Support Giga AM transducer V2 (#2136)

scripts/nemo/GigaAM/export-onnx-ctc-v2.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 import gigaam
 import onnx
 import torch
@@ -27,7 +28,13 @@ def add_meta_data(filename: str, meta_data: dict[str, str]):
 
 def main() -> None:
     model_name = "v2_ctc"
-    model = gigaam.load_model(model_name, fp16_encoder=False, use_flash=False, download_root=".")
+    model = gigaam.load_model(
+        model_name, fp16_encoder=False, use_flash=False, download_root="."
+    )
+
+    # use characters
+    # space is 0
+    # <blk> is the last token
     with open("./tokens.txt", "w", encoding="utf-8") as f:
         for i, s in enumerate(model.cfg["labels"]):
             f.write(f"{s} {i}\n")
@@ -53,5 +60,5 @@ def main() -> None:
     )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()