> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pixeltable.com/llms.txt
> Use this file to discover all available pages before exploring further.
# audio
> 
# module pixeltable.functions.audio
Pixeltable UDFs for `AudioType`.
## iterator audio\_splitter()
```python Signature theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
audio_splitter(
audio: Any,
chunk_duration_sec: float,
*,
overlap_sec: float = 0.0,
min_chunk_duration_sec: float = 0.0
)
```
Iterator over chunks of an audio file. The audio file is split into smaller chunks,
where the duration of each chunk is determined by chunk\_duration\_sec.
The iterator yields audio chunks as pxt.Audio, along with the start and end time of each chunk.
If the input contains no audio, no chunks are yielded.
**Parameters:**
* **`chunk_duration_sec`** (`float`): Audio chunk duration in seconds
* **`overlap_sec`** (`float`, default: `0.0`): Overlap between consecutive chunks in seconds
* **`min_chunk_duration_sec`** (`float`, default: `0.0`): Drop the last chunk if it is smaller than min\_chunk\_duration\_sec
**Examples:**
This example assumes an existing table `tbl` with a column `audio` of type `pxt.Audio`. Create a view that splits all audio files into chunks of 30 seconds with 5 seconds overlap:
```python theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
pxt.create_view(
'audio_chunks',
tbl,
iterator=audio_splitter(
tbl.audio, chunk_duration_sec=30.0, overlap_sec=5.0
),
)
```
## udf encode\_audio()
```python Signature theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
@pxt.udf
encode_audio(
audio_data: pxt.Array[float32],
*,
input_sample_rate: pxt.Int,
format: pxt.String,
output_sample_rate: pxt.Int | None = None
) -> pxt.Audio
```
Encodes an audio clip represented as an array into a specified audio format.
**Parameters:**
* **`audio_data`** (`pxt.Array[float32]`): 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`** (`pxt.Int`): The sample rate of the input audio data.
* **`format`** (`pxt.String`): The desired output audio format. The supported formats are 'wav', 'mp3', 'flac', and 'mp4'.
* **`output_sample_rate`** (`pxt.Int | 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:
```python theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
t.add_computed_column(
audio_file=encode_audio(
t.audio_data, input_sample_rate=t.sample_rate, format='flac'
)
)
```
## udf get\_metadata()
```python Signature theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
@pxt.udf
get_metadata(audio: pxt.Audio) -> pxt.Json
```
Gets various metadata associated with an audio file and returns it as a dictionary.
**Parameters:**
* **`audio`** (`pxt.Audio`): The audio to get metadata for.
**Returns:**
* `pxt.Json`: A `dict` such as the following:
```json theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
{
'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`:
```python theme={"theme":{"light":"light-plus","dark":"dark-plus"}}
tbl.select(tbl.audio_col.get_metadata()).collect()
```