08.Samples/SampleHuffman_Umpah/SampleHuffman_Umpah.ino

This example demonstrates the Sample class.

/*
 Example playing samples encoded with Huffman compression.
 
 Demonstrates the SampleHuffman class.
 SampleHuffman, most of this explanation, and the audio2huff.py script are adapted from "audioout",
 an Arduino sketch by Thomas Grill, 2011 http//grrrr.org.
 
 Huffman decoding is used on sample differentials,
 saving 50-70% of space for 8 bit data, depending on the sample rate.
 
 This implementation just plays back one sample each time next() is called, with no
 speed or other adjustments.  It's slow, so it's likely you will only be able to play one sound at a time.
 
 Audio data, Huffman decoder table, sample rate and bit depth are defined
 in a sounddata.h header file.  This file can be generated for a sound file with the
 accompanying Python script audio2huff.py, in Mozzi/extras/python/
 
 Invoke with:
 python audio2huff.py --sndfile=arduinosnd.wav --hdrfile=sounddata.h --bits=8 --name=soundtablename
 
 You can resample and dither your audio file with SOX,
 e.g. to 8 bits depth @ Mozzi's 16384 Hz  sample rate:
 sox fullglory.wav -b 8 -r 16384 arduinosnd.wav
 
 Alternatively you can export a sound from Audacity, which seems to have less noticeable or no dithering,
 using Project Rate 16384 Hz and these output options:
 Other uncompressed files, Header: WAV(Microsoft), Encoding: Unsigned 8 bit PCM
 
 The header file contains two lengthy arrays:
 One is "SOUNDDATA" which must fit into Flash RAM (available in total: 32k for ATMega328)
 The other is "HUFFMAN" which must also fit into Flash RAM
 
 Circuit:
  Audio output on digital pin 9 on a Uno or similar, or
  DAC/A14 on Teensy 3.1, or
  check the README or http://sensorium.github.io/Mozzi/
 
   Mozzi documentation/API
   https://sensorium.github.io/Mozzi/doc/html/index.html
 
   Mozzi help/discussion/announcements:
   https://groups.google.com/forum/#!forum/mozzi-users
 
   Copyright 2013-2024 Tim Barrass and the Mozzi Team
 
   Mozzi is licensed under the GNU Lesser General Public Licence (LGPL) Version 2.1 or later.
*/
 
#include <Mozzi.h>
#include <SampleHuffman.h>
#include "umpah_huff.h"
 
SampleHuffman umpah(UMPAH_SOUNDDATA,UMPAH_HUFFMAN,UMPAH_SOUNDDATA_BITS);
 
void setup() {
  umpah.setLoopingOn();
  startMozzi();
}
 
 
void updateControl(){
}
 
 
AudioOutput updateAudio(){
  return MonoOutput::from8Bit(umpah.next());
}
 
 
void loop() {
  audioHook();
}