WAV encoding

Author: pschatzmann

.vscode/settings.json

@@ -0,0 +1,18 @@
+{
+    "files.associations": {
+        "ostream": "cpp",
+        "cullsettings": "cpp",
+        "types": "cpp",
+        "*.tcc": "cpp",
+        "functional": "cpp",
+        "string_view": "cpp",
+        "quat": "cpp",
+        "vec2d": "cpp",
+        "vec2f": "cpp",
+        "vec3d": "cpp",
+        "vec3f": "cpp",
+        "vec4d": "cpp",
+        "vec4f": "cpp",
+        "tuple": "cpp"
+    }
+}

README.md

@@ -90,6 +90,8 @@ Here are a couple of simple test sketches to demo different output destinations:
 - [streams-generator-dac](/examples/streams-generator-dac) Output of generated sound on ESP32 internal DAC via I2S
 - [streams-generator-a2dp](/examples/streams-generator-a2dp) Output of generated sound on Bluetooth Speaker using A2DP
 - [streams-adc-serial](/examples/streams-adc-serial) Displaying input from analog microphone on the Serial Plotter
+- [streams-memory_wav-serial](/examples/streams-memory_wav-serial) Decoding of WAV from Flash memory and display on the Serial Plotter
+- [streams-generator-webserver_wav](/examples/streams-generator-webserver_wav) Encoding of WAV from generated sound returned via Webserver
 
 And some more useful examples:
 
@@ -149,7 +151,7 @@ This is currently work in progress:
 | I2S                    | tested  |
 | Files (RAW, MP3...)    | tested  |
 | Streams                | tested  |
-| WAV encoding/deconding | open    |          
+| WAV encoding/deconding | tested    |          
 | AAC encoding/deconding | open    |          
 | int24_t                | tested  |           
 

examples/streams-generator-webserver_wav/README.md

@@ -0,0 +1,4 @@
+# Webserver
+
+With the help of the ESP32 WIFI functionality we can implement a simple web server. 
+In the example we use a Sine Wave generator as sound source and return the result as an WAV file

examples/streams-generator-webserver_wav/streams-generator-server_wav.ino

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+#include <WiFi.h>
+#include "AudioTools.h"
+
+using namespace audio_tools;
+
+const char *ssid = "ssid";
+const char *password = "password";
+WiFiServer server(80);
+WiFiClient client;
+
+const int sample_rate = 10000;
+const int data_length = 100000;
+const int channels = 1;
+
+SineWaveGenerator<int16_t> sineWave;                      // subclass of SoundGenerator with max amplitude of 32000
+GeneratedSoundStream<int16_t> in(sineWave, channels);     // Stream generated from sine wave
+StreamCopy copier;                                        // buffered copy
+WAVEncoder encoder;
+AudioOutputStream wav_stream(encoder); // WAV output stream
+
+void setup()
+{
+  Serial.begin(115200);
+  AudioLogger::instance().begin(Serial,AudioLogger::Debug);
+
+  WiFi.begin(ssid, password);
+  while (WiFi.status() != WL_CONNECTED)
+  {
+    delay(500);
+    Serial.print(".");
+  }
+
+  Serial.println("");
+  Serial.println("WiFi connected.");
+  Serial.println("IP address: ");
+  Serial.println(WiFi.localIP());
+
+  server.begin();
+  sineWave.begin(sample_rate, B4);
+
+  in.begin();
+}
+
+
+void processClient() {
+  if (client)  { // if you get a client,
+    Serial.println("New Client."); // print a message out the serial port
+    String currentLine = "";       // make a String to hold incoming data from the client
+    while (client.connected()) { // loop while the client's connected
+      if (client.available()) { // if there's bytes to read from the client,
+        char c = client.read(); // read a byte, then
+        Serial.write(c);        // print it out the serial monitor
+        if (c == '\n') { // if the byte is a newline character
+
+          // if the current line is blank, you got two newline characters in a row.
+          // that's the end of the client HTTP request, so send a response:
+          if (currentLine.length() == 0){
+            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
+            // and a content-type so the client knows what's coming, then a blank line:
+            client.println("HTTP/1.1 200 OK");
+            client.println("Content-type:audio/wav");
+            client.println();
+
+            // set up wav encoder
+            auto config = encoder.defaultConfig();
+            config.channels = channels;
+            config.sample_rate = sample_rate;
+            //config.data_length = data_length;
+            config.is_streamed = true;
+            encoder.begin(client, config);
+
+            Serial.println("Returning WAV stream...");
+            copier.begin(wav_stream, in);
+            // break out of the while loop:
+            break;
+          } else { // if you got a newline, then clear currentLine:
+            currentLine = "";
+          }
+        }
+        else if (c != '\r')
+        { // if you got anything else but a carriage return character,
+          currentLine += c; // add it to the end of the currentLine
+        }
+      }
+    }
+  }  
+}
+
+void loop() {
+  if (!client.connected()) {
+    client = server.available(); // listen for incoming clients
+    processClient();
+  } else {
+    // We are connected: copy input from source to wav output
+    if (encoder){
+      copier.copy();
+      if (!encoder) {
+        Serial.println("stop client...");
+        client.stop();
+      }
+    }
+  }
+}

examples/streams-memory_wav-serial/README.md

@@ -0,0 +1,5 @@
+#Decoding a WAV file
+
+In this example we decode a WAV file into RAW output and send it to the Serial output. The audio chain is:
+
+MemoryStream -> AudioOutputStream -> WAVDecoder -> CsvStream