diff --git a/examples/aishell/asr0/conf/deepspeech2.yaml b/examples/aishell/asr0/conf/deepspeech2.yaml
index fb6998647..913354f5d 100644
--- a/examples/aishell/asr0/conf/deepspeech2.yaml
+++ b/examples/aishell/asr0/conf/deepspeech2.yaml
@@ -15,50 +15,53 @@ max_output_input_ratio: .inf
 ###########################################
 #              Dataloader                 #
 ###########################################
-batch_size: 64 # one gpu
-mean_std_filepath: data/mean_std.json
-unit_type: char
 vocab_filepath: data/lang_char/vocab.txt 
-augmentation_config: conf/augmentation.json
-random_seed: 0
-spm_model_prefix: 
-spectrum_type: linear
+spm_model_prefix: ''
+unit_type: 'char'
+preprocess_config: conf/preprocess.yaml
 feat_dim: 161
-delta_delta: False
 stride_ms: 10.0
-window_ms: 20.0
-n_fft: None
-max_freq: None
-target_sample_rate: 16000
-use_dB_normalization: True
-target_dB: -20
-dither: 1.0
-keep_transcription_text: False
-sortagrad: True
-shuffle_method: batch_shuffle
-num_workers: 2
+window_ms: 25.0
+sortagrad: 0 # Feed samples from shortest to longest ; -1: enabled for all epochs, 0: disabled, other: enabled for 'other' epochs 
+batch_size: 64
+maxlen_in: 512  # if input length  > maxlen-in, batchsize is automatically reduced
+maxlen_out: 150  # if output length > maxlen-out, batchsize is automatically reduced
+minibatches: 0 # for debug
+batch_count: auto
+batch_bins: 0 
+batch_frames_in: 0
+batch_frames_out: 0
+batch_frames_inout: 0
+num_workers: 8
+subsampling_factor: 1
+num_encs: 1
 
 ############################################
 #           Network Architecture           #
 ############################################
 num_conv_layers: 2
-num_rnn_layers: 3
+num_rnn_layers: 5
 rnn_layer_size: 1024
-use_gru: True 
-share_rnn_weights: False
+rnn_direction: bidirect # [forward, bidirect]
+num_fc_layers: 0
+fc_layers_size_list: -1,
+use_gru: False 
 blank_id: 0
-ctc_grad_norm_type: instance 
-
+  
+  
 ###########################################
 #                Training                 #
 ###########################################
-n_epoch: 80
+n_epoch: 50
 accum_grad: 1
-lr: 2.0e-3
-lr_decay: 0.83
+lr: 5.0e-4
+lr_decay: 0.93
 weight_decay: 1.0e-6
 global_grad_clip: 3.0
-log_interval: 100
+dist_sampler: False
+log_interval: 1
 checkpoint:
   kbest_n: 50
   latest_n: 5
+
+  
diff --git a/examples/aishell/asr0/conf/deepspeech2_online.yaml b/examples/aishell/asr0/conf/deepspeech2_online.yaml
index ef01ac595..a53e19f37 100644
--- a/examples/aishell/asr0/conf/deepspeech2_online.yaml
+++ b/examples/aishell/asr0/conf/deepspeech2_online.yaml
@@ -15,28 +15,26 @@ max_output_input_ratio: .inf
 ###########################################
 #              Dataloader                 #
 ###########################################
-batch_size: 64 # one gpu
-mean_std_filepath: data/mean_std.json
-unit_type: char
 vocab_filepath: data/lang_char/vocab.txt 
-augmentation_config: conf/augmentation.json
-random_seed: 0
-spm_model_prefix: 
-spectrum_type: linear #linear, mfcc, fbank
+spm_model_prefix: ''
+unit_type: 'char'
+preprocess_config: conf/preprocess.yaml
 feat_dim: 161
-delta_delta: False
 stride_ms: 10.0
-window_ms: 20.0
-n_fft: None
-max_freq: None
-target_sample_rate: 16000
-use_dB_normalization: True
-target_dB: -20
-dither: 1.0
-keep_transcription_text: False
-sortagrad: True
-shuffle_method: batch_shuffle
-num_workers: 0
+window_ms: 25.0
+sortagrad: 0 # Feed samples from shortest to longest ; -1: enabled for all epochs, 0: disabled, other: enabled for 'other' epochs 
+batch_size: 64
+maxlen_in: 512  # if input length  > maxlen-in, batchsize is automatically reduced
+maxlen_out: 150  # if output length > maxlen-out, batchsize is automatically reduced
+minibatches: 0 # for debug
+batch_count: auto
+batch_bins: 0 
+batch_frames_in: 0
+batch_frames_out: 0
+batch_frames_inout: 0
+num_workers: 8
+subsampling_factor: 1
+num_encs: 1
 
 ############################################
 #           Network Architecture           #
@@ -54,12 +52,13 @@ blank_id: 0
 ###########################################
 #                Training                 #
 ###########################################
-n_epoch: 65
+n_epoch: 30
 accum_grad: 1
 lr: 5.0e-4
 lr_decay: 0.93
 weight_decay: 1.0e-6
 global_grad_clip: 3.0
+dist_sampler: False
 log_interval: 100
 checkpoint:
   kbest_n: 50
diff --git a/examples/aishell/asr0/conf/tuning/decode.yaml b/examples/aishell/asr0/conf/tuning/decode.yaml
index 5778e6565..7dbc6fa82 100644
--- a/examples/aishell/asr0/conf/tuning/decode.yaml
+++ b/examples/aishell/asr0/conf/tuning/decode.yaml
@@ -2,9 +2,9 @@ decode_batch_size: 128
 error_rate_type: cer 
 decoding_method: ctc_beam_search
 lang_model_path: data/lm/zh_giga.no_cna_cmn.prune01244.klm
-alpha: 1.9
-beta: 5.0
-beam_size: 300
+alpha: 2.2
+beta: 4.3
+beam_size: 500
 cutoff_prob: 0.99
 cutoff_top_n: 40
 num_proc_bsearch: 10
diff --git a/examples/aishell/asr0/local/data.sh b/examples/aishell/asr0/local/data.sh
index ec692eba6..8722c1ca3 100755
--- a/examples/aishell/asr0/local/data.sh
+++ b/examples/aishell/asr0/local/data.sh
@@ -33,12 +33,13 @@ if [ ${stage} -le 0 ] && [ ${stop_stage} -ge 0 ]; then
     num_workers=$(nproc)
     python3 ${MAIN_ROOT}/utils/compute_mean_std.py \
     --manifest_path="data/manifest.train.raw" \
-    --spectrum_type="linear" \
+    --spectrum_type="fbank" \
+    --feat_dim=161 \
     --delta_delta=false \
     --stride_ms=10 \
-    --window_ms=20 \
+    --window_ms=25 \
     --sample_rate=16000 \
-    --use_dB_normalization=True \
+    --use_dB_normalization=False \
     --num_samples=2000 \
     --num_workers=${num_workers} \
     --output_path="data/mean_std.json"
diff --git a/examples/aishell/asr0/run.sh b/examples/aishell/asr0/run.sh
index 114af5a97..0358b821d 100755
--- a/examples/aishell/asr0/run.sh
+++ b/examples/aishell/asr0/run.sh
@@ -7,8 +7,7 @@ stage=0
 stop_stage=100
 conf_path=conf/deepspeech2.yaml    #conf/deepspeech2.yaml or conf/deepspeech2_online.yaml
 decode_conf_path=conf/tuning/decode.yaml
-avg_num=1
-model_type=offline    # offline or online
+avg_num=10
 audio_file=data/demo_01_03.wav
 
 source ${MAIN_ROOT}/utils/parse_options.sh || exit 1;
diff --git a/examples/librispeech/asr0/conf/deepspeech2.yaml b/examples/librispeech/asr0/conf/deepspeech2.yaml
index 0307b9f39..cca695fe5 100644
--- a/examples/librispeech/asr0/conf/deepspeech2.yaml
+++ b/examples/librispeech/asr0/conf/deepspeech2.yaml
@@ -15,51 +15,51 @@ max_output_input_ratio: .inf
 ###########################################
 #              Dataloader                 #
 ###########################################
-batch_size: 20
-mean_std_filepath: data/mean_std.json
-unit_type: char
-vocab_filepath: data/lang_char/vocab.txt
-augmentation_config: conf/augmentation.json
-random_seed: 0
-spm_model_prefix: 
-spectrum_type: linear
-feat_dim: 
-target_sample_rate: 16000
-max_freq: None
-n_fft: None
+vocab_filepath: data/lang_char/vocab.txt 
+spm_model_prefix: ''
+unit_type: 'char'
+preprocess_config: conf/preprocess.yaml
+feat_dim: 161
 stride_ms: 10.0
-window_ms: 20.0
-delta_delta: False
-dither: 1.0
-use_dB_normalization: True 
-target_dB: -20
-random_seed: 0
-keep_transcription_text: False
-sortagrad: True 
-shuffle_method: batch_shuffle
-num_workers: 2
+window_ms: 25.0
+sortagrad: 0 # Feed samples from shortest to longest ; -1: enabled for all epochs, 0: disabled, other: enabled for 'other' epochs 
+batch_size: 64
+maxlen_in: 512  # if input length  > maxlen-in, batchsize is automatically reduced
+maxlen_out: 150  # if output length > maxlen-out, batchsize is automatically reduced
+minibatches: 0 # for debug
+batch_count: auto
+batch_bins: 0 
+batch_frames_in: 0
+batch_frames_out: 0
+batch_frames_inout: 0
+num_workers: 8
+subsampling_factor: 1
+num_encs: 1
 
 ############################################
 #           Network Architecture           #
 ############################################
 num_conv_layers: 2
-num_rnn_layers: 3
-rnn_layer_size: 2048
+num_rnn_layers: 5
+rnn_layer_size: 1024
+rnn_direction: bidirect
+num_fc_layers: 0
+fc_layers_size_list: -1
 use_gru: False 
-share_rnn_weights: True
 blank_id: 0
   
 
 ###########################################
 #                Training                 #
 ###########################################
-n_epoch: 50
+n_epoch: 15
 accum_grad: 1
-lr: 1.0e-3
-lr_decay: 0.83
+lr: 5.0e-4
+lr_decay: 0.93
 weight_decay: 1.0e-6
 global_grad_clip: 5.0
-log_interval: 100
+dist_sampler: False
+log_interval: 1
 checkpoint:
   kbest_n: 50
   latest_n: 5
diff --git a/examples/librispeech/asr0/conf/deepspeech2_online.yaml b/examples/librispeech/asr0/conf/deepspeech2_online.yaml
index a0d2bcfe2..93421ef44 100644
--- a/examples/librispeech/asr0/conf/deepspeech2_online.yaml
+++ b/examples/librispeech/asr0/conf/deepspeech2_online.yaml
@@ -15,39 +15,36 @@ max_output_input_ratio: .inf
 ###########################################
 #              Dataloader                 #
 ###########################################
-batch_size: 15
-mean_std_filepath: data/mean_std.json
-unit_type: char
-vocab_filepath: data/lang_char/vocab.txt
-augmentation_config: conf/augmentation.json
-random_seed: 0
-spm_model_prefix: 
-spectrum_type: linear
-feat_dim: 
-target_sample_rate: 16000
-max_freq: None
-n_fft: None
+vocab_filepath: data/lang_char/vocab.txt 
+spm_model_prefix: ''
+unit_type: 'char'
+preprocess_config: conf/preprocess.yaml
+feat_dim: 161
 stride_ms: 10.0
-window_ms: 20.0
-delta_delta: False
-dither: 1.0
-use_dB_normalization: True 
-target_dB: -20
-random_seed: 0
-keep_transcription_text: False
-sortagrad: True 
-shuffle_method: batch_shuffle
-num_workers: 0
+window_ms: 25.0
+sortagrad: 0 # Feed samples from shortest to longest ; -1: enabled for all epochs, 0: disabled, other: enabled for 'other' epochs 
+batch_size: 64
+maxlen_in: 512  # if input length  > maxlen-in, batchsize is automatically reduced
+maxlen_out: 150  # if output length > maxlen-out, batchsize is automatically reduced
+minibatches: 0 # for debug
+batch_count: auto
+batch_bins: 0 
+batch_frames_in: 0
+batch_frames_out: 0
+batch_frames_inout: 0
+num_workers: 8
+subsampling_factor: 1
+num_encs: 1
 
 ############################################
 #           Network Architecture           #
 ############################################
 num_conv_layers: 2
-num_rnn_layers: 3
-rnn_layer_size: 2048
+num_rnn_layers: 5
+rnn_layer_size: 1024
 rnn_direction: forward
-num_fc_layers: 2
-fc_layers_size_list: 512, 256
+num_fc_layers: 0
+fc_layers_size_list: -1
 use_gru: False 
 blank_id: 0
   
@@ -55,13 +52,13 @@ blank_id: 0
 ###########################################
 #                Training                 #
 ###########################################
-n_epoch: 50
-accum_grad: 4
-lr: 1.0e-3
-lr_decay: 0.83
+n_epoch: 65
+accum_grad: 1
+lr: 5.0e-4
+lr_decay: 0.93
 weight_decay: 1.0e-6
 global_grad_clip: 5.0
-log_interval: 100
+log_interval: 1
 checkpoint:
   kbest_n: 50
   latest_n: 5
diff --git a/examples/librispeech/asr0/local/data.sh b/examples/librispeech/asr0/local/data.sh
index b97e8c211..a28fddc96 100755
--- a/examples/librispeech/asr0/local/data.sh
+++ b/examples/librispeech/asr0/local/data.sh
@@ -49,12 +49,13 @@ if [ ${stage} -le 0 ] && [ ${stop_stage} -ge 0 ]; then
     python3 ${MAIN_ROOT}/utils/compute_mean_std.py \
     --manifest_path="data/manifest.train.raw" \
     --num_samples=2000 \
-    --spectrum_type="linear" \
+    --spectrum_type="fbank" \
+    --feat_dim=161 \
     --delta_delta=false \
     --sample_rate=16000 \
     --stride_ms=10 \
-    --window_ms=20 \
-    --use_dB_normalization=True \
+    --window_ms=25 \
+    --use_dB_normalization=False \
     --num_workers=${num_workers} \
     --output_path="data/mean_std.json"
 
diff --git a/examples/librispeech/asr0/local/test.sh b/examples/librispeech/asr0/local/test.sh
index ea40046b1..5654a8794 100755
--- a/examples/librispeech/asr0/local/test.sh
+++ b/examples/librispeech/asr0/local/test.sh
@@ -4,6 +4,8 @@ if [ $# != 4 ];then
     echo "usage: ${0} config_path decode_config_path ckpt_path_prefix model_type"
     exit -1
 fi
+stage=0
+stop_stage=100
 
 ngpu=$(echo $CUDA_VISIBLE_DEVICES | awk -F "," '{print NF}')
 echo "using $ngpu gpus..."
@@ -19,17 +21,44 @@ if [ $? -ne 0 ]; then
    exit 1
 fi
 
