I think the transient filtering is only done on the recording side, performed by the ADC.
The 88.2Khz recorded signal is delayed and then processed.
Quote:Ritter describes the HDCD approach to this problem: "We slightly delay the 88.2kHz signal, not enough to cause any sync problems but enough that we can do a continuous Fast Fourier Transform. The resultant information is digitally analyzed in real time by an algorithm that determines, based upon a model of the mechanics of hearing and psychoacoustics, what is perceptually dominant in the signal from instant to instant. And that information is used to optimize the decimation filter. One moment you might have a sudden sharp transient, so it uses a filter with minimum time dispersion to pass the transient cleanly. The next instant, there might be a cymbal crash, so it uses a filter that minimizes alias distortion. All the filters are the same length, so you are not getting a phase shift as this is going on."
Here:http://mixonline.com/mag/audio_pacific_ ... nics_hdcd/
I don't see what relation this may have to the playback side, the DF.
But I may be missing something.
You can upsample, and then...???
The PMD200 accepts sample rates up to 96Khz, but then what?
Play with the signal and you'll loose the HDCD, the DF won't decode it.