DRAFT Support for filters

Author: pschatzmann

README.md

@@ -54,8 +54,6 @@ Here is an simple example which streams a file from the Flash Memory and writes
 #include "AudioTools.h"
 #include "StarWars30.h"
 
-using namespace audio_tools;  
-
 uint8_t channels = 2;
 uint16_t sample_rate = 22050;
 

examples/examples-audiokit/streams-audiokit-filter-audiokit/streams-audiokit-filter-audiokit.ino

@@ -0,0 +1,48 @@
+/**
+ * @file streams-kit-filter-kit.ino
+ * @brief Copy audio from I2S to I2S using an FIR filter
+ * @author Phil Schatzmann
+ * @copyright GPLv3
+ * #TODO testing is outstanding
+ */
+
+#include "AudioTools.h"
+#include "AudioLibs/AudioKit.h"
+ 
+uint16_t sample_rate=44100;
+uint16_t channels = 2;
+AudioKitStream kit;
+
+// copy filtered values
+FilteredStream<int16_t, float> inFiltered(kit, channels);  // Defiles the filter as BaseConverter
+StreamCopy copier(kit, inFiltered);               // copies sound into i2s
+
+// define FIR filter
+float coef[] = { 0.021, 0.096, 0.146, 0.096, 0.021};
+
+// Arduino Setup
+void setup(void) {  
+  // Open Serial 
+  Serial.begin(115200);
+  // change to Warning to improve the quality
+  AudioLogger::instance().begin(Serial, AudioLogger::Info); 
+
+  // setup filters for all available channels
+  inFiltered.setFilter(0, new FIR<float>(coef));
+  inFiltered.setFilter(1, new FIR<float>(coef));
+
+  // start I2S in
+  Serial.println("starting KIT...");
+  auto config = kit.defaultConfig(RX_TX_MODE);
+  config.sample_rate = sample_rate; 
+  config.sd_active = false;
+  config.input_device = AUDIO_HAL_ADC_INPUT_LINE2;
+  kit.begin(config);
+
+  Serial.println("KIT started...");
+}
+
+// Arduino loop - copy sound to out 
+void loop() {
+  copier.copy();
+}

examples/examples-basic-api/base-adc-a2dp/base-adc-a2dp.ino

@@ -5,7 +5,8 @@
  * 
  * @author Phil Schatzmann
  * @copyright GPLv3
- * 
+* #TODO retest is outstanding
+* 
  */
 // Add this in your sketch or change the setting in AudioConfig.h
 #define USE_A2DP
@@ -24,11 +25,13 @@ BluetoothA2DPSource a2dp_source;
 ConverterScaler<int16_t> scaler(1.0, -26427, 32700 );
 
 // callback used by A2DP to provide the sound data
-int32_t get_sound_data(Frame* data, int32_t len) {
-    arrayOf2int16_t *data_arrays = (arrayOf2int16_t *) data;
+int32_t get_sound_data(Frame* frames, int32_t count) {
+    uint8_t *data = (uint8_t*)frames;
+    int channels = 2;
+    size_t len = count * channels * sizeof(int16_t);
    // the ADC provides data in 16 bits
-    size_t result_len = adc.read(data_arrays, len);   
-    scaler.convert(data_arrays, result_len);
+    size_t result_len = adc.readBytes(data, len);   
+    scaler.convert(data, result_len);
     return result_len;
 }
 

examples/examples-basic-api/base-adc-serial/base-adc-serial.ino

@@ -5,6 +5,7 @@
  * 
  * @author Phil Schatzmann
  * @copyright GPLv3
+ * #TODO retest is outstanding
  */
 
 // Add this in your sketch or change the setting in AudioConfig.h
@@ -19,8 +20,8 @@
  */ 
 
 AnalogAudio adc;
-const int32_t max_buffer_len = 512;
-int16_t buffer[max_buffer_len][2];
+const int32_t max_buffer_len = 1024;
+uint8_t buffer[max_buffer_len];
 // The data has a center of around 26427, so we we need to shift it down to bring the center to 0
 ConverterScaler<int16_t> scaler(1.0, -26427, 32700 );
 
@@ -36,13 +37,15 @@ void setup(void) {
 
 // Arduino loop - repeated processing 
 void loop() {
-  size_t len = adc.read(buffer, max_buffer_len); 
+  size_t len = adc.readBytes(buffer, max_buffer_len); 
   // move center to 0 and scale the values
   scaler.convert(buffer, len);
 
