Source code for diffsptk.modules.imsvq
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import torch
from torch import nn
[docs]
class InverseMultiStageVectorQuantization(nn.Module):
"""See `this page <https://sp-nitech.github.io/sptk/latest/main/imsvq.html>`_
for details.
"""
def __init__(self):
super().__init__()
[docs]
def forward(self, indices, codebooks):
"""Perform inverse residual vector quantization.
Parameters
----------
indices : Tensor [shape=(..., Q)]
Codebook indices.
codebooks : Tensor [shape=(Q, K, M+1)]
Codebooks.
Returns
-------
xq : Tensor [shape=(..., M+1)]
Quantized vectors.
Examples
--------
>>> msvq = diffsptk.MultiStageVectorQuantization(4, 3, 2)
>>> imsvq = diffsptk.InverseMultiStageVectorQuantization()
>>> indices = torch.tensor([[0, 1], [1, 0]])
>>> xq = imsvq(indices, msvq.codebooks)
>>> xq
tensor([[-0.8029, -0.1674, 0.5697, 0.9734, 0.1920],
[ 0.0720, -1.0491, -0.4491, -0.2043, -0.3582]])
"""
target_shape = list(indices.shape[:-1])
target_shape.append(codebooks.size(-1))
xq = 0
for i in range(indices.size(-1)):
code_vector = torch.index_select(
codebooks[i], 0, indices[..., i].view(-1).long()
)
xq = xq + code_vector
xq = xq.view(target_shape)
return xq