Digital Filtering of Recordings

[roger_wilco]

Hi,

I would like to implement digital filtering on signals, as I record them. I know how to implement the filter, but I'm not sure where to get access to the data stream.

Currently I am accessing the data in pcm-pp.c::fiq_record(). This allows me to either pass the samples along or not, between `value = IISFIFOS_RD` and `*dma_rec_data.p++ = value`, but if I do any computation, even `value /= 2`, I get what sounds like max. volume white noise.

I'm pretty sure that this isn't a good place to get at the data (looks like it won't work on most hardware; I have a Sansa c240), but for the moment I'm happy enough with it if I can understand what format the samples are in. Can someone enlighten me?