[Model] Support multiple images for qwen-vl (vllm-project#8247)

Signed-off-by: Alex-Brooks <Alex.Brooks@ibm.com>
Co-authored-by: Cyrus Leung <cyrus.tl.leung@gmail.com>
Co-authored-by: DarkLight1337 <tlleungac@connect.ust.hk>

Author: alex-jw-brooks

docs/source/models/supported_models.rst

@@ -254,7 +254,7 @@ Multimodal Language Models
     -
   * - :code:`QWenLMHeadModel`
     - Qwen-VL
-    - Image\ :sup:`E`
+    - Image\ :sup:`E+`
     - :code:`Qwen/Qwen-VL`, :code:`Qwen/Qwen-VL-Chat`, etc.
     -
   * - :code:`Qwen2VLForConditionalGeneration`

examples/offline_inference_vision_language_multi_image.py

@@ -19,7 +19,39 @@
 ]
 
 
-def load_phi3v(question, image_urls: List[str]):
+def load_qwenvl_chat(question: str, image_urls: List[str]):
+    model_name = "Qwen/Qwen-VL-Chat"
+    llm = LLM(
+        model=model_name,
+        trust_remote_code=True,
+        max_num_seqs=5,
+        limit_mm_per_prompt={"image": len(image_urls)},
+    )
+    placeholders = "".join(f"Picture {i}: <img></img>\n"
+                           for i, _ in enumerate(image_urls, start=1))
+
+    # This model does not have a chat_template attribute on its tokenizer,
+    # so we need to explicitly pass it. We use ChatML since it's used in the
+    # generation utils of the model:
+    # https://huggingface.co/Qwen/Qwen-VL-Chat/blob/main/qwen_generation_utils.py#L265
+    tokenizer = AutoTokenizer.from_pretrained(model_name,
+                                              trust_remote_code=True)
+
+    # Copied from: https://huggingface.co/docs/transformers/main/en/chat_templating
+    chat_template = "{% if not add_generation_prompt is defined %}{% set add_generation_prompt = false %}{% endif %}{% for message in messages %}{{'<|im_start|>' + message['role'] + '\n' + message['content'] + '<|im_end|>' + '\n'}}{% endfor %}{% if add_generation_prompt %}{{ '<|im_start|>assistant\n' }}{% endif %}"  # noqa: E501
+
+    messages = [{'role': 'user', 'content': f"{placeholders}\n{question}"}]
+    prompt = tokenizer.apply_chat_template(messages,
+                                           tokenize=False,
+                                           add_generation_prompt=True,
+                                           chat_template=chat_template)
+
+    stop_tokens = ["<|endoftext|>", "<|im_start|>", "<|im_end|>"]
+    stop_token_ids = [tokenizer.convert_tokens_to_ids(i) for i in stop_tokens]
+    return llm, prompt, stop_token_ids, None, chat_template
+
+
+def load_phi3v(question: str, image_urls: List[str]):
     llm = LLM(
         model="microsoft/Phi-3.5-vision-instruct",
         trust_remote_code=True,
@@ -30,10 +62,10 @@ def load_phi3v(question, image_urls: List[str]):
                              for i, _ in enumerate(image_urls, start=1))
     prompt = f"<|user|>\n{placeholders}\n{question}<|end|>\n<|assistant|>\n"
     stop_token_ids = None
-    return llm, prompt, stop_token_ids, None
+    return llm, prompt, stop_token_ids, None, None
 
 
-def load_internvl(question, image_urls: List[str]):
+def load_internvl(question: str, image_urls: List[str]):
     model_name = "OpenGVLab/InternVL2-2B"
 
     llm = LLM(
@@ -61,7 +93,7 @@ def load_internvl(question, image_urls: List[str]):
     stop_tokens = ["<|endoftext|>", "<|im_start|>", "<|im_end|>", "<|end|>"]
     stop_token_ids = [tokenizer.convert_tokens_to_ids(i) for i in stop_tokens]
 
-    return llm, prompt, stop_token_ids, None
+    return llm, prompt, stop_token_ids, None, None
 
 
 def load_qwen2_vl(question, image_urls: List[str]):
@@ -111,18 +143,19 @@ def load_qwen2_vl(question, image_urls: List[str]):
     else:
         image_data, _ = process_vision_info(messages)
 
-    return llm, prompt, stop_token_ids, image_data
+    return llm, prompt, stop_token_ids, image_data, None
 
 
 model_example_map = {
     "phi3_v": load_phi3v,
     "internvl_chat": load_internvl,
     "qwen2_vl": load_qwen2_vl,
+    "qwen_vl_chat": load_qwenvl_chat,
 }
 
 
 def run_generate(model, question: str, image_urls: List[str]):
-    llm, prompt, stop_token_ids, image_data = model_example_map[model](
+    llm, prompt, stop_token_ids, image_data, _ = model_example_map[model](
         question, image_urls)
     if image_data is None:
         image_data = [fetch_image(url) for url in image_urls]
@@ -146,29 +179,32 @@ def run_generate(model, question: str, image_urls: List[str]):
 
 
 def run_chat(model: str, question: str, image_urls: List[str]):
-    llm, _, stop_token_ids, _ = model_example_map[model](question, image_urls)
+    llm, _, stop_token_ids, _, chat_template = model_example_map[model](
+        question, image_urls)
 
     sampling_params = SamplingParams(temperature=0.0,
                                      max_tokens=128,
                                      stop_token_ids=stop_token_ids)
-
-    outputs = llm.chat([{
-        "role":
-        "user",
-        "content": [
-            {
-                "type": "text",
-                "text": question,
-            },
-            *({
-                "type": "image_url",
-                "image_url": {
-                    "url": image_url
+    outputs = llm.chat(
+        [{
+            "role":
+            "user",
+            "content": [
+                {
+                    "type": "text",
+                    "text": question,
                 },
-            } for image_url in image_urls),
-        ],
-    }],
-                       sampling_params=sampling_params)
+                *({
+                    "type": "image_url",
+                    "image_url": {
+                        "url": image_url
+                    },
+                } for image_url in image_urls),
+            ],
+        }],
+        sampling_params=sampling_params,
+        chat_template=chat_template,
+    )
 
     for o in outputs:
         generated_text = o.outputs[0].text