def get_encoder_decoder_model(self, config, decoder_config):
encoder_model = Wav2Vec2Model(config).eval()
decoder_model = Speech2Text2ForCausalLM(decoder_config).eval()
return encoder_model, decoder_model
def convert_wav2vec2_checkpoint(
checkpoint_path,
pytorch_dump_folder_path,
dict_path,
encoder_config_path,
decoder_config_path,
vocab_size,
num_decoder_layers,
):
"""
Copy/paste/tweak model's weights to transformers design.
"""
encoder_config = Wav2Vec2Config.from_pretrained(encoder_config_path)
decoder_config = Speech2Text2Config.from_pretrained(
decoder_config_path, vocab_size=vocab_size, decoder_layers=num_decoder_layers, do_stable_layer_norm=True
)
feature_extractor = Wav2Vec2FeatureExtractor(
feature_size=1,
sampling_rate=16000,
padding_value=0,
do_normalize=True,
return_attention_mask=True,
)
model, _, _ = fairseq.checkpoint_utils.load_model_ensemble_and_task(
[checkpoint_path], arg_overrides={"data": "/".join(dict_path.split("/")[:-1])}
)
model = model[0].eval()
# set weights for wav2vec2 encoder
hf_encoder = Wav2Vec2Model(encoder_config)
projection_layer = recursively_load_weights_wav2vec2(model.encoder, hf_encoder)
hf_decoder = Speech2Text2ForCausalLM(decoder_config)
missing_keys, unexpected_keys = hf_decoder.model.decoder.load_state_dict(model.decoder.state_dict(), strict=False)
# set output linear layer
unexpected_keys.remove("embed_out")
hf_decoder.lm_head.weight = nn.Parameter(model.decoder.embed_out.detach())
# layer norm is init to identity matrix so leaving it is fine
logger.warning(f"The following keys are missing when loading the decoder weights: {missing_keys}")
logger.warning(f"The following keys are unexpected when loading the decoder weights: {unexpected_keys}")
hf_wav2vec = SpeechEncoderDecoderModel(encoder=hf_encoder, decoder=hf_decoder)
hf_wav2vec.config.tie_word_embeddings = False
# add projection layer
hf_wav2vec.enc_to_dec_proj.weight = nn.Parameter(projection_layer.weight)
hf_wav2vec.enc_to_dec_proj.bias = nn.Parameter(projection_layer.bias)
vocab_dict = create_vocab_dict(dict_path)
with open(os.path.join(pytorch_dump_folder_path, "vocab.json"), "w") as fp:
json.dump(vocab_dict, fp)
tokenizer = Speech2Text2Tokenizer(os.path.join(pytorch_dump_folder_path, "vocab.json"))
tokenizer.save_pretrained(pytorch_dump_folder_path)
config = hf_wav2vec.config.to_dict()
config["pad_token_id"] = tokenizer.pad_token_id
config["bos_token_id"] = tokenizer.bos_token_id
config["eos_token_id"] = tokenizer.eos_token_id
config["tokenizer_class"] = "speech_to_text_2"
config["feature_extractor_type"] = "wav2vec2"
hf_wav2vec.config = SpeechEncoderDecoderConfig.from_dict(config)
hf_wav2vec.save_pretrained(pytorch_dump_folder_path)
feature_extractor.save_pretrained(pytorch_dump_folder_path)