snowdar_xvector.py

# -*- coding:utf-8 -*-

# Copyright xmuspeech (Author: Snowdar 2020-02-05)

import math
import torch
import torch.nn.functional as F
import libs.support.utils as utils

from libs.nnet import *

class Xvector(TopVirtualNnet):
    """ A composite x-vector framework """
    
    ## Base parameters - components - loss - training strategy.
    def init(self, inputs_dim, num_targets, extend=False, skip_connection=False, 
             mixup=False, mixup_alpha=1.0,
             specaugment=False, specaugment_params={},
             aug_dropout=0., context_dropout=0., hidden_dropout=0., dropout_params={},
             SE=False, se_ratio=4,
             tdnn_layer_params={},
             tdnn6=True, tdnn7_params={},
             pooling="statistics", pooling_params={},
             margin_loss=False, margin_loss_params={},
             use_step=False, step_params={},
             transfer_from="softmax_loss",
             training=True, extracted_embedding="far"):

        ## Params.
        default_dropout_params = {
            "type":"default", # default | random
            "start_p":0.,
            "dim":2,
            "method":"uniform", # uniform | normals
            "continuous":False,
            "inplace":True
        }

        default_tdnn_layer_params = {
            "nonlinearity":'relu', "nonlinearity_params":{"inplace":True},
            "bn-relu":False, "bn":True, "bn_params":{"momentum":0.5, "affine":False, "track_running_stats":True}
        }

        default_pooling_params = {
            "num_nodes":1500,
            "num_head":1,
            "share":True,
            "affine_layers":1,
            "hidden_size":64,
            "context": [0],
            "stddev":True,
            "temperature":False, 
            "fixed":True,
            "stddev":True
        }

        default_margin_loss_params = {
            "method":"am", "m":0.2, 
            "feature_normalize":True, "s":30, 
            "double":False,
            "mhe_loss":False, "mhe_w":0.01,
            "inter_loss":0.,
            "ring_loss":0.,
            "curricular":False
        }

        default_step_params = {
            "margin_warm":False,
            "margin_warm_conf":{"start_epoch":5.,"end_epoch":10.,"offset_margin":-0.2,"init_lambda":0.0},
            "T":None,
            "m":False, "lambda_0":0, "lambda_b":1000, "alpha":5, "gamma":1e-4,
            "s":False, "s_tuple":(30, 12), "s_list":None,
            "t":False, "t_tuple":(0.5, 1.2), 
            "p":False, "p_tuple":(0.5, 0.1)
        }

        dropout_params = utils.assign_params_dict(default_dropout_params, dropout_params)
        tdnn_layer_params = utils.assign_params_dict(default_tdnn_layer_params, tdnn_layer_params)
        # If param is not be specified, default it w.r.t tdnn_layer_params.
        tdnn7_params = utils.assign_params_dict(tdnn_layer_params, tdnn7_params)
        pooling_params = utils.assign_params_dict(default_pooling_params, pooling_params)
        margin_loss_params = utils.assign_params_dict(default_margin_loss_params, margin_loss_params)
        step_params = utils.assign_params_dict(default_step_params, step_params)

        ## Var.
        self.skip_connection = skip_connection
        self.use_step = use_step
        self.step_params = step_params

        self.extracted_embedding = extracted_embedding # For extract.
        
        ## Nnet.
        # Head
        self.mixup = Mixup(alpha=mixup_alpha) if mixup else None
        self.specaugment = SpecAugment(**specaugment_params) if specaugment else None
        self.aug_dropout = get_dropout_from_wrapper(aug_dropout, dropout_params)
        self.context_dropout = ContextDropout(p=context_dropout) if context_dropout > 0 else None
        self.hidden_dropout = get_dropout_from_wrapper(hidden_dropout, dropout_params)