-  for (int j=0;j<len;j++){
-    Serial.print(buffer[j][0]);
+  int16_t *sample = (int16_t*) buffer; 
+  int size = len / 4;
+  for (int j=0; j<size; j++){
+    Serial.print(*sample++);
     Serial.print(", ");
-    Serial.println(buffer[j][1]);
+    Serial.println(*sample++);
   }
 }

examples/examples-basic-api/base-i2s-a2dp/base-i2s-a2dp.ino

@@ -2,10 +2,9 @@
  * @file base-i2s-a2dp.ino
  * @author Phil Schatzmann
  * @brief see https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/base-i2s-a2dp/README.md
- * 
- * @author Phil Schatzmann
- * @copyright GPLv3
- */
+  * @copyright GPLv3
+  * #TODO retest is outstanding
+*/
 
 // Add this in your sketch or change the setting in AudioConfig.h
 #define USE_A2DP
@@ -29,19 +28,15 @@ int32_t buffer[max_buffer_len][2];
 
 // callback used by A2DP to provide the sound data
 int32_t get_sound_data(Frame* data, int32_t len) {
-   size_t req_len = min(max_buffer_len,(size_t) len);
-
-   // the microphone provides data in int32_t -> we read it into the buffer of int32_t data
-   size_t result_len = i2s.read(buffer, req_len);
-
+   uint8_t* data8 = (uint8_t*)data;
+   int bytes = len * 4;
+   size_t result_len = i2s.readBytes(data8, bytes);
    // we have data only in 1 channel but we want to fill both
-   bothChannels.convert(buffer, result_len);
-   
-   // convert buffer to int16 for A2DP
-   converter.convert(buffer, data, result_len);
-   return result_len;
+   bothChannels.convert(data8, bytes);
+   return result_len / 4;
 }
 
+
 // Arduino Setup
 void setup(void) {
   Serial.begin(115200);

examples/examples-stream/streams-adc-serial/streams-adc-serial.ino

@@ -4,17 +4,18 @@
  * @brief see https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/examples-stream/streams-adc-serial/README.md 
  * @author Phil Schatzmann
  * @copyright GPLv3
+ * #TODO retest is outstanding
  */
 
 #include "AudioTools.h"
 
 
 
 uint8_t channels = 2;
-AnalogAudioStream microphone;                 // analog microphone
-CsvStream<int16_t> printer(Serial, channels); // ASCII output stream 
-StreamCopy copier(printer, microphone);       // copies microphone into printer
-ConverterAutoCenter<int16_t> center;          // make sure the avg of the signal is 0
+AnalogAudioStream microphone;                  // analog microphone
+CsvStream<int16_t> printer(Serial, channels);  // ASCII output stream 
+StreamCopy copier(printer, microphone);        // copies microphone into printer
+ConverterAutoCenter<int16_t> center(channels); // make sure the avg of the signal is 0
 
 // Arduino Setup
 void setup(void) {  

examples/examples-stream/streams-analog-serial/streams-analog-serial.ino

@@ -2,23 +2,19 @@
  * @file streams-analog-serial.ino
  * @author Phil Schatzmann
  * @brief see https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/examples-stream/streams-analog-serial/README.md
- * 
- * @author Phil Schatzmann
  * @copyright GPLv3
+ * #TODO retest is outstanding
  */
 
-
 #include "Arduino.h"
 #include "AudioTools.h"
 
-
-
 const uint16_t sample_rate = 44100;
 const uint8_t channels = 2;
 AnalogAudioStream in; 
 CsvStream<int16_t> out(Serial, channels); // ASCII output stream 
 StreamCopy copier(out, in); // copy i2sStream to CsvStream
-ConverterAutoCenter<int16_t> center; // set avg to 0
+ConverterAutoCenter<int16_t> center(channels); // set avg to 0
 
