initial
Dependencies: mbed BSP_DISCO_F746NG mbed-dsp
signal_processing.cpp@2:89234085faae, 2020-02-20 (annotated)
- Committer:
- justenmg
- Date:
- Thu Feb 20 18:33:14 2020 +0000
- Revision:
- 2:89234085faae
- Parent:
- 1:103e3e426b55
- Child:
- 3:51e15bd15778
Feb 20
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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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" |
bmazzeo | 0:c0f52e8223fe | 23 | |
bmazzeo | 0:c0f52e8223fe | 24 | |
bmazzeo | 0:c0f52e8223fe | 25 | /* ---------------------------------------------------------------------- |
bmazzeo | 0:c0f52e8223fe | 26 | ** Defines for signal processing |
bmazzeo | 0:c0f52e8223fe | 27 | ** ------------------------------------------------------------------- */ |
bmazzeo | 0:c0f52e8223fe | 28 | |
bmazzeo | 0:c0f52e8223fe | 29 | #define AUDIO_BLOCK_SAMPLES ((uint32_t)128) // Number of samples (L and R) in audio block (each samples is 16 bits) |
justenmg | 1:103e3e426b55 | 30 | #define BUFFER_LENGTH (WIN_NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1) |
bmazzeo | 0:c0f52e8223fe | 31 | |
bmazzeo | 0:c0f52e8223fe | 32 | /* For Lab Exercise */ |
justenmg | 1:103e3e426b55 | 33 | #define Lab_Execution_Type 2 |
justenmg | 1:103e3e426b55 | 34 | |
justenmg | 1:103e3e426b55 | 35 | float32_t lState[NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1]; |
justenmg | 1:103e3e426b55 | 36 | float32_t rState[NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1]; |
bmazzeo | 0:c0f52e8223fe | 37 | |
justenmg | 1:103e3e426b55 | 38 | float32_t l_buf[BUFFER_LENGTH]; |
justenmg | 1:103e3e426b55 | 39 | float32_t r_buf[BUFFER_LENGTH]; |
bmazzeo | 0:c0f52e8223fe | 40 | |
justenmg | 1:103e3e426b55 | 41 | float32_t* l_buf_head = &l_buf; |
justenmg | 2:89234085faae | 42 | uint16_t l_buf_head_idx = 0; |
justenmg | 1:103e3e426b55 | 43 | float32_t* r_buf_head = &r_buf; |
justenmg | 2:89234085faae | 44 | uint16_t r_buf_head_idx = 0; |
justenmg | 1:103e3e426b55 | 45 | |
justenmg | 1:103e3e426b55 | 46 | arm_fir_instance_f32 filter_left; |
justenmg | 1:103e3e426b55 | 47 | arm_fir_instance_f32 filter_right; |
bmazzeo | 0:c0f52e8223fe | 48 | |
bmazzeo | 0:c0f52e8223fe | 49 | /* FUNCTION DEFINITIONS BELOW */ |
bmazzeo | 0:c0f52e8223fe | 50 | |
bmazzeo | 0:c0f52e8223fe | 51 | /** |
bmazzeo | 0:c0f52e8223fe | 52 | * @brief Initialize filter structures to be used in loops later |
bmazzeo | 0:c0f52e8223fe | 53 | * @retval None |
bmazzeo | 0:c0f52e8223fe | 54 | */ |
bmazzeo | 0:c0f52e8223fe | 55 | void initalize_signal_processing(void) { |
bmazzeo | 0:c0f52e8223fe | 56 | |
bmazzeo | 0:c0f52e8223fe | 57 | switch (Lab_Execution_Type) |
bmazzeo | 0:c0f52e8223fe | 58 | { |
bmazzeo | 0:c0f52e8223fe | 59 | case 0: // Passthrough case |
bmazzeo | 0:c0f52e8223fe | 60 | break; |
bmazzeo | 0:c0f52e8223fe | 61 | |
bmazzeo | 0:c0f52e8223fe | 62 | case 1: // FIR case (ARM) |
