Add E-Branchformer module (#2013)

* Add E-Branchformer module

* update result

examples/aishell/s0/README.md

@@ -203,4 +203,21 @@
 | attention rescoring       | 4.81  |
 | LM + attention rescoring  | 4.46  |
 
+## E-Branchformer Result
 
+* Feature info: using fbank feature, dither=1.0, cmvn, online speed perturb
+* * Model info:
+    * Model Params: 47,570,132
+    * Num Encoder Layer: 17
+    * CNN Kernel Size: 31
+* Training info: lr 0.001, weight_decay: 0.000001, batch size 16, 4 gpu, acc_grad 1, 240 epochs
+* Decoding info: ctc_weight 0.3, average_num 30
+* Git hash: 89962d1dcae18dd3a281782a40e74dd2721ae8fe
+
+| decoding mode          | CER  |
+| ---------------------- | ---- |
+| attention decoder      | 4.73 |
+| ctc greedy search      | 4.77 |
+| ctc prefix beam search | 4.77 |
+| attention rescoring    | 4.39 |
+| LM + attention rescoring  | 4.22  |

examples/aishell/s0/conf/train_ebranchformer.yaml

@@ -0,0 +1,88 @@
+# network architecture
+# encoder related
+encoder: e_branchformer
+encoder_conf:
+    output_size: 256    # dimension of attention
+    attention_heads: 8
+    linear_units: 1024  # the number of units of position-wise feed forward
+    num_blocks: 17      # the number of encoder blocks
+    cgmlp_linear_units: 1024
+    cgmlp_conv_kernel: 31
+    use_linear_after_conv: false
+    gate_activation: identity
+    merge_conv_kernel: 31
+    dropout_rate: 0.1
+    positional_dropout_rate: 0.1
+    attention_dropout_rate: 0.1
+    input_layer: conv2d # encoder input type, you can chose conv2d, conv2d6 and conv2d8
+    activation_type: 'swish'
+    causal: false
+    pos_enc_layer_type: 'rel_pos'
+    attention_layer_type: 'rel_selfattn'
+
+# decoder related
+decoder: transformer
+decoder_conf:
+    attention_heads: 4
+    linear_units: 2048
+    num_blocks: 6
+    dropout_rate: 0.1
+    positional_dropout_rate: 0.1
+    self_attention_dropout_rate: 0.1
+    src_attention_dropout_rate: 0.1
+
+# hybrid CTC/attention
+model_conf:
+    ctc_weight: 0.3
+    lsm_weight: 0.1     # label smoothing option
+    length_normalized_loss: false
+
+dataset_conf:
+    filter_conf:
+        max_length: 40960
+        min_length: 0
+        token_max_length: 200
+        token_min_length: 1
+    resample_conf:
+        resample_rate: 16000
+    speed_perturb: true
+    fbank_conf:
+        num_mel_bins: 80
+        frame_shift: 10
+        frame_length: 25
+        dither: 1.0
+    spec_aug: true
+    spec_aug_conf:
+        num_t_mask: 2
+        num_f_mask: 2
+        max_t: 50
+        max_f: 10
+    spec_sub: true
+    spec_sub_conf:
+        num_t_sub: 3
+        max_t: 30
+    spec_trim: false
+    spec_trim_conf:
+        max_t: 50
+    shuffle: true
+    shuffle_conf:
+        shuffle_size: 1500
+    sort: true
+    sort_conf:
+        sort_size: 500  # sort_size should be less than shuffle_size
+    batch_conf:
+        batch_type: 'static' # static or dynamic
+        batch_size: 16
+
+grad_clip: 5
+accum_grad: 1
+max_epoch: 240
+log_interval: 100
+
+optim: adam
+optim_conf:
+    lr: 0.001
+    weight_decay: 0.000001
+scheduler: warmuplr     # pytorch v1.1.0+ required
+scheduler_conf:
+    warmup_steps: 35000

wenet/branchformer/cgmlp.py

@@ -143,6 +143,7 @@ def __init__(
         dropout_rate: float,
         use_linear_after_conv: bool,
         gate_activation: str,
+        causal: bool = True,
     ):
         super().__init__()
 
@@ -155,6 +156,7 @@ def __init__(
             dropout_rate=dropout_rate,
             use_linear_after_conv=use_linear_after_conv,
             gate_activation=gate_activation,
+            causal=causal,
         )
         self.channel_proj2 = torch.nn.Linear(linear_units // 2, size)