Documentation for adapter fine-tuning (#1545)

docs/source/recipes/Finetune/adapter/finetune_adapter.rst

@@ -0,0 +1,225 @@
+Finetune from a pre-trained Zipformer model with adapters
+=========================================================
+
+This tutorial shows you how to fine-tune a pre-trained **Zipformer**
+transducer model on a new dataset with adapters. 
+Adapters are compact and efficient module that can be integrated into a pre-trained model
+to improve the model's performance on a new domain. Adapters are injected
+between different modules in the well-trained neural network. During training, only the parameters
+in the adapters will be updated. It achieves competitive performance
+while requiring much less GPU memory than full fine-tuning. For more details about adapters,
+please refer to the original `paper <https://arxiv.org/pdf/1902.00751.pdf#/>`_ for more details.
+
+.. HINT::
+
+  We assume you have read the page :ref:`install icefall` and have setup
+  the environment for ``icefall``.
+
+.. HINT::
+
+  We recommend you to use a GPU or several GPUs to run this recipe
+
+For illustration purpose, we fine-tune the Zipformer transducer model
+pre-trained on `LibriSpeech`_ on the small subset of `GigaSpeech`_. You could use your
+own data for fine-tuning if you create a manifest for your new dataset.
+
+Data preparation
+----------------
+
+Please follow the instructions in the `GigaSpeech recipe <https://github.com/k2-fsa/icefall/tree/master/egs/gigaspeech/ASR>`_
+to prepare the fine-tune data used in this tutorial. We only require the small subset in GigaSpeech for this tutorial.
+
+
+Model preparation
+-----------------
+
+We are using the Zipformer model trained on full LibriSpeech (960 hours) as the intialization. The
+checkpoint of the model can be downloaded via the following command:
+
+.. code-block:: bash
+
+    $ GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/Zengwei/icefall-asr-librispeech-zipformer-2023-05-15
+    $ cd icefall-asr-librispeech-zipformer-2023-05-15/exp
+    $ git lfs pull --include "pretrained.pt"
+    $ ln -s pretrained.pt epoch-99.pt
+    $ cd ../data/lang_bpe_500
+    $ git lfs pull --include bpe.model
+    $ cd ../../..
+
+Before fine-tuning, let's test the model's WER on the new domain. The following command performs
+decoding on the GigaSpeech test sets:
+
+.. code-block:: bash
+
+    ./zipformer/decode_gigaspeech.py \
+        --epoch 99 \
+        --avg 1 \
+        --exp-dir icefall-asr-librispeech-zipformer-2023-05-15/exp \
+        --use-averaged-model 0 \
+        --max-duration 1000 \
+        --decoding-method greedy_search
+
+You should see the following numbers:
+
+.. code-block::
+
+    For dev, WER of different settings are:
+    greedy_search	20.06	best for dev
+
+    For test, WER of different settings are:
+    greedy_search	19.27	best for test
+
+
+Fine-tune with adapter
+----------------------
+
+We insert 4 adapters with residual connection in each ``Zipformer2EncoderLayer``. 
+The original model parameters remain untouched during training and only the parameters of
+the adapters are updated. The following command starts a fine-tuning experiment with adapters:
+
+.. code-block:: bash
+    
+    $ do_finetune=1
+    $ use_adapters=1
+    $ adapter_dim=8
+
+    $ ./zipformer_adapter/train.py \
+        --world-size 2 \
+        --num-epochs 20 \
+        --start-epoch 1 \
+        --exp-dir zipformer_adapter/exp_giga_finetune_adapters${use_adapters}_adapter_dim${adapter_dim} \
+        --use-fp16 1 \
+        --base-lr 0.045 \
+        --use-adapters $use_adapters --adapter-dim $adapter_dim \
+        --bpe-model data/lang_bpe_500/bpe.model \
+        --do-finetune $do_finetune \
+        --master-port 13022 \
+        --finetune-ckpt icefall-asr-librispeech-zipformer-2023-05-15/exp/pretrained.pt \
+        --max-duration 1000
+
+The following arguments are related to fine-tuning:
+
+- ``--do-finetune``
+    If True, do fine-tuning by initializing the model from a pre-trained checkpoint.
+    **Note that if you want to resume your fine-tuning experiment from certain epochs, you
+    need to set this to False.**
