MP3 examples

Author: pschatzmann

examples/examples-stream/streams-memory_mp3-analog/streams-memory_mp3-analog.ino

@@ -19,32 +19,32 @@
 
 
 MemoryStream mp3(BabyElephantWalk60_mp3, BabyElephantWalk60_mp3_len);
-AnalogAudioStream out;  // Analog output 
-EncodedAudioStream decoded(&out, new MP3DecoderHelix()); // output to decoder
-StreamCopy copier(decoded, mp3);    // copy in to out
+AnalogAudioStream analog;  // Analog output 
+EncodedAudioStream out(&analog, new MP3DecoderHelix()); // output to decoder
+StreamCopy copier(out, mp3);    // copy in to analog
 
 void setup(){
   Serial.begin(115200);
   AudioLogger::instance().begin(Serial, AudioLogger::Info);  
 
   // update audio info with info from decoder
-  decoded.setNotifyAudioChange(out);
+  out.setNotifyAudioChange(analog);
 
   // begin processing
-  auto cfg = out.defaultConfig();
-  out.begin(cfg);
+  auto cfg = analog.defaultConfig();
+  analog.begin(cfg);
 
-  decoded.begin();
+  out.begin();
 }
 
 void loop(){
   if (mp3) {
     copier.copy();
   } else {
-    auto info = decoded.decoder().audioInfo();
+    auto info = out.decoder().audioInfo();
     LOGI("The audio rate from the mp3 file is %d", info.sample_rate);
     LOGI("The channels from the mp3 file is %d", info.channels);
-    out.end();
+    analog.end();
     stop();
   }
 }

examples/examples-stream/streams-memory_mp3-pwm/streams-memory_mp3-pwm.ino

@@ -17,7 +17,6 @@
 #include "BabyElephantWalk60_mp3.h"
 
 
-
 MemoryStream mp3(BabyElephantWalk60_mp3, BabyElephantWalk60_mp3_len);
 PWMAudioStream out;  // PWM output 
 EncodedAudioStream decoded(&out, new MP3DecoderHelix()); // output to decoder

examples/examples-stream/streams-memory_mp3_short-i2s-2/README.md

@@ -0,0 +1,28 @@
+# Decoding a MP3 file
+
+In this example we decode a very short MP3 file using lebhelix
+
+### External DAC:
+
+![DAC](https://pschatzmann.github.io/arduino-audio-tools/resources/dac.jpeg)
+
+For my tests I am using the 24-bit PCM5102 PCM5102A Stereo DAC Digital-to-analog Converter PLL Voice Module pHAT
+
+I am just using the default pins defined by the framework. However I could change them with the help of the config object. The mute pin can be defined in the constructor of the I2SStream - by not defining anything we use the default which is GPIO23
+
+ 
+DAC  |	ESP32
+-----|----------------
+VCC  |	5V
+GND  |	GND
+BCK  |	BCK (GPIO14)
+DIN  |	OUT (GPIO22)
+LCK  |	BCK (GPIO15)
+FMT  |	GND
+XMT  |	3V (or another GPIO PIN which is set to high)
+
+- DMP - De-emphasis control for 44.1kHz sampling rate(1): Off (Low) / On (High)
+- FLT - Filter select : Normal latency (Low) / Low latency (High)
+- SCL - System clock input (probably SCL on your board).
+- FMT - Audio format selection : I2S (Low) / Left justified (High)
+- XMT - Soft mute control(1): Soft mute (Low) / soft un-mute (High)

examples/examples-stream/streams-memory_mp3_short-i2s-2/streams-memory_mp3_short-i2s-2.ino

