ffmpeg/audio_decoder_ffmpeg.py

import av

from towhee import register
from towhee.operator import PyOperator, OperatorFlag
from towhee.types.audio_frame import AudioFrame


@register(output_schema=['audio_frame'],
          flag=OperatorFlag.REUSEABLE)
class AudioDecoderFFmpeg(PyOperator):
    """
    """

    def __init__(self, batch_size=-1, sample_rate=None, layout=None) -> None:
        super().__init__()
        self._batch_size = batch_size
        self._sample_rate = sample_rate
        self._layout = layout

    def __call__(self, audio_path: str):
        frames = []
        in_container = av.open(audio_path)
        stream = in_container.streams.get(audio=0)[0]
        if self._sample_rate or self._layout:
            resampler = av.AudioResampler(
                format=av.AudioFormat(stream.format.name).packed,
                layout=self._layout if self._layout else 'mono',
                rate=self._sample_rate if self._sample_rate else 8000
                )
        else:
            resampler = None

        if self._batch_size <= 0:
            for frame in in_container.decode(stream):
                if resampler:
                    frame = resampler.resample(frame)[0]
                timestamp = int(frame.time * 1000)
                sample_rate = frame.sample_rate
                layout = frame.layout.name
                ndarray = frame.to_ndarray()
                yield AudioFrame(ndarray, sample_rate, timestamp, layout)
        else:
            for frame in in_container.decode(stream):
                if resampler:
                    frame = resampler.resample(frame)[0]
                timestamp = int(frame.time * 1000)
                sample_rate = frame.sample_rate
                layout = frame.layout.name
                ndarray = frame.to_ndarray()
                frames.append(AudioFrame(ndarray, sample_rate, timestamp, layout))
                if len(frames) == self._batch_size:
                    yield frames
                    frames = []
            if len(frames) != 0:
                yield frames