-python3 -u ${BIN_DIR}/test.py \
---ngpu ${ngpu} \
---config ${config_path} \
---decode_cfg ${decode_config_path} \
---result_file ${ckpt_prefix}.rsl \
---checkpoint_path ${ckpt_prefix} \
---model_type ${model_type}
+if [ ${stage} -le 0 ] && [ ${stop_stage} -ge 0 ]; then
+    # format the reference test file
+    python utils/format_rsl.py \
+        --origin_ref data/manifest.test-clean.raw \
+        --trans_ref data/manifest.test-clean.text
 
-if [ $? -ne 0 ]; then
-    echo "Failed in evaluation!"
-    exit 1
+    python3 -u ${BIN_DIR}/test.py \
+    --ngpu ${ngpu} \
+    --config ${config_path} \
+    --decode_cfg ${decode_config_path} \
+    --result_file ${ckpt_prefix}.rsl \
+    --checkpoint_path ${ckpt_prefix} \
+    --model_type ${model_type}
+
+    if [ $? -ne 0 ]; then
+        echo "Failed in evaluation!"
+        exit 1
+    fi
+
+    python utils/format_rsl.py \
+        --origin_hyp ${ckpt_prefix}.rsl \
+        --trans_hyp ${ckpt_prefix}.rsl.text
+
+    python utils/compute-wer.py --char=1 --v=1 \
+        data/manifest.test-clean.text ${ckpt_prefix}.rsl.text > ${ckpt_prefix}.error
+fi
+
+if [ ${stage} -le 101 ] && [ ${stop_stage} -ge 101 ]; then
+    python utils/format_rsl.py \
+        --origin_ref data/manifest.test-clean.raw \
+        --trans_ref_sclite data/manifest.test.text-clean.sclite
+
+        python utils/format_rsl.py \
+            --origin_hyp ${ckpt_prefix}.rsl \
+            --trans_hyp_sclite ${ckpt_prefix}.rsl.text.sclite
+
+        mkdir -p ${ckpt_prefix}_sclite
+        sclite -i wsj -r data/manifest.test-clean.text.sclite -h  ${ckpt_prefix}.rsl.text.sclite  -e utf-8 -o all -O ${ckpt_prefix}_sclite -c NOASCII
 fi
 
 
diff --git a/examples/librispeech/asr0/run.sh b/examples/librispeech/asr0/run.sh
index ca2c2b9da..d96f65823 100755
--- a/examples/librispeech/asr0/run.sh
+++ b/examples/librispeech/asr0/run.sh
@@ -2,13 +2,12 @@
 set -e
 source path.sh
 
-gpus=0,1,2,3,4,5,6,7
+gpus=0,1,2,3
 stage=0
 stop_stage=100
 conf_path=conf/deepspeech2.yaml
 decode_conf_path=conf/tuning/decode.yaml
-avg_num=30
-model_type=offline
+avg_num=5
 audio_file=data/demo_002_en.wav
 
 source ${MAIN_ROOT}/utils/parse_options.sh || exit 1;
@@ -43,6 +42,11 @@ if [ ${stage} -le 4 ] && [ ${stop_stage} -ge 4 ]; then
 fi
 
 if [ ${stage} -le 5 ] && [ ${stop_stage} -ge 5 ]; then
+    # test export ckpt avg_n
+    CUDA_VISIBLE_DEVICES=0 ./local/test_export.sh ${conf_path} ${decode_conf_path} exp/${ckpt}/checkpoints/${avg_ckpt}.jit ${model_type}|| exit -1
+fi
+
+if [ ${stage} -le 6 ] && [ ${stop_stage} -ge 6 ]; then
     # test a single .wav file
     CUDA_VISIBLE_DEVICES=0 ./local/test_wav.sh ${conf_path} ${decode_conf_path} exp/${ckpt}/checkpoints/${avg_ckpt} ${model_type} ${audio_file} || exit -1
 fi
diff --git a/paddlespeech/cli/asr/infer.py b/paddlespeech/cli/asr/infer.py
index 92f9b0e41..f26901a1e 100644
--- a/paddlespeech/cli/asr/infer.py
+++ b/paddlespeech/cli/asr/infer.py
@@ -138,6 +138,7 @@ class ASRExecutor(BaseExecutor):
             tag = model_type + '-' + lang + '-' + sample_rate_str
             self.task_resource.set_task_model(tag, version=None)
             self.res_path = self.task_resource.res_dir
+
             self.cfg_path = os.path.join(
                 self.res_path, self.task_resource.res_dict['cfg_path'])
             self.ckpt_path = os.path.join(
@@ -158,15 +159,18 @@ class ASRExecutor(BaseExecutor):
         self.config.merge_from_file(self.cfg_path)
 
         with UpdateConfig(self.config):
-            if "deepspeech2online" in model_type or "deepspeech2offline" in model_type:
-                from paddlespeech.s2t.io.collator import SpeechCollator
-                self.vocab = self.config.vocab_filepath
+            if self.config.spm_model_prefix:
+                self.config.spm_model_prefix = os.path.join(
+                    self.res_path, self.config.spm_model_prefix)
+            self.text_feature = TextFeaturizer(
+                unit_type=self.config.unit_type,
+                vocab=self.config.vocab_filepath,
+                spm_model_prefix=self.config.spm_model_prefix)
+            if "deepspeech2" in model_type:
                 self.config.decode.lang_model_path = os.path.join(
                     MODEL_HOME, 'language_model',
                     self.config.decode.lang_model_path)
-                self.collate_fn_test = SpeechCollator.from_config(self.config)
-                self.text_feature = TextFeaturizer(
-                    unit_type=self.config.unit_type, vocab=self.vocab)
+
                 lm_url = self.task_resource.res_dict['lm_url']
                 lm_md5 = self.task_resource.res_dict['lm_md5']
                 self.download_lm(
@@ -174,12 +178,6 @@ class ASRExecutor(BaseExecutor):
                     os.path.dirname(self.config.decode.lang_model_path), lm_md5)
 
             elif "conformer" in model_type or "transformer" in model_type:
-                self.config.spm_model_prefix = os.path.join(
-                    self.res_path, self.config.spm_model_prefix)
-                self.text_feature = TextFeaturizer(
-                    unit_type=self.config.unit_type,
-                    vocab=self.config.vocab_filepath,
-                    spm_model_prefix=self.config.spm_model_prefix)
                 self.config.decode.decoding_method = decode_method
 
             else:
@@ -222,19 +220,7 @@ class ASRExecutor(BaseExecutor):
             logger.info("Preprocess audio_file:" + audio_file)
 
         # Get the object for feature extraction
-        if "deepspeech2online" in model_type or "deepspeech2offline" in model_type:
-            audio, _ = self.collate_fn_test.process_utterance(
-                audio_file=audio_file, transcript=" ")
-            audio_len = audio.shape[0]
-            audio = paddle.to_tensor(audio, dtype='float32')
-            audio_len = paddle.to_tensor(audio_len)
-            audio = paddle.unsqueeze(audio, axis=0)
-            # vocab_list = collate_fn_test.vocab_list
-            self._inputs["audio"] = audio
-            self._inputs["audio_len"] = audio_len
-            logger.info(f"audio feat shape: {audio.shape}")
-
-        elif "conformer" in model_type or "transformer" in model_type:
+        if "deepspeech2" in model_type or "conformer" in model_type or "transformer" in model_type:
             logger.info("get the preprocess conf")
             preprocess_conf = self.config.preprocess_config
             preprocess_args = {"train": False}
@@ -242,7 +228,6 @@ class ASRExecutor(BaseExecutor):
             logger.info("read the audio file")
             audio, audio_sample_rate = soundfile.read(
                 audio_file, dtype="int16", always_2d=True)
-
             if self.change_format:
                 if audio.shape[1] >= 2:
                     audio = audio.mean(axis=1, dtype=np.int16)
@@ -285,7 +270,7 @@ class ASRExecutor(BaseExecutor):
         cfg = self.config.decode
         audio = self._inputs["audio"]
         audio_len = self._inputs["audio_len"]
-        if "deepspeech2online" in model_type or "deepspeech2offline" in model_type:
+        if "deepspeech2" in model_type:
             decode_batch_size = audio.shape[0]
             self.model.decoder.init_decoder(
                 decode_batch_size, self.text_feature.vocab_list,
diff --git a/paddlespeech/resource/model_alias.py b/paddlespeech/resource/model_alias.py
index 2b19ed065..0aeda13d4 100644
--- a/paddlespeech/resource/model_alias.py
+++ b/paddlespeech/resource/model_alias.py
@@ -23,7 +23,7 @@ model_alias = {
     # ---------------------------------
     "deepspeech2offline": ["paddlespeech.s2t.models.ds2:DeepSpeech2Model"],
     "deepspeech2online":
-    ["paddlespeech.s2t.models.ds2_online:DeepSpeech2ModelOnline"],
+    ["paddlespeech.s2t.models.ds2:DeepSpeech2Model"],
     "conformer": ["paddlespeech.s2t.models.u2:U2Model"],
     "conformer_online": ["paddlespeech.s2t.models.u2:U2Model"],
     "transformer": ["paddlespeech.s2t.models.u2:U2Model"],
diff --git a/paddlespeech/resource/pretrained_models.py b/paddlespeech/resource/pretrained_models.py
index 84362f967..f01f9165f 100644
--- a/paddlespeech/resource/pretrained_models.py
+++ b/paddlespeech/resource/pretrained_models.py
@@ -136,9 +136,9 @@ asr_dynamic_pretrained_models = {
     "deepspeech2online_wenetspeech-zh-16k": {
         '1.0': {
             'url':
-            'https://paddlespeech.bj.bcebos.com/s2t/wenetspeech/asr0/asr0_deepspeech2_online_wenetspeech_ckpt_1.0.0a.model.tar.gz',
+            'https://paddlespeech.bj.bcebos.com/s2t/wenetspeech/asr0/asr0_deepspeech2_online_wenetspeech_ckpt_1.0.1.model.tar.gz',
             'md5':
-            'e393d4d274af0f6967db24fc146e8074',
+            'd1be86a3e786042ab64f05161b5fae62',
             'cfg_path':
             'model.yaml',
             'ckpt_path':
@@ -152,13 +152,13 @@ asr_dynamic_pretrained_models = {
     "deepspeech2offline_aishell-zh-16k": {
         '1.0': {
             'url':
-            'https://paddlespeech.bj.bcebos.com/s2t/aishell/asr0/asr0_deepspeech2_aishell_ckpt_0.1.1.model.tar.gz',
+            'https://paddlespeech.bj.bcebos.com/s2t/aishell/asr0/asr0_deepspeech2_offline_aishell_ckpt_1.0.1.model.tar.gz',
             'md5':
-            '932c3593d62fe5c741b59b31318aa314',
+            '4d26066c6f19f52087425dc722ae5b13',
             'cfg_path':
             'model.yaml',
             'ckpt_path':
-            'exp/deepspeech2/checkpoints/avg_1',
+            'exp/deepspeech2/checkpoints/avg_10',
             'lm_url':
             'https://deepspeech.bj.bcebos.com/zh_lm/zh_giga.no_cna_cmn.prune01244.klm',
             'lm_md5':
@@ -168,9 +168,9 @@ asr_dynamic_pretrained_models = {
     "deepspeech2online_aishell-zh-16k": {
         '1.0': {
             'url':
-            'https://paddlespeech.bj.bcebos.com/s2t/aishell/asr0/asr0_deepspeech2_online_aishell_fbank161_ckpt_0.2.1.model.tar.gz',
+            'https://paddlespeech.bj.bcebos.com/s2t/aishell/asr0/asr0_deepspeech2_online_aishell_fbank161_ckpt_1.0.1.model.tar.gz',
             'md5':
-            '98b87b171b7240b7cae6e07d8d0bc9be',
+            'df5ddeac8b679a470176649ac4b78726',
             'cfg_path':
             'model.yaml',
             'ckpt_path':
@@ -188,13 +188,13 @@ asr_dynamic_pretrained_models = {
     "deepspeech2offline_librispeech-en-16k": {
         '1.0': {
             'url':
-            'https://paddlespeech.bj.bcebos.com/s2t/librispeech/asr0/asr0_deepspeech2_librispeech_ckpt_0.1.1.model.tar.gz',
+            'https://paddlespeech.bj.bcebos.com/s2t/librispeech/asr0/asr0_deepspeech2_offline_librispeech_ckpt_1.0.1.model.tar.gz',
             'md5':
-            'f5666c81ad015c8de03aac2bc92e5762',
+            'ed9e2b008a65268b3484020281ab048c',
             'cfg_path':
             'model.yaml',
             'ckpt_path':
-            'exp/deepspeech2/checkpoints/avg_1',
+            'exp/deepspeech2/checkpoints/avg_5',
             'lm_url':
             'https://deepspeech.bj.bcebos.com/en_lm/common_crawl_00.prune01111.trie.klm',
             'lm_md5':
@@ -207,17 +207,17 @@ asr_static_pretrained_models = {
     "deepspeech2offline_aishell-zh-16k": {
         '1.0': {
             'url':
-            'https://paddlespeech.bj.bcebos.com/s2t/aishell/asr0/asr0_deepspeech2_aishell_ckpt_0.1.1.model.tar.gz',
+            'https://paddlespeech.bj.bcebos.com/s2t/aishell/asr0/asr0_deepspeech2_offline_aishell_ckpt_1.0.1.model.tar.gz',
             'md5':
-            '932c3593d62fe5c741b59b31318aa314',
+            '4d26066c6f19f52087425dc722ae5b13',
             'cfg_path':
             'model.yaml',
             'ckpt_path':
-            'exp/deepspeech2/checkpoints/avg_1',
+            'exp/deepspeech2/checkpoints/avg_10',
             'model':
-            'exp/deepspeech2/checkpoints/avg_1.jit.pdmodel',
+            'exp/deepspeech2/checkpoints/avg_10.jit.pdmodel',
             'params':
-            'exp/deepspeech2/checkpoints/avg_1.jit.pdiparams',
+            'exp/deepspeech2/checkpoints/avg_10.jit.pdiparams',
             'lm_url':
             'https://deepspeech.bj.bcebos.com/zh_lm/zh_giga.no_cna_cmn.prune01244.klm',
             'lm_md5':
@@ -830,7 +830,7 @@ vector_dynamic_pretrained_models = {
             'cfg_path':
             'conf/model.yaml',  # the yaml config path
             'ckpt_path':
-            'model/model',  # the format is ${dir}/{model_name}, 
+            'model/model',  # the format is ${dir}/{model_name},
             # so the first 'model' is dir, the second 'model' is the name
             # this means we have a model stored as model/model.pdparams
         },
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/export.py b/paddlespeech/s2t/exps/deepspeech2/bin/export.py
index 62bf191df..049e7b688 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/export.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/export.py
@@ -32,11 +32,9 @@ def main(config, args):
 
 if __name__ == "__main__":
     parser = default_argument_parser()
-    # save jit model to 
+    # save jit model to
     parser.add_argument(
         "--export_path", type=str, help="path of the jit model to save")
-    parser.add_argument(
-        "--model_type", type=str, default='offline', help="offline/online")
     parser.add_argument(
         '--nxpu',
         type=int,
@@ -44,7 +42,6 @@ if __name__ == "__main__":
         choices=[0, 1],
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     args = parser.parse_args()
-    print("model_type:{}".format(args.model_type))
     print_arguments(args)
 