@@ -0,0 +1,47 @@
+/**
+ * @file streams-memory_mp3_short-i2s-2.ino
+ * @author Phil Schatzmann
+ * @brief decode MP3 stream and output as i2s signal
+ * @version 0.1
+ * @date 2021-01-24
+ * 
+ * @copyright Copyright (c) 2021
+ 
+ */
+
+#include "AudioTools.h"
+#include "AudioCodecs/CodecMP3Helix.h"
+#include "zero.h"
+
+
+MemoryStream mp3(zero_mp3, zero_mp3_len);
+I2SStream i2s;  // PWM output 
+MP3DecoderHelix helix;
+EncodedAudioStream out(&i2s, &helix); // output to decoder
+StreamCopy copier(out, mp3);    // copy in to out
+
+void setup(){
+  Serial.begin(115200);
+  AudioLogger::instance().begin(Serial, AudioLogger::Info);  
+
+  // begin processing
+  auto cfg = i2s.defaultConfig();
+  cfg.sample_rate = 24000;
+  cfg.channels = 1;
+  i2s.begin(cfg);
+  out.begin();
+
+  sayWord();
+
+}
+
+void sayWord() {
+  Serial.println("Saying word...");
+  helix.begin(); // so that we can repeatedly call this method
+  copier.copyAll();
+  helix.end(); // flush output
+}
+
+void loop(){
+}
+

examples/examples-stream/streams-memory_mp3_short-i2s-2/zero.h

@@ -0,0 +1,28 @@
+# Decoding a MP3 file
+
+In this example we decode a very short MP3 file using lebhelix
+
+### External DAC:
+
+![DAC](https://pschatzmann.github.io/arduino-audio-tools/resources/dac.jpeg)
+
+For my tests I am using the 24-bit PCM5102 PCM5102A Stereo DAC Digital-to-analog Converter PLL Voice Module pHAT
+
+I am just using the default pins defined by the framework. However I could change them with the help of the config object. The mute pin can be defined in the constructor of the I2SStream - by not defining anything we use the default which is GPIO23
+
+ 
+DAC  |	ESP32
+-----|----------------
+VCC  |	5V
+GND  |	GND
+BCK  |	BCK (GPIO14)
+DIN  |	OUT (GPIO22)
+LCK  |	BCK (GPIO15)
+FMT  |	GND
+XMT  |	3V (or another GPIO PIN which is set to high)
+
+- DMP - De-emphasis control for 44.1kHz sampling rate(1): Off (Low) / On (High)
+- FLT - Filter select : Normal latency (Low) / Low latency (High)
+- SCL - System clock input (probably SCL on your board).
+- FMT - Audio format selection : I2S (Low) / Left justified (High)
+- XMT - Soft mute control(1): Soft mute (Low) / soft un-mute (High)

examples/examples-stream/streams-memory_mp3_short-i2s/README.md

@@ -0,0 +1,45 @@
+/**
+ * @file streams-memory_mp3_short-i2s.ino
+ * @author Phil Schatzmann
+ * @brief decode MP3 stream and output as i2s signal
+ * @version 0.1
+ * @date 2021-01-24
+ * 
+ * @copyright Copyright (c) 2021
+ 
+ */
+
+#include "AudioTools.h"
+#include "AudioCodecs/CodecMP3Helix.h"
+#include "zero.h"
+
+MemoryStream mp3(zero_mp3, zero_mp3_len);
+I2SStream i2s;  
+MP3DecoderHelix helix;
+EncodedAudioStream out(&i2s, &helix); // output to decoder
+StreamCopy copier(out, mp3);    // copy in to i2s
+
+void setup(){
+  Serial.begin(115200);
+  AudioLogger::instance().begin(Serial, AudioLogger::Info);  
+
+  // begin processing
+  auto cfg = i2s.defaultConfig();
+  cfg.sample_rate = 24000;
+  cfg.channels = 1;
+  i2s.begin(cfg);
+  out.begin();
+}
+
+void loop(){
+  if (mp3.available()) {
+    copier.copy();
+  } else {
+    helix.end(); // flush output
+    auto info = out.decoder().audioInfo();
+    LOGI("The audio rate from the mp3 file is %d", info.sample_rate);
+    LOGI("The channels from the mp3 file is %d", info.channels);
+    i2s.end();
+    stop();
+  }
+}