[BugFix] Qwen2.5-Omni streaming code2wav input handling (#3396)

Signed-off-by: yinpeiqi <yinpeiqi809@gmail.com>

vllm_omni/model_executor/models/qwen2_5_omni/pipeline.py

@@ -51,6 +51,7 @@ QWEN2_5_OMNI_PIPELINE = PipelineConfig(
             final_output=True,
             final_output_type="audio",
             engine_output_type="audio",
+            custom_process_input_func=f"{_PROC}.talker2code2wav",
             sampling_constraints={"detokenize": True},
         ),
     ),

vllm_omni/model_executor/models/qwen2_5_omni/qwen2_5_omni.py

@@ -351,10 +351,12 @@ class Qwen2_5OmniForConditionalGeneration(
                 )
             )
 
-            code = code[:-1] if code[-1] == TALKER_CODEC_EOS_TOKEN_ID else code
-            code = code[1:] if code[0] == TALKER_CODEC_BOS_TOKEN_ID else code
+            if code.numel() and code[-1] == TALKER_CODEC_EOS_TOKEN_ID:
+                code = code[:-1]
+            if code.numel() and code[0] == TALKER_CODEC_BOS_TOKEN_ID:
+                code = code[1:]
 
-            audio_tensor = self.generate_audio(code, voice_type)
+            audio_tensor = self.generate_audio(code, voice_type) if code.numel() else torch.zeros(0, device=code.device)
             return OmniOutput(text_hidden_states=None, multimodal_outputs={"model_outputs": audio_tensor})
 
         return OmniOutput(

vllm_omni/model_executor/stage_input_processors/qwen2_5_omni.py

@@ -56,3 +56,28 @@ def thinker2talker(
             )
         )
     return talker_inputs
+
+
+def talker2code2wav(
+    source_outputs,
+    _prompt: OmniTokensPrompt | TextPrompt = None,
+    _requires_multimodal_data: bool = False,
+):
+    code2wav_inputs = []
+    for talker_output in source_outputs:
+        output = talker_output.outputs[0]
+        token_ids = list(output.cumulative_token_ids)
+        if token_ids and token_ids[0] == TALKER_CODEC_START_TOKEN_ID:
+            token_ids = token_ids[1:]
+        if token_ids and token_ids[-1] == TALKER_CODEC_END_TOKEN_ID:
+            token_ids = token_ids[:-1]
+        if not token_ids:
+            continue
+        code2wav_inputs.append(
+            OmniTokensPrompt(
+                prompt_token_ids=token_ids,
+                multi_modal_data=None,
+                mm_processor_kwargs=None,
+            )
+        )
+    return code2wav_inputs