hyperparams.yaml

# Seed needs to be set at top of yaml, before objects with parameters
# are instantiated
seed: 1994
__set_seed: !apply:torch.manual_seed [!ref <seed>]

skip_training: True

output_folder: !ref output_folder_seq2seq_cv_podcast_arhiv_augmentation_128_emb_5000_vocab
output_wer_folder: !ref <output_folder>/
save_folder: !ref <output_folder>/save
train_log: !ref <output_folder>/train_log.txt

lm_folder: LM/output_folder_lm

# Data files
data_folder: "../../data/combined_data/speechbrain_splits"

wav2vec2_hub: facebook/wav2vec2-large-xlsr-53
wav2vec2_folder: !ref <save_folder>/wav2vec2_checkpoint

# pretrained_tokenizer_path: "Tokenizer/output_folder_cv/1K_subword_unigram" # Use this for the CV model
pretrained_tokenizer_path: "Tokenizer/output_folder_cv_podcast_arhiv/5K_subword_unigram" # Use this for the CV+Podcast+Arhiv model

####################### Training Parameters ####################################

number_of_epochs: 50
number_of_ctc_epochs: 15
# batch_size: 16 
# batch_size: 6 # for cv+podcast
batch_size: 6 # for cv+podcast+arhiv
label_smoothing: 0.1
lr: 0.0001
ctc_weight: 0.5

opt_class: !name:torch.optim.Adam
      lr: !ref <lr> 

lr_annealing: !new:speechbrain.nnet.schedulers.NewBobScheduler
   initial_value: !ref <lr>
   improvement_threshold: 0.0025
   annealing_factor: 0.8
   patient: 0

# Dataloader options
num_workers: 4
train_dataloader_opts:
   num_workers: !ref <num_workers>
   batch_size: !ref <batch_size>

valid_dataloader_opts:
   num_workers: !ref <num_workers>
   batch_size: !ref <batch_size>

test_dataloader_opts:
   batch_size: 1

####################### Model Parameters #######################################

dropout: 0.15
wav2vec_output_dim: 1024
emb_size: 128
dec_neurons: 1024
dec_layers: 1

output_neurons: 1000
blank_index: 0
bos_index: 0
eos_index: 0
unk_index: 0

# Decoding parameters
min_decode_ratio: 0.0
max_decode_ratio: 1.0
valid_beam_size: 10
test_beam_size: 10
using_eos_threshold: True
eos_threshold: 1.5
using_max_attn_shift: True
max_attn_shift: 300
temperature: 1.0
ctc_window_size: 200
temperature_lm: 1.25
# Scoring parameters
ctc_weight_decode: 0.0
coverage_penalty: 1.5
lm_weight: 0.0

epoch_counter: !new:speechbrain.utils.epoch_loop.EpochCounter
   limit: !ref <number_of_epochs>

# Wav2vec2 encoder
encoder_w2v2: !new:speechbrain.lobes.models.huggingface_transformers.wav2vec2.Wav2Vec2
    source: !ref <wav2vec2_hub>
    output_norm: True
    freeze: False
    freeze_feature_extractor: True
    save_path: !ref <wav2vec2_folder>
    output_all_hiddens: False

embedding: !new:speechbrain.nnet.embedding.Embedding
   num_embeddings: !ref <output_neurons>
   embedding_dim: !ref <emb_size>

# Attention-based RNN decoder.
decoder: !new:speechbrain.nnet.RNN.AttentionalRNNDecoder
    enc_dim: !ref <wav2vec_output_dim>
    input_size: !ref <emb_size>
    rnn_type: gru
    attn_type: location
    hidden_size: !ref <dec_neurons>
    attn_dim: 512
    num_layers: !ref <dec_layers>
    scaling: 1.0
    channels: 10
    kernel_size: 100
    re_init: True
    dropout: !ref <dropout>

ctc_lin: !new:speechbrain.nnet.linear.Linear
   input_size: !ref <wav2vec_output_dim>
   n_neurons: !ref <output_neurons>

seq_lin: !new:speechbrain.nnet.linear.Linear
   input_size: !ref <dec_neurons>
   n_neurons: !ref <output_neurons>

log_softmax: !new:speechbrain.nnet.activations.Softmax
   apply_log: True

ctc_cost: !name:speechbrain.nnet.losses.ctc_loss
   blank_index: !ref <blank_index>

nll_cost: !name:speechbrain.nnet.losses.nll_loss
   label_smoothing: 0.1

# This is the RNNLM that is used according to the Huggingface repository
# NB: It has to match the pre-trained RNNLM!!
#lm_model: !new:speechbrain.lobes.models.RNNLM.RNNLM
#   output_neurons: !ref <output_neurons>
#   embedding_dim: !ref <emb_size>
#   activation: !name:torch.nn.LeakyReLU
#   dropout: 0.0
#   rnn_layers: 2
#   rnn_neurons: 2048
#   dnn_blocks: 1
#   dnn_neurons: 512
#   return_hidden: True  # For inference

