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ReferenceSpecializedUse the microphone and recorder result types.

Audio types

Two types carry sound out of the capture components. AudioLevel is a snapshot of how loud things are, from Microphone. Recording is a finished audio clip, from AudioRecorder. Both follow the same pattern as Photo and the Location type: a status field says whether real data is present, and failures arrive as values instead of exceptions.

AudioLevel

A measurement of the microphone at the moment the form was submitted.

Field Type Meaning
status str "prompt", "pending", "granted", "denied", "error", or "unavailable".
message str or None A description accompanying failures.
volume float or None Loudness right now, from 0.0 (silence) to 1.0 (as loud as the microphone measures).
peak_volume float or None The loudest moment since the page loaded.
pitch float or None The dominant frequency in Hz, when the sound is loud enough to estimate. 
@route
def check(state: State, mic: AudioLevel) -> Page:
    if mic.volume is None:
        return Page(state, ["No microphone (" + mic.status + ")."])
    if mic.volume > 0.5:
        return Page(state, ["Too loud for the library!"])
    return Page(state, ["Nice and quiet."])

Recording

A completed clip from an AudioRecorder.

Field Type Meaning
status str "prompt", "recording", "granted", "denied", "error", or "unavailable".
message str or None A description accompanying failures.
data_url str or None The recorded audio, or None when nothing has been recorded.
duration float or None Length in seconds.
size int or None Size in bytes.

The data_url plays back directly: hand it to Sound (or Audio) as its source. A recording stored in state can therefore be replayed on any later page.

@route
def playback(state: State, clip: Recording) -> Page:
    if clip.data_url is None:
        return Page(state, ["Nothing recorded (" + clip.status + ")."])
    state.last_clip = clip.data_url
    return Page(state, [
        "Here is your " + str(clip.duration) + " second clip:\n",
        Sound(state.last_clip)
    ])

Notes

  • Check the data field (volume, data_url) for None rather than memorizing status values; the check covers every failure at once.
  • volume is a single number, not a stream: it describes the moment of submission. For reacting to sound as it happens, the Microphone component's on_loud and on_quiet events call routes for you.
  • Recordings can be big. Storing many of them in state makes the app slow to snapshot; keep the latest one, or offer Download instead of a collection.