[opus] CELT CFFT size configuration
Diego Alejandro Parra Guzman
daparrag at correo.udistrital.edu.co
Thu Apr 13 09:04:35 UTC 2017
According with my question.
CELT CFFT size configuration
I'm not completely sure about how the kiss_fft works for sizes which are
not power of two, as occur in the case of celt which calculate the mdct
using a fft sizes of 480, 240, 120, and 60, I guess that internally the
input data is padded with zeros in order to compute efficiently the mdct
using the Cooley and Tukey algorithm.
If I'm correct. Means that technically, I could compute the fft using the
padding strategy and adjust the output such as kissfft done, someone could
confirm if that is possible.
On Wed, Apr 12, 2017 at 2:27 PM, Diego Alejandro Parra Guzman <
daparrag at correo.udistrital.edu.co> wrote:
> Dear all,
> Sorry for this simple and maybe stupid question, I'm working in the
> implementation of opus for ARMv7e microcontroller using a library CMSIS/DSP
> used to calculate the CFFT and MDCT based on the DCT-IV. my question is:
> In the implementation of Celt you have used a fixed length CFFT equal to
> 1920, I want to know if there is some issues which can appear if a change
> that configuration for a cfft of size 2048, some of you could give me some
> support about that?, I ask because the library which I'm using doesn't
> support 1920 size.
> please let me know, I you need I could be more specific.
> thanks you so much.
> Diego Alejandro Parra Guzmán
> Estudiante de ingeniería electrónica
> Universidad distrital FJC
Diego Alejandro Parra Guzmán
Estudiante de ingeniería electrónica
Universidad distrital FJC
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