'프로그램 사용/fft, fftw' 카테고리의 글 목록 (4 Page)

'프로그램 사용/fft, fftw'에 해당되는 글 38건

2022.10.24 FFT
2022.10.19 fftw 예제 와 복소수 처리
2022.10.19 fftw 테스트(tests/bench)
2022.10.19 fftw cross compile
2020.11.25 fft
2020.11.25 fftw
2020.11.25 ffmpeg fft 분석 예제
2017.07.07 FFT 라이브러리

real to complex (0)	2022.11.04
fftw wisdom (0)	2022.11.04
fftw 예제 와 복소수 처리 (0)	2022.10.19
fftw 테스트(tests/bench) (0)	2022.10.19
fftw cross compile (0)	2022.10.19

fftw wisdom (0)	2022.11.04
FFT (0)	2022.10.24
fftw 테스트(tests/bench) (0)	2022.10.19
fftw cross compile (0)	2022.10.19
fft (0)	2020.11.25

fftw-3.3.4/tests/bench -o nthreads=2 --verbose=1 --verify 'ok10bx6bx6e11x13b' --verify 'ik10bx6bx6e11x13b' --verify 'obrd7x13v16' --verify 'ibrd7x13v16' --verify 'ofrd7x13v16' --verify 'ifrd7x13v16' --verify '//obcd7x13v16' --verify '//ibcd7x13v16' --verify '//ofcd7x13v16' --verify '//ifcd7x13v16' --verify 'obcd7x13v16' --verify 'ibcd7x13v16' --verify 'ofcd7x13v16' --verify 'ifcd7x13v16' --verify 'okd10bv127' --verify 'ikd10bv127' --verify '//obr240' --verify '//ibr240' --verify '//ofr240' --verify '//ifr240' --verify 'obr240' --verify 'ibr240' --verify 'ofr240' --verify 'ifr240' --verify '//obc240' --verify '//ibc240' --verify '//ofc240' --verify '//ifc240' --verify 'obc240' --verify 'ibc240' --verify 'ofc240' --verify 'ifc240' --verify 'ok11760e00' --verify 'ik11760e00' --verify 'obr33v31' --verify 'ibr33v31' --verify 'ofr33v31' --verify 'ifr33v31' --verify '//obc33v31' --verify '//ibc33v31' --verify '//ofc33v31' --verify '//ifc33v31' --verify 'obc33v31' --verify 'ibc33v31'

[링크 : https://unix.stackexchange.com/questions/209753/how-do-i-check-if-fftw-installed-correctly]

+

[링크 : https://people.sc.fsu.edu/~jburkardt/c_src/fftw_test/]

[링크 : https://people.sc.fsu.edu/~jburkardt/c_src/fftw_test/fftw_test.html]

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FFT (0)	2022.10.24
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fft (0)	2020.11.25
fftw (0)	2020.11.25

Posted by 구차니

fftw cross compile

[링크 : https://www.fftw.org/download.html]

./configure --prefix=/home/zhouxiaoyong/fftw3_test --disable-fortran --with-slow-timer --host=arm-none-linux-gnueabi --enable-single --enable-neon --enable-shared CC=arm-none-linux-gnueabi-gcc CFLAGS="-march=armv7-a -mfpu=neon -fPIC -ldl -mfloat-abi=softfp"

[링크 : https://codeantenna.com/a/ztGG77F10Z]

The basic usage of FFTW is simple. A typical call to FFTW looks like:
#include <fftw.h>
...
{
     fftw_complex in[N], out[N];
     fftw_plan p;
     ...
     p = fftw_create_plan(N, FFTW_FORWARD, FFTW_ESTIMATE);
     ...
     fftw_one(p, in, out);
     ...
     fftw_destroy_plan(p);
}

For example, code to perform an in-place FFT of a three-dimensional array might look like:
#include <fftw.h>
...
{
     fftw_complex in[L][M][N];
     fftwnd_plan p;
     ...
     p = fftw3d_create_plan(L, M, N, FFTW_FORWARD,
                            FFTW_MEASURE | FFTW_IN_PLACE);
     ...
     fftwnd_one(p, &in[0][0][0], NULL);
     ...
     fftwnd_destroy_plan(p);
}

The following is a brief example in which the wisdom is read from a file, a plan is created (possibly generating more wisdom), and then the wisdom is exported to a string and printed to stdout.
{
     fftw_plan plan;
     char *wisdom_string;
     FILE *input_file;

     /* open file to read wisdom from */
     input_file = fopen("sample.wisdom", "r");
     if (FFTW_FAILURE == fftw_import_wisdom_from_file(input_file))
          printf("Error reading wisdom!\n");
     fclose(input_file); /* be sure to close the file! */

     /* create a plan for N=64, possibly creating and/or using wisdom */
     plan = fftw_create_plan(64,FFTW_FORWARD,
                             FFTW_MEASURE | FFTW_USE_WISDOM);