     # https://yaml.org/type/float.html
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test.py b/paddlespeech/s2t/exps/deepspeech2/bin/test.py
index a7d99e02a..a9828f6e7 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test.py
@@ -32,9 +32,7 @@ def main(config, args):
 
 if __name__ == "__main__":
     parser = default_argument_parser()
-    parser.add_argument(
-        "--model_type", type=str, default='offline', help='offline/online')
-    # save asr result to 
+    # save asr result to
     parser.add_argument(
         "--result_file", type=str, help="path of save the asr result")
     parser.add_argument(
@@ -45,7 +43,6 @@ if __name__ == "__main__":
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     args = parser.parse_args()
     print_arguments(args, globals())
-    print("model_type:{}".format(args.model_type))
 
     # https://yaml.org/type/float.html
     config = CfgNode(new_allowed=True)
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py b/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
index 58815ad63..8db081e7b 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
@@ -38,8 +38,6 @@ if __name__ == "__main__":
     #load jit model from
     parser.add_argument(
         "--export_path", type=str, help="path of the jit model to save")
-    parser.add_argument(
-        "--model_type", type=str, default='offline', help='offline/online')
     parser.add_argument(
         '--nxpu',
         type=int,
@@ -50,7 +48,6 @@ if __name__ == "__main__":
         "--enable-auto-log", action="store_true", help="use auto log")
     args = parser.parse_args()
     print_arguments(args, globals())
-    print("model_type:{}".format(args.model_type))
 
     # https://yaml.org/type/float.html
     config = CfgNode(new_allowed=True)
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py b/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py
index a909dd416..90b7d8a18 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py
@@ -23,7 +23,6 @@ from yacs.config import CfgNode
 from paddlespeech.s2t.frontend.featurizer.text_featurizer import TextFeaturizer
 from paddlespeech.s2t.io.collator import SpeechCollator
 from paddlespeech.s2t.models.ds2 import DeepSpeech2Model
-from paddlespeech.s2t.models.ds2_online import DeepSpeech2ModelOnline
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils import mp_tools
 from paddlespeech.s2t.utils.checkpoint import Checkpoint
@@ -113,12 +112,7 @@ class DeepSpeech2Tester_hub():
             config.input_dim = self.collate_fn_test.feature_size
             config.output_dim = self.collate_fn_test.vocab_size
 
-        if self.args.model_type == 'offline':
-            model = DeepSpeech2Model.from_config(config)
-        elif self.args.model_type == 'online':
-            model = DeepSpeech2ModelOnline.from_config(config)
-        else:
-            raise Exception("wrong model type")
+        model = DeepSpeech2Model.from_config(config)
 
         self.model = model
 
@@ -172,8 +166,6 @@ def main(config, args):
 
 if __name__ == "__main__":
     parser = default_argument_parser()
-    parser.add_argument(
-        "--model_type", type=str, default='offline', help='offline/online')
     parser.add_argument("--audio_file", type=str, help='audio file path')
     # save asr result to
     parser.add_argument(
@@ -184,7 +176,6 @@ if __name__ == "__main__":
         print("Please input the audio file path")
         sys.exit(-1)
     check(args.audio_file)
-    print("model_type:{}".format(args.model_type))
 
     # https://yaml.org/type/float.html
     config = CfgNode(new_allowed=True)
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/train.py b/paddlespeech/s2t/exps/deepspeech2/bin/train.py
index 3906b2fc6..fee7079d9 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/train.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/train.py
@@ -31,8 +31,6 @@ def main(config, args):
 
 if __name__ == "__main__":
     parser = default_argument_parser()
-    parser.add_argument(
-        "--model_type", type=str, default='offline', help='offline/online')
     parser.add_argument(
         '--nxpu',
         type=int,
@@ -40,7 +38,6 @@ if __name__ == "__main__":
         choices=[0, 1],
         help="if nxpu == 0 and ngpu == 0, use cpu.")
     args = parser.parse_args()
-    print("model_type:{}".format(args.model_type))
     print_arguments(args, globals())
 
     # https://yaml.org/type/float.html
diff --git a/paddlespeech/s2t/exps/deepspeech2/model.py b/paddlespeech/s2t/exps/deepspeech2/model.py
index 3c2eaab72..5aa8e3743 100644
--- a/paddlespeech/s2t/exps/deepspeech2/model.py
+++ b/paddlespeech/s2t/exps/deepspeech2/model.py
@@ -23,16 +23,12 @@ import paddle
 from paddle import distributed as dist
 from paddle import inference
 from paddle.io import DataLoader
+from paddlespeech.s2t.io.dataloader import BatchDataLoader
 
 from paddlespeech.s2t.frontend.featurizer.text_featurizer import TextFeaturizer
-from paddlespeech.s2t.io.collator import SpeechCollator
 from paddlespeech.s2t.io.dataset import ManifestDataset
-from paddlespeech.s2t.io.sampler import SortagradBatchSampler
-from paddlespeech.s2t.io.sampler import SortagradDistributedBatchSampler
 from paddlespeech.s2t.models.ds2 import DeepSpeech2InferModel
 from paddlespeech.s2t.models.ds2 import DeepSpeech2Model
-from paddlespeech.s2t.models.ds2_online import DeepSpeech2InferModelOnline
-from paddlespeech.s2t.models.ds2_online import DeepSpeech2ModelOnline
 from paddlespeech.s2t.training.gradclip import ClipGradByGlobalNormWithLog
 from paddlespeech.s2t.training.reporter import report
 from paddlespeech.s2t.training.timer import Timer
@@ -136,18 +132,13 @@ class DeepSpeech2Trainer(Trainer):
         config = self.config.clone()
         with UpdateConfig(config):
             if self.train:
-                config.input_dim = self.train_loader.collate_fn.feature_size
-                config.output_dim = self.train_loader.collate_fn.vocab_size
+                config.input_dim = self.train_loader.feat_dim
+                config.output_dim = self.train_loader.vocab_size
             else:
-                config.input_dim = self.test_loader.collate_fn.feature_size
-                config.output_dim = self.test_loader.collate_fn.vocab_size
+                config.input_dim = self.test_loader.feat_dim
+                config.output_dim = self.test_loader.vocab_size
 
-        if self.args.model_type == 'offline':
-            model = DeepSpeech2Model.from_config(config)
-        elif self.args.model_type == 'online':
-            model = DeepSpeech2ModelOnline.from_config(config)
-        else:
-            raise Exception("wrong model type")
+        model = DeepSpeech2Model.from_config(config)
         if self.parallel:
             model = paddle.DataParallel(model)
 
@@ -175,76 +166,81 @@ class DeepSpeech2Trainer(Trainer):
         config = self.config.clone()
         config.defrost()
         if self.train:
-            # train
-            config.manifest = config.train_manifest
-            train_dataset = ManifestDataset.from_config(config)
-            if self.parallel:
-                batch_sampler = SortagradDistributedBatchSampler(
-                    train_dataset,
-                    batch_size=config.batch_size,
-                    num_replicas=None,
-                    rank=None,
-                    shuffle=True,
-                    drop_last=True,
-                    sortagrad=config.sortagrad,
-                    shuffle_method=config.shuffle_method)
-            else:
-                batch_sampler = SortagradBatchSampler(
-                    train_dataset,
-                    shuffle=True,
-                    batch_size=config.batch_size,
-                    drop_last=True,
-                    sortagrad=config.sortagrad,
-                    shuffle_method=config.shuffle_method)
-
-            config.keep_transcription_text = False
-            collate_fn_train = SpeechCollator.from_config(config)
-            self.train_loader = DataLoader(
-                train_dataset,
-                batch_sampler=batch_sampler,
-                collate_fn=collate_fn_train,
-                num_workers=config.num_workers)
-
-            # dev
-            config.manifest = config.dev_manifest
-            dev_dataset = ManifestDataset.from_config(config)
-
-            config.augmentation_config = ""
-            config.keep_transcription_text = False
-            collate_fn_dev = SpeechCollator.from_config(config)
-            self.valid_loader = DataLoader(
-                dev_dataset,
-                batch_size=int(config.batch_size),
-                shuffle=False,
-                drop_last=False,
-                collate_fn=collate_fn_dev,
-                num_workers=config.num_workers)
-            logger.info("Setup train/valid  Dataloader!")
+            # train/valid dataset, return token ids
+            self.train_loader = BatchDataLoader(
+                json_file=config.train_manifest,
+                train_mode=True,
+                sortagrad=config.sortagrad,
+                batch_size=config.batch_size,
+                maxlen_in=config.maxlen_in,
+                maxlen_out=config.maxlen_out,
+                minibatches=config.minibatches,
+                mini_batch_size=self.args.ngpu,
+                batch_count=config.batch_count,
+                batch_bins=config.batch_bins,
+                batch_frames_in=config.batch_frames_in,
+                batch_frames_out=config.batch_frames_out,
+                batch_frames_inout=config.batch_frames_inout,
+                preprocess_conf=config.preprocess_config,
+                n_iter_processes=config.num_workers,
+                subsampling_factor=1,
+                num_encs=1,
+                dist_sampler=config.get('dist_sampler', False),
+                shortest_first=False)
+
+            self.valid_loader = BatchDataLoader(
+                json_file=config.dev_manifest,
+                train_mode=False,
+                sortagrad=False,
+                batch_size=config.batch_size,
+                maxlen_in=float('inf'),
+                maxlen_out=float('inf'),
+                minibatches=0,
+                mini_batch_size=self.args.ngpu,
+                batch_count='auto',
+                batch_bins=0,
+                batch_frames_in=0,
+                batch_frames_out=0,
+                batch_frames_inout=0,
+                preprocess_conf=config.preprocess_config,
+                n_iter_processes=config.num_workers,
+                subsampling_factor=1,
+                num_encs=1,
+                dist_sampler=config.get('dist_sampler', False),
+                shortest_first=False)
+            logger.info("Setup train/valid Dataloader!")
         else:
-            # test
-            config.manifest = config.test_manifest
-            test_dataset = ManifestDataset.from_config(config)
-
-            config.augmentation_config = ""
-            config.keep_transcription_text = True
-            collate_fn_test = SpeechCollator.from_config(config)
             decode_batch_size = config.get('decode', dict()).get(
                 'decode_batch_size', 1)
-            self.test_loader = DataLoader(
-                test_dataset,
+            # test dataset, return raw text
+            self.test_loader = BatchDataLoader(
+                json_file=config.test_manifest,
+                train_mode=False,
+                sortagrad=False,
                 batch_size=decode_batch_size,
-                shuffle=False,
-                drop_last=False,
-                collate_fn=collate_fn_test,
-                num_workers=config.num_workers)
-            logger.info("Setup test  Dataloader!")
+                maxlen_in=float('inf'),
+                maxlen_out=float('inf'),
+                minibatches=0,
+                mini_batch_size=1,
+                batch_count='auto',
+                batch_bins=0,
+                batch_frames_in=0,
+                batch_frames_out=0,
+                batch_frames_inout=0,
+                preprocess_conf=config.preprocess_config,
+                n_iter_processes=1,
+                subsampling_factor=1,
+                num_encs=1)
+            logger.info("Setup test/align Dataloader!")
 
 
 class DeepSpeech2Tester(DeepSpeech2Trainer):
     def __init__(self, config, args):
         super().__init__(config, args)
         self._text_featurizer = TextFeaturizer(
-            unit_type=config.unit_type, vocab=None)
+            unit_type=config.unit_type,
+            vocab=config.vocab_filepath)
+        self.vocab_list = self._text_featurizer.vocab_list
 
     def ordid2token(self, texts, texts_len):
         """ ord() id to chr() chr """
@@ -252,7 +248,8 @@ class DeepSpeech2Tester(DeepSpeech2Trainer):
         for text, n in zip(texts, texts_len):
             n = n.numpy().item()
             ids = text[:n]
-            trans.append(''.join([chr(i) for i in ids]))
+            #trans.append(''.join([chr(i) for i in ids]))
+            trans.append(self._text_featurizer.defeaturize(ids.numpy().tolist()))
         return trans
 
     def compute_metrics(self,
@@ -307,8 +304,8 @@ class DeepSpeech2Tester(DeepSpeech2Trainer):
 
