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MP3 (.mp3)

Background & Context

    • MIME types: audio/mpeg, audio/mpeg3, audio/x-mpeg-3MP3 digital audio format, known as MPEG Audio Layer 3.
    • A lossy compression scheme commonly used for consumer audio streaming, storage, transfer, and playback, which can also be used on the web.
    • Binary file format.
    • Follows the ISO/IEC 11172-3 and ISO/IEC 13818-3 standard.
    • Supports a few sampling frequencies from 8kHz to 48kHz.
    • Supports up to two audio channels.

Import & Export

  • Import["file.mp3"] imports an MP3 file, returning an audio object.
  • Import["file.mp3",elem] imports the specified element from an MP3 file.
  • The import format can be specified with Import["file","MP3"] or Import["file",{"MP3",elem,…}].
  • Export["file.mp3",expr] exports an audio or sound object to an MP3 file.
  • Sound objects including notes are rasterized to sampled audio.
  • See the following reference pages for full general information:
  • Import, Exportimport from or export to a file
    CloudImport, CloudExportimport from or export to a cloud object
    ImportString, ExportStringimport from or export to a string
    ImportByteArray, ExportByteArrayimport from or export to a byte array

Import Elements

  • General Import elements:
  • "Elements" list of elements and options available in this file
    "Summary"summary of the file
    "Rules"list of rules for all available elements
  • Data representation elements:
  • "Audio"audio signal given as an Audio object
    "AudioFile"audio signal given as an out-of-core Audio object
    "Data"raw audio samples, given as a list of real numbers, each sublist representing an individual audio channel
    "SampledSoundList"audio signal given as a SampledSoundList object
    "Sound"audio signal given as a Sound object
  • Import by default uses the "Audio" element for short MP3 files and the "AudioFile" element otherwise.
  • Advanced Import element:
  • "AudioChannels"number of audio channels
    "Duration"duration of the audio given in seconds
    "Length"number of samples
    "SampleRate"number of amplitude samples per second and channel
  • Metadata elements:
  • "MetaInformation"interpreted metadata as quantities, dates, locations, etc.
    "RawMetaInformation"uninterpreted metadata including strings and numbers only
  • Available metadata tags include ID3v1, ID3v2 and APE.
  • Multiple channels are represented as an array of audio samples.

Options

Examples

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Basic Examples  (2)

Import an MP3 file:

Wolfram Language code: Import["ExampleData/car.mp3"]

Generate an audio signal and export to MP3:

Wolfram Language code: audio = AudioGenerator["Sin"]
Wolfram Language code: Export["sample.mp3", audio]

Scope  (4)

Show all import elements available in this file:

Wolfram Language code: Import["ExampleData/car.mp3", "Elements"]

Import audio properties:

Wolfram Language code: Import["ExampleData/car.mp3", {{"AudioChannels", "SampleRate"}}]

Generate an audio signal and export to MP3:

Wolfram Language code: audio = AudioGenerator["Sin"]
Wolfram Language code: Export["sample.mp3", audio, CompressionLevel -> 1]//FileByteCount
Wolfram Language code: Export["sample.mp3", audio, CompressionLevel -> .5]//FileByteCount

Compare to a size of a WAV file:

Wolfram Language code: Export["sample.wav", audio]//FileByteCount

Use ExportString and ImportString with an MP3:

Wolfram Language code: Play[Sin[300t Sin[20t]], {t, 0, 1}]
Wolfram Language code: str = ExportString[Play[Sin[300t Sin[20t]], {t, 0, 1}], "MP3"];
Wolfram Language code: ImportString[str, "Audio"]

Import Elements  (14)

Available Elements  (3)

List of available elements:

Wolfram Language code: Import["ExampleData/car.mp3", "Elements"]

Get audio-related information as a list of rules:

Wolfram Language code: Import["ExampleData/car.mp3", "Rules"]//Short

Import some audio options:

Wolfram Language code: Import["ExampleData/car.mp3", "Options"]

The "Options" element does not return all options that are present in the imported audio object:

Wolfram Language code: Import["ExampleData/car.mp3"]//Options

Data Representation  (5)

"Audio"  (1)

Get an audio signal given as an Audio object:

Wolfram Language code: Import["ExampleData/car.mp3", "Audio"]

"AudioFile"  (1)

Get an audio signal given as an out-of-core Audio object:

Wolfram Language code: Import["ExampleData/car.mp3", "AudioFile"]

"Data"  (1)

Get raw audio samples, given as a list of real numbers:

Wolfram Language code: data = Import["ExampleData/car.mp3", "Data"]

Create audio from imported data:

Wolfram Language code: Audio[data]

"SampledSoundList"  (1)

Get an audio signal given as a SampledSoundList object:

Wolfram Language code: Import["ExampleData/car.mp3", "SampledSoundList"]

