initial
Dependencies: mbed BSP_DISCO_F746NG mbed-dsp
signal_processing.cpp@5:a658cda1d619, 2020-03-06 (annotated)
- Committer:
- justenmg
- Date:
- Fri Mar 06 01:41:05 2020 +0000
- Revision:
- 5:a658cda1d619
- Parent:
- 4:99de9b4005d2
- Child:
- 6:291e341f0d71
march 5
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
bmazzeo | 0:c0f52e8223fe | 1 | /** |
bmazzeo | 0:c0f52e8223fe | 2 | ****************************************************************************** |
bmazzeo | 0:c0f52e8223fe | 3 | * @file signal_processing.c |
bmazzeo | 0:c0f52e8223fe | 4 | * @author Brian Mazzeo |
bmazzeo | 0:c0f52e8223fe | 5 | * @date 2020 |
bmazzeo | 0:c0f52e8223fe | 6 | * @brief This file provides a set of code for signal processing in 487. |
bmazzeo | 0:c0f52e8223fe | 7 | * Parts are taken from example code from STMIcroelectronics |
bmazzeo | 0:c0f52e8223fe | 8 | ****************************************************************************** |
bmazzeo | 0:c0f52e8223fe | 9 | * @attention |
bmazzeo | 0:c0f52e8223fe | 10 | * This code was specifically developed for BYU ECEn 487 course |
bmazzeo | 0:c0f52e8223fe | 11 | * Introduction to Digital Signal Processing. |
bmazzeo | 0:c0f52e8223fe | 12 | * |
bmazzeo | 0:c0f52e8223fe | 13 | * |
bmazzeo | 0:c0f52e8223fe | 14 | ****************************************************************************** |
bmazzeo | 0:c0f52e8223fe | 15 | */ |
bmazzeo | 0:c0f52e8223fe | 16 | |
bmazzeo | 0:c0f52e8223fe | 17 | #include "mbed.h" |
bmazzeo | 0:c0f52e8223fe | 18 | #include "stm32746g_discovery_lcd.h" |
bmazzeo | 0:c0f52e8223fe | 19 | #include "arm_math.h" |
bmazzeo | 0:c0f52e8223fe | 20 | #include "arm_const_structs.h" |
bmazzeo | 0:c0f52e8223fe | 21 | #include "filter_coefficients.h" |
justenmg | 1:103e3e426b55 | 22 | #include "our_filter.h" |
justenmg | 3:51e15bd15778 | 23 | #include "windowed.h" |
justenmg | 3:51e15bd15778 | 24 | #include "signal_processing.h" |
bmazzeo | 0:c0f52e8223fe | 25 | |
bmazzeo | 0:c0f52e8223fe | 26 | |
bmazzeo | 0:c0f52e8223fe | 27 | /* ---------------------------------------------------------------------- |
bmazzeo | 0:c0f52e8223fe | 28 | ** Defines for signal processing |
bmazzeo | 0:c0f52e8223fe | 29 | ** ------------------------------------------------------------------- */ |
bmazzeo | 0:c0f52e8223fe | 30 | |
bmazzeo | 0:c0f52e8223fe | 31 | #define AUDIO_BLOCK_SAMPLES ((uint32_t)128) // Number of samples (L and R) in audio block (each samples is 16 bits) |
justenmg | 5:a658cda1d619 | 32 | #define CONV_LENGTH (WIN_NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1) |
justenmg | 5:a658cda1d619 | 33 | #define BUFFER_LENGTH (WIN_NUM_TAPS - 1) |
justenmg | 5:a658cda1d619 | 34 | #define FFT_BUFFER_LENGTH 2048 |
justenmg | 5:a658cda1d619 | 35 | #define FFT_LENGTH 1024 |
justenmg | 5:a658cda1d619 | 36 | #define PADDED_FILTER_LENGTH (WIN_NUM_TAPS + 2*(AUDIO_BLOCK_SAMPLES - 1)) |
bmazzeo | 0:c0f52e8223fe | 37 | |
bmazzeo | 0:c0f52e8223fe | 38 | /* For Lab Exercise */ |
justenmg | 5:a658cda1d619 | 39 | #define Lab_Execution_Type 6 |
justenmg | 5:a658cda1d619 | 40 | |
justenmg | 5:a658cda1d619 | 41 | float32_t padded_filter[PADDED_FILTER_LENGTH]; |
justenmg | 1:103e3e426b55 | 42 | |