         # Initialized the decoder in model
         decode_cfg = self.config.decode
-        vocab_list = self.test_loader.collate_fn.vocab_list
-        decode_batch_size = self.test_loader.batch_size
+        vocab_list = self.vocab_list
+        decode_batch_size = decode_cfg.decode_batch_size
         self.model.decoder.init_decoder(
             decode_batch_size, vocab_list, decode_cfg.decoding_method,
             decode_cfg.lang_model_path, decode_cfg.alpha, decode_cfg.beta,
@@ -338,17 +335,9 @@ class DeepSpeech2Tester(DeepSpeech2Trainer):
 
     @paddle.no_grad()
     def export(self):
-        if self.args.model_type == 'offline':
-            infer_model = DeepSpeech2InferModel.from_pretrained(
-                self.test_loader, self.config, self.args.checkpoint_path)
-        elif self.args.model_type == 'online':
-            infer_model = DeepSpeech2InferModelOnline.from_pretrained(
-                self.test_loader, self.config, self.args.checkpoint_path)
-        else:
-            raise Exception("wrong model type")
-
+        infer_model = DeepSpeech2InferModel.from_pretrained(
+            self.test_loader, self.config, self.args.checkpoint_path)
         infer_model.eval()
-        feat_dim = self.test_loader.collate_fn.feature_size
         static_model = infer_model.export()
         logger.info(f"Export code: {static_model.forward.code}")
         paddle.jit.save(static_model, self.args.export_path)
@@ -376,10 +365,10 @@ class DeepSpeech2ExportTester(DeepSpeech2Tester):
 
         # Initialized the decoder in model
         decode_cfg = self.config.decode
-        vocab_list = self.test_loader.collate_fn.vocab_list
-        if self.args.model_type == "online":
+        vocab_list = self.vocab_list
+        if self.config.rnn_direction == "forward":
             decode_batch_size = 1
-        elif self.args.model_type == "offline":
+        elif self.config.rnn_direction == "bidirect":
             decode_batch_size = self.test_loader.batch_size
         else:
             raise Exception("wrong model type")
@@ -412,11 +401,11 @@ class DeepSpeech2ExportTester(DeepSpeech2Tester):
         self.model.decoder.del_decoder()
 
     def compute_result_transcripts(self, audio, audio_len):
-        if self.args.model_type == "online":
+        if self.config.rnn_direction == "forward":
             output_probs, output_lens, trans_batch = self.static_forward_online(
                 audio, audio_len, decoder_chunk_size=1)
             result_transcripts = [trans[-1] for trans in trans_batch]
-        elif self.args.model_type == "offline":
+        elif self.config.rnn_direction == "bidirect":
             output_probs, output_lens = self.static_forward_offline(audio,
                                                                     audio_len)
             batch_size = output_probs.shape[0]
diff --git a/paddlespeech/s2t/models/ds2/conv.py b/paddlespeech/s2t/models/ds2/conv.py
index 4e766e793..448d4d1bb 100644
--- a/paddlespeech/s2t/models/ds2/conv.py
+++ b/paddlespeech/s2t/models/ds2/conv.py
@@ -11,161 +11,23 @@
 # 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 paddle import nn
-from paddle.nn import functional as F
+import paddle
 
-from paddlespeech.s2t.modules.activation import brelu
-from paddlespeech.s2t.modules.mask import make_non_pad_mask
-from paddlespeech.s2t.utils.log import Log
+from paddlespeech.s2t.modules.subsampling import Conv2dSubsampling4
 
-logger = Log(__name__).getlog()
 
-__all__ = ['ConvStack', "conv_output_size"]
+class Conv2dSubsampling4Pure(Conv2dSubsampling4):
+    def __init__(self, idim: int, odim: int, dropout_rate: float):
+        super().__init__(idim, odim, dropout_rate, None)
+        self.output_dim = ((idim - 1) // 2 - 1) // 2 * odim
+        self.receptive_field_length = 2 * (
+            3 - 1) + 3  # stride_1 * (kernel_size_2 - 1) + kerel_size_1
 
-
-def conv_output_size(I, F, P, S):
-    # https://stanford.edu/~shervine/teaching/cs-230/cheatsheet-convolutional-neural-networks#hyperparameters
-    # Output size after Conv:
-    #   By noting I the length of the input volume size, 
-    #   F the length of the filter, 
-    #   P the amount of zero padding, 
-    #   S the stride,
-    #   then the output size O of the feature map along that dimension is given by:
-    #       O = (I - F + Pstart + Pend) // S + 1
-    #   When Pstart == Pend == P, we can replace Pstart + Pend by 2P.
-    #   When Pstart == Pend == 0
-    #       O = (I - F - S) // S
-    # https://iq.opengenus.org/output-size-of-convolution/
-    # Output height = (Input height + padding height top + padding height bottom - kernel height) / (stride height) + 1
-    # Output width = (Output width + padding width right + padding width left - kernel width) / (stride width) + 1
-    return (I - F + 2 * P - S) // S
-
-
-# receptive field calculator
-# https://fomoro.com/research/article/receptive-field-calculator
-# https://stanford.edu/~shervine/teaching/cs-230/cheatsheet-convolutional-neural-networks#hyperparameters
-# https://distill.pub/2019/computing-receptive-fields/
-# Rl-1 = Sl * Rl + (Kl - Sl) 
-
-
-class ConvBn(nn.Layer):
-    """Convolution layer with batch normalization.
-
-    :param kernel_size: The x dimension of a filter kernel. Or input a tuple for
-                        two image dimension.
-    :type kernel_size: int|tuple|list
-    :param num_channels_in: Number of input channels.
-    :type num_channels_in: int
-    :param num_channels_out: Number of output channels.
-    :type num_channels_out: int
-    :param stride: The x dimension of the stride. Or input a tuple for two 
-                image dimension. 
-    :type stride: int|tuple|list
-    :param padding: The x dimension of the padding. Or input a tuple for two
-                    image dimension.
-    :type padding: int|tuple|list
-    :param act: Activation type, relu|brelu
-    :type act: string
-    :return: Batch norm layer after convolution layer.
-    :rtype: Variable
-
-    """
-
-    def __init__(self, num_channels_in, num_channels_out, kernel_size, stride,
-                 padding, act):
-
-        super().__init__()
-        assert len(kernel_size) == 2
-        assert len(stride) == 2
-        assert len(padding) == 2
-        self.kernel_size = kernel_size
-        self.stride = stride
-        self.padding = padding
-
-        self.conv = nn.Conv2D(
-            num_channels_in,
-            num_channels_out,
-            kernel_size=kernel_size,
-            stride=stride,
-            padding=padding,
-            weight_attr=None,
-            bias_attr=False,
-            data_format='NCHW')
-
-        self.bn = nn.BatchNorm2D(
-            num_channels_out,
-            weight_attr=None,
-            bias_attr=None,
-            data_format='NCHW')
-        self.act = F.relu if act == 'relu' else brelu
-
-    def forward(self, x, x_len):
-        """
-        x(Tensor): audio, shape [B, C, D, T]
-        """
+    def forward(self, x: paddle.Tensor,
+                x_len: paddle.Tensor) -> [paddle.Tensor, paddle.Tensor]:
+        x = x.unsqueeze(1)  # (b, c=1, t, f)
         x = self.conv(x)
-        x = self.bn(x)
-        x = self.act(x)
-
-        x_len = (x_len - self.kernel_size[1] + 2 * self.padding[1]
-                 ) // self.stride[1] + 1
-
-        # reset padding part to 0
-        masks = make_non_pad_mask(x_len)  #[B, T]
-        masks = masks.unsqueeze(1).unsqueeze(1)  # [B, 1, 1, T]
-        # TODO(Hui Zhang): not support bool multiply
-        # masks = masks.type_as(x)
-        masks = masks.astype(x.dtype)
-        x = x.multiply(masks)
-        return x, x_len
-
-
-class ConvStack(nn.Layer):
-    """Convolution group with stacked convolution layers.
-
-    :param feat_size: audio feature dim.
-    :type feat_size: int
-    :param num_stacks: Number of stacked convolution layers.
-    :type num_stacks: int
-    """
-
-    def __init__(self, feat_size, num_stacks):
-        super().__init__()
-        self.feat_size = feat_size  # D
-        self.num_stacks = num_stacks
-
-        self.conv_in = ConvBn(
-            num_channels_in=1,
-            num_channels_out=32,
-            kernel_size=(41, 11),  #[D, T]
-            stride=(2, 3),
-            padding=(20, 5),
-            act='brelu')
-
-        out_channel = 32
-        convs = [
-            ConvBn(
-                num_channels_in=32,
-                num_channels_out=out_channel,
-                kernel_size=(21, 11),
-                stride=(2, 1),
-                padding=(10, 5),
-                act='brelu') for i in range(num_stacks - 1)
-        ]
-        self.conv_stack = nn.LayerList(convs)
-
-        # conv output feat_dim
-        output_height = (feat_size - 1) // 2 + 1
-        for i in range(self.num_stacks - 1):
-            output_height = (output_height - 1) // 2 + 1
-        self.output_height = out_channel * output_height
-
-    def forward(self, x, x_len):
-        """
-        x: shape [B, C, D, T]
-        x_len : shape [B]
-        """
-        x, x_len = self.conv_in(x, x_len)
-        for i, conv in enumerate(self.conv_stack):
-            x, x_len = conv(x, x_len)
+        #b, c, t, f = paddle.shape(x) #not work under jit
+        x = x.transpose([0, 2, 1, 3]).reshape([0, 0, -1])
+        x_len = ((x_len - 1) // 2 - 1) // 2
         return x, x_len
diff --git a/paddlespeech/s2t/models/ds2/deepspeech2.py b/paddlespeech/s2t/models/ds2/deepspeech2.py
index 9c6b66c25..3f2c76ced 100644
--- a/paddlespeech/s2t/models/ds2/deepspeech2.py
+++ b/paddlespeech/s2t/models/ds2/deepspeech2.py
@@ -13,15 +13,14 @@
 # limitations under the License.
 """Deepspeech2 ASR Model"""
 import paddle
+import paddle.nn.functional as F
 from paddle import nn
 
-from paddlespeech.s2t.models.ds2.conv import ConvStack
-from paddlespeech.s2t.models.ds2.rnn import RNNStack
+from paddlespeech.s2t.models.ds2.conv import Conv2dSubsampling4Pure
 from paddlespeech.s2t.modules.ctc import CTCDecoder
 from paddlespeech.s2t.utils import layer_tools
 from paddlespeech.s2t.utils.checkpoint import Checkpoint
 from paddlespeech.s2t.utils.log import Log
-
 logger = Log(__name__).getlog()
 
 __all__ = ['DeepSpeech2Model', 'DeepSpeech2InferModel']
@@ -32,72 +31,197 @@ class CRNNEncoder(nn.Layer):
                  feat_size,
                  dict_size,
                  num_conv_layers=2,
-                 num_rnn_layers=3,
+                 num_rnn_layers=4,
                  rnn_size=1024,
-                 use_gru=False,
-                 share_rnn_weights=True):
+                 rnn_direction='forward',
+                 num_fc_layers=2,
+                 fc_layers_size_list=[512, 256],
+                 use_gru=False):
         super().__init__()
         self.rnn_size = rnn_size
         self.feat_size = feat_size  # 161 for linear
         self.dict_size = dict_size
-
-        self.conv = ConvStack(feat_size, num_conv_layers)
-
-        i_size = self.conv.output_height  # H after conv stack
-        self.rnn = RNNStack(
-            i_size=i_size,
-            h_size=rnn_size,
-            num_stacks=num_rnn_layers,
-            use_gru=use_gru,
-            share_rnn_weights=share_rnn_weights)
+        self.num_rnn_layers = num_rnn_layers
+        self.num_fc_layers = num_fc_layers
+        self.rnn_direction = rnn_direction
+        self.fc_layers_size_list = fc_layers_size_list
+        self.use_gru = use_gru
+        self.conv = Conv2dSubsampling4Pure(feat_size, 32, dropout_rate=0.0)
+
+        self.output_dim = self.conv.output_dim
+
+        i_size = self.conv.output_dim
+        self.rnn = nn.LayerList()
+        self.layernorm_list = nn.LayerList()
+        self.fc_layers_list = nn.LayerList()
+        if rnn_direction == 'bidirect' or rnn_direction == 'bidirectional':
+            layernorm_size = 2 * rnn_size
+        elif rnn_direction == 'forward':
+            layernorm_size = rnn_size
+        else:
+            raise Exception("Wrong rnn direction")
+        for i in range(0, num_rnn_layers):
+            if i == 0:
+                rnn_input_size = i_size
+            else:
+                rnn_input_size = layernorm_size
+            if use_gru is True:
+                self.rnn.append(
+                    nn.GRU(
+                        input_size=rnn_input_size,
+                        hidden_size=rnn_size,
+                        num_layers=1,
+                        direction=rnn_direction))
+            else:
+                self.rnn.append(
+                    nn.LSTM(
+                        input_size=rnn_input_size,
+                        hidden_size=rnn_size,
+                        num_layers=1,
+                        direction=rnn_direction))
+            self.layernorm_list.append(nn.LayerNorm(layernorm_size))
+            self.output_dim = layernorm_size
+
+        fc_input_size = layernorm_size
+        for i in range(self.num_fc_layers):
+            self.fc_layers_list.append(
+                nn.Linear(fc_input_size, fc_layers_size_list[i]))
+            fc_input_size = fc_layers_size_list[i]
+            self.output_dim = fc_layers_size_list[i]
 
     @property
     def output_size(self):
-        return self.rnn_size * 2
+        return self.output_dim
 
-    def forward(self, audio, audio_len):
+    def forward(self, x, x_lens, init_state_h_box=None, init_state_c_box=None):
         """Compute Encoder outputs
 
