Problem initializing plan about fftw3 HOT 2 CLOSED

I would edit the code (or use a debugger) to print the value of nDftSamples in snd2fftw's main.c when it prints out ERR_FAIL_TO_INITIALIZE_PLAN (see the code); that should help you diagnose the problem. Basically, it must be passing invalid arguments to fftw_plan_dft_r2c_1d, and you'll need to debug that.

However, this really sounds like a bug in snd2fftw (or an error in how you are using it) rather than a bug in FFTW, so I'm going to close this issue.

from fftw3.

I understand that this is a bug in snd2fftw rather than fftw, but this is the first Google result for "Fail to initialize FFTW plan.", so I figured I'd update the thread with the actual fix:

At lines 404 and 532 of main.c, snd2fftw calls fftw_plan_dft_r2c_1d with flags=FFTW_FORWARD, which isn't a valid flag for fftw_plan_dtf_*. The easiest fix is to pass FFTW_MEASURE (or FFTW_ESTIMATE) instead.

(This worked for me, with FFTW 3.3.8 installed on Linux, after making a few separate Windows->Linux portability patches.)

I'll submit a request for a fix to the author, but the source hasn't seen updates in >5 years, so future users may just have to manually patch themselves.

from fftw3.