justenmg | 1:103e3e426b55 | 43 | float32_t lState[NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1]; |
justenmg | 1:103e3e426b55 | 44 | float32_t rState[NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1]; |
bmazzeo | 0:c0f52e8223fe | 45 | |
justenmg | 1:103e3e426b55 | 46 | float32_t l_buf[BUFFER_LENGTH]; |
justenmg | 1:103e3e426b55 | 47 | float32_t r_buf[BUFFER_LENGTH]; |
bmazzeo | 0:c0f52e8223fe | 48 | |
justenmg | 5:a658cda1d619 | 49 | float32_t l_buf2[FFT_LENGTH]; |
justenmg | 5:a658cda1d619 | 50 | float32_t r_buf2[FFT_LENGTH]; |
justenmg | 5:a658cda1d619 | 51 | |
justenmg | 1:103e3e426b55 | 52 | arm_fir_instance_f32 filter_left; |
justenmg | 1:103e3e426b55 | 53 | arm_fir_instance_f32 filter_right; |
bmazzeo | 0:c0f52e8223fe | 54 | |
justenmg | 4:99de9b4005d2 | 55 | float32_t fft_buf[FFT_BUFFER_LENGTH]; |
justenmg | 5:a658cda1d619 | 56 | float32_t ifft_buf[FFT_BUFFER_LENGTH]; |
justenmg | 4:99de9b4005d2 | 57 | |
justenmg | 4:99de9b4005d2 | 58 | float32_t fft_of_filter[FFT_BUFFER_LENGTH]; |
justenmg | 4:99de9b4005d2 | 59 | |
justenmg | 4:99de9b4005d2 | 60 | |
bmazzeo | 0:c0f52e8223fe | 61 | /* FUNCTION DEFINITIONS BELOW */ |
bmazzeo | 0:c0f52e8223fe | 62 | |
bmazzeo | 0:c0f52e8223fe | 63 | /** |
bmazzeo | 0:c0f52e8223fe | 64 | * @brief Initialize filter structures to be used in loops later |
bmazzeo | 0:c0f52e8223fe | 65 | * @retval None |
bmazzeo | 0:c0f52e8223fe | 66 | */ |
justenmg | 4:99de9b4005d2 | 67 | void initalize_signal_processing(void) |
justenmg | 4:99de9b4005d2 | 68 | { |
bmazzeo | 0:c0f52e8223fe | 69 | |
bmazzeo | 0:c0f52e8223fe | 70 | switch (Lab_Execution_Type) |
bmazzeo | 0:c0f52e8223fe | 71 | { |
bmazzeo | 0:c0f52e8223fe | 72 | case 0: // Passthrough case |
bmazzeo | 0:c0f52e8223fe | 73 | break; |
bmazzeo | 0:c0f52e8223fe | 74 | |
bmazzeo | 0:c0f52e8223fe | 75 | case 1: // FIR case (ARM) |
justenmg | 1:103e3e426b55 | 76 | arm_fir_init_f32(&filter_left, NUM_TAPS, (float32_t *)&Filter_coeffs, (float32_t *)&lState, AUDIO_BLOCK_SAMPLES); |
justenmg | 1:103e3e426b55 | 77 | arm_fir_init_f32(&filter_right, NUM_TAPS, (float32_t *)&Filter_coeffs, (float32_t *)&rState, AUDIO_BLOCK_SAMPLES); |
bmazzeo | 0:c0f52e8223fe | 78 | break; |
bmazzeo | 0:c0f52e8223fe | 79 | |
bmazzeo | 0:c0f52e8223fe | 80 | case 2: // FIR case (student) |
justenmg | 1:103e3e426b55 | 81 | arm_fir_init_f32(&filter_left, OUR_NUM_TAPS, (float32_t *)&our_Filter_coeffs, (float32_t *)&lState, AUDIO_BLOCK_SAMPLES); |
justenmg | 1:103e3e426b55 | 82 | arm_fir_init_f32(&filter_right, OUR_NUM_TAPS, (float32_t *)&our_Filter_coeffs, (float32_t *)&rState, AUDIO_BLOCK_SAMPLES); |
bmazzeo | 0:c0f52e8223fe | 83 | break; |
bmazzeo | 0:c0f52e8223fe | 84 | |
justenmg | 5:a658cda1d619 | 85 | case 3: // conv Overlap-add |
justenmg | 4:99de9b4005d2 | 86 | filter_conv_init(); |
bmazzeo | 0:c0f52e8223fe | 87 | break; |
bmazzeo | 0:c0f52e8223fe | 88 | |
justenmg | 4:99de9b4005d2 | 89 | case 4: // FFT Overlap-add |
justenmg | 4:99de9b4005d2 | 90 | filter_fft_init(); |
justenmg | 4:99de9b4005d2 | 91 | break; |
justenmg | 4:99de9b4005d2 | 92 | |
justenmg | 4:99de9b4005d2 | 93 | case 5: // FFT Overlap-add with real-imag efficiency |
justenmg | 4:99de9b4005d2 | 94 | filter_fft_init(); |
