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  1. /* Audio Library for Teensy 3.X
  2. * Copyright (c) 2014, Jonathan Payne (jon@jonnypayne.com)
  3. * Based on Effect_Fade by Paul Stoffregen
  4. * Development of this audio library was funded by PJRC.COM, LLC by sales of
  5. * Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
  6. * open source software by purchasing Teensy or other PJRC products.
  7. *
  8. * Permission is hereby granted, free of charge, to any person obtaining a copy
  9. * of this software and associated documentation files (the "Software"), to deal
  10. * in the Software without restriction, including without limitation the rights
  11. * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12. * copies of the Software, and to permit persons to whom the Software is
  13. * furnished to do so, subject to the following conditions:
  14. *
  15. * The above copyright notice, development funding notice, and this permission
  16. * notice shall be included in all copies or substantial portions of the Software.
  17. *
  18. * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19. * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20. * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21. * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22. * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23. * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24. * THE SOFTWARE.
  25. */
  26. #ifndef effect_bitcrusher_h_
  27. #define effect_bitcrusher_h_
  28. #include "Arduino.h"
  29. #include "AudioStream.h"
  30. class AudioEffectBitcrusher : public AudioStream
  31. {
  32. public:
  33. AudioEffectBitcrusher(void)
  34. : AudioStream(1, inputQueueArray) {}
  35. void bits(uint8_t b) {
  36. if (b > 16) b = 16;
  37. else if (b == 0) b = 1;
  38. crushBits = b;
  39. }
  40. void sampleRate(float hz) {
  41. int n = (AUDIO_SAMPLE_RATE_EXACT / hz) + 0.5;
  42. if (n < 1) n = 1;
  43. else if (n > 64) n = 64;
  44. sampleStep = n;
  45. }
  46. virtual void update(void);
  47. private:
  48. uint8_t crushBits; // 16 = off
  49. uint8_t sampleStep; // the number of samples to double up. This simple technique only allows a few stepped positions.
  50. audio_block_t *inputQueueArray[1];
  51. };
  52. #endif