tokenizer: !new:sentencepiece.SentencePieceProcessor
  model_file: 1000_unigram.model

modules:
   encoder_w2v2: !ref <encoder_w2v2>
   embedding: !ref <embedding>
   decoder: !ref <decoder>
   ctc_lin: !ref <ctc_lin>
   seq_lin: !ref <seq_lin>
     #lm_model: !ref <lm_model>

model: !new:torch.nn.ModuleList
   - [!ref <encoder_w2v2>, !ref <embedding>, !ref <decoder>, !ref <ctc_lin>, !ref <seq_lin>]

############################## Decoding & optimiser ############################
#coverage_scorer: !new:speechbrain.decoders.scorer.CoverageScorer
#   vocab_size: !ref <output_neurons>
#
#rnnlm_scorer: !new:speechbrain.decoders.scorer.RNNLMScorer
#   language_model: !ref <lm_model>
#   temperature: !ref <temperature_lm>
#
#scorer: !new:speechbrain.decoders.scorer.ScorerBuilder
#   full_scorers: [!ref <rnnlm_scorer>,
#                  !ref <coverage_scorer>]
#   weights:
#      rnnlm: !ref <lm_weight>
#      coverage: !ref <coverage_penalty>


# Search
greedy_search: !new:speechbrain.decoders.S2SRNNGreedySearcher
    embedding: !ref <embedding>
    decoder: !ref <decoder>
    linear: !ref <seq_lin>
    bos_index: !ref <bos_index>
    eos_index: !ref <eos_index>
    min_decode_ratio: !ref <min_decode_ratio>
    max_decode_ratio: !ref <max_decode_ratio>

test_search: !new:speechbrain.decoders.S2SRNNBeamSearcher
    embedding: !ref <embedding>
    decoder: !ref <decoder>
    linear: !ref <seq_lin>
    bos_index: !ref <bos_index>
    eos_index: !ref <eos_index>
    min_decode_ratio: !ref <min_decode_ratio>
    max_decode_ratio: !ref <max_decode_ratio>
    beam_size: !ref <test_beam_size>
    eos_threshold: !ref <eos_threshold>
    using_max_attn_shift: !ref <using_max_attn_shift>
    max_attn_shift: !ref <max_attn_shift>
    temperature: !ref <temperature>
      #scorer: !ref <scorer>


############################## Augmentations ###################################

# Speed perturbation
speed_perturb: !new:speechbrain.augment.time_domain.SpeedPerturb
   orig_freq: 16000
   speeds: [95, 100, 105]

# Frequency drop: randomly drops a number of frequency bands to zero.
drop_freq: !new:speechbrain.augment.time_domain.DropFreq
   drop_freq_low: 0
   drop_freq_high: 1
   drop_freq_count_low: 1
   drop_freq_count_high: 3
   drop_freq_width: 0.05

# Time drop: randomly drops a number of temporal chunks.
drop_chunk: !new:speechbrain.augment.time_domain.DropChunk
   drop_length_low: 1000
   drop_length_high: 2000
   drop_count_low: 1
   drop_count_high: 5

# Augmenter: Combines previously defined augmentations to perform data augmentation
wav_augment: !new:speechbrain.augment.augmenter.Augmenter
   concat_original: False
   min_augmentations: 1
   max_augmentations: 3
   augment_prob: 0.5
   augmentations: [
      !ref <speed_perturb>,
      !ref <drop_freq>,
      !ref <drop_chunk>]


############################## Logging and Pretrainer ##########################

checkpointer: !new:speechbrain.utils.checkpoints.Checkpointer
   checkpoints_dir: !ref <save_folder>
   recoverables:
      model: !ref <model>
      scheduler: !ref <lr_annealing>
      counter: !ref <epoch_counter>

train_logger: !new:speechbrain.utils.train_logger.FileTrainLogger
   save_file: !ref <train_log>

error_rate_computer: !name:speechbrain.utils.metric_stats.ErrorRateStats

cer_computer: !name:speechbrain.utils.metric_stats.ErrorRateStats
   split_tokens: True


# The pretrainer allows a mapping between pretrained files and instances that
# are declared in the yaml. E.g here, we will download the file lm.ckpt
# and it will be loaded into "lm" which is pointing to the <lm_model> defined
# before.
#pretrainer: !new:speechbrain.utils.parameter_transfer.Pretrainer
#   collect_in: !ref <lm_folder>
#   loadables:
#      lm: !ref <lm_model>
#   paths:
#      lm: !ref <lm_folder>/save/CKPT+2024-07-19+14-16-05+00/model.ckpt