KWS with CTCloss training and CTC prefix beam search detection.

examples/hi_xiaowen/s0/README.md

@@ -1,3 +1,5 @@
+Comparison among different backbones,
+all models use Max-Pooling loss.
 FRRs with FAR fixed at once per hour:
 
 | model                 | params(K) | epoch     | hi_xiaowen | nihao_wenwen |
@@ -8,3 +10,58 @@ FRRs with FAR fixed at once per hour:
 | DS_TCN(spec_aug)      | 287       | 80(avg30) | 0.008176   | 0.005075     |
 | MDTC                  | 156       | 80(avg10) | 0.007142   | 0.005920     |
 | MDTC_Small            | 31        | 80(avg10) | 0.005357   | 0.005920     |
+
+Next, we use CTC loss to train the model, with DS_TCN and FSMN backbones.
+and we use CTC prefix beam search to decode and detect keywords,
+the detection is either in non-streaming or streaming fashion.
+
+Since the FAR is pretty low when using CTC loss,
+the follow results are FRRs with FAR fixed at once per 12 hours:
+
+Comparison between Max-pooling and CTC loss.
+The CTC model is fine-tuned with base model pretrained on WenetSpeech(23 epoch, not converged).
+FRRs with FAR fixed at once per 12 hours
+
+| model                 | loss        | hi_xiaowen | nihao_wenwen | model ckpt |
+|-----------------------|-------------|------------|--------------|------------|
+| DS_TCN(spec_aug)      | Max-pooling | 0.051217   | 0.021896     | [dstcn-maxpooling](https://modelscope.cn/models/thuduj12/kws_wenwen_dstcn/files) |
+| DS_TCN(spec_aug)      | CTC         | 0.056574   | 0.056856     | [dstcn-ctc](https://modelscope.cn/models/thuduj12/kws_wenwen_dstcn_ctc/files) |
+
+
+Comparison between DS_TCN(Pretrained with Wenetspeech, 23 epoch, not converged)
+and FSMN(Pretained with modelscope released xiaoyunxiaoyun model, fully converged).
+FRRs with FAR fixed at once per 12 hours:
+
+| model                 | params(K)   | hi_xiaowen | nihao_wenwen | model ckpt                                                                    |
+|-----------------------|-------------|------------|--------------|-------------------------------------------------------------------------------|
+| DS_TCN(spec_aug)      | 955         | 0.056574   | 0.056856     | [dstcn-ctc](https://modelscope.cn/models/thuduj12/kws_wenwen_dstcn_ctc/files) |
+| FSMN(spec_aug)        | 756         | 0.031012   | 0.022460     | [fsmn-ctc](https://modelscope.cn/models/thuduj12/kws_wenwen_fsmn_ctc/files) |
+
+Now, the DSTCN model with CTC loss may not get the best performance, because the
+pretraining phase is not sufficiently converged. We recommend you use pretrained
+FSMN model as initial checkpoint to train your own model.
+
+Comparison Between stream_score_ctc and score_ctc.
+FRRs with FAR fixed at once per 12 hours:
+
+| model                 | stream      | hi_xiaowen | nihao_wenwen |
+|-----------------------|-------------|------------|--------------|
+| DS_TCN(spec_aug)      | no          | 0.056574   | 0.056856     |
+| DS_TCN(spec_aug)      | yes         | 0.132694   | 0.057044     |
+| FSMN(spec_aug)        | no          | 0.031012   | 0.022460     |
+| FSMN(spec_aug)        | yes         | 0.115215   | 0.020205     |
+
+Note: when using CTC prefix beam search to detect keywords in streaming case(detect in each frame),
+we record the probability of a keyword in a decoding path once the keyword appears in this path.
+Actually the probability will increase through the time, so we record a lower value of probability,
+which result in a higher False Rejection Rate in Detection Error Tradeoff result.
+The actual FRR will be lower than the DET curve gives in a given threshold.
+
+On some small data KWS tasks, we believe the FSMN-CTC model is more robust
+compared with the classification model using CE/Max-pooling loss.
+For more infomation and results of FSMN-CTC KWS model, you can click [modelscope](https://modelscope.cn/models/damo/speech_charctc_kws_phone-wenwen/summary).
+
+For realtime CTC-KWS, we should process wave input on streaming-fashion,
+include feature extraction, keyword decoding and detection and some postprocessing.
+Here is a [demo](https://modelscope.cn/studios/thuduj12/KWS_Nihao_Xiaojing/summary) in python,
+the core code is in wekws/bin/stream_kws_ctc.py, you can refer it to implement the runtime code.

