93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
/* SoX Resampler Library Copyright (c) 2007-13 robs@users.sourceforge.net
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* Licence for this file: LGPL v2.1 See LICENCE for details. */
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static int * LSX_FFT_BR;
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static DFT_FLOAT * LSX_FFT_SC;
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static int FFT_LEN = -1;
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static ccrw2_t FFT_CACHE_CCRW;
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void LSX_INIT_FFT_CACHE(void)
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{
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if (FFT_LEN >= 0)
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return;
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assert(LSX_FFT_BR == NULL);
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assert(LSX_FFT_SC == NULL);
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assert(FFT_LEN == -1);
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ccrw2_init(FFT_CACHE_CCRW);
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FFT_LEN = 0;
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}
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void LSX_CLEAR_FFT_CACHE(void)
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{
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assert(FFT_LEN >= 0);
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ccrw2_clear(FFT_CACHE_CCRW);
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free(LSX_FFT_BR);
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free(LSX_FFT_SC);
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LSX_FFT_SC = NULL;
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LSX_FFT_BR = NULL;
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FFT_LEN = -1;
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}
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static bool UPDATE_FFT_CACHE(int len)
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{
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LSX_INIT_FFT_CACHE();
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assert(lsx_is_power_of_2(len));
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assert(FFT_LEN >= 0);
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ccrw2_become_reader(FFT_CACHE_CCRW);
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if (len > FFT_LEN) {
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ccrw2_cease_reading(FFT_CACHE_CCRW);
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ccrw2_become_writer(FFT_CACHE_CCRW);
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if (len > FFT_LEN) {
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int old_n = FFT_LEN;
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FFT_LEN = len;
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LSX_FFT_BR = realloc(LSX_FFT_BR, dft_br_len(FFT_LEN) * sizeof(*LSX_FFT_BR));
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LSX_FFT_SC = realloc(LSX_FFT_SC, dft_sc_len(FFT_LEN) * sizeof(*LSX_FFT_SC));
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if (!old_n) {
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LSX_FFT_BR[0] = 0;
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#if SOXR_LIB
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atexit(LSX_CLEAR_FFT_CACHE);
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#endif
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}
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return true;
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}
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ccrw2_cease_writing(FFT_CACHE_CCRW);
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ccrw2_become_reader(FFT_CACHE_CCRW);
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}
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return false;
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}
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static void DONE_WITH_FFT_CACHE(bool is_writer)
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{
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if (is_writer)
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ccrw2_cease_writing(FFT_CACHE_CCRW);
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else ccrw2_cease_reading(FFT_CACHE_CCRW);
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}
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void LSX_SAFE_RDFT(int len, int type, DFT_FLOAT * d)
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{
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bool is_writer = UPDATE_FFT_CACHE(len);
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LSX_RDFT(len, type, d, LSX_FFT_BR, LSX_FFT_SC);
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DONE_WITH_FFT_CACHE(is_writer);
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}
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void LSX_SAFE_CDFT(int len, int type, DFT_FLOAT * d)
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{
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bool is_writer = UPDATE_FFT_CACHE(len);
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LSX_CDFT(len, type, d, LSX_FFT_BR, LSX_FFT_SC);
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DONE_WITH_FFT_CACHE(is_writer);
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}
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#undef UPDATE_FFT_CACHE
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#undef LSX_SAFE_RDFT
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#undef LSX_SAFE_CDFT
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#undef LSX_RDFT
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#undef LSX_INIT_FFT_CACHE
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#undef LSX_FFT_SC
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#undef LSX_FFT_BR
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#undef LSX_CLEAR_FFT_CACHE
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#undef LSX_CDFT
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#undef FFT_LEN
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#undef FFT_CACHE_CCRW
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#undef DONE_WITH_FFT_CACHE
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#undef DFT_FLOAT
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