction of the window: quarter, half, full, or eighth. Smaller hops overlap more and track change more smoothly.
• Window: analysis window shape: hann, blackman, or rect.

Notes

• Input must be stereo.
• Frames emit at the hop rate, so this stage works at block rate rather than per sample.
• For a transparent analyze-then-resynthesize round trip, match all three settings on the paired Spectrum ISTFT and prefer an overlapping hop such as quarter or half.

Parameters

This operator does not expose user parameters in the extracted schema.

Catalog metadata

Roles

• transform

Tags

None listed.

Search groups

• audio
• spectrum