justenmg | 4:99de9b4005d2 | 95 | break; |
justenmg | 4:99de9b4005d2 | 96 | |
justenmg | 4:99de9b4005d2 | 97 | case 6: // OS FFT RI |
justenmg | 4:99de9b4005d2 | 98 | filter_fft_init(); |
bmazzeo | 0:c0f52e8223fe | 99 | break; |
bmazzeo | 0:c0f52e8223fe | 100 | |
bmazzeo | 0:c0f52e8223fe | 101 | |
bmazzeo | 0:c0f52e8223fe | 102 | } |
bmazzeo | 0:c0f52e8223fe | 103 | } |
bmazzeo | 0:c0f52e8223fe | 104 | |
bmazzeo | 0:c0f52e8223fe | 105 | /** |
bmazzeo | 0:c0f52e8223fe | 106 | * @brief Process audio channel signals |
bmazzeo | 0:c0f52e8223fe | 107 | * @param L_channel_in: Pointer to Left channel data input (float32_t) |
bmazzeo | 0:c0f52e8223fe | 108 | * @param R_channel_in: Pointer to Right channel data input (float32_t) |
bmazzeo | 0:c0f52e8223fe | 109 | * @param L_channel_out: Pointer to Left channel data output (float32_t) |
bmazzeo | 0:c0f52e8223fe | 110 | * @param R_channel_out: Pointer to Right channel data output (float32_t) |
bmazzeo | 0:c0f52e8223fe | 111 | * @param Signal_Length: length of data to process |
bmazzeo | 0:c0f52e8223fe | 112 | * @retval None |
bmazzeo | 0:c0f52e8223fe | 113 | */ |
bmazzeo | 0:c0f52e8223fe | 114 | void process_audio_channel_signals(float32_t* L_channel_in, float32_t* R_channel_in, float32_t* L_channel_out, float32_t* R_channel_out, uint16_t Signal_Length) |
bmazzeo | 0:c0f52e8223fe | 115 | { |
bmazzeo | 0:c0f52e8223fe | 116 | char buf[70]; |
bmazzeo | 0:c0f52e8223fe | 117 | BSP_LCD_SetFont(&Font8); |
bmazzeo | 0:c0f52e8223fe | 118 | BSP_LCD_SetTextColor(LCD_COLOR_CYAN); |
bmazzeo | 0:c0f52e8223fe | 119 | sprintf(buf, "Processing Signals" ); |
bmazzeo | 0:c0f52e8223fe | 120 | BSP_LCD_DisplayStringAt(0, 200, (uint8_t *) buf, LEFT_MODE); |
bmazzeo | 0:c0f52e8223fe | 121 | |
bmazzeo | 0:c0f52e8223fe | 122 | switch(Lab_Execution_Type) |
bmazzeo | 0:c0f52e8223fe | 123 | { |
bmazzeo | 0:c0f52e8223fe | 124 | case 0: // Passthrough case |
justenmg | 2:89234085faae | 125 | arm_copy_f32(L_channel_in, L_channel_out, Signal_Length); |
justenmg | 2:89234085faae | 126 | arm_copy_f32(R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 127 | break; |
bmazzeo | 0:c0f52e8223fe | 128 | |
bmazzeo | 0:c0f52e8223fe | 129 | case 1: // FIR case (ARM) |
justenmg | 2:89234085faae | 130 | arm_fir_f32(&filter_left, L_channel_in, L_channel_out, Signal_Length); |
justenmg | 2:89234085faae | 131 | arm_fir_f32(&filter_right, R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 132 | break; |
bmazzeo | 0:c0f52e8223fe | 133 | |
bmazzeo | 0:c0f52e8223fe | 134 | case 2: // FIR case (student) |
justenmg | 2:89234085faae | 135 | arm_fir_f32(&filter_left, L_channel_in, L_channel_out, Signal_Length); |
justenmg | 2:89234085faae | 136 | arm_fir_f32(&filter_right, R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 137 | break; |
bmazzeo | 0:c0f52e8223fe | 138 | |
justenmg | 4:99de9b4005d2 | 139 | case 3: // OA CONV |
justenmg | 5:a658cda1d619 | 140 | filter_OA_CONV(l_buf, L_channel_in, L_channel_out, Signal_Length); |
justenmg | 5:a658cda1d619 | 141 | filter_OA_CONV(r_buf, R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 142 | break; |
bmazzeo | 0:c0f52e8223fe | 143 | |
justenmg | 4:99de9b4005d2 | 144 | case 4: // OA FFT Overlap-add |
