The output of STFT is (channel, frequency, time, 2), meaning for each channel, the columns are the Fourier transform of a certain window, so as we travel horizontally we can see each column (the Fourier transformed waveform) change over time. This matches the output of librosa so we no longer need to transpose in our test comparisons with Spectrogram, MelScale, MelSpectrogram, and MFCC. Moreover, because of these new conventions, we deprecated LC2CL and BLC2CBL which were used to transfer from one shape of signal to another.
As part of this release, we're also introducing support for complex numbers via tensors of dimension (..., 2), and providing magphase to convert such a tensor into its magnitude and phase, and similarly complex_norm and angle.
The details of the standardization are provided in the README.
Functionals, Transformations, and Kaldi Compatibility