Implement gamma correction for volume LED

This commit is contained in:
Jan-Henrik 2020-04-24 00:38:05 +02:00
parent f3bd60700f
commit 77721bcd00
5 changed files with 92 additions and 1 deletions

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@ -1,8 +1,11 @@
#pragma once #pragma once
#include "../resources.h"
#include "stm32f0xx_hal_gpio.h" #include "stm32f0xx_hal_gpio.h"
#include <stm32f0xx_hal.h> #include <stm32f0xx_hal.h>
using namespace stereo_mix;
const uint8_t kNumChannels = 4; const uint8_t kNumChannels = 4;
static const uint16_t kGpioPins[] = { GPIO_PIN_7, GPIO_PIN_15, GPIO_PIN_13, GPIO_PIN_14 }; static const uint16_t kGpioPins[] = { GPIO_PIN_7, GPIO_PIN_15, GPIO_PIN_13, GPIO_PIN_14 };
@ -26,7 +29,7 @@ class Leds {
pwm_counter += 2; pwm_counter += 2;
for (size_t i = 0; i < kNumChannels; i++) { for (size_t i = 0; i < kNumChannels; i++) {
if (intensities[0] && intensities[i] >= pwm_counter) { if (intensities[0] && lut_led_gamma[intensities[i]] >= pwm_counter) {
HAL_GPIO_WritePin(kGpioPorts[i], kGpioPins[i], GPIO_PIN_SET); HAL_GPIO_WritePin(kGpioPorts[i], kGpioPins[i], GPIO_PIN_SET);
} else { } else {
HAL_GPIO_WritePin(kGpioPorts[i], kGpioPins[i], GPIO_PIN_RESET); HAL_GPIO_WritePin(kGpioPorts[i], kGpioPins[i], GPIO_PIN_RESET);

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@ -3120,5 +3120,77 @@ const uint16_t* lookup_table_u16_table[] = {
lut_right_cos_pan, lut_right_cos_pan,
}; };
const uint8_t lut_led_gamma[] = {
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 1, 1,
1, 1, 1, 1,
1, 1, 1, 2,
2, 2, 2, 2,
2, 3, 3, 3,
3, 3, 4, 4,
4, 4, 5, 5,
5, 5, 6, 6,
6, 7, 7, 7,
8, 8, 8, 9,
9, 9, 10, 10,
11, 11, 11, 12,
12, 13, 13, 14,
14, 14, 15, 15,
16, 16, 17, 17,
18, 18, 19, 20,
20, 21, 21, 22,
22, 23, 24, 24,
25, 25, 26, 27,
27, 28, 29, 29,
30, 31, 31, 32,
33, 33, 34, 35,
36, 36, 37, 38,
39, 40, 40, 41,
42, 43, 44, 44,
45, 46, 47, 48,
49, 50, 51, 51,
52, 53, 54, 55,
56, 57, 58, 59,
60, 61, 62, 63,
64, 65, 66, 67,
68, 69, 70, 71,
72, 73, 75, 76,
77, 78, 79, 80,
81, 83, 84, 85,
86, 87, 88, 90,
91, 92, 93, 95,
96, 97, 98, 100,
101, 102, 104, 105,
106, 107, 109, 110,
112, 113, 114, 116,
117, 118, 120, 121,
123, 124, 126, 127,
129, 130, 131, 133,
134, 136, 137, 139,
141, 142, 144, 145,
147, 148, 150, 151,
153, 155, 156, 158,
160, 161, 163, 165,
166, 168, 170, 171,
173, 175, 176, 178,
180, 182, 183, 185,
187, 189, 191, 192,
194, 196, 198, 200,
202, 203, 205, 207,
209, 211, 213, 215,
217, 219, 221, 223,
225, 226, 228, 230,
232, 234, 236, 238,
241, 243, 245, 247,
249, 251, 253, 255,
};
const uint8_t* lookup_table_u8_table[] = {
lut_led_gamma,
};
} // namespace stereo_mix } // namespace stereo_mix

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@ -44,15 +44,20 @@ typedef uint8_t ResourceId;
extern const uint16_t* lookup_table_u16_table[]; extern const uint16_t* lookup_table_u16_table[];
extern const uint8_t* lookup_table_u8_table[];
extern const uint16_t lut_linear_to_exp[]; extern const uint16_t lut_linear_to_exp[];
extern const uint16_t lut_left_sin_pan[]; extern const uint16_t lut_left_sin_pan[];
extern const uint16_t lut_right_cos_pan[]; extern const uint16_t lut_right_cos_pan[];
extern const uint8_t lut_led_gamma[];
#define LUT_LINEAR_TO_EXP 0 #define LUT_LINEAR_TO_EXP 0
#define LUT_LINEAR_TO_EXP_SIZE 4096 #define LUT_LINEAR_TO_EXP_SIZE 4096
#define LUT_LEFT_SIN_PAN 1 #define LUT_LEFT_SIN_PAN 1
#define LUT_LEFT_SIN_PAN_SIZE 4096 #define LUT_LEFT_SIN_PAN_SIZE 4096
#define LUT_RIGHT_COS_PAN 2 #define LUT_RIGHT_COS_PAN 2
#define LUT_RIGHT_COS_PAN_SIZE 4096 #define LUT_RIGHT_COS_PAN_SIZE 4096
#define LUT_LED_GAMMA 0
#define LUT_LED_GAMMA_SIZE 256
} // namespace stereo_mix } // namespace stereo_mix

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@ -1,5 +1,6 @@
import numpy as np import numpy as np
lookup_tables_u16 = [] lookup_tables_u16 = []
lookup_tables_u8 = []
ADC_RESOLUTION = 4096 ADC_RESOLUTION = 4096
OUTPUT_RESOLUTION = 2 ** 16 - 1 OUTPUT_RESOLUTION = 2 ** 16 - 1
@ -26,3 +27,11 @@ r_pan = np.round(r_pan * OUTPUT_RESOLUTION)
lookup_tables_u16.append(('left_sin_pan', l_pan)) lookup_tables_u16.append(('left_sin_pan', l_pan))
lookup_tables_u16.append(('right_cos_pan', r_pan)) lookup_tables_u16.append(('right_cos_pan', r_pan))
# led gamma correction
gamma = 2.1
max_in = 255
max_out = 255
input_vals = np.linspace(0, max_in, num=max_in + 1)
gamma_correction = ((input_vals / max_in) ** gamma) * max_out + 0.5
lookup_tables_u8.append(('led_gamma', np.floor(gamma_correction)))

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@ -74,4 +74,6 @@ create_specialized_manager = True
resources = [ resources = [
(lookup_tables.lookup_tables_u16, (lookup_tables.lookup_tables_u16,
'lookup_table_u16', 'LUT', 'uint16_t', int, False), 'lookup_table_u16', 'LUT', 'uint16_t', int, False),
(lookup_tables.lookup_tables_u8,
'lookup_table_u8', 'LUT', 'uint8_t', int, False),
] ]