Fix Qwen3-TTS tensor paths to match HuggingFace model structure

The HuggingFace model uses different tensor name prefixes:
- talker.model.text_embedding instead of model.embed_tokens
- talker.codec_head instead of lm_head
- talker.code_predictor.model.codec_embedding instead of code_embeddings
- talker.code_predictor.lm_head instead of output_heads

Also removed input_proj which doesn't exist in the HF model.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/makima/src/tts/qwen3/model.rs b/makima/src/tts/qwen3/model.rs
index 8a1e986..e19e5f9 100644
--- a/makima/src/tts/qwen3/model.rs
+++ b/makima/src/tts/qwen3/model.rs
@@ -389,9 +389,12 @@ pub struct Qwen3Model {
 
 impl Qwen3Model {
     pub fn new(config: &Qwen3LmConfig, vb: VarBuilder) -> Result<Self> {
-        let model_vb = vb.pp("model");
+        // HuggingFace Qwen3-TTS uses "talker.model.*" prefix
+        let talker_vb = vb.pp("talker");
+        let model_vb = talker_vb.pp("model");
 
-        let embed_tokens = embedding(config.vocab_size, config.hidden_size, model_vb.pp("embed_tokens"))?;
+        // Text embedding (called "text_embedding" in HF, not "embed_tokens")
+        let embed_tokens = embedding(config.vocab_size, config.hidden_size, model_vb.pp("text_embedding"))?;
 
         let mut layers = Vec::with_capacity(config.num_hidden_layers);
         for i in 0..config.num_hidden_layers {
@@ -401,8 +404,8 @@ impl Qwen3Model {
 
         let norm = rms_norm(config.hidden_size, config.rms_norm_eps, model_vb.pp("norm"))?;
 
-        // LM head — may or may not share weights with embed_tokens
-        let lm_head = linear_no_bias(config.hidden_size, config.vocab_size, vb.pp("lm_head"))?;
+        // Codec head (called "codec_head" in HF, not "lm_head")
+        let lm_head = linear_no_bias(config.hidden_size, config.vocab_size, talker_vb.pp("codec_head"))?;
 
         let dtype = vb.dtype();
         let device = vb.device().clone();