         Args:
-            audio (Tensor): [B, Tmax, D]
-            text (Tensor): [B, Umax]
-            audio_len (Tensor): [B]
-            text_len (Tensor): [B]
-        Returns:
+            x (Tensor): [B, T, D]
+            x_lens (Tensor): [B]
+            init_state_h_box(Tensor): init_states h for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
+            init_state_c_box(Tensor): init_states c for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
+        Return:
             x (Tensor): encoder outputs, [B, T, D]
             x_lens (Tensor): encoder length, [B]
+            final_state_h_box(Tensor): final_states h for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
+            final_state_c_box(Tensor): final_states c for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
         """
-        # [B, T, D]  -> [B, D, T]
-        audio = audio.transpose([0, 2, 1])
-        # [B, D, T] -> [B, C=1, D, T]
-        x = audio.unsqueeze(1)
-        x_lens = audio_len
+        if init_state_h_box is not None:
+            init_state_list = None
+
+            if self.use_gru is True:
+                init_state_h_list = paddle.split(
+                    init_state_h_box, self.num_rnn_layers, axis=0)
+                init_state_list = init_state_h_list
+            else:
+                init_state_h_list = paddle.split(
+                    init_state_h_box, self.num_rnn_layers, axis=0)
+                init_state_c_list = paddle.split(
+                    init_state_c_box, self.num_rnn_layers, axis=0)
+                init_state_list = [(init_state_h_list[i], init_state_c_list[i])
+                                   for i in range(self.num_rnn_layers)]
+        else:
+            init_state_list = [None] * self.num_rnn_layers
 
-        # convolution group
         x, x_lens = self.conv(x, x_lens)
+        final_chunk_state_list = []
+        for i in range(0, self.num_rnn_layers):
+            x, final_state = self.rnn[i](x, init_state_list[i],
+                                         x_lens)  #[B, T, D]
+            final_chunk_state_list.append(final_state)
+            x = self.layernorm_list[i](x)
+
+        for i in range(self.num_fc_layers):
+            x = self.fc_layers_list[i](x)
+            x = F.relu(x)
+
+        if self.use_gru is True:
+            final_chunk_state_h_box = paddle.concat(
+                final_chunk_state_list, axis=0)
+            final_chunk_state_c_box = init_state_c_box
+        else:
+            final_chunk_state_h_list = [
+                final_chunk_state_list[i][0] for i in range(self.num_rnn_layers)
+            ]
+            final_chunk_state_c_list = [
+                final_chunk_state_list[i][1] for i in range(self.num_rnn_layers)
+            ]
+            final_chunk_state_h_box = paddle.concat(
+                final_chunk_state_h_list, axis=0)
+            final_chunk_state_c_box = paddle.concat(
+                final_chunk_state_c_list, axis=0)
+
+        return x, x_lens, final_chunk_state_h_box, final_chunk_state_c_box
+
+    def forward_chunk_by_chunk(self, x, x_lens, decoder_chunk_size=8):
+        """Compute Encoder outputs
 
-        # convert data from convolution feature map to sequence of vectors
-        #B, C, D, T = paddle.shape(x)  # not work under jit
-        x = x.transpose([0, 3, 1, 2])  #[B, T, C, D]
-        #x = x.reshape([B, T, C * D])  #[B, T, C*D]  # not work under jit
-        x = x.reshape([0, 0, -1])  #[B, T, C*D]
-
-        # remove padding part
-        x, x_lens = self.rnn(x, x_lens)  #[B, T, D]
-        return x, x_lens
+        Args:
+            x (Tensor): [B, T, D]
+            x_lens (Tensor): [B]
+            decoder_chunk_size: The chunk size of decoder
+        Returns:
+            eouts_list (List of Tensor): The list of encoder outputs in chunk_size: [B, chunk_size, D] * num_chunks
+            eouts_lens_list (List of Tensor): The list of  encoder length in chunk_size: [B] * num_chunks
+            final_state_h_box(Tensor): final_states h for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
+            final_state_c_box(Tensor): final_states c for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
+        """
+        subsampling_rate = self.conv.subsampling_rate
+        receptive_field_length = self.conv.receptive_field_length
+        chunk_size = (decoder_chunk_size - 1
+                      ) * subsampling_rate + receptive_field_length
+        chunk_stride = subsampling_rate * decoder_chunk_size
+        max_len = x.shape[1]
+        assert (chunk_size <= max_len)
+
+        eouts_chunk_list = []
+        eouts_chunk_lens_list = []
+        if (max_len - chunk_size) % chunk_stride != 0:
+            padding_len = chunk_stride - (max_len - chunk_size) % chunk_stride
+        else:
+            padding_len = 0
+        padding = paddle.zeros((x.shape[0], padding_len, x.shape[2]))
+        padded_x = paddle.concat([x, padding], axis=1)
+        num_chunk = (max_len + padding_len - chunk_size) / chunk_stride + 1
+        num_chunk = int(num_chunk)
+        chunk_state_h_box = None
+        chunk_state_c_box = None
+        final_state_h_box = None
+        final_state_c_box = None
+        for i in range(0, num_chunk):
+            start = i * chunk_stride
+            end = start + chunk_size
+            x_chunk = padded_x[:, start:end, :]
+
+            x_len_left = paddle.where(x_lens - i * chunk_stride < 0,
+                                      paddle.zeros_like(x_lens),
+                                      x_lens - i * chunk_stride)
+            x_chunk_len_tmp = paddle.ones_like(x_lens) * chunk_size
+            x_chunk_lens = paddle.where(x_len_left < x_chunk_len_tmp,
+                                        x_len_left, x_chunk_len_tmp)
+
+            eouts_chunk, eouts_chunk_lens, chunk_state_h_box, chunk_state_c_box = self.forward(
+                x_chunk, x_chunk_lens, chunk_state_h_box, chunk_state_c_box)
+
+            eouts_chunk_list.append(eouts_chunk)
+            eouts_chunk_lens_list.append(eouts_chunk_lens)
+        final_state_h_box = chunk_state_h_box
+        final_state_c_box = chunk_state_c_box
+        return eouts_chunk_list, eouts_chunk_lens_list, final_state_h_box, final_state_c_box
 
 
 class DeepSpeech2Model(nn.Layer):
     """The DeepSpeech2 network structure.
 
-    :param audio_data: Audio spectrogram data layer.
-    :type audio_data: Variable
-    :param text_data: Transcription text data layer.
-    :type text_data: Variable
+    :param audio: Audio spectrogram data layer.
+    :type audio: Variable
+    :param text: Transcription text data layer.
+    :type text: Variable
     :param audio_len: Valid sequence length data layer.
     :type audio_len: Variable
-    :param masks: Masks data layer to reset padding.
-    :type masks: Variable
+    :param feat_size: feature size for audio.
+    :type feat_size: int
     :param dict_size: Dictionary size for tokenized transcription.
     :type dict_size: int
     :param num_conv_layers: Number of stacking convolution layers.
@@ -106,37 +230,41 @@ class DeepSpeech2Model(nn.Layer):
     :type num_rnn_layers: int
     :param rnn_size: RNN layer size (dimension of RNN cells).
     :type rnn_size: int
+    :param num_fc_layers: Number of stacking FC layers.
+    :type num_fc_layers: int
+    :param fc_layers_size_list: The list of FC layer sizes.
+    :type fc_layers_size_list: [int,]
     :param use_gru: Use gru if set True. Use simple rnn if set False.
     :type use_gru: bool
-    :param share_rnn_weights: Whether to share input-hidden weights between
-                              forward and backward direction RNNs.
-                              It is only available when use_gru=False.
-    :type share_weights: bool
     :return: A tuple of an output unnormalized log probability layer (
              before softmax) and a ctc cost layer.
     :rtype: tuple of LayerOutput
     """
 
-    def __init__(self,
-                 feat_size,
-                 dict_size,
-                 num_conv_layers=2,
-                 num_rnn_layers=3,
-                 rnn_size=1024,
-                 use_gru=False,
-                 share_rnn_weights=True,
-                 blank_id=0,
-                 ctc_grad_norm_type=None):
+    def __init__(
+            self,
+            feat_size,
+            dict_size,
+            num_conv_layers=2,
+            num_rnn_layers=4,
+            rnn_size=1024,
+            rnn_direction='forward',
+            num_fc_layers=2,
+            fc_layers_size_list=[512, 256],
+            use_gru=False,
+            blank_id=0,
+            ctc_grad_norm_type=None, ):
         super().__init__()
         self.encoder = CRNNEncoder(
             feat_size=feat_size,
             dict_size=dict_size,
             num_conv_layers=num_conv_layers,
             num_rnn_layers=num_rnn_layers,
+            rnn_direction=rnn_direction,
+            num_fc_layers=num_fc_layers,
+            fc_layers_size_list=fc_layers_size_list,
             rnn_size=rnn_size,
-            use_gru=use_gru,
-            share_rnn_weights=share_rnn_weights)
-        assert (self.encoder.output_size == rnn_size * 2)
+            use_gru=use_gru)
 
         self.decoder = CTCDecoder(
             odim=dict_size,  # <blank> is in  vocab
@@ -151,7 +279,7 @@ class DeepSpeech2Model(nn.Layer):
         """Compute Model loss
 
         Args:
-            audio (Tensors): [B, T, D]
+            audio (Tensor): [B, T, D]
             audio_len (Tensor): [B]
             text (Tensor): [B, U]
             text_len (Tensor): [B]
@@ -159,22 +287,22 @@ class DeepSpeech2Model(nn.Layer):
         Returns:
             loss (Tensor): [1]
         """
-        eouts, eouts_len = self.encoder(audio, audio_len)
+        eouts, eouts_len, final_state_h_box, final_state_c_box = self.encoder(
+            audio, audio_len, None, None)
         loss = self.decoder(eouts, eouts_len, text, text_len)
         return loss
 
     @paddle.no_grad()
     def decode(self, audio, audio_len):
         # decoders only accept string encoded in utf-8
-
         # Make sure the decoder has been initialized
-        eouts, eouts_len = self.encoder(audio, audio_len)
+        eouts, eouts_len, final_state_h_box, final_state_c_box = self.encoder(
+            audio, audio_len, None, None)
         probs = self.decoder.softmax(eouts)
         batch_size = probs.shape[0]
         self.decoder.reset_decoder(batch_size=batch_size)
         self.decoder.next(probs, eouts_len)
         trans_best, trans_beam = self.decoder.decode()
-
         return trans_best
 
     @classmethod
@@ -196,13 +324,15 @@ class DeepSpeech2Model(nn.Layer):
             The model built from pretrained result.
         """
         model = cls(
-            feat_size=dataloader.collate_fn.feature_size,
-            dict_size=dataloader.collate_fn.vocab_size,
+            feat_size=dataloader.feat_dim,
+            dict_size=dataloader.vocab_size,
             num_conv_layers=config.num_conv_layers,
             num_rnn_layers=config.num_rnn_layers,
             rnn_size=config.rnn_layer_size,
+            rnn_direction=config.rnn_direction,
+            num_fc_layers=config.num_fc_layers,
+            fc_layers_size_list=config.fc_layers_size_list,
             use_gru=config.use_gru,
-            share_rnn_weights=config.share_rnn_weights,
             blank_id=config.blank_id,
             ctc_grad_norm_type=config.get('ctc_grad_norm_type', None), )
         infos = Checkpoint().load_parameters(
@@ -229,8 +359,10 @@ class DeepSpeech2Model(nn.Layer):
             num_conv_layers=config.num_conv_layers,
             num_rnn_layers=config.num_rnn_layers,
             rnn_size=config.rnn_layer_size,
+            rnn_direction=config.rnn_direction,
+            num_fc_layers=config.num_fc_layers,
+            fc_layers_size_list=config.fc_layers_size_list,
             use_gru=config.use_gru,
-            share_rnn_weights=config.share_rnn_weights,
             blank_id=config.blank_id,
             ctc_grad_norm_type=config.get('ctc_grad_norm_type', None), )
         return model
@@ -240,28 +372,46 @@ class DeepSpeech2InferModel(DeepSpeech2Model):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
-    def forward(self, audio, audio_len):
-        """export model function
-
-        Args:
-            audio (Tensor): [B, T, D]
-            audio_len (Tensor): [B]
-
-        Returns:
-            probs: probs after softmax
-        """
-        eouts, eouts_len = self.encoder(audio, audio_len)
-        probs = self.decoder.softmax(eouts)
-        return probs, eouts_len
+    def forward(self, audio_chunk, audio_chunk_lens, chunk_state_h_box=None,
+                chunk_state_c_box=None):
+        if self.encoder.rnn_direction == "forward":
+            eouts_chunk, eouts_chunk_lens, final_state_h_box, final_state_c_box = self.encoder(
+                audio_chunk, audio_chunk_lens, chunk_state_h_box, chunk_state_c_box)
+            probs_chunk = self.decoder.softmax(eouts_chunk)
+            return probs_chunk, eouts_chunk_lens, final_state_h_box, final_state_c_box
+        elif self.encoder.rnn_direction == "bidirect":
+            eouts, eouts_len, _, _ = self.encoder(audio_chunk, audio_chunk_lens)
+            probs = self.decoder.softmax(eouts)
+            return probs, eouts_len
+        else:
+            raise Exception("wrong model type")
 
