- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

Hello,

I would like to perform a basic fft of audio data:

N real samples -----> N/2+1 complex numbers (No need to obtain the conjugate symmetric other half...)

Furthermore I would like the complex numbers to be in the MKL_Complex format, not separate arrays for real and complex.

How do I set up such an fft using the dfti interface?

I must say the documentation is annoyingly confusing! Can someone spare me the pain?

Thanks in advance!

Link Copied

8 Replies

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

Thanks, but I have yet to find an example that covers what I want to do.

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

basic_sp_real_dft_1d.c

for single-precision floating point or

basic_dp_real_dft_1d.c

for double-precision floating point in the examples\dftc sub-directory of Intel MKL look like the closest to what you want. Maybe you could take a look and tell us how what you want is different.

Todd

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

Thank you very much for your help! Unfortunately those files do not exist anywhere in ..\Intel\ComposerXE-2011\mkl\examples

Maybe I don't have the most recent version of MKL. I got it a year ago or so. Have those examples been added recently?

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

*...\Intel\ComposerXE-2011\mkl\examples\dftc\source*?

The examples have been there for quite a while, even in earlier versions of MKL 10.3.

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

163 files, but none of those mentioned above.

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

Looks like you use MKL 10.3.4 or earlier.

I attach the source code of basic_sp_real_dft_1d.c for your convenience.

The sequence of steps needed to compute FFT is described on the first page of FFT documentation.

We would appreciate if you shared what in the documentation caused your confusion, for we could improve it.

Thanks

Dima

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content

Thanks for the code, I'll check it out. Sorry for my late reply, I have been overwhelmed with work:)

One thing struck me, the example uses malloc() rateher than mkl_malloc. Surely 16 byte aligned allocation using mkl_malloc must be required for maxiumum performance, am I wrong?

Topic Options

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page