support ivector training in pytorch model

egs/aishell/s10/chain/egs_dataset.py

@@ -151,13 +151,17 @@ def __call__(self, batch):
                     self.egs_left_context + self.egs_right_context
 
             # TODO(fangjun): support ivector
-            assert len(eg.inputs) == 1
             assert eg.inputs[0].name == 'input'
 
             _feats = kaldi.FloatMatrix()
             eg.inputs[0].features.GetMatrix(_feats)
             feats = _feats.numpy()
 
+            if len(eg.inputs) > 1:
+                _ivectors = kaldi.FloatMatrix()
+                eg.inputs[1].features.GetMatrix(_ivectors)
+                ivectors = _ivectors.numpy()
+
             assert feats.shape[0] == batch_size * frames_per_sequence
 
             feat_list = []
@@ -173,6 +177,9 @@ def __call__(self, batch):
                 end_index -= 1  # remove the rightmost frame added for frame shift
                 feat = feats[start_index:end_index:, :]
                 feat = splice_feats(feat)
+                if len(eg.inputs) > 1:
+                    repeat_ivector = torch.from_numpy(ivectors[i]).repeat(feat.shape[0], 1)
+                    feat = torch.cat((torch.from_numpy(feat), repeat_ivector), dim=1).numpy()
                 feat_list.append(feat)
 
             batched_feat = np.stack(feat_list, axis=0)
@@ -182,7 +189,10 @@ def __call__(self, batch):
             # the first -2 is from extra left/right context
             # the second -2 is from lda feats splicing
             assert batched_feat.shape[1] == frames_per_sequence - 4
-            assert batched_feat.shape[2] == feats.shape[-1] * 3
+            if len(eg.inputs) > 1:
+                assert batched_feat.shape[2] == feats.shape[-1] * 3 + ivectors.shape[-1]
+            else:
+                assert batched_feat.shape[2] == feats.shape[-1] * 3
 
             torch_feat = torch.from_numpy(batched_feat).float()
             feature_list.append(torch_feat)

egs/aishell/s10/chain/feat_dataset.py

@@ -4,7 +4,7 @@
 # Apache 2.0
 
 import os
-
+import math
 import numpy as np
 import torch
 
@@ -22,13 +22,18 @@
 def get_feat_dataloader(feats_scp,
                         model_left_context,
                         model_right_context,
+                        frames_per_chunk=51,
+                        ivector_scp=None,
+                        ivector_period=10,
                         batch_size=16,
                         num_workers=10):
-    dataset = FeatDataset(feats_scp=feats_scp)
+    dataset = FeatDataset(feats_scp=feats_scp, ivector_scp=ivector_scp)
 
     collate_fn = FeatDatasetCollateFunc(model_left_context=model_left_context,
                                         model_right_context=model_right_context,
-                                        frame_subsampling_factor=3)
+                                        frame_subsampling_factor=3,
+                                        frames_per_chunk=frames_per_chunk,
+                                        ivector_period=ivector_period)
 
     dataloader = DataLoader(dataset,
                             batch_size=batch_size,
@@ -55,21 +60,36 @@ def _add_model_left_right_context(x, left_context, right_context):
 
 class FeatDataset(Dataset):
 
-    def __init__(self, feats_scp):
+    def __init__(self, feats_scp, ivector_scp=None):
         assert os.path.isfile(feats_scp)
 
         self.feats_scp = feats_scp
 
-        # items is a list of [key, rxfilename]
-        items = list()
+        # items is a dict of {key: [key, rxfilename, ivec]}
+        items = dict()
 
         with open(feats_scp, 'r') as f:
             for line in f:
                 split = line.split()
                 assert len(split) == 2
-                items.append(split)
-
-        self.items = items
+                uttid, rxfilename =split
+                assert uttid not in items
+                items[uttid] = [uttid, rxfilename, None]
+        if ivector_scp:
+            self.ivector_scp = ivector_scp
+            expected_count = len(items)
+            n = 0
+            with open(ivector_scp, 'r') as f:
+                for line in f:
+                    uttid_rxfilename = line.split()
+                    assert len(uttid_rxfilename) == 2
+                    uttid, rxfilename = uttid_rxfilename
+                    assert uttid in items
+                    items[uttid][-1] = rxfilename
+                    n += 1
+            assert n == expected_count
+
+        self.items = list(items.values())
 
         self.num_items = len(self.items)
 
@@ -81,6 +101,8 @@ def __getitem__(self, i):
 
     def __str__(self):
         s = 'feats scp: {}\n'.format(self.feats_scp)
+        if self.ivector_scp:
+            s += 'ivector_scp scp: {}\n'.format(self.ivector_scp)
         s += 'num utt: {}\n'.format(self.num_items)
         return s
 