justenmg | 5:a658cda1d619 | 145 | filter_OA_FFT(l_buf, fft_buf, ifft_buf, L_channel_in, L_channel_out, Signal_Length); |
justenmg | 5:a658cda1d619 | 146 | filter_OA_FFT(r_buf, fft_buf, ifft_buf, R_channel_in, R_channel_out, Signal_Length); |
justenmg | 4:99de9b4005d2 | 147 | break; |
justenmg | 4:99de9b4005d2 | 148 | |
justenmg | 4:99de9b4005d2 | 149 | case 5: // FFT Overlap-add with real-imag efficiency |
justenmg | 5:a658cda1d619 | 150 | filter_OA_FFT_RI(l_buf, r_buf, fft_buf, ifft_buf, L_channel_in, R_channel_in, L_channel_out, R_channel_out, Signal_Length); |
justenmg | 4:99de9b4005d2 | 151 | break; |
justenmg | 4:99de9b4005d2 | 152 | |
justenmg | 4:99de9b4005d2 | 153 | case 6: // OS FFT RI |
justenmg | 5:a658cda1d619 | 154 | filter_OS_FFT_RI(l_buf2, r_buf2, fft_buf, ifft_buf, L_channel_in, R_channel_in, L_channel_out, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 155 | break; |
bmazzeo | 0:c0f52e8223fe | 156 | |
bmazzeo | 0:c0f52e8223fe | 157 | |
bmazzeo | 0:c0f52e8223fe | 158 | } |
bmazzeo | 0:c0f52e8223fe | 159 | /* Change font back */ |
bmazzeo | 0:c0f52e8223fe | 160 | BSP_LCD_SetFont(&Font16); |
bmazzeo | 0:c0f52e8223fe | 161 | } |
justenmg | 1:103e3e426b55 | 162 | |
justenmg | 2:89234085faae | 163 | //buffer: pointer to the storage buffer for the filter output |
justenmg | 2:89234085faae | 164 | //buf_length: the length of the storage buffer (len_filter + len_batch - 1) |
justenmg | 5:a658cda1d619 | 165 | |
justenmg | 5:a658cda1d619 | 166 | void filter_OA_CONV(float32_t* overlap_buffer, float32_t* d_in, float32_t* d_out, uint16_t sig_length) |
justenmg | 1:103e3e426b55 | 167 | { |
justenmg | 1:103e3e426b55 | 168 | float32_t result = 0; |
justenmg | 2:89234085faae | 169 | |
justenmg | 5:a658cda1d619 | 170 | //shift the data sample and convolve |
justenmg | 5:a658cda1d619 | 171 | for(uint16_t shift = 0; shift < CONV_LENGTH; shift++) |
justenmg | 1:103e3e426b55 | 172 | { |
justenmg | 5:a658cda1d619 | 173 | result = 0; |
justenmg | 5:a658cda1d619 | 174 | //multiply-add the shifted, reversed data sample to the padded filter |
justenmg | 5:a658cda1d619 | 175 | for(int i=0; i<sig_length; i++) |
justenmg | 5:a658cda1d619 | 176 | { |
justenmg | 5:a658cda1d619 | 177 | result += padded_filter[i + shift] * d_in[i]; |
justenmg | 5:a658cda1d619 | 178 | } |
justenmg | 5:a658cda1d619 | 179 | |
justenmg | 5:a658cda1d619 | 180 | // overlap-add to the buffer |
justenmg | 5:a658cda1d619 | 181 | //overlap_buffer[shift] += result; |
justenmg | 5:a658cda1d619 | 182 | |
justenmg | 3:51e15bd15778 | 183 | if(shift < sig_length) |
justenmg | 2:89234085faae | 184 | { |
justenmg | 5:a658cda1d619 | 185 | d_out[shift] = overlap_buffer[shift] + result; |
justenmg | 2:89234085faae | 186 | } |
justenmg | 5:a658cda1d619 | 187 | else if(shift < BUFFER_LENGTH) |
justenmg | 2:89234085faae | 188 | { |
justenmg | 5:a658cda1d619 | 189 | overlap_buffer[shift - sig_length] = overlap_buffer[shift] + result; |
justenmg | 4:99de9b4005d2 | 190 | } |
justenmg | 4:99de9b4005d2 | 191 | else |
justenmg | 4:99de9b4005d2 | 192 | { |
justenmg | 5:a658cda1d619 | 193 | overlap_buffer[shift - sig_length] = result; |
justenmg | 4:99de9b4005d2 | 194 | } |
