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1-D DCTs

Question asked by nxp on Mar 17, 2014
Latest reply on Mar 25, 2014 by gpan



I need some pointers to which libraries would be most appropriate to use.


I want to use some DFTs and DCTs for processing 1-D real data - I am completely new to the Blackfin architecture so I am trying to work as much as possible in C or with function calls.


For doing the DFT I am managing with the "rfft_fr16" functions in VisualDSP++. The "N" for my data is always a power of 2 and performance is good. However I also need to do a DCT on sets of samples where the buffer size "N" is not a power of 2. Are there any reasonably efficient library functions out there to implement this (or which I could implement using a padded buffer of say N=128)?


The only DCT library I found on is the one implementing the 8x8 DCT for image compression purposes, namely "r8x8dct.asm" but of course this doesn't handle 1-D data.


If no libraries exist I might have to roll my own function, but of course there are performance concerns there!


Thanks in advance for any hints.