@@ -90,26 +112,36 @@ class FeatDatasetCollateFunc:
     def __init__(self,
                  model_left_context,
                  model_right_context,
-                 frame_subsampling_factor=3):
+                 frame_subsampling_factor=3,
+                 frames_per_chunk=51,
+                 ivector_period=10):
         '''
         We need `frame_subsampling_factor` because we want to know
         the number of output frames of different waves in the same batch
         '''
         self.model_left_context = model_left_context
         self.model_right_context = model_right_context
         self.frame_subsampling_factor = frame_subsampling_factor
+        self.frames_per_chunk = frames_per_chunk
+        self.ivector_period = ivector_period
 
     def __call__(self, batch):
         '''
         batch is a list of [key, rxfilename]
         '''
         key_list = []
         feat_list = []
+        ivector_list = []
+        ivector_len_list = []
         output_len_list = []
+        subsampled_frames_per_chunk = (self.frames_per_chunk // 
+                                    self.frame_subsampling_factor)
         for b in batch:
-            key, rxfilename = b
+            key, rxfilename, ivector_rxfilename = b
             key_list.append(key)
             feat = kaldi.read_mat(rxfilename).numpy()
+            if ivector_rxfilename:
+                ivector = kaldi.read_mat(ivector_rxfilename).numpy() # L // 10 * C
             feat_len = feat.shape[0]
             output_len = (feat_len + self.frame_subsampling_factor -
                           1) // self.frame_subsampling_factor
@@ -118,12 +150,32 @@ def __call__(self, batch):
             feat = _add_model_left_right_context(feat, self.model_left_context,
                                                  self.model_right_context)
             feat = splice_feats(feat)
-            feat_list.append(feat)
-            # no need to sort the feat by length
 
-        # the user should sort utterances by length offline
-        # to avoid unnecessary padding
+            # now we split feat to chunk, then we can do decode by chunk
+            input_num_frames = (feat.shape[0] + 2 
+                                - self.model_left_context - self.model_right_context)
+            for i in range(0, output_len, subsampled_frames_per_chunk):
+                # input len:418 -> output len:140 -> output chunk:[0, 17, 34, 51, 68, 85, 102, 119, 136]
+                first_output = i * self.frame_subsampling_factor
+                last_output = min(input_num_frames, \
+                    first_output + (subsampled_frames_per_chunk-1) * self.frame_subsampling_factor)
+                first_input = first_output
+                last_input = last_output + self.model_left_context + self.model_right_context
+                input_x = feat[first_input:last_input+1, :]
+                if ivector_rxfilename:
+                    ivector_index = (first_output + last_output) // 2 // self.ivector_period
+                    input_ivector = ivector[ivector_index, :].reshape(1,-1)
+                    feat_list.append(np.concatenate((input_x, 
+                                            np.repeat(input_ivector, input_x.shape[0], axis=0)), 
+                                            axis=-1))
+                else:
+                    feat_list.append(input_x)
+
         padded_feat = pad_sequence(
             [torch.from_numpy(feat).float() for feat in feat_list],
             batch_first=True)
+
+        assert sum([math.ceil(l / subsampled_frames_per_chunk) for l in output_len_list]) \
+                    == padded_feat.shape[0]
+
         return key_list, padded_feat, output_len_list

egs/aishell/s10/chain/inference.py

@@ -6,6 +6,7 @@
 import logging
 import os
 import sys
+import math
 
 import torch
 from torch.utils.dlpack import to_dlpack
@@ -38,6 +39,7 @@ def main():
     model = get_chain_model(
         feat_dim=args.feat_dim,
         output_dim=args.output_dim,
+        ivector_dim=args.ivector_dim,
         lda_mat_filename=args.lda_mat_filename,
         hidden_dim=args.hidden_dim,
         bottleneck_dim=args.bottleneck_dim,
@@ -64,22 +66,29 @@ def main():
 
     dataloader = get_feat_dataloader(
         feats_scp=args.feats_scp,
+        ivector_scp=args.ivector_scp,
         model_left_context=args.model_left_context,
         model_right_context=args.model_right_context,
-        batch_size=32)
-
+        batch_size=32,
+        num_workers=10)
+    subsampling_factor = 3
+    subsampled_frames_per_chunk = args.frames_per_chunk // subsampling_factor
     for batch_idx, batch in enumerate(dataloader):
         key_list, padded_feat, output_len_list = batch
         padded_feat = padded_feat.to(device)
         with torch.no_grad():
             nnet_output, _ = model(padded_feat)
 