justenmg | 4:99de9b4005d2 | 195 | } |
justenmg | 4:99de9b4005d2 | 196 | return; |
justenmg | 4:99de9b4005d2 | 197 | } |
justenmg | 4:99de9b4005d2 | 198 | |
justenmg | 4:99de9b4005d2 | 199 | |
justenmg | 4:99de9b4005d2 | 200 | |
justenmg | 5:a658cda1d619 | 201 | void filter_OA_FFT( |
justenmg | 5:a658cda1d619 | 202 | float32_t* overlap_buffer, |
justenmg | 5:a658cda1d619 | 203 | float32_t* fft_buffer, |
justenmg | 5:a658cda1d619 | 204 | float32_t* ifft_buffer, |
justenmg | 5:a658cda1d619 | 205 | float32_t* d_in, |
justenmg | 5:a658cda1d619 | 206 | float32_t* d_out, |
justenmg | 5:a658cda1d619 | 207 | uint16_t sig_length) |
justenmg | 4:99de9b4005d2 | 208 | { |
justenmg | 5:a658cda1d619 | 209 | //fill the FFT buffer |
justenmg | 5:a658cda1d619 | 210 | for(int i=0; i < FFT_LENGTH; i++) |
justenmg | 4:99de9b4005d2 | 211 | { |
justenmg | 5:a658cda1d619 | 212 | if(i < sig_length) |
justenmg | 2:89234085faae | 213 | { |
justenmg | 5:a658cda1d619 | 214 | fft_buffer[2*i] = d_in[i]; |
justenmg | 5:a658cda1d619 | 215 | fft_buffer[2*i+1] = 0; |
justenmg | 2:89234085faae | 216 | } |
justenmg | 2:89234085faae | 217 | else |
justenmg | 2:89234085faae | 218 | { |
justenmg | 5:a658cda1d619 | 219 | fft_buffer[2*i] = 0; |
justenmg | 5:a658cda1d619 | 220 | fft_buffer[2*i+1] = 0; |
justenmg | 2:89234085faae | 221 | } |
justenmg | 1:103e3e426b55 | 222 | } |
justenmg | 2:89234085faae | 223 | |
justenmg | 5:a658cda1d619 | 224 | //perform FFT in place |
justenmg | 5:a658cda1d619 | 225 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, fft_buffer, 0, 1); |
justenmg | 5:a658cda1d619 | 226 | |
justenmg | 5:a658cda1d619 | 227 | |
justenmg | 5:a658cda1d619 | 228 | //multiply with filter FFT |
justenmg | 5:a658cda1d619 | 229 | arm_cmplx_mult_cmplx_f32(fft_buffer, fft_of_filter, ifft_buffer, FFT_LENGTH); |
justenmg | 5:a658cda1d619 | 230 | |
justenmg | 5:a658cda1d619 | 231 | //perform inverse FFT in place |
justenmg | 5:a658cda1d619 | 232 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, ifft_buffer, 1, 1); |
justenmg | 5:a658cda1d619 | 233 | |
justenmg | 5:a658cda1d619 | 234 | // overlap-add to the buffer |
justenmg | 5:a658cda1d619 | 235 | for(uint16_t i = 0; i < CONV_LENGTH; i++) |
justenmg | 2:89234085faae | 236 | { |
justenmg | 5:a658cda1d619 | 237 | if(i < sig_length) |
justenmg | 2:89234085faae | 238 | { |
justenmg | 5:a658cda1d619 | 239 | d_out[i] = ifft_buffer[2*i] + overlap_buffer[i]; |
justenmg | 5:a658cda1d619 | 240 | } |
justenmg | 5:a658cda1d619 | 241 | else if(i < BUFFER_LENGTH) |
justenmg | 5:a658cda1d619 | 242 | { |
justenmg | 5:a658cda1d619 | 243 | overlap_buffer[i - sig_length] = overlap_buffer[i] + ifft_buffer[2*i]; |
justenmg | 2:89234085faae | 244 | } |
justenmg | 2:89234085faae | 245 | else |
justenmg | 2:89234085faae | 246 | { |
justenmg | 5:a658cda1d619 | 247 | overlap_buffer[i - sig_length] = ifft_buffer[2*i]; |
justenmg | 2:89234085faae | 248 | } |
justenmg | 5:a658cda1d619 | 249 | } |
justenmg | 4:99de9b4005d2 | 250 | return; |
justenmg | 4:99de9b4005d2 | 251 | } |
justenmg | 4:99de9b4005d2 | 252 | |
justenmg | 4:99de9b4005d2 | 253 | |
justenmg | 5:a658cda1d619 | 254 | //The overlap-add method uses previous outputs to adjust the filtered |