justenmg | 1:103e3e426b55 | 63 | arm_fir_init_f32(&filter_left, NUM_TAPS, (float32_t *)&Filter_coeffs, (float32_t *)&lState, AUDIO_BLOCK_SAMPLES); |
justenmg | 1:103e3e426b55 | 64 | arm_fir_init_f32(&filter_right, NUM_TAPS, (float32_t *)&Filter_coeffs, (float32_t *)&rState, AUDIO_BLOCK_SAMPLES); |
bmazzeo | 0:c0f52e8223fe | 65 | break; |
bmazzeo | 0:c0f52e8223fe | 66 | |
bmazzeo | 0:c0f52e8223fe | 67 | case 2: // FIR case (student) |
justenmg | 1:103e3e426b55 | 68 | arm_fir_init_f32(&filter_left, OUR_NUM_TAPS, (float32_t *)&our_Filter_coeffs, (float32_t *)&lState, AUDIO_BLOCK_SAMPLES); |
justenmg | 1:103e3e426b55 | 69 | arm_fir_init_f32(&filter_right, OUR_NUM_TAPS, (float32_t *)&our_Filter_coeffs, (float32_t *)&rState, AUDIO_BLOCK_SAMPLES); |
bmazzeo | 0:c0f52e8223fe | 70 | break; |
bmazzeo | 0:c0f52e8223fe | 71 | |
bmazzeo | 0:c0f52e8223fe | 72 | case 3: // FFT Overlap-add |
justenmg | 2:89234085faae | 73 | filter_init(); |
bmazzeo | 0:c0f52e8223fe | 74 | break; |
bmazzeo | 0:c0f52e8223fe | 75 | |
bmazzeo | 0:c0f52e8223fe | 76 | case 4: // FFT Overlap-add with real-imag efficiency |
bmazzeo | 0:c0f52e8223fe | 77 | break; |
bmazzeo | 0:c0f52e8223fe | 78 | |
bmazzeo | 0:c0f52e8223fe | 79 | |
bmazzeo | 0:c0f52e8223fe | 80 | } |
bmazzeo | 0:c0f52e8223fe | 81 | } |
bmazzeo | 0:c0f52e8223fe | 82 | |
bmazzeo | 0:c0f52e8223fe | 83 | /** |
bmazzeo | 0:c0f52e8223fe | 84 | * @brief Process audio channel signals |
bmazzeo | 0:c0f52e8223fe | 85 | * @param L_channel_in: Pointer to Left channel data input (float32_t) |
bmazzeo | 0:c0f52e8223fe | 86 | * @param R_channel_in: Pointer to Right channel data input (float32_t) |
bmazzeo | 0:c0f52e8223fe | 87 | * @param L_channel_out: Pointer to Left channel data output (float32_t) |
bmazzeo | 0:c0f52e8223fe | 88 | * @param R_channel_out: Pointer to Right channel data output (float32_t) |
bmazzeo | 0:c0f52e8223fe | 89 | * @param Signal_Length: length of data to process |
bmazzeo | 0:c0f52e8223fe | 90 | * @retval None |
bmazzeo | 0:c0f52e8223fe | 91 | */ |
bmazzeo | 0:c0f52e8223fe | 92 | 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 | 93 | { |
bmazzeo | 0:c0f52e8223fe | 94 | char buf[70]; |
bmazzeo | 0:c0f52e8223fe | 95 | BSP_LCD_SetFont(&Font8); |
bmazzeo | 0:c0f52e8223fe | 96 | BSP_LCD_SetTextColor(LCD_COLOR_CYAN); |
bmazzeo | 0:c0f52e8223fe | 97 | sprintf(buf, "Processing Signals" ); |
bmazzeo | 0:c0f52e8223fe | 98 | BSP_LCD_DisplayStringAt(0, 200, (uint8_t *) buf, LEFT_MODE); |
bmazzeo | 0:c0f52e8223fe | 99 | |
bmazzeo | 0:c0f52e8223fe | 100 | switch(Lab_Execution_Type) |
bmazzeo | 0:c0f52e8223fe | 101 | { |
bmazzeo | 0:c0f52e8223fe | 102 | case 0: // Passthrough case |
justenmg | 2:89234085faae | 103 | arm_copy_f32(L_channel_in, L_channel_out, Signal_Length); |
justenmg | 2:89234085faae | 104 | arm_copy_f32(R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 105 | break; |
bmazzeo | 0:c0f52e8223fe | 106 | |
bmazzeo | 0:c0f52e8223fe | 107 | case 1: // FIR case (ARM) |