examples/hi_xiaowen/s0/conf/ds_tcn_ctc.yaml

@@ -0,0 +1,50 @@
+dataset_conf:
+    filter_conf:
+        max_length: 2048
+        min_length: 0
+    resample_conf:
+        resample_rate: 16000
+    speed_perturb: false
+    feature_extraction_conf:
+        feature_type: 'fbank'
+        num_mel_bins: 40
+        frame_shift: 10
+        frame_length: 25
+        dither: 1.0
+    spec_aug: true
+    spec_aug_conf:
+        num_t_mask: 1
+        num_f_mask: 1
+        max_t: 20
+        max_f: 10
+    shuffle: true
+    shuffle_conf:
+        shuffle_size: 1500
+    batch_conf:
+        batch_size: 256
+
+model:
+    hidden_dim: 256
+    preprocessing:
+        type: linear
+    backbone:
+        type: tcn
+        ds: true
+        num_layers: 4
+        kernel_size: 8
+        dropout: 0.1
+    activation:
+        type: identity
+
+
+optim: adam
+optim_conf:
+    lr: 0.001
+    weight_decay: 0.0001
+
+training_config:
+    grad_clip: 5
+    max_epoch: 80
+    log_interval: 10
+    criterion: ctc
+

examples/hi_xiaowen/s0/conf/ds_tcn_ctc_base.yaml

@@ -0,0 +1,50 @@
+dataset_conf:
+    filter_conf:
+        max_length: 2048
+        min_length: 0
+    resample_conf:
+        resample_rate: 16000
+    speed_perturb: false
+    feature_extraction_conf:
+        feature_type: 'fbank'
+        num_mel_bins: 40
+        frame_shift: 10
+        frame_length: 25
+        dither: 1.0
+    spec_aug: true
+    spec_aug_conf:
+        num_t_mask: 1
+        num_f_mask: 1
+        max_t: 20
+        max_f: 10
+    shuffle: true
+    shuffle_conf:
+        shuffle_size: 1500
+    batch_conf:
+        batch_size: 200
+
+model:
+    hidden_dim: 256
+    preprocessing:
+        type: linear
+    backbone:
+        type: tcn
+        ds: true
+        num_layers: 4
+        kernel_size: 8
+        dropout: 0.1
+    activation:
+        type: identity
+
+
+optim: adam
+optim_conf:
+    lr: 0.001
+    weight_decay: 0.0001
+
+training_config:
+    grad_clip: 5
+    max_epoch: 50
+    log_interval: 100
+    criterion: ctc
+

examples/hi_xiaowen/s0/conf/fsmn_ctc.yaml

@@ -0,0 +1,64 @@
+dataset_conf:
+    filter_conf:
+        max_length: 2048
+        min_length: 0
+    resample_conf:
+        resample_rate: 16000
+    speed_perturb: false
+    feature_extraction_conf:
+        feature_type: 'fbank'
+        num_mel_bins: 80
+        frame_shift: 10
+        frame_length: 25
+        dither: 1.
+    context_expansion: true
+    context_expansion_conf:
+        left: 2
+        right: 2
+    frame_skip: 3
+    spec_aug: true
+    spec_aug_conf:
+        num_t_mask: 1
+        num_f_mask: 1
+        max_t: 20
+        max_f: 10
+    shuffle: true
+    shuffle_conf:
+        shuffle_size: 1500
+    batch_conf:
+        batch_size: 256
+
+model:
+    input_dim: 400
+    preprocessing:
+        type: none
+    hidden_dim: 128
+    backbone:
+        type: fsmn
+        input_affine_dim: 140
+        num_layers: 4
+        linear_dim: 250
+        proj_dim: 128
+        left_order: 10
+        right_order: 2
+        left_stride: 1
+        right_stride: 1
+        output_affine_dim: 140
+    classifier:
+        type: identity
+        dropout: 0.1
+    activation:
+        type: identity
+
+
+optim: adam
+optim_conf:
+    lr: 0.001
+    weight_decay: 0.0001
+
+training_config:
+    grad_clip: 5
+    max_epoch: 80
+    log_interval: 10
+    criterion: ctc
+

examples/hi_xiaowen/s0/run.sh

@@ -3,8 +3,8 @@
 
 . ./path.sh
 
-stage=0
-stop_stage=4
+stage=$1
+stop_stage=$2
 num_keywords=2
 
 config=conf/ds_tcn.yaml
@@ -98,6 +98,7 @@ if [ ${stage} -le 3 ] && [ ${stop_stage} -ge 3 ]; then
   python wekws/bin/score.py \
     --config $dir/config.yaml \
     --test_data data/test/data.list \
+    --gpu 0 \
     --batch_size 256 \
     --checkpoint $score_checkpoint \
     --score_file $result_dir/score.txt  \
@@ -111,6 +112,12 @@ if [ ${stage} -le 3 ] && [ ${stop_stage} -ge 3 ]; then
       --score_file $result_dir/score.txt \
       --stats_file $result_dir/stats.${keyword}.txt
   done
+
+  # plot det curve
+  python wekws/bin/plot_det_curve.py \
+      --keywords_dict dict/words.txt \
+      --stats_dir  $result_dir \
+      --figure_file $result_dir/det.png
 fi