justenmg | 5:a658cda1d619 | 255 | //output to be more representative of the continuous version of the signal |
justenmg | 5:a658cda1d619 | 256 | void filter_OA_FFT_RI( |
justenmg | 5:a658cda1d619 | 257 | float32_t* overlap_buffer1, |
justenmg | 5:a658cda1d619 | 258 | float32_t* overlap_buffer2, |
justenmg | 5:a658cda1d619 | 259 | float32_t* fft_buffer, |
justenmg | 5:a658cda1d619 | 260 | float32_t* ifft_buffer, |
justenmg | 5:a658cda1d619 | 261 | float32_t* d_in1, |
justenmg | 5:a658cda1d619 | 262 | float32_t* d_in2, |
justenmg | 5:a658cda1d619 | 263 | float32_t* d_out1, |
justenmg | 5:a658cda1d619 | 264 | float32_t* d_out2, |
justenmg | 5:a658cda1d619 | 265 | uint16_t sig_length) |
justenmg | 5:a658cda1d619 | 266 | { |
justenmg | 5:a658cda1d619 | 267 | //fill the FFT buffer |
justenmg | 5:a658cda1d619 | 268 | for(int i=0; i < FFT_LENGTH; i++) |
justenmg | 5:a658cda1d619 | 269 | { |
justenmg | 5:a658cda1d619 | 270 | if(i < sig_length) |
justenmg | 5:a658cda1d619 | 271 | { |
justenmg | 5:a658cda1d619 | 272 | fft_buffer[2*i] = d_in1[i]; |
justenmg | 5:a658cda1d619 | 273 | fft_buffer[2*i+1] = d_in2[i]; |
justenmg | 5:a658cda1d619 | 274 | } |
justenmg | 5:a658cda1d619 | 275 | else |
justenmg | 5:a658cda1d619 | 276 | { |
justenmg | 5:a658cda1d619 | 277 | fft_buffer[2*i] = 0; |
justenmg | 5:a658cda1d619 | 278 | fft_buffer[2*i+1] = 0; |
justenmg | 5:a658cda1d619 | 279 | } |
justenmg | 5:a658cda1d619 | 280 | } |
justenmg | 4:99de9b4005d2 | 281 | |
justenmg | 5:a658cda1d619 | 282 | //perform FFT in place |
justenmg | 5:a658cda1d619 | 283 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, fft_buffer, 0, 1); |
justenmg | 5:a658cda1d619 | 284 | |
justenmg | 5:a658cda1d619 | 285 | |
justenmg | 5:a658cda1d619 | 286 | //multiply with filter FFT |
justenmg | 5:a658cda1d619 | 287 | arm_cmplx_mult_cmplx_f32(fft_buffer, fft_of_filter, ifft_buffer, FFT_LENGTH); |
justenmg | 5:a658cda1d619 | 288 | |
justenmg | 5:a658cda1d619 | 289 | |
justenmg | 5:a658cda1d619 | 290 | //perform inverse FFT in place |
justenmg | 5:a658cda1d619 | 291 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, ifft_buffer, 1, 1); |
justenmg | 5:a658cda1d619 | 292 | |
justenmg | 5:a658cda1d619 | 293 | // overlap-add to the buffer |
justenmg | 5:a658cda1d619 | 294 | for(uint16_t i = 0; i < CONV_LENGTH; i++) |
justenmg | 5:a658cda1d619 | 295 | { |
justenmg | 5:a658cda1d619 | 296 | if(i < sig_length) |
justenmg | 5:a658cda1d619 | 297 | { |
justenmg | 5:a658cda1d619 | 298 | d_out1[i] = ifft_buffer[2*i] + overlap_buffer1[i]; |
justenmg | 5:a658cda1d619 | 299 | d_out2[i] = ifft_buffer[2*i+1] + overlap_buffer2[i]; |
justenmg | 5:a658cda1d619 | 300 | } |
justenmg | 5:a658cda1d619 | 301 | else if(i < BUFFER_LENGTH) |
justenmg | 5:a658cda1d619 | 302 | { |
justenmg | 5:a658cda1d619 | 303 | overlap_buffer1[i - sig_length] = overlap_buffer1[i] + ifft_buffer[2*i]; |
justenmg | 5:a658cda1d619 | 304 | overlap_buffer2[i - sig_length] = overlap_buffer2[i] + ifft_buffer[2*i+1]; |
justenmg | 5:a658cda1d619 | 305 | } |
justenmg | 5:a658cda1d619 | 306 | else |
justenmg | 5:a658cda1d619 | 307 | { |
justenmg | 5:a658cda1d619 | 308 | overlap_buffer1[i - sig_length] = ifft_buffer[2*i]; |