        # Frame level
        self.tdnn1 = ReluBatchNormTdnnLayer(inputs_dim,512,[-2,-1,0,1,2], **tdnn_layer_params)
        self.se1 = SEBlock(512, ratio=se_ratio) if SE else None
        self.ex_tdnn1 = ReluBatchNormTdnnLayer(512,512, **tdnn_layer_params) if extend else None
        self.tdnn2 = ReluBatchNormTdnnLayer(512,512,[-2,0,2], **tdnn_layer_params)
        self.se2 = SEBlock(512, ratio=se_ratio) if SE else None
        self.ex_tdnn2 = ReluBatchNormTdnnLayer(512,512, **tdnn_layer_params) if extend else None
        self.tdnn3 = ReluBatchNormTdnnLayer(512,512,[-3,0,3], **tdnn_layer_params)
        self.se3 = SEBlock(512, ratio=se_ratio) if SE else None
        self.ex_tdnn3 = ReluBatchNormTdnnLayer(512,512, **tdnn_layer_params) if extend else None
        self.ex_tdnn4 = ReluBatchNormTdnnLayer(512,512,[-4,0,4], **tdnn_layer_params) if extend else None
        self.se4 = SEBlock(512, ratio=se_ratio) if SE and extend else None
        self.ex_tdnn5 = ReluBatchNormTdnnLayer(512,512, **tdnn_layer_params) if extend else None
        self.tdnn4 = ReluBatchNormTdnnLayer(512,512, **tdnn_layer_params)

        num_nodes = pooling_params.pop("num_nodes")

        self.tdnn5 = ReluBatchNormTdnnLayer(512, num_nodes, **tdnn_layer_params)

        # Pooling
        stddev = pooling_params.pop("stddev")
        if pooling == "lde":
            self.stats = LDEPooling(num_nodes, c_num=pooling_params["num_head"])
        elif pooling == "attentive":
            self.stats = AttentiveStatisticsPooling(num_nodes, affine_layers=pooling_params["affine_layers"], 
                                                    hidden_size=pooling_params["hidden_size"], 
                                                    context=pooling_params["context"], stddev=stddev)
        elif pooling == "multi-head":
            self.stats = MultiHeadAttentionPooling(num_nodes, stddev=stddev, **pooling_params)
        elif pooling == "multi-resolution":
            self.stats = MultiResolutionMultiHeadAttentionPooling(num_nodes, **pooling_params)
        elif pooling == "xi-postmean-softplus2":
            self.stats = xivec_stdinit_softplus2_prec_pooling(num_nodes, hidden_size=pooling_params["hidden_size"], stddev=False)
        elif pooling == "xi-postdist-softplus2":
            self.stats = xivec_stdinit_softplus2_prec_pooling(num_nodes, hidden_size=pooling_params["hidden_size"], stddev=True)
        else:
            self.stats = StatisticsPooling(num_nodes, stddev=stddev)

        stats_dim = self.stats.get_output_dim()

        # Segment level
        if tdnn6:
            self.tdnn6 = ReluBatchNormTdnnLayer(stats_dim, 512, **tdnn_layer_params)
            tdnn7_dim = 512
        else:
            self.tdnn6 = None
            tdnn7_dim = stats_dim

        if tdnn7_params["nonlinearity"] == "default":
            tdnn7_params["nonlinearity"] = tdnn_layer_params["nonlinearity"]

        self.tdnn7 = ReluBatchNormTdnnLayer(tdnn7_dim,512, **tdnn7_params)

        # Loss
        # Do not need when extracting embedding.
        if training :
            if margin_loss:
                self.loss = MarginSoftmaxLoss(512, num_targets, **margin_loss_params)
                if self.use_step and self.step_params["margin_warm"]:
                    self.margin_warm = MarginWarm(**step_params["margin_warm_conf"])
            else:
                self.loss = SoftmaxLoss(512, num_targets)

            self.wrapper_loss = MixupLoss(self.loss, self.mixup) if mixup else None

            # An example to using transform-learning without initializing loss.affine parameters
            self.transform_keys = ["tdnn1","tdnn2","tdnn3","tdnn4","tdnn5","stats","tdnn6","tdnn7",
                                   "ex_tdnn1","ex_tdnn2","ex_tdnn3","ex_tdnn4","ex_tdnn5",
                                   "se1","se2","se3","se4", "loss"]

            if margin_loss and transfer_from == "softmax_loss":
                # For softmax_loss to am_softmax_loss
                self.rename_transform_keys = {"loss.affine.weight":"loss.weight"} 
    @torch.jit.unused
    @utils.for_device_free
    def forward(self, inputs, x_len: torch.Tensor=torch.empty(0)):
        """
        @inputs: a 3-dimensional tensor (a batch), including [samples-index, frames-dim-index, frames-index]
        """