     /* ... do some computations with the plan ... */

     /* always destroy plans when you are done */
     fftw_destroy_plan(plan);

     /* write the wisdom to a string */
     wisdom_string = fftw_export_wisdom_to_string();
     if (wisdom_string != NULL) {
          printf("Accumulated wisdom: %s\n",wisdom_string);

          /* Just for fun, destroy and restore the wisdom */
          fftw_forget_wisdom(); /* all gone! */
          fftw_import_wisdom_from_string(wisdom_string);
          /* wisdom is back! */

          fftw_free(wisdom_string); /* deallocate it since we're done */
     }
}

[링크 : http://www.fftw.org/fftw2_doc/fftw_2.html]

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'프로그램 사용 > fft, fftw' 카테고리의 다른 글

fftw 예제 와 복소수 처리 (0)	2022.10.19
fftw 테스트(tests/bench) (0)	2022.10.19
fft (0)	2020.11.25
fftw (0)	2020.11.25
ffmpeg fft 분석 예제 (0)	2020.11.25

Posted by 구차니

fft

이산 코사인 변환 DCT(discrete cosine transform)

이산 푸리에 변환 DFT(discrete Fourier transform)

type-II DCT DCT

type-III DCT 역DCT, IDCT

실수 신호에 대하여, 변환 결과물이 복소수로 나오는 DFT

DCT는 실수로만 결과물이 나오기 때문에, 처리하기가 간편하여 신호처리 및 영상처리에 널리 사용

[링크 : https://ko.wikipedia.org/wiki/이산_코사인_변환]

[링크 : https://ko.wikipedia.org/wiki/이산_푸리에_변환]

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fftw 테스트(tests/bench) (0)	2022.10.19
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fftw (0)	2020.11.25
ffmpeg fft 분석 예제 (0)	2020.11.25
FFT 라이브러리 (0)	2017.07.07

Posted by 구차니

fftw

예전에 찾은적이 있네..

fft를 위한 라이브러리인데 도대체 어떤 함수를 써서 분석을 하고

주파수 대역은 어떤식으로 맵핑이 가능한건질 모르겠다.

[링크 : http://www.fftw.org/]

[링크 : https://github.com/FFTW/fftw3]

[링크 : https://iamaman.tistory.com/652]

+

2020.11.26

[링크 : http://www.fftw.org/fftw2_doc/fftw_2.html]

[링크 : http://www.fftw.org/fftw3_doc/Complex-One_002dDimensional-DFTs.html]

[링크 : http://www.fftw.org/fftw3_doc/Complex-DFTs.html]

[링크 : https://darkpgmr.tistory.com/171]

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fftw 테스트(tests/bench) (0)	2022.10.19
fftw cross compile (0)	2022.10.19
fft (0)	2020.11.25
ffmpeg fft 분석 예제 (0)	2020.11.25
FFT 라이브러리 (0)	2017.07.07

Posted by 구차니

ffmpeg fft 분석 예제

일단은 마이크로 raw audio나 wav를 받아서 분석하는걸 찾아봐야겠다.

[링크 : https://www.ffmpeg.org/doxygen/trunk/fft-test_8c-source.html]

[링크 : https://www.ffmpeg.org/doxygen/trunk/fft_8c_source.html]

[링크 : https://www.ffmpeg.org/doxygen/3.3/group__lavc__fft.html]

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FFT 라이브러리 (0)	2017.07.07

Posted by 구차니

FFT 라이브러리

[링크 : http://fftw.org/]

[링크 : https://stackoverflow.com/questions/5685765/computing-fft-and-if]

일단 3.3.5 에서 NEON 지원을 하는데 64비트 ARM일 경우에만 되는 듯?

FFTW 3.3.5 Jul 31, 2016

New SIMD support:

Power8 VSX instructions in single and double precision. To use, add --enable-vsx to configure.

Support for AVX2 (256-bit FMA instructions). To use, add --enable-avx2 to configure.

Experimental support for AVX512 and KCVI. (--enable-avx512, --enable-kcvi) This code is expected to work but the FFTW maintainers do not have hardware to test it.

Support for AVX128/FMA (for some AMD machines) (--enable-avx128-fma)

Double precision Neon SIMD for aarch64. This code is expected to work but the FFTW maintainers do not have hardware to test it.ft-with-fftw-library-c

[링크 : http://www.fftw.org/release-notes.html]

AArch64 was introduced in ARMv8-A and is included in subsequent versions of ARMV8-A

[링크 : https://en.wikipedia.org/wiki/ARM_architecture#AArch64_features]

[링크 : https://libav.org/]

[링크 : https://libav.org/documentation/doxygen/master/group__lavc__fft.html]

[링크 : https://www.ffmpeg.org/doxygen/trunk/fft-test_8c-source.html]

[링크 : https://stackoverflow.com/questions/8002560/what-is-the-fastest-fft-library-for-ios-android-arm-devices]