[Feature] Support output modalities control per request (#298)

Signed-off-by: Gaohan123 <hgaoaf@connect.ust.hk>

docs/user_guide/examples/offline_inference/qwen2_5_omni.md

@@ -38,6 +38,14 @@ Then run the command below.
 bash run_single_prompt.sh
 ```
 
+### Modality control
+If you want to control output modalities, e.g. only output text, you can run the command below:
+```bash
+python end2end.py --output-wav output_audio \
+                  --query-type mixed_modalities \
+                  --modalities text
+```
+
 #### Using Local Media Files
 The `end2end.py` script supports local media files (audio, video, image) via CLI arguments:
 

docs/user_guide/examples/offline_inference/qwen3_omni.md

@@ -33,6 +33,14 @@ If you have not enough memory, you can set thinker with tensor parallel. Just ru
 bash run_single_prompt_tp.sh
 ```
 
+### Modality control
+If you want to control output modalities, e.g. only output text, you can run the command below:
+```bash
+python end2end.py --output-wav output_audio \
+                  --query-type use_audio \
+                  --modalities text
+```
+
 #### Using Local Media Files
 The `end2end.py` script supports local media files (audio, video, image) via command-line arguments:
 

docs/user_guide/examples/online_serving/qwen2_5_omni.md

@@ -27,7 +27,7 @@ Get into the example folder
 cd examples/online_serving/qwen2_5_omni
 ```
 
-####  Send request via python
+#### Send request via python
 
 ```bash
 python openai_chat_completion_client_for_multimodal_generation.py --query-type mixed_modalities
@@ -73,6 +73,14 @@ python openai_chat_completion_client_for_multimodal_generation.py \
 bash run_curl_multimodal_generation.sh mixed_modalities
 ```
 
+## Modality control
+If you want to control output modalities, e.g. only output text, you can run the command below:
+```bash
+python openai_chat_completion_client_for_multimodal_generation.py \
+    --query-type mixed_modalities \
+    --modalities text
+```
+
 ## Run Local Web UI Demo
 
 This Web UI demo allows users to interact with the model through a web browser.

docs/user_guide/examples/online_serving/qwen3_omni.md

@@ -81,13 +81,21 @@ sudo apt update
 sudo apt install ffmpeg
 ```
 
+## Modality control
+If you want to control output modalities, e.g. only output text, you can run the command below:
+```bash
+python openai_chat_completion_client_for_multimodal_generation.py \
+    --query-type use_image \
+    --modalities text
+```
+
 ## Run Local Web UI Demo
 
 This Web UI demo allows users to interact with the model through a web browser.
 
 ### Running Gradio Demo
 
-Once vllm and vllm-omni are installed, you can launch the web service built on AsyncOmni by
+Once vllm and vllm-omni are installed, you can launch the web service built on AsyncOmni by:
 
 ```bash
 python gradio_demo.py  --model Qwen/Qwen3-Omni-30B-A3B-Instruct --port 7861