        x = inputs

        x = self.auto(self.mixup, x)
        x = self.auto(self.specaugment, x)
        x = self.auto(self.aug_dropout, x)
        x = self.auto(self.context_dropout, x)

        x = self.tdnn1(x)
        if self.skip_connection:
            identity = x
        x = self.auto(self.se1, x)
        x = self.auto(self.ex_tdnn1, x)
        x = self.tdnn2(x)
        x = self.auto(self.se2, x)
        x = self.auto(self.ex_tdnn2, x)
        x = self.tdnn3(x)
        x = self.auto(self.se3, x)
        x = self.auto(self.ex_tdnn3, x)
        x = self.auto(self.ex_tdnn4, x)
        x = self.auto(self.se4, x)
        x = self.auto(self.ex_tdnn5, x)
        x = self.tdnn4(x)
        if self.skip_connection:
            x = x + identity
        x = self.tdnn5(x)
        x = self.stats(x)
        x = self.auto(self.tdnn6, x)
        x = self.tdnn7(x)
        x = self.auto(self.hidden_dropout, x)
        return x

    @utils.for_device_free
    def get_loss(self, inputs, targets):
        """Should call get_loss() after forward() with using Xvector model function.
        e.g.:
            m=Xvector(20,10)
            loss=m.get_loss(m(inputs),targets)

        model.get_loss [custom] -> loss.forward [custom]
          |
          v
        model.get_accuracy [custom] -> loss.get_accuracy [custom] -> loss.compute_accuracy [static] -> loss.predict [static]
        """
        if self.wrapper_loss is not None:
            return self.wrapper_loss(inputs, targets)
        else:
            return self.loss(inputs, targets)

    @utils.for_device_free
    def get_accuracy(self, targets):
        """Should call get_accuracy() after get_loss().
        @return: return accuracy
        """
        if self.wrapper_loss is not None:
            return self.wrapper_loss.get_accuracy(targets)
        else:
            return self.loss.get_accuracy(targets)

    @for_extract_embedding(maxChunk=10000, isMatrix=True)
    def extract_embedding(self, inputs):
        """
        inputs: a 3-dimensional tensor with batch-dim = 1 or normal features matrix
        return: an 1-dimensional vector after processed by decorator
        """

        x = inputs

        x = self.tdnn1(x)
        if self.skip_connection:
            identity = x
        x = self.auto(self.se1, x)
        x = self.auto(self.ex_tdnn1, x)
        x = self.tdnn2(x)
        x = self.auto(self.se2, x)
        x = self.auto(self.ex_tdnn2, x)
        x = self.tdnn3(x)
        x = self.auto(self.se3, x)
        x = self.auto(self.ex_tdnn3, x)
        x = self.auto(self.ex_tdnn4, x)
        x = self.auto(self.se4, x)
        x = self.auto(self.ex_tdnn5, x)
        x = self.tdnn4(x)
        if self.skip_connection:
            x = x + identity
        x = self.tdnn5(x)
        x = self.stats(x)

        if self.extracted_embedding == "far" :
            assert self.tdnn6 is not None
            xvector = self.tdnn6.affine(x)
        elif self.extracted_embedding == "near_affine":
            x = self.auto(self.tdnn6, x)
            xvector = self.tdnn7.affine(x)
        elif self.extracted_embedding == "near":
            x = self.auto(self.tdnn6, x)
            xvector = self.tdnn7(x)

        return xvector

    def extract_embedding_jit(self, x: torch.Tensor, position: str = 'near') -> torch.Tensor:
        """
        inputs: a 3-dimensional tensor with batch-dim = 1 or normal features matrix
        return: an 1-dimensional vector after processed by decorator
        """

        # Tensor shape is not modified in libs.nnet.resnet.py for calling free, such as using this framework in cv.
        x = x.unsqueeze(1)
        x = self.repvgg(x)
        x = x.reshape(x.shape[0], x.shape[1]*x.shape[2], x.shape[3])
        x = self.stats(x)

        if position == "far" and self.fc1 is not None:
            xvector = self.fc1.affine(x)
        elif position == "near_affine":
            if self.fc1 is not None:
                x=self.fc1(x)
            xvector = self.fc2.affine(x)
        elif position == "near":
            if self.fc1 is not None:
                x=self.fc1(x)
            xvector = self.fc2(x)
            # xvector = F.normalize(xvector)

