equalizer - release

components/squeezelite/equalizer.c

@@ -0,0 +1,89 @@
+/* 
+ *  Squeezelite for esp32
+ *
+ *  (c) Philippe G. 2020, philippe_44@outlook.com
+ *
+ * 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/>.
+ *
+ */
+ 
+#include "squeezelite.h" 
+#include "equalizer.h"
+#include "esp_equalizer.h"
+ 
+#define EQ_BANDS	10
+
+static log_level loglevel = lINFO;
+ 
+static struct {
+	void *handle;
+	float gain[EQ_BANDS];
+	bool update;
+} equalizer = { .update = true };
+ 
+/****************************************************************************************
+ * open equalizer
+ */
+void equalizer_open(u32_t sample_rate) {
+	if (sample_rate != 11025 && sample_rate != 22050 && sample_rate != 44100 && sample_rate != 48000) {
+		LOG_WARN("equalizer only supports 11025, 22050, 44100 and 48000 sample rates, not %u", sample_rate);
+		return;
+	}	
+	
+	equalizer.handle = esp_equalizer_init(2, sample_rate, EQ_BANDS, 0);
+	equalizer.update = false;
+    
+	if (equalizer.handle) {
+		LOG_INFO("equalizer initialized");
+		for (int i = 0; i < EQ_BANDS; i++) {
+			esp_equalizer_set_band_value(equalizer.handle, equalizer.gain[i], i, 0);
+			esp_equalizer_set_band_value(equalizer.handle, equalizer.gain[i], i, 1);
+		}
+	} else {
+		LOG_WARN("can't init equalizer");
+	}	
+}	
+
+/****************************************************************************************
+ * close equalizer
+ */
+void equalizer_close(void) {
+	if (equalizer.handle) {
+		esp_equalizer_uninit(equalizer.handle);
+		equalizer.handle = NULL;
+	}
+}	
+
+/****************************************************************************************
+ * update equalizer gain
+ */
+void equalizer_update(s8_t *gain) {
+	for (int i = 0; i < EQ_BANDS; i++) equalizer.gain[i] = gain[i];
+	equalizer.update = true;
+}
+
+/****************************************************************************************
+ * process equalizer 
+ */
+void equalizer_process(u8_t *buf, u32_t bytes, u32_t sample_rate) {
+	// don't want to process with output locked, so tak ethe small risk to miss one parametric update
+	if (equalizer.update) {
+		equalizer_close();
+		equalizer_open(sample_rate);
+	}
+	
+	if (equalizer.handle) {
+		esp_equalizer_process(equalizer.handle, buf, bytes, sample_rate, 2);
+	}	
+}