         num = len(key_list)
+        first = 0
         for i in range(num):
             key = key_list[i]
             output_len = output_len_list[i]
-            value = nnet_output[i, :output_len, :]
+            target_len = math.ceil(output_len / subsampled_frames_per_chunk)
+            result = nnet_output[first:first + target_len, :, :].split(1, 0)
+            value = torch.cat(result, dim=1)[0, :output_len, :]
             value = value.cpu()
+            first += target_len
 
             m = kaldi.SubMatrixFromDLPack(to_dlpack(value))
             m = Matrix(m)

egs/aishell/s10/chain/model.py

@@ -17,6 +17,7 @@
 
 def get_chain_model(feat_dim,
                     output_dim,
+                    ivector_dim,
                     hidden_dim,
                     bottleneck_dim,
                     prefinal_bottleneck_dim,
@@ -25,6 +26,7 @@ def get_chain_model(feat_dim,
                     lda_mat_filename=None):
     model = ChainModel(feat_dim=feat_dim,
                        output_dim=output_dim,
+                       ivector_dim=ivector_dim,
                        lda_mat_filename=lda_mat_filename,
                        hidden_dim=hidden_dim,
                        bottleneck_dim=bottleneck_dim,
@@ -82,6 +84,7 @@ class ChainModel(nn.Module):
     def __init__(self,
                  feat_dim,
                  output_dim,
+                 ivector_dim=0,
                  lda_mat_filename=None,
                  hidden_dim=1024,
                  bottleneck_dim=128,
@@ -97,8 +100,9 @@ def __init__(self,
         assert len(kernel_size_list) == len(subsampling_factor_list)
         num_layers = len(kernel_size_list)
 
+        input_dim = feat_dim * 3 + ivector_dim
         # tdnn1_affine requires [N, T, C]
-        self.tdnn1_affine = nn.Linear(in_features=feat_dim * 3,
+        self.tdnn1_affine = nn.Linear(in_features=input_dim,
                                       out_features=hidden_dim)
 
         # tdnn1_batchnorm requires [N, C, T]
@@ -142,11 +146,11 @@ def __init__(self,
         if lda_mat_filename:
             logging.info('Use LDA from {}'.format(lda_mat_filename))
             self.lda_A, self.lda_b = load_lda_mat(lda_mat_filename)
-            assert feat_dim * 3 == self.lda_A.shape[0]
+            assert input_dim == self.lda_A.shape[0]
             self.has_LDA = True
         else:
             logging.info('replace LDA with BatchNorm')
-            self.input_batch_norm = nn.BatchNorm1d(num_features=feat_dim * 3,
+            self.input_batch_norm = nn.BatchNorm1d(num_features=input_dim,
                                                    affine=False)
             self.has_LDA = False
 

egs/aishell/s10/chain/options.py

@@ -27,6 +27,23 @@ def _set_inference_args(parser):
                         dest='feats_scp',
                         help='feats.scp filename, required for inference',
                         type=str)
+
+    parser.add_argument('--frames-per-chunk',
+                        dest='frames_per_chunk',
+                        help='frames per chunk',
+                        type=int,
+                        default=51)
+
+    parser.add_argument('--ivector-scp',
+                        dest='ivector_scp',
+                        help='ivector.scp filename, required for ivector inference',
+                        type=str)
+
+    parser.add_argument('--ivector-period',
+                        dest='ivector_period',
+                        help='ivector period',
+                        type=int,
+                        default=10)
 
     parser.add_argument('--model-left-context',
                         dest='model_left_context',
@@ -228,10 +245,17 @@ def get_args():
 
     parser.add_argument('--feat-dim',
                         dest='feat_dim',
-                        help='nn input dimension',
+                        help='nn input 0 dimension',
                         required=True,
                         type=int)
 
+    parser.add_argument('--ivector-dim',
+                        dest='ivector_dim',
+                        help='nn input 1 dimension',
+                        required=False,
+                        default=0,
+                        type=int)
+
     parser.add_argument('--output-dim',
                         dest='output_dim',
                         help='nn output dimension',

egs/aishell/s10/chain/train.py

@@ -270,6 +270,7 @@ def process_job(learning_rate, local_rank=None):
     model = get_chain_model(
         feat_dim=args.feat_dim,
         output_dim=args.output_dim,
+        ivector_dim=args.ivector_dim,
         lda_mat_filename=args.lda_mat_filename,
         hidden_dim=args.hidden_dim,
         bottleneck_dim=args.bottleneck_dim,

egs/aishell/s10/conf/online_cmvn.conf

@@ -0,0 +1 @@
+# configuration file for apply-cmvn-online, used when invoking online2-wav-nnet3-latgen-faster.