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# Speech Recognition Pre-Training


## Wav2Vec2 Speech Pre-Training

The script [`run_speech_wav2vec2_pretraining_no_trainer.py`](https://github.com/huggingface/transformers/blob/master/examples/pytorch/speech-pretraining/run_wav2vec2_pretraining_no_trainer.py) can be used to pre-train a [Wav2Vec2](https://huggingface.co/transformers/model_doc/wav2vec2.html?highlight=wav2vec2) model from scratch.

In the script [`run_speech_wav2vec2_pretraining_no_trainer`](https://github.com/huggingface/transformers/blob/master/examples/pytorch/speech-pretraining/run_wav2vec2_pretraining_no_trainer.py), a Wav2Vec2 model is pre-trained on audio data alone using [Wav2Vec2's contrastive loss objective](https://arxiv.org/abs/2006.11477).

The following examples show how to fine-tune a `"base"`-sized Wav2Vec2 model as well as a `"large"`-sized Wav2Vec2 model using [`accelerate`](https://github.com/huggingface/accelerate).


---
**NOTE 1**

Wav2Vec2's pre-training is known to be quite unstable.
It is advised to do a couple of test runs with a smaller dataset,
*i.e.* `--dataset_config_names clean clean`, `--dataset_split_names validation test`
to find good hyper-parameters for `learning_rate`, `batch_size`, `num_warmup_steps`,
and the optimizer.
A good metric to observe during training is the gradient norm which should ideally be between 0.5 and 2.

---

---
**NOTE 2**

When training a model on large datasets it is recommended to run the data preprocessing 
in a first run in a **non-distributed** mode via `--preprocessing_only` so that 
when running the  model in **distributed** mode in a second step the preprocessed data
can easily be loaded on each distributed device.

---

### Demo

In this demo run we pre-train a `"base-sized"` Wav2Vec2 model simply only on the validation
and test data of [librispeech_asr](https://huggingface.co/datasets/librispeech_asr).

The demo is run on two Titan RTX (24 GB RAM each). In case you have less RAM available 
per device, consider reducing `--batch_size` and/or the `--max_duration_in_seconds`.


```bash
accelerate launch run_wav2vec2_pretraining_no_trainer.py \
	--dataset_name="librispeech_asr" \
	--dataset_config_names clean clean \
	--dataset_split_names validation test \
	--model_name_or_path="patrickvonplaten/wav2vec2-base-v2" \
	--output_dir="./wav2vec2-pretrained-demo" \
	--max_train_steps="20000" \
	--num_warmup_steps="32000" \
	--gradient_accumulation_steps="8" \
	--learning_rate="0.005" \
	--weight_decay="0.01" \
	--max_duration_in_seconds="20.0" \
	--min_duration_in_seconds="2.0" \
	--logging_steps="1" \
	--saving_steps="10000" \
	--per_device_train_batch_size="8" \
	--per_device_eval_batch_size="8" \
	--adam_beta1="0.9" \
	--adam_beta2="0.98" \
	--adam_epsilon="1e-06" \
	--gradient_checkpointing \
```

The results of this run can be seen [here](https://wandb.ai/patrickvonplaten/wav2vec2-pretrained-demo/reports/Wav2Vec2-PreTraining-Demo-Run--VmlldzoxMDk3MjAw?accessToken=oa05s1y57lizo2ocxy3k01g6db1u4pt8m6ur2n8nl4cb0ug02ms2cw313kb8ruch).

### Base

TODO (currently running...)


### Large

To pre-train `"large-sized"` Wav2Vec2 model, *e.g.* [facebook/wav2vec2-large-lv60](https://huggingface.co/facebook/wav2vec2-large-lv60), 
on [librispeech_asr](https://huggingface.co/datasets/librispeech_asr), the following command can be run:

```bash
accelerate launch run_pretrain_no_trainer.py \ 
	--dataset_name=librispeech_asr \
	--dataset_config_names clean clean other \
	--dataset_split_names train.100 train.360 train.500 \
	--output_dir=./test \
	--max_train_steps=200000 \
	--num_warmup_steps=32000 \
	--gradient_accumulation_steps=8 \
	--learning_rate=0.001 \
	--weight_decay=0.01 \
	--max_duration_in_seconds=20.0 \
	--min_duration_in_seconds=2.0 \
	--model_name_or_path=./ 
	--logging_steps=1 \
	--saving_steps=10000 \
	--per_device_train_batch_size=2 \
	--per_device_eval_batch_size=4 \
	--adam_beta1=0.9 \
	--adam_beta2=0.98 \
	--adam_epsilon=1e-06 \
	--gradient_checkpointing \
```

The experiment was run on 8 GPU V100 (16 GB RAM each) for 7 days. 
In case you have more than 8 GPUs available for a higher effective `batch_size`,
it is recommended to increase the `learning_rate` to `0.005` for faster convergence.

The results of this run can be seen [here](https://wandb.ai/patrickvonplaten/pretraining-wav2vec2/reports/Wav2Vec2-Large--VmlldzoxMTAwODM4?accessToken=wm3qzcnldrwsa31tkvf2pdmilw3f63d4twtffs86ou016xjbyilh55uoi3mo1qzc) and the checkpoint pretrained for 120,000 steps can be accessed [here](https://huggingface.co/patrickvonplaten/wav2vec2-large-repro-960h-libri-120k-steps)
