[VLM] Update Qwen3-VL max_num_video_tokens calculation for configurable video profiling (#25557)

Signed-off-by: Isotr0py <[email protected]>
Signed-off-by: Roger Wang <[email protected]>
Co-authored-by: Roger Wang <[email protected]>

Author: Isotr0py

vllm/model_executor/models/qwen2_vl.py

@@ -79,7 +79,7 @@
 logger = init_logger(__name__)
 
 # For profile run
-_MAX_FRAMES_PER_VIDEO = 32
+_MAX_FRAMES_PER_VIDEO = 14
 
 # === Vision Inputs === #
 
@@ -932,6 +932,7 @@ def get_num_image_tokens(
         _, num_image_tokens = self._get_vision_info(
             image_width=image_width,
             image_height=image_height,
+            num_frames=1,
             image_processor=image_processor,
         )
         return num_image_tokens
@@ -956,6 +957,7 @@ def get_image_size_with_most_features(self) -> ImageSize:
         max_image_size, _ = self._get_vision_info(
             image_width=9999999,
             image_height=9999999,
+            num_frames=1,
             image_processor=None,
         )
         return max_image_size
@@ -969,10 +971,12 @@ def get_max_image_tokens(self) -> int:
             image_processor=None,
         )
 
-    def _get_max_video_frames(self, max_tokens: int) -> int:
+    def _get_max_video_frames(self,
+                              max_tokens: int,
+                              start_num_frames: int = 1) -> int:
         target_width, target_height = self.get_image_size_with_most_features()
 
-        num_frames = 0
+        num_frames = start_num_frames
 
         while True:
             next_num_frames = num_frames + 1
@@ -994,12 +998,13 @@ def get_num_frames_with_most_features(
         self,
         seq_len: int,
         mm_counts: Mapping[str, int],
+        max_frames_per_video: int = _MAX_FRAMES_PER_VIDEO,
     ) -> int:
         max_videos = mm_counts.get("video", 0)
 
         max_total_frames = self._get_max_video_frames(seq_len)
         max_frames_per_video = min(max_total_frames // max(max_videos, 1),
-                                   _MAX_FRAMES_PER_VIDEO)
+                                   max_frames_per_video)
 
         return max(max_frames_per_video, 1)
 

vllm/model_executor/models/qwen3_vl.py

@@ -33,11 +33,14 @@
 import torch.nn.functional as F
 from transformers import BatchFeature
 from transformers.models.qwen2_vl import Qwen2VLImageProcessorFast
-from transformers.models.qwen2_vl.image_processing_qwen2_vl import smart_resize
+from transformers.models.qwen2_vl.image_processing_qwen2_vl import (
+    smart_resize as image_smart_resize)
 from transformers.models.qwen3_vl import (Qwen3VLProcessor,
                                           Qwen3VLVideoProcessor)
 from transformers.models.qwen3_vl.configuration_qwen3_vl import (
     Qwen3VLConfig, Qwen3VLVisionConfig)
+from transformers.models.qwen3_vl.video_processing_qwen3_vl import (
+    smart_resize as video_smart_resize)
 from transformers.video_utils import VideoMetadata
 
 from vllm.attention.layer import check_upstream_fa_availability
@@ -85,6 +88,9 @@
 
 logger = init_logger(__name__)
 
+# Official recommended max pixels is 24576 * 32 * 32
+_MAX_FRAMES_PER_VIDEO = 24576
+
 
 class Qwen3_VisionPatchEmbed(nn.Module):
 
@@ -593,24 +599,39 @@ def _get_vision_info(
         image_height: int,
         num_frames: int = 2,
         do_resize: bool = True,
-        image_processor: Optional[Qwen2VLImageProcessorFast],
+        image_processor: Optional[Union[Qwen2VLImageProcessorFast,
+                                        Qwen3VLVideoProcessor]],
     ) -> tuple[ImageSize, int]:
-        if image_processor is None:
+        if image_processor is None and num_frames > 1:
+            image_processor = self.get_video_processor()
+        elif image_processor is None:
             image_processor = self.get_image_processor()
 
+        is_video = isinstance(image_processor, Qwen3VLVideoProcessor)
+
         hf_config = self.get_hf_config()
         vision_config = hf_config.vision_config
         patch_size = vision_config.patch_size
         merge_size = vision_config.spatial_merge_size
         temporal_patch_size = vision_config.temporal_patch_size
 
         if do_resize:
+            if is_video:
+                smart_resize = video_smart_resize
+                extra_kwargs = {
+                    "num_frames": num_frames,
+                    "temporal_factor": temporal_patch_size
+                }
+            else:
+                smart_resize = image_smart_resize
+                extra_kwargs = {}
             resized_height, resized_width = smart_resize(
                 height=image_height,
                 width=image_width,
                 factor=patch_size * merge_size,
                 min_pixels=image_processor.size["shortest_edge"],
                 max_pixels=image_processor.size["longest_edge"],
+                **extra_kwargs,
             )
             preprocessed_size = ImageSize(width=resized_width,
                                           height=resized_height)
@@ -629,6 +650,39 @@ def _get_vision_info(
 
         return preprocessed_size, num_vision_tokens
 
+    def _get_max_video_frames(self,
+                              max_tokens: int,
+                              start_num_frames: int = 2) -> int:
+        return super()._get_max_video_frames(max_tokens,
+                                             start_num_frames=start_num_frames)
+
+    def get_num_frames_with_most_features(
+        self,
+        seq_len: int,
+        mm_counts: Mapping[str, int],
+    ) -> int:
+        return super().get_num_frames_with_most_features(
+            seq_len, mm_counts, max_frames_per_video=_MAX_FRAMES_PER_VIDEO)
+
+    def get_max_video_tokens(
+        self,
+        seq_len: int,
+        mm_counts: Mapping[str, int],
+    ) -> int:
+        target_width, target_height = self.get_image_size_with_most_features()
+        video_soft_tokens = self.get_num_video_tokens(
+            image_width=target_width,
+            image_height=target_height,
+            num_frames=self.get_num_frames_with_most_features(
+                seq_len, mm_counts),
+            image_processor=None,
+        )
+
+        # NOTE: By default in Qwen3-VL, one video token is converted to
+        # "<{timestamp} seconds>" (on average 9.5 tokens) + vision_start_token + video_token + vision_end_token # noqa: E501
+        formatted_video_soft_tokens = video_soft_tokens * 12.5
+        return int(formatted_video_soft_tokens)
+
     def _calculate_timestamps(self, indices: list[int] | torch.Tensor,
                               video_fps: float, merge_size: int):
         if not isinstance(indices, list):
@@ -698,15 +752,21 @@ def get_dummy_mm_data(
             self.info.get_image_size_with_most_features())
         target_num_frames = self.info.get_num_frames_with_most_features(
             seq_len, mm_counts)
+        target_video_size, _ = self.info._get_vision_info(
+            image_width=target_width,
+            image_height=target_height,
+            num_frames=target_num_frames,
+            image_processor=self.info.get_video_processor(),
+        )
         return {
             "image":
             self._get_dummy_images(width=target_width,
                                    height=target_height,
                                    num_images=num_images),
             "video":
             self._get_dummy_videos(
-                width=target_width,
-                height=target_height,
+                width=target_video_size.width,
+                height=target_video_size.height,
                 num_frames=target_num_frames,
                 num_videos=num_videos,
             ),