+
+- ``use-adapters``
+    If adapters are used during fine-tuning.
+
+- ``--adapter-dim``
+    The bottleneck dimension of the adapter module. Typically a small number.
+
+You should notice that in the training log, the total number of trainale parameters is shown:
+
+.. code-block::
+
+    2024-02-22 21:22:03,808 INFO [train.py:1277] A total of 761344 trainable parameters (1.148% of the whole model)
+    
+The trainable parameters only makes up 1.15% of the entire model parameters, so the training will be much faster
+and requires less memory than full fine-tuning.
+
+
+Decoding
+--------
+
+After training, let's test the WERs. To test the WERs on the GigaSpeech set,
+you can execute the following command:
+
+.. code-block:: bash
+
+    $ epoch=20
+    $ avg=10
+    $ use_adapters=1
+    $ adapter_dim=8
+    
+    % ./zipformer/decode.py \
+        --epoch $epoch \
+        --avg $avg \
+        --use-averaged-model 1 \
+        --exp-dir zipformer_adapter/exp_giga_finetune_adapters${use_adapters}_adapter_dim${adapter_dim} \
+        --max-duration 600 \
+        --use-adapters $use_adapters \
+        --adapter-dim $adapter_dim \
+        --decoding-method greedy_search
+
+You should see the following numbers:
+
+.. code-block::
+
+    For dev, WER of different settings are:
+    greedy_search	15.44	best for dev
+
+    For test, WER of different settings are:
+    greedy_search	15.42	best for test
+
+
+The WER on test set is improved from 19.27 to 15.42, demonstrating the effectiveness of adapters.
+
+The same model can be used to perform decoding on LibriSpeech test sets. You can deactivate the adapters
+to keep the same performance of the original model:
+
+.. code-block:: bash
+
+    $ epoch=20
+    $ avg=1
+    $ use_adapters=0
+    $ adapter_dim=8
+    
+    % ./zipformer/decode.py \
+        --epoch $epoch \
+        --avg $avg \
+        --use-averaged-model 1 \
+        --exp-dir zipformer_adapter/exp_giga_finetune_adapters${use_adapters}_adapter_dim${adapter_dim} \
+        --max-duration 600 \
+        --use-adapters $use_adapters \
+        --adapter-dim $adapter_dim \
+        --decoding-method greedy_search
+
+
+.. code-block::
+
+    For dev, WER of different settings are:
+    greedy_search	2.23	best for test-clean
+
+    For test, WER of different settings are:
+    greedy_search	4.96	best for test-other
+
+The numbers are the same as reported in `icefall <https://github.com/k2-fsa/icefall/blob/master/egs/librispeech/ASR/RESULTS.md#normal-scaled-model-number-of-model-parameters-65549011-ie-6555-m>`_. So adapter-based
+fine-tuning is also very flexible as the same model can be used for decoding on the original and target domain.
+
+
+Export the model
+----------------
+
+After training, the model can be exported to ``onnx`` format easily using the following command:
+
+.. code-block:: bash
+
+    $ use_adapters=1
+    $ adapter_dim=16
+
+    $ ./zipformer_adapter/export-onnx.py \
+        --tokens icefall-asr-librispeech-zipformer-2023-05-15/data/lang_bpe_500/tokens.txt \
+        --use-averaged-model 1 \
+        --epoch 20 \
+        --avg 10 \
+        --exp-dir zipformer_adapter/exp_giga_finetune_adapters${use_adapters}_adapter_dim${adapter_dim} \
+        --use-adapters $use_adapters \
+        --adapter-dim $adapter_dim \
+        --num-encoder-layers "2,2,3,4,3,2" \
+        --downsampling-factor "1,2,4,8,4,2" \
+        --feedforward-dim "512,768,1024,1536,1024,768" \
+        --num-heads "4,4,4,8,4,4" \
+        --encoder-dim "192,256,384,512,384,256" \
+        --query-head-dim 32 \
+        --value-head-dim 12 \
+        --pos-head-dim 4 \
+        --pos-dim 48 \
+        --encoder-unmasked-dim "192,192,256,256,256,192" \
+        --cnn-module-kernel "31,31,15,15,15,31" \
+        --decoder-dim 512 \
+        --joiner-dim 512 \
+        --causal False \
+        --chunk-size "16,32,64,-1" \
+        --left-context-frames "64,128,256,-1"

docs/source/recipes/Finetune/index.rst

@@ -13,3 +13,4 @@ data to improve the performance on new domains.
    :caption: Table of Contents
 
    from_supervised/finetune_zipformer
+   adapter/finetune_adapter