     def export(self):
-        static_model = paddle.jit.to_static(
-            self,
-            input_spec=[
-                paddle.static.InputSpec(
-                    shape=[None, None, self.encoder.feat_size],
-                    dtype='float32'),  # audio, [B,T,D]
-                paddle.static.InputSpec(shape=[None],
-                                        dtype='int64'),  # audio_length, [B]
-            ])
+        if self.encoder.rnn_direction == "forward":
+            static_model = paddle.jit.to_static(
+                self,
+                input_spec=[
+                    paddle.static.InputSpec(
+                        shape=[None, None,
+                               self.encoder.feat_size],  #[B, chunk_size, feat_dim]
+                        dtype='float32'),
+                    paddle.static.InputSpec(shape=[None],
+                                            dtype='int64'),  # audio_length, [B]
+                    paddle.static.InputSpec(
+                        shape=[None, None, None], dtype='float32'),
+                    paddle.static.InputSpec(
+                        shape=[None, None, None], dtype='float32')
+                ])
+        elif self.encoder.rnn_direction == "bidirect":
+            static_model = paddle.jit.to_static(
+                self,
+                input_spec=[
+                    paddle.static.InputSpec(
+                        shape=[None, None, self.encoder.feat_size],
+                        dtype='float32'),  # audio, [B,T,D]
+                    paddle.static.InputSpec(shape=[None],
+                                            dtype='int64'),  # audio_length, [B]
+                ])
+        else:
+            raise Exception("wrong model type")
         return static_model
diff --git a/paddlespeech/s2t/models/ds2/rnn.py b/paddlespeech/s2t/models/ds2/rnn.py
deleted file mode 100644
index f655b2d82..000000000
--- a/paddlespeech/s2t/models/ds2/rnn.py
+++ /dev/null
@@ -1,315 +0,0 @@
-# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
-#
-# 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.
-import math
-
-import paddle
-from paddle import nn
-from paddle.nn import functional as F
-from paddle.nn import initializer as I
-
-from paddlespeech.s2t.modules.activation import brelu
-from paddlespeech.s2t.modules.mask import make_non_pad_mask
-from paddlespeech.s2t.utils.log import Log
-
-logger = Log(__name__).getlog()
-
-__all__ = ['RNNStack']
-
-
-class RNNCell(nn.RNNCellBase):
-    r"""
-    Elman RNN (SimpleRNN) cell. Given the inputs and previous states, it
-    computes the outputs and updates states.
-    The formula used is as follows:
-    .. math::
-        h_{t} & = act(x_{t} + b_{ih} + W_{hh}h_{t-1} + b_{hh})
-        y_{t} & = h_{t}
-
-    where :math:`act` is for :attr:`activation`.
-    """
-
-    def __init__(self,
-                 hidden_size: int,
-                 activation="tanh",
-                 weight_ih_attr=None,
-                 weight_hh_attr=None,
-                 bias_ih_attr=None,
-                 bias_hh_attr=None,
-                 name=None):
-        super().__init__()
-        std = 1.0 / math.sqrt(hidden_size)
-        self.weight_hh = self.create_parameter(
-            (hidden_size, hidden_size),
-            weight_hh_attr,
-            default_initializer=I.Uniform(-std, std))
-        self.bias_ih = None
-        self.bias_hh = self.create_parameter(
-            (hidden_size, ),
-            bias_hh_attr,
-            is_bias=True,
-            default_initializer=I.Uniform(-std, std))
-
-        self.hidden_size = hidden_size
-        if activation not in ["tanh", "relu", "brelu"]:
-            raise ValueError(
-                "activation for SimpleRNNCell should be tanh or relu, "
-                "but get {}".format(activation))
-        self.activation = activation
-        self._activation_fn = paddle.tanh \
-            if activation == "tanh" \
-            else F.relu
-        if activation == 'brelu':
-            self._activation_fn = brelu
-
-    def forward(self, inputs, states=None):
-        if states is None:
-            states = self.get_initial_states(inputs, self.state_shape)
-        pre_h = states
-        i2h = inputs
-        if self.bias_ih is not None:
-            i2h += self.bias_ih
-        h2h = paddle.matmul(pre_h, self.weight_hh, transpose_y=True)
-        if self.bias_hh is not None:
-            h2h += self.bias_hh
-        h = self._activation_fn(i2h + h2h)
-        return h, h
-
-    @property
-    def state_shape(self):
-        return (self.hidden_size, )
-
-
-class GRUCell(nn.RNNCellBase):
-    r"""
-    Gated Recurrent Unit (GRU) RNN cell. Given the inputs and previous states,
-    it computes the outputs and updates states.
-    The formula for GRU used is as follows:
-    ..  math::
-        r_{t} & = \sigma(W_{ir}x_{t} + b_{ir} + W_{hr}h_{t-1} + b_{hr})
-        z_{t} & = \sigma(W_{iz}x_{t} + b_{iz} + W_{hz}h_{t-1} + b_{hz})
-        \widetilde{h}_{t} & = \tanh(W_{ic}x_{t} + b_{ic} + r_{t} * (W_{hc}h_{t-1} + b_{hc}))
-        h_{t} & = z_{t} * h_{t-1} + (1 - z_{t}) * \widetilde{h}_{t}
-        y_{t} & = h_{t}
-
-    where :math:`\sigma` is the sigmoid fucntion, and * is the elemetwise
-    multiplication operator.
-    """
-
-    def __init__(self,
-                 input_size: int,
-                 hidden_size: int,
-                 weight_ih_attr=None,
-                 weight_hh_attr=None,
-                 bias_ih_attr=None,
-                 bias_hh_attr=None,
-                 name=None):
-        super().__init__()
-        std = 1.0 / math.sqrt(hidden_size)
-        self.weight_hh = self.create_parameter(
-            (3 * hidden_size, hidden_size),
-            weight_hh_attr,
-            default_initializer=I.Uniform(-std, std))
-        self.bias_ih = None
-        self.bias_hh = self.create_parameter(
-            (3 * hidden_size, ),
-            bias_hh_attr,
-            is_bias=True,
-            default_initializer=I.Uniform(-std, std))
-
-        self.hidden_size = hidden_size
-        self.input_size = input_size
-        self._gate_activation = F.sigmoid
-        self._activation = paddle.tanh
-
-    def forward(self, inputs, states=None):
-        if states is None:
-            states = self.get_initial_states(inputs, self.state_shape)
-
-        pre_hidden = states
-        x_gates = inputs
-        if self.bias_ih is not None:
-            x_gates = x_gates + self.bias_ih
-        h_gates = paddle.matmul(pre_hidden, self.weight_hh, transpose_y=True)
-        if self.bias_hh is not None:
-            h_gates = h_gates + self.bias_hh
-
-        x_r, x_z, x_c = paddle.split(x_gates, num_or_sections=3, axis=1)
-        h_r, h_z, h_c = paddle.split(h_gates, num_or_sections=3, axis=1)
-
-        r = self._gate_activation(x_r + h_r)
-        z = self._gate_activation(x_z + h_z)
-        c = self._activation(x_c + r * h_c)  # apply reset gate after mm
-        h = (pre_hidden - c) * z + c
-        # https://www.paddlepaddle.org.cn/documentation/docs/zh/api/paddle/fluid/layers/dynamic_gru_cn.html#dynamic-gru
-
-        return h, h
-
-    @property
-    def state_shape(self):
-        r"""
-        The `state_shape` of GRUCell is a shape `[hidden_size]` (-1 for batch
-        size would be automatically inserted into shape). The shape corresponds
-        to the shape of :math:`h_{t-1}`.
-        """
-        return (self.hidden_size, )
-
-
-class BiRNNWithBN(nn.Layer):
-    """Bidirectonal simple rnn layer with sequence-wise batch normalization.
-    The batch normalization is only performed on input-state weights.
-
-    :param size: Dimension of RNN cells.
-    :type size: int
-    :param share_weights: Whether to share input-hidden weights between
-                          forward and backward directional RNNs.
-    :type share_weights: bool
-    :return: Bidirectional simple rnn layer.
-    :rtype: Variable
-    """
-
-    def __init__(self, i_size: int, h_size: int, share_weights: bool):
-        super().__init__()
-        self.share_weights = share_weights
-        if self.share_weights:
-            #input-hidden weights shared between bi-directional rnn.
-            self.fw_fc = nn.Linear(i_size, h_size, bias_attr=False)
-            # batch norm is only performed on input-state projection
-            self.fw_bn = nn.BatchNorm1D(
-                h_size, bias_attr=None, data_format='NLC')
-            self.bw_fc = self.fw_fc
-            self.bw_bn = self.fw_bn
-        else:
-            self.fw_fc = nn.Linear(i_size, h_size, bias_attr=False)
-            self.fw_bn = nn.BatchNorm1D(
-                h_size, bias_attr=None, data_format='NLC')
-            self.bw_fc = nn.Linear(i_size, h_size, bias_attr=False)
-            self.bw_bn = nn.BatchNorm1D(
-                h_size, bias_attr=None, data_format='NLC')
-
-        self.fw_cell = RNNCell(hidden_size=h_size, activation='brelu')
-        self.bw_cell = RNNCell(hidden_size=h_size, activation='brelu')
-        self.fw_rnn = nn.RNN(
-            self.fw_cell, is_reverse=False, time_major=False)  #[B, T, D]
-        self.bw_rnn = nn.RNN(
-            self.fw_cell, is_reverse=True, time_major=False)  #[B, T, D]
-
-    def forward(self, x: paddle.Tensor, x_len: paddle.Tensor):
-        # x, shape [B, T, D]
-        fw_x = self.fw_bn(self.fw_fc(x))
-        bw_x = self.bw_bn(self.bw_fc(x))
-        fw_x, _ = self.fw_rnn(inputs=fw_x, sequence_length=x_len)
-        bw_x, _ = self.bw_rnn(inputs=bw_x, sequence_length=x_len)
-        x = paddle.concat([fw_x, bw_x], axis=-1)
-        return x, x_len
-
-
-class BiGRUWithBN(nn.Layer):
-    """Bidirectonal gru layer with sequence-wise batch normalization.
-    The batch normalization is only performed on input-state weights.
-
-    :param name: Name of the layer.
-    :type name: string
-    :param input: Input layer.
-    :type input: Variable
-    :param size: Dimension of GRU cells.
-    :type size: int
-    :param act: Activation type.
-    :type act: string
-    :return: Bidirectional GRU layer.
-    :rtype: Variable
-    """
-
-    def __init__(self, i_size: int, h_size: int):
-        super().__init__()
-        hidden_size = h_size * 3
-
-        self.fw_fc = nn.Linear(i_size, hidden_size, bias_attr=False)
-        self.fw_bn = nn.BatchNorm1D(
-            hidden_size, bias_attr=None, data_format='NLC')
-        self.bw_fc = nn.Linear(i_size, hidden_size, bias_attr=False)
-        self.bw_bn = nn.BatchNorm1D(
-            hidden_size, bias_attr=None, data_format='NLC')
-
-        self.fw_cell = GRUCell(input_size=hidden_size, hidden_size=h_size)
-        self.bw_cell = GRUCell(input_size=hidden_size, hidden_size=h_size)
-        self.fw_rnn = nn.RNN(
-            self.fw_cell, is_reverse=False, time_major=False)  #[B, T, D]
-        self.bw_rnn = nn.RNN(
-            self.fw_cell, is_reverse=True, time_major=False)  #[B, T, D]
-
-    def forward(self, x, x_len):
-        # x, shape [B, T, D]
-        fw_x = self.fw_bn(self.fw_fc(x))
-        bw_x = self.bw_bn(self.bw_fc(x))
-        fw_x, _ = self.fw_rnn(inputs=fw_x, sequence_length=x_len)
-        bw_x, _ = self.bw_rnn(inputs=bw_x, sequence_length=x_len)
-        x = paddle.concat([fw_x, bw_x], axis=-1)
-        return x, x_len
-
-
-class RNNStack(nn.Layer):
-    """RNN group with stacked bidirectional simple RNN or GRU layers.
-
-    :param input: Input layer.
-    :type input: Variable
-    :param size: Dimension of RNN cells in each layer.
-    :type size: int
-    :param num_stacks: Number of stacked rnn layers.
-    :type num_stacks: int
-    :param use_gru: Use gru if set True. Use simple rnn if set False.
-    :type use_gru: bool
-    :param share_rnn_weights: Whether to share input-hidden weights between
-                              forward and backward directional RNNs.
-                              It is only available when use_gru=False.
-    :type share_weights: bool
-    :return: Output layer of the RNN group.
-    :rtype: Variable
-    """
-
-    def __init__(self,
-                 i_size: int,
-                 h_size: int,
-                 num_stacks: int,
-                 use_gru: bool,
-                 share_rnn_weights: bool):
-        super().__init__()
-        rnn_stacks = []
-        for i in range(num_stacks):
-            if use_gru:
-                #default:GRU using tanh
-                rnn_stacks.append(BiGRUWithBN(i_size=i_size, h_size=h_size))
-            else:
-                rnn_stacks.append(
-                    BiRNNWithBN(
-                        i_size=i_size,
-                        h_size=h_size,
-                        share_weights=share_rnn_weights))
-            i_size = h_size * 2
-
-        self.rnn_stacks = nn.LayerList(rnn_stacks)
-
-    def forward(self, x: paddle.Tensor, x_len: paddle.Tensor):
-        """
-        x: shape [B, T, D]
-        x_len: shpae [B]
-        """
-        for i, rnn in enumerate(self.rnn_stacks):
-            x, x_len = rnn(x, x_len)
-            masks = make_non_pad_mask(x_len)  #[B, T]
-            masks = masks.unsqueeze(-1)  # [B, T, 1]
-            # TODO(Hui Zhang): not support bool multiply
-            masks = masks.astype(x.dtype)
-            x = x.multiply(masks)
-
-        return x, x_len
diff --git a/paddlespeech/s2t/models/ds2_online/__init__.py b/paddlespeech/s2t/models/ds2_online/__init__.py
deleted file mode 100644
index de772b645..000000000
--- a/paddlespeech/s2t/models/ds2_online/__init__.py
+++ /dev/null
@@ -1,31 +0,0 @@
-# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
-#
-# 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 .deepspeech2 import DeepSpeech2InferModelOnline
-from .deepspeech2 import DeepSpeech2ModelOnline
-from paddlespeech.s2t.utils import dynamic_pip_install
-import sys
-
-try:
-    import paddlespeech_ctcdecoders
-except ImportError:
-    try:
-        package_name = 'paddlespeech_ctcdecoders'
-        if sys.platform != "win32":
-            dynamic_pip_install.install(package_name)
-    except Exception:
-        raise RuntimeError(
-            "Can not install package paddlespeech_ctcdecoders on your system. \
-                The DeepSpeech2 model is not supported for your system")
-
-__all__ = ['DeepSpeech2ModelOnline', 'DeepSpeech2InferModelOnline']
diff --git a/paddlespeech/s2t/models/ds2_online/conv.py b/paddlespeech/s2t/models/ds2_online/conv.py
deleted file mode 100644
index 25a9715a3..000000000
--- a/paddlespeech/s2t/models/ds2_online/conv.py
+++ /dev/null
@@ -1,33 +0,0 @@
-# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
-#
-# 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.
-import paddle
-
-from paddlespeech.s2t.modules.subsampling import Conv2dSubsampling4
-
-
-class Conv2dSubsampling4Online(Conv2dSubsampling4):
-    def __init__(self, idim: int, odim: int, dropout_rate: float):
-        super().__init__(idim, odim, dropout_rate, None)
-        self.output_dim = ((idim - 1) // 2 - 1) // 2 * odim
-        self.receptive_field_length = 2 * (
-            3 - 1) + 3  # stride_1 * (kernel_size_2 - 1) + kerel_size_1
-
-    def forward(self, x: paddle.Tensor,
-                x_len: paddle.Tensor) -> [paddle.Tensor, paddle.Tensor]:
-        x = x.unsqueeze(1)  # (b, c=1, t, f)
-        x = self.conv(x)
-        #b, c, t, f = paddle.shape(x) #not work under jit
-        x = x.transpose([0, 2, 1, 3]).reshape([0, 0, -1])
-        x_len = ((x_len - 1) // 2 - 1) // 2
-        return x, x_len
diff --git a/paddlespeech/s2t/models/ds2_online/deepspeech2.py b/paddlespeech/s2t/models/ds2_online/deepspeech2.py
deleted file mode 100644
index 9574a62bd..000000000
--- a/paddlespeech/s2t/models/ds2_online/deepspeech2.py
+++ /dev/null
@@ -1,397 +0,0 @@
-# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
-#
-# 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.
-"""Deepspeech2 ASR Online Model"""
-import paddle
-import paddle.nn.functional as F
-from paddle import nn
-
-from paddlespeech.s2t.models.ds2_online.conv import Conv2dSubsampling4Online
-from paddlespeech.s2t.modules.ctc import CTCDecoder
-from paddlespeech.s2t.utils import layer_tools
-from paddlespeech.s2t.utils.checkpoint import Checkpoint
