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tf.signal.frame

TensorFlow 1 version View source on GitHub

Expands signal's axis dimension into frames of frame_length.

tf.signal.frame(
    signal, frame_length, frame_step, pad_end=False, pad_value=0, axis=-1, name=None
)

Slides a window of size frame_length over signal's axis dimension with a stride of frame_step, replacing the axis dimension with [frames, frame_length] frames.

If pad_end is True, window positions that are past the end of the axis dimension are padded with pad_value until the window moves fully past the end of the dimension. Otherwise, only window positions that fully overlap the axis dimension are produced.

For example:

# A batch size 3 tensor of 9152 audio samples.
audio = tf.random.normal([3, 9152])

# Compute overlapping frames of length 512 with a step of 180 (frames overlap
# by 332 samples). By default, only 50 frames are generated since the last
# 152 samples do not form a full frame.
frames = tf.signal.frame(audio, 512, 180)
frames.shape.assert_is_compatible_with([3, 50, 512])

# When pad_end is enabled, the final frame is kept (padded with zeros).
frames = tf.signal.frame(audio, 512, 180, pad_end=True)
frames.shape.assert_is_compatible_with([3, 51, 512])

Args:

  • signal: A [..., samples, ...] Tensor. The rank and dimensions may be unknown. Rank must be at least 1.
  • frame_length: The frame length in samples. An integer or scalar Tensor.
  • frame_step: The frame hop size in samples. An integer or scalar Tensor.
  • pad_end: Whether to pad the end of signal with pad_value.
  • pad_value: An optional scalar Tensor to use where the input signal does not exist when pad_end is True.
  • axis: A scalar integer Tensor indicating the axis to frame. Defaults to the last axis. Supports negative values for indexing from the end.
  • name: An optional name for the operation.

Returns:

A Tensor of frames with shape [..., frames, frame_length, ...].

Raises:

  • ValueError: If frame_length, frame_step, pad_value, or axis are not scalar.