121 lines
3.6 KiB
C
121 lines
3.6 KiB
C
#include "dl_rfft.h"
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#include "esp_attr.h"
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#include "esp_log.h"
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#include <math.h>
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#include <string.h>
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static const char *TAG = "dl rfft";
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dl_fft_f32_t *dl_rfft_f32_init(int fft_point, uint32_t caps)
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{
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if (!dl_is_power_of_two(fft_point)) {
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ESP_LOGE(TAG, "FFT point must be power of two");
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return NULL;
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}
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dl_fft_f32_t *handle = (dl_fft_f32_t *)heap_caps_malloc(sizeof(dl_fft_f32_t), caps);
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if (!handle) {
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ESP_LOGE(TAG, "Failed to allocate FFT handle");
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return NULL;
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}
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handle->fft_table = NULL;
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handle->rfft_table = NULL;
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handle->bitrev_table = NULL;
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handle->fft_point = fft_point;
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handle->log2n = dl_power_of_two(fft_point);
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// rfft table
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handle->rfft_table = dl_gen_rfft_table_f32(fft_point, caps);
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if (!handle->rfft_table) {
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ESP_LOGE(TAG, "Failed to generate FFT table");
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dl_rfft_f32_deinit(handle);
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return NULL;
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}
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if (handle->log2n % 2 == 1) {
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handle->bitrev_table = dl_gen_bitrev4r_table(fft_point, caps, &handle->bitrev_size);
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handle->fft_table = dl_gen_fft4r_table_f32(fft_point, caps);
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if (!handle->fft_table) {
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ESP_LOGE(TAG, "Failed to generate FFT table");
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dl_rfft_f32_deinit(handle);
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return NULL;
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}
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} else {
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handle->bitrev_table = dl_gen_bitrev2r_table(fft_point >> 1, caps, &handle->bitrev_size);
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handle->fft_table = dl_gen_fftr2_table_f32(fft_point >> 1, caps);
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if (!handle->fft_table) {
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ESP_LOGE(TAG, "Failed to generate FFT table");
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dl_rfft_f32_deinit(handle);
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return NULL;
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}
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}
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return handle;
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}
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void dl_rfft_f32_deinit(dl_fft_f32_t *handle)
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{
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if (handle) {
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if (handle->fft_table) {
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free(handle->fft_table);
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}
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if (handle->rfft_table) {
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free(handle->rfft_table);
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}
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if (handle->bitrev_table) {
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free(handle->bitrev_table);
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}
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free(handle);
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}
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}
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esp_err_t dl_rfft_f32_run(dl_fft_f32_t *handle, float *data)
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{
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if (!handle || !data) {
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return ESP_FAIL;
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}
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int fft_point = handle->fft_point;
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float *fft_table = handle->fft_table;
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float *rfft_table = handle->rfft_table;
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if (handle->log2n % 2 == 1) {
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dl_fft4r_fc32(data, fft_point >> 1, fft_table, fft_point);
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dl_bitrev4r_fc32_ansi(data, fft_point >> 1, handle->bitrev_table, handle->bitrev_size);
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} else {
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dl_fft2r_fc32(data, fft_point >> 1, fft_table);
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dl_bitrev2r_fc32_ansi(data, fft_point >> 1, handle->bitrev_table, handle->bitrev_size);
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}
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// Convert one complex vector with length N/2 to one real spectrum vector with length N/2
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dl_rfft_post_proc_fc32_ansi(data, fft_point >> 1, rfft_table);
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return ESP_OK;
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}
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esp_err_t dl_irfft_f32_run(dl_fft_f32_t *handle, float *data)
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{
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if (!handle || !data) {
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return ESP_FAIL;
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}
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int fft_point = handle->fft_point;
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float *fft_table = handle->fft_table;
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float *rfft_table = handle->rfft_table;
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float scale = 2.0 / fft_point;
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dl_rfft_pre_proc_fc32_ansi(data, fft_point >> 1, rfft_table);
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if (handle->log2n % 2 == 1) {
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dl_ifft4r_fc32(data, fft_point >> 1, fft_table, fft_point);
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dl_bitrev4r_fc32_ansi(data, fft_point >> 1, handle->bitrev_table, handle->bitrev_size);
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} else {
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dl_ifft2r_fc32(data, fft_point >> 1, fft_table);
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dl_bitrev2r_fc32_ansi(data, fft_point >> 1, handle->bitrev_table, handle->bitrev_size);
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}
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// Scale by 1/N
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for (int i = 0; i < fft_point; i++) {
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data[i] *= scale;
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}
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return ESP_OK;
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}
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