-from paddlespeech.s2t.utils.log import Log
-logger = Log(__name__).getlog()
-
-__all__ = ['DeepSpeech2ModelOnline', 'DeepSpeech2InferModelOnline']
-
-
-class CRNNEncoder(nn.Layer):
-    def __init__(self,
-                 feat_size,
-                 dict_size,
-                 num_conv_layers=2,
-                 num_rnn_layers=4,
-                 rnn_size=1024,
-                 rnn_direction='forward',
-                 num_fc_layers=2,
-                 fc_layers_size_list=[512, 256],
-                 use_gru=False):
-        super().__init__()
-        self.rnn_size = rnn_size
-        self.feat_size = feat_size  # 161 for linear
-        self.dict_size = dict_size
-        self.num_rnn_layers = num_rnn_layers
-        self.num_fc_layers = num_fc_layers
-        self.rnn_direction = rnn_direction
-        self.fc_layers_size_list = fc_layers_size_list
-        self.use_gru = use_gru
-        self.conv = Conv2dSubsampling4Online(feat_size, 32, dropout_rate=0.0)
-
-        self.output_dim = self.conv.output_dim
-
-        i_size = self.conv.output_dim
-        self.rnn = nn.LayerList()
-        self.layernorm_list = nn.LayerList()
-        self.fc_layers_list = nn.LayerList()
-        if rnn_direction == 'bidirect' or rnn_direction == 'bidirectional':
-            layernorm_size = 2 * rnn_size
-        elif rnn_direction == 'forward':
-            layernorm_size = rnn_size
-        else:
-            raise Exception("Wrong rnn direction")
-        for i in range(0, num_rnn_layers):
-            if i == 0:
-                rnn_input_size = i_size
-            else:
-                rnn_input_size = layernorm_size
-            if use_gru is True:
-                self.rnn.append(
-                    nn.GRU(
-                        input_size=rnn_input_size,
-                        hidden_size=rnn_size,
-                        num_layers=1,
-                        direction=rnn_direction))
-            else:
-                self.rnn.append(
-                    nn.LSTM(
-                        input_size=rnn_input_size,
-                        hidden_size=rnn_size,
-                        num_layers=1,
-                        direction=rnn_direction))
-            self.layernorm_list.append(nn.LayerNorm(layernorm_size))
-            self.output_dim = layernorm_size
-
-        fc_input_size = layernorm_size
-        for i in range(self.num_fc_layers):
-            self.fc_layers_list.append(
-                nn.Linear(fc_input_size, fc_layers_size_list[i]))
-            fc_input_size = fc_layers_size_list[i]
-            self.output_dim = fc_layers_size_list[i]
-
-    @property
-    def output_size(self):
-        return self.output_dim
-
-    def forward(self, x, x_lens, init_state_h_box=None, init_state_c_box=None):
-        """Compute Encoder outputs
-
-        Args:
-            x (Tensor): [B, T, D]
-            x_lens (Tensor): [B]
-            init_state_h_box(Tensor): init_states h for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
-            init_state_c_box(Tensor): init_states c for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
-        Return:
-            x (Tensor): encoder outputs, [B, T, D]
-            x_lens (Tensor): encoder length, [B]
-            final_state_h_box(Tensor): final_states h for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
-            final_state_c_box(Tensor): final_states c for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
-        """
-        if init_state_h_box is not None:
-            init_state_list = None
-
-            if self.use_gru is True:
-                init_state_h_list = paddle.split(
-                    init_state_h_box, self.num_rnn_layers, axis=0)
-                init_state_list = init_state_h_list
-            else:
-                init_state_h_list = paddle.split(
-                    init_state_h_box, self.num_rnn_layers, axis=0)
-                init_state_c_list = paddle.split(
-                    init_state_c_box, self.num_rnn_layers, axis=0)
-                init_state_list = [(init_state_h_list[i], init_state_c_list[i])
-                                   for i in range(self.num_rnn_layers)]
-        else:
-            init_state_list = [None] * self.num_rnn_layers
-
-        x, x_lens = self.conv(x, x_lens)
-        final_chunk_state_list = []
-        for i in range(0, self.num_rnn_layers):
-            x, final_state = self.rnn[i](x, init_state_list[i],
-                                         x_lens)  #[B, T, D]
-            final_chunk_state_list.append(final_state)
-            x = self.layernorm_list[i](x)
-
-        for i in range(self.num_fc_layers):
-            x = self.fc_layers_list[i](x)
-            x = F.relu(x)
-
-        if self.use_gru is True:
-            final_chunk_state_h_box = paddle.concat(
-                final_chunk_state_list, axis=0)
-            final_chunk_state_c_box = init_state_c_box
-        else:
-            final_chunk_state_h_list = [
-                final_chunk_state_list[i][0] for i in range(self.num_rnn_layers)
-            ]
-            final_chunk_state_c_list = [
-                final_chunk_state_list[i][1] for i in range(self.num_rnn_layers)
-            ]
-            final_chunk_state_h_box = paddle.concat(
-                final_chunk_state_h_list, axis=0)
-            final_chunk_state_c_box = paddle.concat(
-                final_chunk_state_c_list, axis=0)
-
-        return x, x_lens, final_chunk_state_h_box, final_chunk_state_c_box
-
-    def forward_chunk_by_chunk(self, x, x_lens, decoder_chunk_size=8):
-        """Compute Encoder outputs
-
-        Args:
-            x (Tensor): [B, T, D]
-            x_lens (Tensor): [B]
-            decoder_chunk_size: The chunk size of decoder
-        Returns:
-            eouts_list (List of Tensor): The list of encoder outputs in chunk_size: [B, chunk_size, D] * num_chunks
-            eouts_lens_list (List of Tensor): The list of  encoder length in chunk_size: [B] * num_chunks
-            final_state_h_box(Tensor): final_states h for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
-            final_state_c_box(Tensor): final_states c for RNN layers: [num_rnn_layers * num_directions, batch_size, hidden_size]
-        """
-        subsampling_rate = self.conv.subsampling_rate
-        receptive_field_length = self.conv.receptive_field_length
-        chunk_size = (decoder_chunk_size - 1
-                      ) * subsampling_rate + receptive_field_length
-        chunk_stride = subsampling_rate * decoder_chunk_size
-        max_len = x.shape[1]
-        assert (chunk_size <= max_len)
-
-        eouts_chunk_list = []
-        eouts_chunk_lens_list = []
-        if (max_len - chunk_size) % chunk_stride != 0:
-            padding_len = chunk_stride - (max_len - chunk_size) % chunk_stride
-        else:
-            padding_len = 0
-        padding = paddle.zeros((x.shape[0], padding_len, x.shape[2]))
-        padded_x = paddle.concat([x, padding], axis=1)
-        num_chunk = (max_len + padding_len - chunk_size) / chunk_stride + 1
-        num_chunk = int(num_chunk)
-        chunk_state_h_box = None
-        chunk_state_c_box = None
-        final_state_h_box = None
-        final_state_c_box = None
-        for i in range(0, num_chunk):
-            start = i * chunk_stride
-            end = start + chunk_size
-            x_chunk = padded_x[:, start:end, :]
-
-            x_len_left = paddle.where(x_lens - i * chunk_stride < 0,
-                                      paddle.zeros_like(x_lens),
-                                      x_lens - i * chunk_stride)
-            x_chunk_len_tmp = paddle.ones_like(x_lens) * chunk_size
-            x_chunk_lens = paddle.where(x_len_left < x_chunk_len_tmp,
-                                        x_len_left, x_chunk_len_tmp)
-
-            eouts_chunk, eouts_chunk_lens, chunk_state_h_box, chunk_state_c_box = self.forward(
-                x_chunk, x_chunk_lens, chunk_state_h_box, chunk_state_c_box)
-
-            eouts_chunk_list.append(eouts_chunk)
-            eouts_chunk_lens_list.append(eouts_chunk_lens)
-        final_state_h_box = chunk_state_h_box
-        final_state_c_box = chunk_state_c_box
-        return eouts_chunk_list, eouts_chunk_lens_list, final_state_h_box, final_state_c_box
-
-
-class DeepSpeech2ModelOnline(nn.Layer):
-    """The DeepSpeech2 network structure for online.
-
-    :param audio: Audio spectrogram data layer.
-    :type audio: Variable
-    :param text: Transcription text data layer.
-    :type text: Variable
-    :param audio_len: Valid sequence length data layer.
-    :type audio_len: Variable
-    :param feat_size: feature size for audio.
-    :type feat_size: int
-    :param dict_size: Dictionary size for tokenized transcription.
-    :type dict_size: int
-    :param num_conv_layers: Number of stacking convolution layers.
-    :type num_conv_layers: int
-    :param num_rnn_layers: Number of stacking RNN layers.
-    :type num_rnn_layers: int
-    :param rnn_size: RNN layer size (dimension of RNN cells).
-    :type rnn_size: int
-    :param num_fc_layers: Number of stacking FC layers.
-    :type num_fc_layers: int
-    :param fc_layers_size_list: The list of FC layer sizes.
-    :type fc_layers_size_list: [int,]
-    :param use_gru: Use gru if set True. Use simple rnn if set False.
-    :type use_gru: bool
-    :return: A tuple of an output unnormalized log probability layer (
-             before softmax) and a ctc cost layer.
-    :rtype: tuple of LayerOutput
-    """
-
-    def __init__(
-            self,
-            feat_size,
-            dict_size,
-            num_conv_layers=2,
-            num_rnn_layers=4,
-            rnn_size=1024,
-            rnn_direction='forward',
-            num_fc_layers=2,
-            fc_layers_size_list=[512, 256],
-            use_gru=False,
-            blank_id=0,
-            ctc_grad_norm_type=None, ):
-        super().__init__()
-        self.encoder = CRNNEncoder(
-            feat_size=feat_size,
-            dict_size=dict_size,
-            num_conv_layers=num_conv_layers,
-            num_rnn_layers=num_rnn_layers,
-            rnn_direction=rnn_direction,
-            num_fc_layers=num_fc_layers,
-            fc_layers_size_list=fc_layers_size_list,
-            rnn_size=rnn_size,
-            use_gru=use_gru)
-
-        self.decoder = CTCDecoder(
-            odim=dict_size,  # <blank> is in  vocab
-            enc_n_units=self.encoder.output_size,
-            blank_id=blank_id,
-            dropout_rate=0.0,
-            reduction=True,  # sum
-            batch_average=True,  # sum / batch_size
-            grad_norm_type=ctc_grad_norm_type)
-
-    def forward(self, audio, audio_len, text, text_len):
-        """Compute Model loss
-
-        Args:
-            audio (Tensor): [B, T, D]
-            audio_len (Tensor): [B]
-            text (Tensor): [B, U]
-            text_len (Tensor): [B]
-
-        Returns:
-            loss (Tensor): [1]
-        """
-        eouts, eouts_len, final_state_h_box, final_state_c_box = self.encoder(
-            audio, audio_len, None, None)
-        loss = self.decoder(eouts, eouts_len, text, text_len)
-        return loss
-
-    @paddle.no_grad()
-    def decode(self, audio, audio_len):
-        # decoders only accept string encoded in utf-8
-        # Make sure the decoder has been initialized
-        eouts, eouts_len, final_state_h_box, final_state_c_box = self.encoder(
-            audio, audio_len, None, None)
-        probs = self.decoder.softmax(eouts)
-        batch_size = probs.shape[0]
-        self.decoder.reset_decoder(batch_size=batch_size)
-        self.decoder.next(probs, eouts_len)
-        trans_best, trans_beam = self.decoder.decode()
-        return trans_best
-
-    @classmethod
-    def from_pretrained(cls, dataloader, config, checkpoint_path):
-        """Build a DeepSpeech2Model model from a pretrained model.
-        Parameters
-        ----------
-        dataloader: paddle.io.DataLoader
-
-        config: yacs.config.CfgNode
-            model configs
-
-        checkpoint_path: Path or str
-            the path of pretrained model checkpoint, without extension name
-
-        Returns
-        -------
-        DeepSpeech2ModelOnline
-            The model built from pretrained result.
-        """
-        model = cls(
-            feat_size=dataloader.collate_fn.feature_size,
-            dict_size=dataloader.collate_fn.vocab_size,
-            num_conv_layers=config.num_conv_layers,
-            num_rnn_layers=config.num_rnn_layers,
-            rnn_size=config.rnn_layer_size,
-            rnn_direction=config.rnn_direction,
-            num_fc_layers=config.num_fc_layers,
-            fc_layers_size_list=config.fc_layers_size_list,
-            use_gru=config.use_gru,
-            blank_id=config.blank_id,
-            ctc_grad_norm_type=config.get('ctc_grad_norm_type', None), )
-        infos = Checkpoint().load_parameters(
-            model, checkpoint_path=checkpoint_path)
-        logger.info(f"checkpoint info: {infos}")
-        layer_tools.summary(model)
-        return model
-
-    @classmethod
-    def from_config(cls, config):
-        """Build a DeepSpeec2ModelOnline from config
-        Parameters
-
-        config: yacs.config.CfgNode
-            config
-        Returns
-        -------
-        DeepSpeech2ModelOnline
-            The model built from config.
-        """
-        model = cls(
-            feat_size=config.input_dim,
-            dict_size=config.output_dim,
-            num_conv_layers=config.num_conv_layers,
-            num_rnn_layers=config.num_rnn_layers,
-            rnn_size=config.rnn_layer_size,
-            rnn_direction=config.rnn_direction,
-            num_fc_layers=config.num_fc_layers,
-            fc_layers_size_list=config.fc_layers_size_list,
-            use_gru=config.use_gru,
-            blank_id=config.blank_id,
-            ctc_grad_norm_type=config.get('ctc_grad_norm_type', None), )
-        return model
-
-
-class DeepSpeech2InferModelOnline(DeepSpeech2ModelOnline):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-
-    def forward(self, audio_chunk, audio_chunk_lens, chunk_state_h_box,
-                chunk_state_c_box):
-        eouts_chunk, eouts_chunk_lens, final_state_h_box, final_state_c_box = self.encoder(
-            audio_chunk, audio_chunk_lens, chunk_state_h_box, chunk_state_c_box)
-        probs_chunk = self.decoder.softmax(eouts_chunk)
-        return probs_chunk, eouts_chunk_lens, final_state_h_box, final_state_c_box
-
-    def export(self):
-        static_model = paddle.jit.to_static(
-            self,
-            input_spec=[
-                paddle.static.InputSpec(
-                    shape=[None, None,
-                           self.encoder.feat_size],  #[B, chunk_size, feat_dim]
-                    dtype='float32'),
-                paddle.static.InputSpec(shape=[None],
-                                        dtype='int64'),  # audio_length, [B]
-                paddle.static.InputSpec(
-                    shape=[None, None, None], dtype='float32'),
-                paddle.static.InputSpec(
-                    shape=[None, None, None], dtype='float32')
-            ])
-        return static_model
diff --git a/paddlespeech/server/engine/asr/online/asr_engine.py b/paddlespeech/server/engine/asr/online/asr_engine.py
index 14715bf35..a52219730 100644
--- a/paddlespeech/server/engine/asr/online/asr_engine.py
+++ b/paddlespeech/server/engine/asr/online/asr_engine.py
@@ -25,7 +25,6 @@ from paddlespeech.cli.log import logger
 from paddlespeech.cli.utils import MODEL_HOME
 from paddlespeech.resource import CommonTaskResource
 from paddlespeech.s2t.frontend.featurizer.text_featurizer import TextFeaturizer
-from paddlespeech.s2t.frontend.speech import SpeechSegment
 from paddlespeech.s2t.modules.ctc import CTCDecoder
 from paddlespeech.s2t.transform.transformation import Transformation
 from paddlespeech.s2t.utils.tensor_utils import add_sos_eos
@@ -66,10 +65,13 @@ class PaddleASRConnectionHanddler:
         self.text_feature = self.asr_engine.executor.text_feature
 
