audiocore – Support for audio samples¶
Available on these boards
- class audiocore.RawSample(buffer: circuitpython_typing.ReadableBuffer, *, channel_count: int = 1, sample_rate: int = 8000)¶
A raw audio sample buffer in memory
Create a RawSample based on the given buffer of signed values. If channel_count is more than 1 then each channel’s samples should alternate. In other words, for a two channel buffer, the first sample will be for channel 1, the second sample will be for channel two, the third for channel 1 and so on.
- Parameters
Simple 8ksps 440 Hz sin wave:
import audiocore import audioio import board import array import time import math # Generate one period of sine wav. length = 8000 // 440 sine_wave = array.array("h", [0] * length) for i in range(length): sine_wave[i] = int(math.sin(math.pi * 2 * i / length) * (2 ** 15)) dac = audioio.AudioOut(board.SPEAKER) sine_wave = audiocore.RawSample(sine_wave) dac.play(sine_wave, loop=True) time.sleep(1) dac.stop()
- sample_rate :Optional[int]¶
32 bit value that dictates how quickly samples are played in Hertz (cycles per second). When the sample is looped, this can change the pitch output without changing the underlying sample. This will not change the sample rate of any active playback. Call
playagain to change it.
- __exit__() None¶
Automatically deinitializes the hardware when exiting a context. See Lifetime and ContextManagers for more info.
- class audiocore.WaveFile(file: BinaryIO, buffer: circuitpython_typing.WriteableBuffer)¶
Load a wave file for audio playback
A .wav file prepped for audio playback. Only mono and stereo files are supported. Samples must be 8 bit unsigned or 16 bit signed. If a buffer is provided, it will be used instead of allocating an internal buffer, which can prevent memory fragmentation.
Load a .wav file for playback with
audioio.AudioOutoraudiobusio.I2SOut.- Parameters
file (BinaryIO) – Already opened wave file
buffer (WriteableBuffer) – Optional pre-allocated buffer, that will be split in half and used for double-buffering of the data. The buffer must be 8 to 1024 bytes long. If not provided, two 256 byte buffers are initially allocated internally.
Playing a wave file from flash:
import board import audiocore import audioio import digitalio # Required for CircuitPlayground Express speaker_enable = digitalio.DigitalInOut(board.SPEAKER_ENABLE) speaker_enable.switch_to_output(value=True) data = open("cplay-5.1-16bit-16khz.wav", "rb") wav = audiocore.WaveFile(data) a = audioio.AudioOut(board.A0) print("playing") a.play(wav) while a.playing: pass print("stopped")
- sample_rate :int¶
32 bit value that dictates how quickly samples are loaded into the DAC in Hertz (cycles per second). When the sample is looped, this can change the pitch output without changing the underlying sample.
- bits_per_sample :int¶
Bits per sample. (read only)
- channel_count :int¶
Number of audio channels. (read only)
- __exit__() None¶
Automatically deinitializes the hardware when exiting a context. See Lifetime and ContextManagers for more info.