        else:
            raise TypeError("Expected far or near position, but got {}".format(position))

        return xvector

    @torch.jit.export
    def extract_embedding_whole(self, input: torch.Tensor, position: str = 'near', maxChunk: int = 4000, isMatrix: bool = True):
        with torch.no_grad():
            if isMatrix:
                input = torch.unsqueeze(input, dim=0)
                input = input.transpose(1, 2)
            num_frames = input.shape[2]
            num_split = (num_frames + maxChunk - 1) // maxChunk
            split_size = num_frames // num_split
            offset = 0
            embedding_stats = torch.zeros(1, self.embd_dim, 1).to(input.device)
            for _ in range(0, num_split-1):
                this_embedding = self.extract_embedding_jit(
                    input[:, :, offset:offset+split_size], position)
                offset += split_size
                embedding_stats += split_size*this_embedding

            last_embedding = self.extract_embedding_jit(
                input[:, :, offset:], position)

            embedding = (embedding_stats + (num_frames-offset)
                        * last_embedding) / num_frames
            return torch.squeeze(embedding.transpose(1, 2)).cpu()

    @torch.jit.export
    def embedding_dim(self) -> int:
        """ Export interface for c++ call, return embedding dim of the model
        """

        return self.embd_dim


    def get_warmR_T(self,T_0, T_mult, epoch):
        n = int(math.log(max(0.05, (epoch / T_0 * (T_mult - 1) + 1)), T_mult))
        T_cur = epoch - T_0 * (T_mult ** n - 1) / (T_mult - 1)
        T_i = T_0 * T_mult ** (n)
        return T_cur, T_i

    def compute_decay_value(self, start, end, T_cur, T_i):
        # Linear decay in every cycle time.
        return start - (start - end)/(T_i-1) * (T_cur%T_i)

    def step(self, epoch, this_iter, epoch_batchs):
        # Heated up for t and s.
        # Decay for margin and dropout p.
        if self.use_step:
            if self.step_params["m"]:
                current_postion = epoch*epoch_batchs + this_iter
                lambda_factor = max(self.step_params["lambda_0"],
                                    self.step_params["lambda_b"]*(1+self.step_params["gamma"]*current_postion)**(-self.step_params["alpha"]))
                lambda_m = 1/(1 + lambda_factor)
                self.loss.step(lambda_m)

            if self.step_params["T"] is not None and (self.step_params["t"] or self.step_params["p"]):
                T_cur, T_i = self.get_warmR_T(*self.step_params["T"], epoch)
                T_cur = T_cur*epoch_batchs + this_iter
                T_i = T_i * epoch_batchs

            if self.step_params["t"]:
                self.loss.t = self.compute_decay_value(
                    *self.step_params["t_tuple"], T_cur, T_i)

            if self.step_params["p"]:
                self.aug_dropout.p = self.compute_decay_value(
                    *self.step_params["p_tuple"], T_cur, T_i)

            if self.step_params["s"]:
                self.loss.s = self.step_params["s_tuple"][self.step_params["s_list"][epoch]]

    def step_iter(self, epoch, cur_step):
        # For iterabledataset
        if self.use_step:
            if self.step_params["margin_warm"]:
                offset_margin, lambda_m = self.margin_warm.step(cur_step)
                lambda_m = max(1e-3,lambda_m)
                self.loss.step(lambda_m,offset_margin)
            if self.step_params["m"]:
                lambda_factor = max(self.step_params["lambda_0"],
                                    self.step_params["lambda_b"]*(1+self.step_params["gamma"]*cur_step)**(-self.step_params["alpha"]))
                lambda_m = 1/(1 + lambda_factor)
                self.loss.step(lambda_m)

            if self.step_params["T"] is not None and (self.step_params["t"] or self.step_params["p"]):
                T_cur, T_i = self.get_warmR_T(*self.step_params["T"], cur_step)

            if self.step_params["t"]:
                self.loss.t = self.compute_decay_value(
                    *self.step_params["t_tuple"], T_cur, T_i)

            if self.step_params["p"]:
                self.aug_dropout.p = self.compute_decay_value(
                    *self.step_params["p_tuple"], T_cur, T_i)

            if self.step_params["s"]:
                self.loss.s = self.step_params["s_tuple"][self.step_params["s_list"][epoch]]