"Sound"  (1)

Get an audio signal given as an Sound object:

Wolfram Language code: Import["ExampleData/car.mp3", "Sound"]

Metadata  (6)

"AudioChannels"  (1)

Get the number of audio channels:

Wolfram Language code: Import["ExampleData/car.mp3", "AudioChannels"]

"Duration"  (1)

Get the duration of the audio given in seconds:

Wolfram Language code: Import["ExampleData/car.mp3", "Duration"]

"Length"  (1)

Get the number of samples:

Wolfram Language code: Import["ExampleData/car.mp3", "Length"]

"MetaInformation"  (1)

Get the audio metadata:

Wolfram Language code: Import["ExampleData/car.mp3", "MetaInformation"]

"RawMetaInformation"  (1)

Get the audio metadata in a raw form:

Wolfram Language code: Import["ExampleData/car.mp3", "RawMetaInformation"]

"SampleRate"  (1)

Get the number of amplitude samples per second and channel:

Wolfram Language code: Import["ExampleData/car.mp3", "SampleRate"]

Import Options  (6)

"AudioChannels"  (2)

Generate a stereo MP3 file:

Wolfram Language code: Export["stereo.mp3", AudioPan[AudioGenerator["Sin"], Sin[2Pi#]&]]

By default, the number of audio channels is set to be Automatic:

Wolfram Language code: AudioChannels[Import["stereo.mp3"]]

Specify all the audio channels to be imported:

Wolfram Language code: AudioChannels[Import["stereo.mp3", "AudioChannels" -> All]]

Import the second channel only:

Wolfram Language code: AudioChannels[Import["stereo.mp3", "AudioChannels" -> {2}]]

IncludeMetaInformation  (3)

By default, all available metadata is imported:

Wolfram Language code: Options[Import["ExampleData/car.mp3", "Audio"], MetaInformation]

Import an audio file with no metadata:

Wolfram Language code: Options[Import["ExampleData/car.mp3", "Audio", IncludeMetaInformation -> None], MetaInformation]

Import the audio with only specified classes of metadata:

Wolfram Language code: Options[Import["ExampleData/car.mp3", "Audio", IncludeMetaInformation -> {"RawID3v2"}], MetaInformation]

SampleRate  (1)

By default, the sample rate is extracted from the file:

Wolfram Language code: Options[Import["ExampleData/car.mp3"], SampleRate]

Specify the sample rate of the imported sound:

Wolfram Language code: Options[Import["ExampleData/car.mp3", SampleRate -> 8000], SampleRate]

Export Options  (5)

"AudioChannels" (1)

By default, the audio is exported using the default number of channels:

Wolfram Language code: i = \!\(\*AudioBox["![Embedded Audio Player](audio://content-4dde0)"]\);
Wolfram Language code: Export["test.mp3", i]
Wolfram Language code: Import[%, "AudioChannels"]

Specify the number of channels of exported audio:

Wolfram Language code: Export["test.mp3", i, "AudioChannels" -> {1}]
Wolfram Language code: Import[%, "AudioChannels"]

CompressionLevel (1)

By default, the audio is exported using the 0.5 compression level:

Wolfram Language code: i = \!\(\*AudioBox["![Embedded Audio Player](audio://content-6ue63)"]\);
Wolfram Language code: ByteCount[i]
Wolfram Language code: Export["test.mp3", i]
Wolfram Language code: FileByteCount[%]

Specify the encoding of exported audio:

Wolfram Language code: Export["test.mp3", i, CompressionLevel -> 1]
Wolfram Language code: FileByteCount[%]

IncludeMetaInformation (2)

By default, all existing metainformation is exported:

Wolfram Language code: i = \!\(\*AudioBox["![Embedded Audio Player](audio://content-ixnyc)"]\);
Wolfram Language code: Options[i, MetaInformation]
Wolfram Language code: Export["test.mp3", i]
Wolfram Language code: Options[Import[%], MetaInformation]

Specify the metadata to include:

Wolfram Language code: Export["test.mp3", \!\(\*AudioBox["![Embedded Audio Player](audio://content-ixnyc)"]\), IncludeMetaInformation -> None]
Wolfram Language code: Options[Import[%], MetaInformation]

SampleRate  (1)

By default, the audio is exported using the default sample rate:

Wolfram Language code: i = \!\(\*AudioBox["![Embedded Audio Player](audio://content-6ue63)"]\);
Wolfram Language code: Options[i, SampleRate]
Wolfram Language code: Export["test.mp3", i]
Wolfram Language code: Import[%, "SampleRate"]

Specify the sample rate of exported audio:

Wolfram Language code: Export["test.mp3", i, SampleRate -> 44100]
Wolfram Language code: Import[%, "SampleRate"]