Kyma Forum
  Kyma Support
  Block FFT delays?

Post New Topic  Post A Reply
profile | register | preferences | faq | search

next newest topic | next oldest topic
Author Topic:   Block FFT delays?
David McClain
Member 		posted 08 May 2001 04:55         Edit/Delete Message   Reply w/Quote
Hi, I measured the overall delay from input to an FFT directly to final output from an inverse FFT at 7 block sizes worth.

I am a bit mystified by this particular size. I would have expected perhaps 2 blocks worth, or maybe some other even number. But why 7 (= 3.5 blocks per FFT)?

- DM

IP: Logged

SSC
Administrator 		posted 08 May 2001 09:17         Edit/Delete Message   Reply w/Quote
It's double-buffered so that the entire FFT does not have to be computed in a single sample tick between each block of samples (but can be spread out over the block).

IP: Logged

David McClain
Member 		posted 08 May 2001 11:22         Edit/Delete Message   Reply w/Quote
Okay... that gets us to 4 blocks with overlap in input FFT with output inverse FFT. (3 stages per FFT Sound - input, compute, output)


. . input_fwd
. . . . . . . compute_fwd
. . . . . . . . . . . . output_fwd
. . . . . . . . . . . . input_inv
. . . . . . . . . . . . . . . . . compute_inv
. . . . . . . . . . . . . . . . . . . . . . . output_inv

Why 7?

- DM

[This message has been edited by David McClain (edited 08 May 2001).]

IP: Logged

All times are CT (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply

Contact Us | Symbolic Sound Home

This forum is provided solely for the support and edification of the customers of Symbolic Sound Corporation.


Ultimate Bulletin Board 5.45c