justenmg | 2:89234085faae | 108 | arm_fir_f32(&filter_left, L_channel_in, L_channel_out, Signal_Length); |
justenmg | 2:89234085faae | 109 | arm_fir_f32(&filter_right, R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 110 | break; |
bmazzeo | 0:c0f52e8223fe | 111 | |
bmazzeo | 0:c0f52e8223fe | 112 | case 2: // FIR case (student) |
justenmg | 2:89234085faae | 113 | arm_fir_f32(&filter_left, L_channel_in, L_channel_out, Signal_Length); |
justenmg | 2:89234085faae | 114 | arm_fir_f32(&filter_right, R_channel_in, R_channel_out, Signal_Length); |
bmazzeo | 0:c0f52e8223fe | 115 | break; |
bmazzeo | 0:c0f52e8223fe | 116 | |
bmazzeo | 0:c0f52e8223fe | 117 | case 3: // FFT Overlap-add |
justenmg | 2:89234085faae | 118 | filter(l_buf, l_buf_head, l_buf_head_idx, L_channel_in, L_channel_out, Signal_Length, BUFFER_LENGTH); |
justenmg | 2:89234085faae | 119 | filter(r_buf, r_buf_head, r_buf_head_idx, R_channel_in, R_channel_out, Signal_Length, BUFFER_LENGTH); |
bmazzeo | 0:c0f52e8223fe | 120 | break; |
bmazzeo | 0:c0f52e8223fe | 121 | |
bmazzeo | 0:c0f52e8223fe | 122 | case 4: // FFT Overlap-add with real-imag efficiency |
bmazzeo | 0:c0f52e8223fe | 123 | break; |
bmazzeo | 0:c0f52e8223fe | 124 | |
bmazzeo | 0:c0f52e8223fe | 125 | |
bmazzeo | 0:c0f52e8223fe | 126 | } |
bmazzeo | 0:c0f52e8223fe | 127 | /* Change font back */ |
bmazzeo | 0:c0f52e8223fe | 128 | BSP_LCD_SetFont(&Font16); |
bmazzeo | 0:c0f52e8223fe | 129 | } |
justenmg | 1:103e3e426b55 | 130 | |
justenmg | 2:89234085faae | 131 | //buffer: pointer to the storage buffer for the filter output |
justenmg | 2:89234085faae | 132 | //buf_length: the length of the storage buffer (len_filter + len_batch - 1) |
justenmg | 2:89234085faae | 133 | void filter(float32_t* buffer_begin, float32_t* buffer_head, uint16_t buffer_head_idx, float32_t* d_in, float32_t* d_out, uint16_t sig_length, uint16_t buf_length) |
justenmg | 1:103e3e426b55 | 134 | { |
justenmg | 2:89234085faae | 135 | float32_t* data_sample = d_in+sig_length-1; |
justenmg | 2:89234085faae | 136 | float32_t* filter_sample = filter; |
justenmg | 1:103e3e426b55 | 137 | float32_t result = 0; |
justenmg | 2:89234085faae | 138 | uint16_t conv_length = 0; |
justenmg | 2:89234085faae | 139 | float32_t* buffer_data_location = buffer_head; |
justenmg | 2:89234085faae | 140 | |
justenmg | 2:89234085faae | 141 | //convolve and save to buffer |
justenmg | 2:89234085faae | 142 | for(uint16_t shift = 0; shift < buf_length; shift++) |
justenmg | 1:103e3e426b55 | 143 | { |
justenmg | 2:89234085faae | 144 | //shift |
justenmg | 2:89234085faae | 145 | if(shift < sig_lenth) |
justenmg | 2:89234085faae | 146 | { |
justenmg | 2:89234085faae | 147 | conv_length = shift + 1; |
justenmg | 2:89234085faae | 148 | } |
justenmg | 2:89234085faae | 149 | else if(shift >= sig_lenth && shift < filt_length) |
justenmg | 2:89234085faae | 150 | { |
justenmg | 2:89234085faae | 151 | conv_length = sig_lenth; |
