[Model] Add IndexTTS2 text-to-speech support (#3838)

Signed-off-by: BeatSeat <wendavid552@gmail.com>
Signed-off-by: David <david@podcast.ai>
Signed-off-by: wendavid552 <wendavid552@gmail.com>
Signed-off-by: WenDavid <davidzhangcf@foxmail.com>

vllm_omni/model_executor/models/indextts2/gpt/embeddings.py

@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""Learned position embeddings for IndexTTS2 GPT model."""
+
+import torch
+import torch.nn as nn
+
+
+class LearnedPositionEmbeddings(nn.Module):
+    def __init__(self, seq_len: int, model_dim: int, init: float = 0.02):
+        super().__init__()
+        self.emb = nn.Embedding(seq_len, model_dim)
+        self.emb.weight.data.normal_(mean=0.0, std=init)
+
+    def forward(self, x: torch.Tensor) -> torch.Tensor:
+        sl = x.shape[1]
+        return self.emb(torch.arange(0, sl, device=x.device))
+
+    def get_fixed_embedding(self, ind: int, dev: torch.device) -> torch.Tensor:
+        return self.emb(torch.tensor([ind], device=dev)).unsqueeze(0)