         if "deepspeech2" in self.model_type:
-            from paddlespeech.s2t.io.collator import SpeechCollator
             self.am_predictor = self.asr_engine.executor.am_predictor
 
-            self.collate_fn_test = SpeechCollator.from_config(self.model_config)
+            # extract feat, new only fbank in conformer model
+            self.preprocess_conf = self.model_config.preprocess_config
+            self.preprocess_args = {"train": False}
+            self.preprocessing = Transformation(self.preprocess_conf)
+
             self.decoder = CTCDecoder(
                 odim=self.model_config.output_dim,  # <blank> is in  vocab
                 enc_n_units=self.model_config.rnn_layer_size * 2,
@@ -89,10 +91,8 @@ class PaddleASRConnectionHanddler:
                 cfg.num_proc_bsearch)
 
             # frame window and frame shift, in samples unit
-            self.win_length = int(self.model_config.window_ms / 1000 *
-                                  self.sample_rate)
-            self.n_shift = int(self.model_config.stride_ms / 1000 *
-                               self.sample_rate)
+            self.win_length = self.preprocess_conf.process[0]['win_length']
+            self.n_shift = self.preprocess_conf.process[0]['n_shift']
 
         elif "conformer" in self.model_type or "transformer" in self.model_type:
             # acoustic model
@@ -114,20 +114,15 @@ class PaddleASRConnectionHanddler:
             raise ValueError(f"Not supported: {self.model_type}")
 
     def extract_feat(self, samples):
-        # we compute the elapsed time of first char occuring 
+        # we compute the elapsed time of first char occuring
         # and we record the start time at the first pcm sample arraving
 
         if "deepspeech2online" in self.model_type:
-            # self.reamined_wav stores all the samples, 
+            # self.reamined_wav stores all the samples,
             # include the original remained_wav and this package samples
             samples = np.frombuffer(samples, dtype=np.int16)
             assert samples.ndim == 1
 
-            # pcm16 -> pcm 32
-            # pcm2float will change the orignal samples, 
-            # so we shoule do pcm2float before concatenate
-            samples = pcm2float(samples)
-
             if self.remained_wav is None:
                 self.remained_wav = samples
             else:
@@ -137,26 +132,11 @@ class PaddleASRConnectionHanddler:
                 f"The connection remain the audio samples: {self.remained_wav.shape}"
             )
 
-            # read audio
-            speech_segment = SpeechSegment.from_pcm(
-                self.remained_wav, self.sample_rate, transcript=" ")
-            # audio augment
-            self.collate_fn_test.augmentation.transform_audio(speech_segment)
-
-            # extract speech feature
-            spectrum, transcript_part = self.collate_fn_test._speech_featurizer.featurize(
-                speech_segment, self.collate_fn_test.keep_transcription_text)
-            # CMVN spectrum
-            if self.collate_fn_test._normalizer:
-                spectrum = self.collate_fn_test._normalizer.apply(spectrum)
-
-            # spectrum augment
-            feat = self.collate_fn_test.augmentation.transform_feature(spectrum)
-
-            # audio_len is frame num
-            frame_num = feat.shape[0]
-            feat = paddle.to_tensor(feat, dtype='float32')
-            feat = paddle.unsqueeze(feat, axis=0)
+            # fbank
+            feat = self.preprocessing(self.remained_wav,
+                                         **self.preprocess_args)
+            feat = paddle.to_tensor(
+                feat, dtype="float32").unsqueeze(axis=0)
 
             if self.cached_feat is None:
                 self.cached_feat = feat
@@ -170,8 +150,11 @@ class PaddleASRConnectionHanddler:
             if self.device is None:
                 self.device = self.cached_feat.place
 
-            self.num_frames += frame_num
-            self.remained_wav = self.remained_wav[self.n_shift * frame_num:]
+            # cur frame step
+            num_frames = feat.shape[1]
+
+            self.num_frames += num_frames
+            self.remained_wav = self.remained_wav[self.n_shift * num_frames:]
 
             logger.info(
                 f"process the audio feature success, the connection feat shape: {self.cached_feat.shape}"
@@ -190,7 +173,7 @@ class PaddleASRConnectionHanddler:
                 f"This package receive {samples.shape[0]} pcm data. Global samples:{self.num_samples}"
             )
 
-            # self.reamined_wav stores all the samples, 
+            # self.reamined_wav stores all the samples,
             # include the original remained_wav and this package samples
             if self.remained_wav is None:
                 self.remained_wav = samples
@@ -246,7 +229,7 @@ class PaddleASRConnectionHanddler:
 
     def reset(self):
         if "deepspeech2" in self.model_type:
-            # for deepspeech2 
+            # for deepspeech2
             # init state
             self.chunk_state_h_box = np.zeros(
                 (self.model_config.num_rnn_layers, 1,
@@ -275,7 +258,7 @@ class PaddleASRConnectionHanddler:
 
         ## conformer
 
-        # cache for conformer online 
+        # cache for conformer online
         self.subsampling_cache = None
         self.elayers_output_cache = None
         self.conformer_cnn_cache = None
@@ -359,7 +342,7 @@ class PaddleASRConnectionHanddler:
             # update feat cache
             self.cached_feat = self.cached_feat[:, end - cached_feature_num:, :]
 
-            # return trans_best[0]            
+            # return trans_best[0]
         elif "conformer" in self.model_type or "transformer" in self.model_type:
             try:
                 logger.info(
@@ -565,7 +548,7 @@ class PaddleASRConnectionHanddler:
 
     @paddle.no_grad()
     def rescoring(self):
-        """Second-Pass Decoding, 
+        """Second-Pass Decoding,
         only for conformer and transformer model.
         """
         if "deepspeech2" in self.model_type:
@@ -652,11 +635,11 @@ class PaddleASRConnectionHanddler:
         ## asr results
         # hyps[0][0]: the sentence word-id in the vocab with a tuple
         # hyps[0][1]: the sentence decoding probability with all paths
-        ## timestamp 
+        ## timestamp
         # hyps[0][2]: viterbi_blank ending probability
         # hyps[0][3]: viterbi_non_blank dending probability
         # hyps[0][4]: current_token_prob,
-        # hyps[0][5]: times_viterbi_blank ending timestamp, 
+        # hyps[0][5]: times_viterbi_blank ending timestamp,
         # hyps[0][6]: times_titerbi_non_blank encding timestamp.
         self.hyps = [hyps[best_index][0]]
         logger.info(f"best hyp ids: {self.hyps}")
@@ -752,16 +735,19 @@ class ASRServerExecutor(ASRExecutor):
         self.config = CfgNode(new_allowed=True)
         self.config.merge_from_file(self.cfg_path)
 
+        if self.config.spm_model_prefix:
+            self.config.spm_model_prefix = os.path.join(
+                self.res_path, self.config.spm_model_prefix)
+        self.text_feature = TextFeaturizer(
+            unit_type=self.config.unit_type,
+            vocab=self.config.vocab_filepath,
+            spm_model_prefix=self.config.spm_model_prefix)
+        self.vocab = self.config.vocab_filepath
         with UpdateConfig(self.config):
             if "deepspeech2" in model_type:
-                from paddlespeech.s2t.io.collator import SpeechCollator
-                self.vocab = self.config.vocab_filepath
                 self.config.decode.lang_model_path = os.path.join(
                     MODEL_HOME, 'language_model',
                     self.config.decode.lang_model_path)
-                self.collate_fn_test = SpeechCollator.from_config(self.config)
-                self.text_feature = TextFeaturizer(
-                    unit_type=self.config.unit_type, vocab=self.vocab)
 
                 lm_url = self.task_resource.res_dict['lm_url']
                 lm_md5 = self.task_resource.res_dict['lm_md5']
@@ -772,14 +758,6 @@ class ASRServerExecutor(ASRExecutor):
 
             elif "conformer" in model_type or "transformer" in model_type:
                 logger.info("start to create the stream conformer asr engine")
-                if self.config.spm_model_prefix:
-                    self.config.spm_model_prefix = os.path.join(
-                        self.res_path, self.config.spm_model_prefix)
-                self.vocab = self.config.vocab_filepath
-                self.text_feature = TextFeaturizer(
-                    unit_type=self.config.unit_type,
-                    vocab=self.config.vocab_filepath,
-                    spm_model_prefix=self.config.spm_model_prefix)
                 # update the decoding method
                 if decode_method:
                     self.config.decode.decoding_method = decode_method
diff --git a/paddlespeech/server/engine/asr/paddleinference/asr_engine.py b/paddlespeech/server/engine/asr/paddleinference/asr_engine.py
index b030293f7..c83f52936 100644
--- a/paddlespeech/server/engine/asr/paddleinference/asr_engine.py
+++ b/paddlespeech/server/engine/asr/paddleinference/asr_engine.py
@@ -54,6 +54,7 @@ class ASRServerExecutor(ASRExecutor):
 
         sample_rate_str = '16k' if sample_rate == 16000 else '8k'
         tag = model_type + '-' + lang + '-' + sample_rate_str
+        self.max_len = 50
         self.task_resource.set_task_model(model_tag=tag)
         if cfg_path is None or am_model is None or am_params is None:
             self.res_path = self.task_resource.res_dir
@@ -80,22 +81,24 @@ class ASRServerExecutor(ASRExecutor):
         self.config.merge_from_file(self.cfg_path)
 
         with UpdateConfig(self.config):
-            if "deepspeech2online" in model_type or "deepspeech2offline" in model_type:
-                from paddlespeech.s2t.io.collator import SpeechCollator
+            if "deepspeech2" in model_type:
                 self.vocab = self.config.vocab_filepath
+                if self.config.spm_model_prefix:
+                    self.config.spm_model_prefix = os.path.join(
+                        self.res_path, self.config.spm_model_prefix)
+                self.text_feature = TextFeaturizer(
+                    unit_type=self.config.unit_type, vocab=self.vocab,
+                    spm_model_prefix=self.config.spm_model_prefix)
                 self.config.decode.lang_model_path = os.path.join(
                     MODEL_HOME, 'language_model',
                     self.config.decode.lang_model_path)
-                self.collate_fn_test = SpeechCollator.from_config(self.config)
-                self.text_feature = TextFeaturizer(
-                    unit_type=self.config.unit_type, vocab=self.vocab)
 
                 lm_url = self.task_resource.res_dict['lm_url']
                 lm_md5 = self.task_resource.res_dict['lm_md5']
                 self.download_lm(
                     lm_url,
                     os.path.dirname(self.config.decode.lang_model_path), lm_md5)
-            elif "conformer" in model_type or "transformer" in model_type or "wenetspeech" in model_type:
+            elif "conformer" in model_type or "transformer" in model_type:
                 raise Exception("wrong type")
             else:
                 raise Exception("wrong type")
@@ -125,7 +128,7 @@ class ASRServerExecutor(ASRExecutor):
         cfg = self.config.decode
         audio = self._inputs["audio"]
         audio_len = self._inputs["audio_len"]
-        if "deepspeech2online" in model_type or "deepspeech2offline" in model_type:
+        if "deepspeech2" in model_type:
             decode_batch_size = audio.shape[0]
             # init once
             self.decoder.init_decoder(
@@ -192,7 +195,7 @@ class ASREngine(BaseEngine):
         return True
 
     def run(self, audio_data):
-        """engine run 
+        """engine run
 
         Args:
             audio_data (bytes): base64.b64decode