justenmg | 2:89234085faae | 152 | } |
justenmg | 2:89234085faae | 153 | else if(shift >= filt_length) |
justenmg | 2:89234085faae | 154 | { |
justenmg | 2:89234085faae | 155 | conv_length = sig_lenth - (shift - filt_length + 1) |
justenmg | 2:89234085faae | 156 | } |
justenmg | 2:89234085faae | 157 | |
justenmg | 2:89234085faae | 158 | result = 0; |
justenmg | 2:89234085faae | 159 | //multiply-add |
justenmg | 2:89234085faae | 160 | for(i=0; i<conv_length; i++) |
justenmg | 2:89234085faae | 161 | { |
justenmg | 2:89234085faae | 162 | result += (*filter_sample) * (*data_sample); |
justenmg | 2:89234085faae | 163 | filter_sample++; |
justenmg | 2:89234085faae | 164 | data_sample--; |
justenmg | 2:89234085faae | 165 | } |
justenmg | 2:89234085faae | 166 | |
justenmg | 2:89234085faae | 167 | // save to the buffer |
justenmg | 2:89234085faae | 168 | *buffer_data_location += result; |
justenmg | 2:89234085faae | 169 | //increment, looping back to beginning of buffer |
justenmg | 2:89234085faae | 170 | if(buffer_data_location == (buffer_begin + buf_length - 1)) |
justenmg | 2:89234085faae | 171 | { |
justenmg | 2:89234085faae | 172 | buffer_data_location = buffer_begin; |
justenmg | 2:89234085faae | 173 | } |
justenmg | 2:89234085faae | 174 | else |
justenmg | 2:89234085faae | 175 | { |
justenmg | 2:89234085faae | 176 | buffer_data_location++; |
justenmg | 2:89234085faae | 177 | } |
justenmg | 1:103e3e426b55 | 178 | } |
justenmg | 2:89234085faae | 179 | |
justenmg | 2:89234085faae | 180 | //copy from buffer to d_out |
justenmg | 2:89234085faae | 181 | buffer_data_location = buffer_head; |
justenmg | 2:89234085faae | 182 | for(int i=0; i < sig_lenth; i++) |
justenmg | 2:89234085faae | 183 | { |
justenmg | 2:89234085faae | 184 | d_out[i] = *buffer_data_location; |
justenmg | 2:89234085faae | 185 | *buffer_data_location = 0; |
justenmg | 2:89234085faae | 186 | //increment, looping back to beginning of buffer |
justenmg | 2:89234085faae | 187 | if(buffer_data_location + i == (buffer_begin + buf_length - 1)) |
justenmg | 2:89234085faae | 188 | { |
justenmg | 2:89234085faae | 189 | buffer_data_location = buffer_begin; |
justenmg | 2:89234085faae | 190 | } |
justenmg | 2:89234085faae | 191 | else |
justenmg | 2:89234085faae | 192 | { |
justenmg | 2:89234085faae | 193 | buffer_data_location++; |
justenmg | 2:89234085faae | 194 | } |
justenmg | 2:89234085faae | 195 | } |
justenmg | 2:89234085faae | 196 | return; |
justenmg | 1:103e3e426b55 | 197 | } |
justenmg | 1:103e3e426b55 | 198 | |
justenmg | 2:89234085faae | 199 | void filter_init() |
justenmg | 1:103e3e426b55 | 200 | { |
justenmg | 2:89234085faae | 201 | for(int i=0; i < BUFFER_LENGTH; i++) |
justenmg | 1:103e3e426b55 | 202 | { |
justenmg | 2:89234085faae | 203 | l_buf[i] = 0; |
justenmg | 2:89234085faae | 204 | r_buf[i] = 0; |
justenmg | 1:103e3e426b55 | 205 | } |
justenmg | 1:103e3e426b55 | 206 | } |