 // Arduino Setup
 void setup(void) {

examples/examples-stream/streams-i2s-filter-i2s/streams-i2s-filter-i2s.ino

@@ -0,0 +1,69 @@
+/**
+ * @file streams-i2s-filter-i2s.ino
+ * @brief Copy audio from I2S to I2S using an FIR filter
+ * @author Phil Schatzmann
+ * @copyright GPLv3
+ */
+
+#include "AudioTools.h"
+ 
+uint16_t sample_rate=44100;
+uint16_t channels = 2;
+I2SStream in;
+I2SStream out; 
+
+// copy filtered values
+ConverterNChannels<int16_t> converter(channels);  // Defiles the filter as BaseConverter
+FilteredStream<int16_t, float> inFiltered(in);    // 
+StreamCopy copier(out, inFiltered);               // copies sound into i2s
+
+// define FIR filter parameters
+float coef[] = { 0.021, 0.096, 0.146, 0.096, 0.021};
+
+
+// Arduino Setup
+void setup(void) {  
+  // Open Serial 
+  Serial.begin(115200);
+  // change to Warning to improve the quality
+  AudioLogger::instance().begin(Serial, AudioLogger::Info); 
+
+  // setup filters for all available channels
+  inFiltered.setFilter(0, new FIR<float>(coef));
+  inFiltered.setFilter(1, new FIR<float>(coef));
+
+  // start I2S in
+  Serial.println("starting I2S...");
+  auto config_in = in.defaultConfig(RX_MODE);
+  config_in.sample_rate = sample_rate; 
+  config_in.bits_per_sample = 16;
+  config_in.i2s_format = I2S_STD_FORMAT;
+  config_in.is_master = true;
+  config_in.port_no = 0;
+  config_in.pin_ws = 14;
+  config_in.pin_bck = 15;
+  config_in.pin_data = 16;
+  // config_in.fixed_mclk = sample_rate * 256
+  // config_in.pin_mck = 2
+
+  in.begin(config_in);
+
+  // start I2S out
+  auto config_out = out.defaultConfig(TX_MODE);
+  config_out.sample_rate = sample_rate; 
+  config_out.bits_per_sample = 16;
+  config_out.i2s_format = I2S_STD_FORMAT;
+  config_out.is_master = true;
+  config_out.port_no = 1;
+  config_out.pin_ws = 17;
+  config_out.pin_bck = 18;
+  config_out.pin_data = 19;
+  out.begin(config_out);
+
+  Serial.println("I2S started...");
+}
+
+// Arduino loop - copy sound to out 
+void loop() {
+  copier.copy();
+}

examples/examples-stream/streams-i2s-i2s/streams-i2s-i2s.ino

@@ -1,16 +1,18 @@
 /**
- * @file streams-i2s-i2s.ino
- * @brief Copy audio from I2S to I2S
+ * @file streams-i2s-filter-i2s.ino
+ * @brief Copy audio from I2S to I2S using an FIR filter
  * @author Phil Schatzmann
  * @copyright GPLv3
  */
+
+#include "AudioTools.h"
 
-uint16_t sample_rate=96000;
+uint16_t sample_rate=44100;
 uint16_t channels = 2;
 I2SStream in;
 I2SStream out; 
-StreamCopy copier(out, in);                             // copies sound into i2s
-ConverterScaler<int16_t> scaler(0.8, 0, 1000);
+StreamCopy copier(out, in); // copies sound into i2s
+
 
 // Arduino Setup
 void setup(void) {  
@@ -25,13 +27,13 @@ void setup(void) {
   config_in.sample_rate = sample_rate; 
   config_in.bits_per_sample = 16;
   config_in.i2s_format = I2S_STD_FORMAT;
+  config_in.is_master = true;
   config_in.port_no = 0;
-  config_in.pin_ws = 12;
-  config_in.pin_bck = 13;
-  config_in.pin_data = 14;
-  config_in.is_master = false;
-  //config.pin_mck = 2; // wenn ESP master
-  //config.fixed_mclk = ? //wenn ESP master 
+  config_in.pin_ws = 14;
+  config_in.pin_bck = 15;
+  config_in.pin_data = 16;
+  // config_in.fixed_mclk = sample_rate * 256
+  // config_in.pin_mck = 2
   in.begin(config_in);
 
   // start I2S out
@@ -41,15 +43,15 @@ void setup(void) {
   config_out.i2s_format = I2S_STD_FORMAT;
   config_out.is_master = true;
   config_out.port_no = 1;
-  config_out.pin_ws = 32;
-  config_out.pin_bck = 35;
-  config_out.pin_data = 34;
+  config_out.pin_ws = 17;
+  config_out.pin_bck = 18;
+  config_out.pin_data = 19;
   out.begin(config_out);
 
   Serial.println("I2S started...");
 }
 
 // Arduino loop - copy sound to out 
 void loop() {
-  copier.copy(scaler);
+  copier.copy();
 }

examples/sandbox/streams-adc-a2dp/streams-adc-a2dp.ino

@@ -3,9 +3,8 @@
  * @author Phil Schatzmann
  * @brief We use a mcp6022 analog microphone as input and send the data to A2DP
  * see https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/examples-stream/streams-adc-a2dp/README.md
- * 
- * @author Phil Schatzmann
  * @copyright GPLv3
+ * #TODO retest is outstanding
  * 
  */
 // Add this in your sketch or change the setting in AudioConfig.h
@@ -18,7 +17,7 @@
 AnalogAudioStream in; // analog mic
 A2DPStream out = A2DPStream::instance() ; // A2DP output - A2DPStream is a singleton!
 StreamCopy copier(out, in); // copy in to out
-ConverterAutoCenter<int16_t> center; // The data has a center of around 26427, so we we need to shift it down to bring the center to 0
+ConverterAutoCenter<int16_t> center(2); // The data has a center of around 26427, so we we need to shift it down to bring the center to 0
 
 // Arduino Setup
 void setup(void) {