justenmg | 5:a658cda1d619 | 309 | overlap_buffer2[i - sig_length] = ifft_buffer[2*i+1]; |
justenmg | 5:a658cda1d619 | 310 | } |
justenmg | 5:a658cda1d619 | 311 | } |
justenmg | 2:89234085faae | 312 | return; |
justenmg | 1:103e3e426b55 | 313 | } |
justenmg | 1:103e3e426b55 | 314 | |
justenmg | 4:99de9b4005d2 | 315 | |
justenmg | 5:a658cda1d619 | 316 | //The overlap-save method uses previous inputs to perform a |
justenmg | 5:a658cda1d619 | 317 | //more representative filtering operation |
justenmg | 5:a658cda1d619 | 318 | void filter_OS_FFT_RI( |
justenmg | 5:a658cda1d619 | 319 | float32_t* save_buffer1, |
justenmg | 5:a658cda1d619 | 320 | float32_t* save_buffer2, |
justenmg | 5:a658cda1d619 | 321 | float32_t* fft_buffer, |
justenmg | 5:a658cda1d619 | 322 | float32_t* ifft_buffer, |
justenmg | 5:a658cda1d619 | 323 | float32_t* d_in1, |
justenmg | 5:a658cda1d619 | 324 | float32_t* d_in2, |
justenmg | 5:a658cda1d619 | 325 | float32_t* d_out1, |
justenmg | 5:a658cda1d619 | 326 | float32_t* d_out2, |
justenmg | 5:a658cda1d619 | 327 | uint16_t sig_length) |
justenmg | 4:99de9b4005d2 | 328 | { |
justenmg | 5:a658cda1d619 | 329 | //shift the save buffers by the input data size |
justenmg | 5:a658cda1d619 | 330 | for(int i=0; i < FFT_LENGTH; i++) |
justenmg | 5:a658cda1d619 | 331 | { |
justenmg | 5:a658cda1d619 | 332 | if(i < FFT_LENGTH - sig_length) |
justenmg | 5:a658cda1d619 | 333 | { |
justenmg | 5:a658cda1d619 | 334 | save_buffer1[i] = save_buffer1[i+sig_length]; |
justenmg | 5:a658cda1d619 | 335 | save_buffer2[i] = save_buffer2[i+sig_length]; |
justenmg | 5:a658cda1d619 | 336 | } |
justenmg | 5:a658cda1d619 | 337 | else |
justenmg | 5:a658cda1d619 | 338 | { |
justenmg | 5:a658cda1d619 | 339 | save_buffer1[i] = 0; |
justenmg | 5:a658cda1d619 | 340 | save_buffer2[i] = 0; |
justenmg | 5:a658cda1d619 | 341 | } |
justenmg | 5:a658cda1d619 | 342 | } |
justenmg | 5:a658cda1d619 | 343 | |
justenmg | 5:a658cda1d619 | 344 | //insert new data into save buffer |
justenmg | 5:a658cda1d619 | 345 | for(int i=0; i < sig_length; i++) |
justenmg | 5:a658cda1d619 | 346 | { |
justenmg | 5:a658cda1d619 | 347 | save_buffer1[(FFT_LENGTH - sig_length) + i] = d_in1[i]; |
justenmg | 5:a658cda1d619 | 348 | save_buffer2[(FFT_LENGTH - sig_length) + i] = d_in2[i]; |
justenmg | 5:a658cda1d619 | 349 | } |
justenmg | 5:a658cda1d619 | 350 | |
justenmg | 5:a658cda1d619 | 351 | //fill the FFT buffer |
justenmg | 5:a658cda1d619 | 352 | for(int i=0; i < FFT_LENGTH; i++) |
justenmg | 5:a658cda1d619 | 353 | { |
justenmg | 5:a658cda1d619 | 354 | fft_buffer[2*i] = save_buffer1[i]; |
justenmg | 5:a658cda1d619 | 355 | fft_buffer[2*i+1] = save_buffer2[i]; |
justenmg | 5:a658cda1d619 | 356 | } |
justenmg | 5:a658cda1d619 | 357 | |
justenmg | 5:a658cda1d619 | 358 | //perform FFT in place |
justenmg | 5:a658cda1d619 | 359 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, fft_buffer, 0, 1); |
justenmg | 5:a658cda1d619 | 360 | |
justenmg | 5:a658cda1d619 | 361 | |
justenmg | 5:a658cda1d619 | 362 | //multiply with filter FFT |
justenmg | 5:a658cda1d619 | 363 | arm_cmplx_mult_cmplx_f32(fft_buffer, fft_of_filter, ifft_buffer, FFT_LENGTH); |
justenmg | 5:a658cda1d619 | 364 | |
