:mod:`audiomp3`
===============

.. py:module:: audiomp3

.. autoapi-nested-parse::

   Support for MP3-compressed audio files



.. raw:: html

    <p>
    <details>
    <summary>Available on these boards</summary>
    <ul>
    <li> ARAMCON Badge 2019
    <li> ARAMCON2 Badge
    <li> Adafruit CLUE nRF52840 Express
    <li> Adafruit Circuit Playground Bluefruit
    <li> Adafruit EdgeBadge
    <li> Adafruit Feather Bluefruit Sense
    <li> Adafruit Feather M4 CAN
    <li> Adafruit Feather M4 Express
    <li> Adafruit Feather RP2040
    <li> Adafruit Feather STM32F405 Express
    <li> Adafruit Feather nRF52840 Express
    <li> Adafruit Grand Central M4 Express
    <li> Adafruit Hallowing M4 Express
    <li> Adafruit ItsyBitsy M4 Express
    <li> Adafruit ItsyBitsy RP2040
    <li> Adafruit ItsyBitsy nRF52840 Express
    <li> Adafruit KB2040
    <li> Adafruit LED Glasses Driver nRF52840
    <li> Adafruit Macropad RP2040
    <li> Adafruit Matrix Portal M4
    <li> Adafruit Metro M4 Airlift Lite
    <li> Adafruit Metro M4 Express
    <li> Adafruit Metro nRF52840 Express
    <li> Adafruit Monster M4SK
    <li> Adafruit PyGamer
    <li> Adafruit PyPortal
    <li> Adafruit PyPortal Pynt
    <li> Adafruit PyPortal Titano
    <li> Adafruit Pybadge
    <li> Adafruit QT Py RP2040
    <li> Adafruit QT2040 Trinkey
    <li> Adafruit Trellis M4 Express
    <li> AloriumTech Evo M51
    <li> Arduino Nano 33 BLE
    <li> Arduino Nano RP2040 Connect
    <li> AtelierDuMaker nRF52840 Breakout
    <li> BDMICRO VINA-D51
    <li> BLE-SS dev board Multi Sensor
    <li> BastBLE
    <li> BlueMicro840
    <li> CP32-M4
    <li> Capable Robot Programmable USB Hub
    <li> Challenger NB RP2040 WiFi
    <li> Challenger RP2040 LTE
    <li> Challenger RP2040 WiFi
    <li> CircuitBrains Deluxe
    <li> Cytron Maker Nano RP2040
    <li> Cytron Maker Pi RP2040
    <li> DynOSSAT-EDU-OBC
    <li> Electronut Labs Blip
    <li> Electronut Labs Papyr
    <li> EncoderPad RP2040
    <li> HiiBot BlueFi
    <li> IkigaiSense Vita nRF52840
    <li> MDBT50Q-DB-40
    <li> MDBT50Q-RX Dongle
    <li> MEOWBIT
    <li> MakerDiary nRF52840 MDK
    <li> MakerDiary nRF52840 MDK USB Dongle
    <li> Makerdiary M60 Keyboard
    <li> Makerdiary Pitaya Go
    <li> Makerdiary nRF52840 M.2 Developer Kit
    <li> Melopero Shake RP2040
    <li> Mini SAM M4
    <li> Oak Dev Tech BREAD2040
    <li> Open Hardware Summit 2020 Badge
    <li> PCA10056 nRF52840-DK
    <li> PCA10059 nRF52840 Dongle
    <li> Particle Argon
    <li> Particle Boron
    <li> Particle Xenon
    <li> Pimoroni Interstate 75
    <li> Pimoroni Keybow 2040
    <li> Pimoroni PGA2040
    <li> Pimoroni Pico LiPo (16MB)
    <li> Pimoroni Pico LiPo (4MB)
    <li> Pimoroni PicoSystem
    <li> Pimoroni Plasma 2040
    <li> Pimoroni Tiny 2040
    <li> PyCubedv04
    <li> PyCubedv04-MRAM
    <li> PyCubedv05
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    <li> PyKey60
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    <li> RP2040 Stamp
    <li> Raspberry Pi Pico
    <li> Robo HAT MM1 M4
    <li> SAM E54 Xplained Pro
    <li> SAM32v26
    <li> STM32F412G_DISCO
    <li> STM32F4_DISCO
    <li> Seeeduino Wio Terminal
    <li> Silicognition LLC M4-Shim
    <li> SparkFun MicroMod RP2040 Processor
    <li> SparkFun MicroMod SAMD51 Processor
    <li> SparkFun MicroMod nRF52840 Processor
    <li> SparkFun Pro Micro RP2040
    <li> SparkFun Pro nRF52840 Mini
    <li> SparkFun STM32 MicroMod Processor
    <li> SparkFun Thing Plus - RP2040
    <li> SparkFun Thing Plus - SAMD51
    <li> Swan R5
    <li> TG-Boards' Datalore IP M4
    <li> TG-Watch
    <li> THUNDERPACK_v11
    <li> THUNDERPACK_v12
    <li> Teknikio Bluebird
    <li> The Open Book Feather
    <li> TinkeringTech ScoutMakes Azul
    <li> UARTLogger II
    <li> WarmBit BluePixel nRF52840
    <li> nice!nano
    <li> stm32f411ce-blackpill-with-flash
    </ul>
    </details>
    </p>




.. py:class:: MP3Decoder(file: BinaryIO, buffer: _typing.WriteableBuffer)

   Load a mp3 file for audio playback

   Load a .mp3 file for playback with `audioio.AudioOut` or `audiobusio.I2SOut`.

   :param typing.BinaryIO file: Already opened mp3 file
   :param ~_typing.WriteableBuffer buffer: Optional pre-allocated buffer, that will be split in half and used for double-buffering of the data. If not provided, two buffers are allocated internally.  The specific buffer size required depends on the mp3 file.


   Playing a mp3 file from flash::

     import board
     import audiomp3
     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-16bit-16khz-64kbps.mp3", "rb")
     mp3 = audiomp3.MP3Decoder(data)
     a = audioio.AudioOut(board.A0)

     print("playing")
     a.play(mp3)
     while a.playing:
       pass
     print("stopped")

   .. py:attribute:: file
      :annotation: :BinaryIO

      File to play back.


   .. py:attribute:: sample_rate
      :annotation: :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.


   .. py:attribute:: bits_per_sample
      :annotation: :int

      Bits per sample. (read only)


   .. py:attribute:: channel_count
      :annotation: :int

      Number of audio channels. (read only)


   .. py:attribute:: rms_level
      :annotation: :float

      The RMS audio level of a recently played moment of audio. (read only)


   .. py:method:: deinit() -> None

      Deinitialises the MP3 and releases all memory resources for reuse.


   .. py:method:: __enter__() -> MP3Decoder

      No-op used by Context Managers.


   .. py:method:: __exit__() -> None

      Automatically deinitializes the hardware when exiting a context. See
      :ref:`lifetime-and-contextmanagers` for more info.