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Allow the user to create fully custom filters.

This commit is contained in:
george-norton 2023-06-22 17:14:20 +01:00
parent 66943e9c84
commit 6c627d22fd
2 changed files with 60 additions and 22 deletions
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66
firmware/code/configuration_manager.c
View File

@ -103,10 +103,8 @@ bool validate_filter_configuration(filter_configuration_tlv *filters)
case BANDPASSPEAK:
case NOTCH:
case ALLPASS: {
//filter2 *args = (filter2 *)ptr;
//printf("Found Filter %d: %0.2f %0.2f\n", args->type, args->f0, args->Q);
if (remaining < sizeof(filter2)) {
printf("Error! Not enough data left for filter2 (%d)..\n", remaining);
printf("Error! Not enough data left for filter2 (%d)\n", remaining);
return false;
}
ptr += sizeof(filter2);
@ -115,15 +113,27 @@ bool validate_filter_configuration(filter_configuration_tlv *filters)
case PEAKING:
case LOWSHELF:
case HIGHSHELF: {
//filter3 *args = (filter3 *)ptr;
//printf("Found Filter %d: %0.2f %0.2f %0.2f\n", args->type, args->f0, args->db_gain, args->Q);
if (remaining < sizeof(filter3)) {
printf("Error! Not enough data left for filter3 (%d)..\n", remaining);
printf("Error! Not enough data left for filter3 (%d)\n", remaining);
return false;
}
ptr += sizeof(filter3);
break;
}
case CUSTOMIIR: {
filter6 *args = (filter6 *)ptr;
if (remaining < sizeof(filter6)) {
printf("Error! Not enough data left for filter6 (%d)\n", remaining);
return false;
}
if (args->a0 == 0.0) {
printf("Error! The a0 co-efficient of an IIR filter must not be 0.\n");
return false;
}
ptr += sizeof(filter6);
break;
}
default:
printf("Unknown filter type\n");
return false;
@ -164,26 +174,42 @@ void apply_filter_configuration(filter_configuration_tlv *filters) {
case PEAKING: INIT_FILTER3(peaking);
case LOWSHELF: INIT_FILTER3(lowshelf);
case HIGHSHELF: INIT_FILTER3(highshelf);
case CUSTOMIIR: {
filter6 *args = (filter6 *)ptr;
uint32_t checksum = 0;
for (int i = 0; i < sizeof(filter6) / 4; i++) checksum ^= ((uint32_t*) args)[i];
if (checksum != bqf_filter_checksum[filter_stages]) {
bqf_filters_left[filter_stages].a0 = fix16_from_dbl(1.0);
bqf_filters_left[filter_stages].a1 = fix16_from_dbl(args->a1/args->a0);
bqf_filters_left[filter_stages].a2 = fix16_from_dbl(args->a2/args->a0);
bqf_filters_left[filter_stages].b0 = fix16_from_dbl(args->b0/args->a0);
bqf_filters_left[filter_stages].b1 = fix16_from_dbl(args->b1/args->a0);
bqf_filters_left[filter_stages].b2 = fix16_from_dbl(args->b2/args->a0);
memcpy(&bqf_filters_right[filter_stages], &bqf_filters_left[filter_stages], sizeof(bqf_coeff_t));
bqf_filter_checksum[filter_stages] = checksum;
}
ptr += sizeof(filter6);
type_changed = true; // Always flush our memory
break;
}
default:
break;
}
filter_stages++;
}
if (type_changed) {
// The memory structure stores the last 2 input samples, we can replay them into
// the new filter rather than starting again from scratch.
fix16_t left[2] = { bqf_filters_mem_left[filter_stages].x_2, bqf_filters_mem_left[filter_stages].x_1 };
fix16_t right[2] = { bqf_filters_mem_right[filter_stages].x_2, bqf_filters_mem_right[filter_stages].x_1 };
if (type_changed) {
// The memory structure stores the last 2 input samples, we can replay them into
// the new filter rather than starting again from scratch.
fix16_t left[2] = { bqf_filters_mem_left[0].x_2, bqf_filters_mem_left[0].x_1 };
fix16_t right[2] = { bqf_filters_mem_right[0].x_2, bqf_filters_mem_right[0].x_1 };
for (int i=0; i<filter_stages; i++) {
bqf_memreset(&bqf_filters_mem_left[i]);
bqf_memreset(&bqf_filters_mem_right[i]);
bqf_memreset(&bqf_filters_mem_left[filter_stages]);
bqf_memreset(&bqf_filters_mem_right[filter_stages]);
left[0] = bqf_transform(left[0], &bqf_filters_left[i], &bqf_filters_mem_left[i]);
left[1] = bqf_transform(left[1], &bqf_filters_left[i], &bqf_filters_mem_left[i]);
right[0] = bqf_transform(right[0], &bqf_filters_right[i], &bqf_filters_mem_right[i]);
right[1] = bqf_transform(right[1], &bqf_filters_right[i], &bqf_filters_mem_right[i]);
left[0] = bqf_transform(left[0], &bqf_filters_left[filter_stages], &bqf_filters_mem_left[filter_stages]);
left[1] = bqf_transform(left[1], &bqf_filters_left[filter_stages], &bqf_filters_mem_left[filter_stages]);
right[0] = bqf_transform(right[0], &bqf_filters_right[filter_stages], &bqf_filters_mem_right[filter_stages]);
right[1] = bqf_transform(right[1], &bqf_filters_right[filter_stages], &bqf_filters_mem_right[filter_stages]);
}
filter_stages++;
}
}

16
firmware/code/configuration_types.h
View File

@ -17,7 +17,7 @@
#include <stdint.h>
#define FLASH_MAGIC 0x2E8AFEDD
#define CONFIG_VERSION 1
#define CONFIG_VERSION 2
#define MINIMUM_CONFIG_VERSION 1
enum structure_types {
@ -65,6 +65,17 @@ typedef struct __attribute__((__packed__)) _filter3 {
double Q;
} filter3;
typedef struct __attribute__((__packed__)) _filter6 {
uint8_t type;
uint8_t reserved[3];
double a0;
double a1;
double a2;
double b0;
double b1;
double b2;
} filter6;
enum filter_type {
LOWPASS = 0,
HIGHPASS,
@ -74,7 +85,8 @@ enum filter_type {
ALLPASS,
PEAKING,
LOWSHELF,
HIGHSHELF
HIGHSHELF,
CUSTOMIIR
};
typedef struct __attribute__((__packed__)) _flash_header_tlv {