justenmg | 5:a658cda1d619 | 365 | |
justenmg | 5:a658cda1d619 | 366 | //perform inverse FFT in place |
justenmg | 5:a658cda1d619 | 367 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, ifft_buffer, 1, 1); |
justenmg | 5:a658cda1d619 | 368 | |
justenmg | 5:a658cda1d619 | 369 | // copy to output buffer |
justenmg | 5:a658cda1d619 | 370 | for(uint16_t i = CONV_LENGTH - sig_length; i < CONV_LENGTH; i++) |
justenmg | 5:a658cda1d619 | 371 | { |
justenmg | 5:a658cda1d619 | 372 | d_out1[i] = ifft_buffer[2*i]; |
justenmg | 5:a658cda1d619 | 373 | d_out2[i] = ifft_buffer[2*i+1]; |
justenmg | 5:a658cda1d619 | 374 | } |
justenmg | 4:99de9b4005d2 | 375 | return; |
justenmg | 4:99de9b4005d2 | 376 | } |
justenmg | 4:99de9b4005d2 | 377 | |
justenmg | 4:99de9b4005d2 | 378 | |
justenmg | 4:99de9b4005d2 | 379 | |
justenmg | 4:99de9b4005d2 | 380 | |
justenmg | 4:99de9b4005d2 | 381 | |
justenmg | 4:99de9b4005d2 | 382 | |
justenmg | 4:99de9b4005d2 | 383 | void filter_conv_init() |
justenmg | 1:103e3e426b55 | 384 | { |
justenmg | 2:89234085faae | 385 | for(int i=0; i < BUFFER_LENGTH; i++) |
justenmg | 1:103e3e426b55 | 386 | { |
justenmg | 2:89234085faae | 387 | l_buf[i] = 0; |
justenmg | 2:89234085faae | 388 | r_buf[i] = 0; |
justenmg | 1:103e3e426b55 | 389 | } |
justenmg | 5:a658cda1d619 | 390 | for(int i=0; i < PADDED_FILTER_LENGTH; i++) |
justenmg | 5:a658cda1d619 | 391 | { |
justenmg | 5:a658cda1d619 | 392 | if((i < AUDIO_BLOCK_SAMPLES - 1) || (i >= WIN_NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1)) |
justenmg | 5:a658cda1d619 | 393 | { |
justenmg | 5:a658cda1d619 | 394 | padded_filter[i] = 0; |
justenmg | 5:a658cda1d619 | 395 | } |
justenmg | 5:a658cda1d619 | 396 | else |
justenmg | 5:a658cda1d619 | 397 | { |
justenmg | 5:a658cda1d619 | 398 | padded_filter[i] = win_filter_coeffs[WIN_NUM_TAPS - 1 - (i - AUDIO_BLOCK_SAMPLES - 1)]; |
justenmg | 5:a658cda1d619 | 399 | } |
justenmg | 5:a658cda1d619 | 400 | } |
justenmg | 5:a658cda1d619 | 401 | |
justenmg | 3:51e15bd15778 | 402 | return; |
justenmg | 1:103e3e426b55 | 403 | } |
justenmg | 4:99de9b4005d2 | 404 | |
justenmg | 4:99de9b4005d2 | 405 | |
justenmg | 4:99de9b4005d2 | 406 | |
justenmg | 4:99de9b4005d2 | 407 | void filter_fft_init() |
justenmg | 4:99de9b4005d2 | 408 | { |
justenmg | 5:a658cda1d619 | 409 | for(int i=0; i < FFT_LENGTH; i++) |
justenmg | 4:99de9b4005d2 | 410 | { |
justenmg | 4:99de9b4005d2 | 411 | if(i < WIN_NUM_TAPS) |
justenmg | 4:99de9b4005d2 | 412 | { |
justenmg | 5:a658cda1d619 | 413 | fft_of_filter[2*i] = win_filter_coeffs[i]; |
justenmg | 5:a658cda1d619 | 414 | fft_of_filter[2*i+1] = 0; |
justenmg | 4:99de9b4005d2 | 415 | } |
justenmg | 4:99de9b4005d2 | 416 | else |
justenmg | 4:99de9b4005d2 | 417 | { |
justenmg | 5:a658cda1d619 | 418 | fft_of_filter[2*i] = 0; |
justenmg | 5:a658cda1d619 | 419 | fft_of_filter[2*i+1] = 0; |
justenmg | 4:99de9b4005d2 | 420 | } |
justenmg | 4:99de9b4005d2 | 421 | } |
justenmg | 4:99de9b4005d2 | 422 | |
justenmg | 4:99de9b4005d2 | 423 | arm_cfft_f32(&arm_cfft_sR_f32_len1024, fft_of_filter, 0, 1); |
justenmg | 4:99de9b4005d2 | 424 | |
justenmg | 4:99de9b4005d2 | 425 | return; |
justenmg | 4:99de9b4005d2 | 426 | } |
justenmg | 5:a658cda1d619 | 427 |