From dfecc5b81a4ebb2358807d6540a3948a2a5b41b0 Mon Sep 17 00:00:00 2001 From: dohe0342 Date: Thu, 16 Feb 2023 17:46:47 +0900 Subject: [PATCH] from local --- .../ASR/conformer_ctc2/combiner.py | 244 ++++++++++++++++++ 1 file changed, 244 insertions(+) create mode 100644 egs/librispeech/ASR/conformer_ctc2/combiner.py diff --git a/egs/librispeech/ASR/conformer_ctc2/combiner.py b/egs/librispeech/ASR/conformer_ctc2/combiner.py new file mode 100644 index 000000000..ff526029d --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc2/combiner.py @@ -0,0 +1,244 @@ +# Copyright 2022 Behavox LLC. (author: Daniil Kulko) +# +# See ../../../../LICENSE for clarification regarding multiple authors +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from typing import List + +import torch + + +class RandomCombine(torch.nn.Module): + """ + This module combines a list of Tensors, all with the same shape, to + produce a single output of that same shape which, in training time, + is a random combination of all the inputs; but which in test time + will be just the last input. + The idea is that the list of Tensors will be a list of outputs of multiple + conformer layers. This has a similar effect as iterated loss. (See: + DEJA-VU: DOUBLE FEATURE PRESENTATION AND ITERATED LOSS IN DEEP TRANSFORMER + NETWORKS). + """ + + def __init__( + self, + num_inputs: int, + final_weight: float = 0.5, + pure_prob: float = 0.5, + stddev: float = 2.0, + ) -> None: + """ + Args: + num_inputs: + The number of tensor inputs, which equals the number of layers' + outputs that are fed into this module. E.g. in an 18-layer neural + net if we output layers 16, 12, 18, num_inputs would be 3. + final_weight: + The amount of weight or probability we assign to the + final layer when randomly choosing layers or when choosing + continuous layer weights. + pure_prob: + The probability, on each frame, with which we choose + only a single layer to output (rather than an interpolation) + stddev: + A standard deviation that we add to log-probs for computing + randomized weights. + The method of choosing which layers, or combinations of layers, to use, + is conceptually as follows:: + With probability `pure_prob`:: + With probability `final_weight`: choose final layer, + Else: choose random non-final layer. + Else:: + Choose initial log-weights that correspond to assigning + weight `final_weight` to the final layer and equal + weights to other layers; then add Gaussian noise + with variance `stddev` to these log-weights, and normalize + to weights (note: the average weight assigned to the + final layer here will not be `final_weight` if stddev>0). + """ + super().__init__() + assert 0 <= pure_prob <= 1, pure_prob + assert 0 < final_weight < 1, final_weight + assert num_inputs >= 1, num_inputs + + self.num_inputs = num_inputs + self.final_weight = final_weight + self.pure_prob = pure_prob + self.stddev = stddev + + self.final_log_weight = ( + torch.tensor((final_weight / (1 - final_weight)) * (self.num_inputs - 1)) + .log() + .item() + ) + + def forward(self, inputs: List[torch.Tensor]) -> torch.Tensor: + """Forward function. + Args: + inputs: + A list of Tensor, e.g. from various layers of a transformer. + All must be the same shape, of (*, num_channels) + Returns: + A Tensor of shape (*, num_channels). In test mode + this is just the final input. + """ + num_inputs = self.num_inputs + assert len(inputs) == num_inputs, f"{len(inputs)}, {num_inputs}" + if not self.training or torch.jit.is_scripting() or len(inputs) == 1: + return inputs[-1] + + # Shape of weights: (*, num_inputs) + num_channels = inputs[0].shape[-1] + num_frames = inputs[0].numel() // num_channels + + ndim = inputs[0].ndim + # stacked_inputs: (num_frames, num_channels, num_inputs) + stacked_inputs = torch.stack(inputs, dim=ndim).reshape( + (num_frames, num_channels, num_inputs) + ) + + # weights: (num_frames, num_inputs) + weights = self._get_random_weights( + inputs[0].dtype, inputs[0].device, num_frames + ) + + weights = weights.reshape(num_frames, num_inputs, 1) + # ans: (num_frames, num_channels, 1) + ans = torch.matmul(stacked_inputs, weights) + # ans: (*, num_channels) + + ans = ans.reshape(inputs[0].shape[:-1] + (num_channels,)) + + return ans + + def _get_random_weights( + self, dtype: torch.dtype, device: torch.device, num_frames: int + ) -> torch.Tensor: + """Return a tensor of random weights, of shape + `(num_frames, self.num_inputs)`, + Args: + dtype: + The data-type desired for the answer, e.g. float, double. + device: + The device needed for the answer. + num_frames: + The number of sets of weights desired + Returns: + A tensor of shape (num_frames, self.num_inputs), such that + `ans.sum(dim=1)` is all ones. + """ + pure_prob = self.pure_prob + if pure_prob == 0.0: + return self._get_random_mixed_weights(dtype, device, num_frames) + elif pure_prob == 1.0: + return self._get_random_pure_weights(dtype, device, num_frames) + else: + p = self._get_random_pure_weights(dtype, device, num_frames) + m = self._get_random_mixed_weights(dtype, device, num_frames) + return torch.where( + torch.rand(num_frames, 1, device=device) < self.pure_prob, p, m + ) + + def _get_random_pure_weights( + self, dtype: torch.dtype, device: torch.device, num_frames: int + ) -> torch.Tensor: + """Return a tensor of random one-hot weights, of shape + `(num_frames, self.num_inputs)`, + Args: + dtype: + The data-type desired for the answer, e.g. float, double. + device: + The device needed for the answer. + num_frames: + The number of sets of weights desired. + Returns: + A one-hot tensor of shape `(num_frames, self.num_inputs)`, with + exactly one weight equal to 1.0 on each frame. + """ + final_prob = self.final_weight + + # final contains self.num_inputs - 1 in all elements + final = torch.full((num_frames,), self.num_inputs - 1, device=device) + # nonfinal contains random integers in [0..num_inputs - 2], these are for non-final weights. + nonfinal = torch.randint(self.num_inputs - 1, (num_frames,), device=device) + + indexes = torch.where( + torch.rand(num_frames, device=device) < final_prob, final, nonfinal + ) + ans = torch.nn.functional.one_hot(indexes, num_classes=self.num_inputs).to( + dtype=dtype + ) + return ans + + def _get_random_mixed_weights( + self, dtype: torch.dtype, device: torch.device, num_frames: int + ) -> torch.Tensor: + """Return a tensor of random one-hot weights, of shape + `(num_frames, self.num_inputs)`, + Args: + dtype: + The data-type desired for the answer, e.g. float, double. + device: + The device needed for the answer. + num_frames: + The number of sets of weights desired. + Returns: + A tensor of shape (num_frames, self.num_inputs), which elements + in [0..1] that sum to one over the second axis, i.e. + `ans.sum(dim=1)` is all ones. + """ + logprobs = ( + torch.randn(num_frames, self.num_inputs, dtype=dtype, device=device) + * self.stddev + ) + logprobs[:, -1] += self.final_log_weight + return logprobs.softmax(dim=1) + + +def _test_random_combine( + final_weight: float, + pure_prob: float, + stddev: float, +) -> None: + print( + f"_test_random_combine: final_weight={final_weight}, " + f"pure_prob={pure_prob}, stddev={stddev}" + ) + num_inputs = 3 + num_channels = 50 + m = RandomCombine( + num_inputs=num_inputs, + final_weight=final_weight, + pure_prob=pure_prob, + stddev=stddev, + ) + + x = [torch.ones(3, 4, num_channels) for _ in range(num_inputs)] + + y = m(x) + assert y.shape == x[0].shape + assert torch.allclose(y, x[0]) # .. since actually all ones. + + +def _test_random_combine_main() -> None: + _test_random_combine(0.999, 0, 0.0) + _test_random_combine(0.5, 0, 0.0) + _test_random_combine(0.999, 0, 0.0) + _test_random_combine(0.5, 0, 0.3) + _test_random_combine(0.5, 1, 0.3) + _test_random_combine(0.5, 0.5, 0.3) + + +if __name__ == "__main__": + _test_random_combine_main()