audio

pixeltable.functions.audio

Pixeltable UDFs for AudioType.

encode_audio

encode_audio(
    audio_data: Array[Float],
    *,
    input_sample_rate: Int,
    format: String,
    output_sample_rate: Int | None = None
) -> Audio

Encodes an audio clip represented as an array into a specified audio format.

Parameters:

• audio_data (Array[Float]) –

  An array of sampled amplitudes. The accepted array shapes are (N,) or (1, N) for mono audio or (2, N) for stereo.

• input_sample_rate (Int) –

  The sample rate of the input audio data.

• format (String) –

  The desired output audio format. The supported formats are 'wav', 'mp3', 'flac', and 'mp4'.

• output_sample_rate (Int | None, default: None ) –

  The desired sample rate for the output audio. Defaults to the input sample rate if unspecified.

Examples:

Add a computed column with encoded FLAC audio files to a table with audio data (as arrays of floats) and sample rates:

t.add_computed_column(
    audio_file=encode_audio(
        t.audio_data, input_sample_rate=t.sample_rate, format='flac'
    )
)

get_metadata

get_metadata(audio: Audio) -> Json

Gets various metadata associated with an audio file and returns it as a dictionary.

Parameters:

• audio (Audio) –

  The audio to get metadata for.

Returns:

• Json –

  A dict such as the following:

  {
      'size': 2568827,
      'streams': [
          {
              'type': 'audio',
              'frames': 0,
              'duration': 2646000,
              'metadata': {},
              'time_base': 2.2675736961451248e-05,
              'codec_context': {
                  'name': 'flac',
                  'profile': None,
                  'channels': 1,
                  'codec_tag': '\x00\x00\x00\x00',
              },
              'duration_seconds': 60.0,
          }
      ],
      'bit_rate': 342510,
      'metadata': {'encoder': 'Lavf61.1.100'},
      'bit_exact': False,
  }
  

Examples:

Extract metadata for files in the audio_col column of the table tbl:

>>> tbl.select(tbl.audio_col.get_metadata()).collect()