Increase config buffer size, and make the bqf_transform function inline

firmware/code/bqf.c

@@ -467,21 +467,6 @@ void bqf_highshelf_config(double fs, double f0, double dBgain, double Q,
     coefficients->a2 = fix3_28_from_dbl(a2);
 }
 
-fix3_28_t bqf_transform(fix3_28_t x, bqf_coeff_t *coefficients, bqf_mem_t *memory) {
-    fix3_28_t y = fix16_mul(coefficients->b0, x) -
-            fix16_mul(coefficients->a1, memory->y_1) +
-            fix16_mul(coefficients->b1, memory->x_1) -
-            fix16_mul(coefficients->a2, memory->y_2) +
-            fix16_mul(coefficients->b2, memory->x_2);
-
-    memory->x_2 = memory->x_1;
-    memory->x_1 = x;
-    memory->y_2 = memory->y_1;
-    memory->y_1 = y;
-
-    return y;
-}
-
 void bqf_memreset(bqf_mem_t *memory) {
     memory->x_1 = fix16_zero;
     memory->x_2 = fix16_zero;

firmware/code/bqf.h

@@ -65,7 +65,8 @@ void bqf_peaking_config(double, double, double, double, bqf_coeff_t *);
 void bqf_lowshelf_config(double, double, double, double, bqf_coeff_t *);
 void bqf_highshelf_config(double, double, double, double, bqf_coeff_t *);
 
-fix3_28_t bqf_transform(fix3_28_t, bqf_coeff_t *, bqf_mem_t *);
+static inline fix3_28_t bqf_transform(fix3_28_t, bqf_coeff_t *, bqf_mem_t *);
 void bqf_memreset(bqf_mem_t *);
 
+#include "bqf.inl"
 #endif

firmware/code/bqf.inl

@@ -0,0 +1,36 @@
+/**
+ * Copyright 2022 Colin Lam, Ploopy Corporation
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPECIAL THANKS TO:
+ * Robert Bristow-Johnson, a.k.a. RBJ
+ * for his exceptional work on biquad formulae as applied to digital
+ * audio filtering, summarised in his pamphlet, "Audio EQ Cookbook".
+ */
+
+static inline fix3_28_t bqf_transform(fix3_28_t x, bqf_coeff_t *coefficients, bqf_mem_t *memory) {
+    fix3_28_t y = fix16_mul(coefficients->b0, x) -
+            fix16_mul(coefficients->a1, memory->y_1) +
+            fix16_mul(coefficients->b1, memory->x_1) -
+            fix16_mul(coefficients->a2, memory->y_2) +
+            fix16_mul(coefficients->b2, memory->x_2);
+
+    memory->x_2 = memory->x_1;
+    memory->x_1 = x;
+    memory->y_2 = memory->y_1;
+    memory->y_1 = y;
+
+    return y;
+}

firmware/code/configuration_manager.c

@@ -74,7 +74,7 @@ const uint8_t *user_configuration = (const uint8_t *) (XIP_BASE + USER_CONFIGURA
  * should handle merging configurations where, for example, only a new
  * filter_configuration_tlv was received.
  */
-#define CFG_BUFFER_SIZE 256
+#define CFG_BUFFER_SIZE 512
 static uint8_t working_configuration[2][CFG_BUFFER_SIZE];
 static uint8_t inactive_working_configuration = 0;
 static uint8_t result_buffer[CFG_BUFFER_SIZE] = { U16_TO_U8S_LE(NOK), U16_TO_U8S_LE(0) };

firmware/code/run.c

@@ -133,9 +133,10 @@ static void __no_inline_not_in_flash_func(_as_audio_packet)(struct usb_endpoint
         }
     }
     else {
-        for (int i = 0; i < samples; i++)
+        for (int i = 0; i < samples; i++) {
             out[i] = fix16_mul(norm_fix3_28_from_s16sample(in[i]), preprocessing.preamp);
         }
+    }
 
     multicore_fifo_push_blocking(samples);