# Model Configuration — LFM2-350M Pretrained + Parallel Codebook Heads
model:
  # Pretrained backbone
  model_id: "LiquidAI/LFM2-350M"
  use_custom_config: false

  # Vocabulary: text (64400) + special (10) + cb1 audio (4032) + IPA (26) = 68468
  text_vocab_size: 64400
  total_vocab_size: 68468

  # Audio token configuration
  audio_codebook_size: 4032
  tokens_per_frame: 1  # Only cb1 in sequence (parallel heads predict cb2/cb3/cb4)
  num_audio_layers: 4
  audio_tokens_start: 64410

  # Parallel codebook heads
  use_parallel_heads: true
  num_parallel_heads: 3

  # Frame-level position encoding
  audio_step: 1

  # Special tokens
  pad_token_id: 64407

  # Model loading
  attn_implementation: "sdpa"
  dtype: "bfloat16"

  # First train = true: resize embeddings from base 65536 to 68442
  first_train: true

  # Learnable RoPE
  use_learnable_rope: true
  alpha_min: 0.1
  alpha_max: 2.0

  # Chained heads (cb2→cb3→cb4 with MLP chain)
  use_chained_heads: true
