pd-tve

pd-tve

A Slowscan Television testcard reference generator inspired by the Spanish TVE custom PM5544 PAL reference signal.

It's not a pretty set of pixels-- there's no pixels involved at all-- the audio waveform output is calculated at every sample, and is as close to Analogue as you can get with a computer. (The 48000 Hz sampling rate was the limit of my USB audio interface..)

Note that the output is a continuous function in the frequency domain, reducing sideband effects from step changes in frequencies that 'downsampled' images produce in normal SSTV software. (See my pd-encode.py project for an image encoder with this feature.)

A few liberties have been made from the original Carta de ajuste reference (those are 95% EBU colour bars, not 75%), and the castellations weren't considered necessary. The resolution gratings have their pitch continuously increased to make mode comparisons easier, as the original's colour carrier interference effect isn't applicable.