[VLM] Cleanup validation and update docs (#6149)

Author: DarkLight1337

vllm/model_executor/models/llava.py

@@ -149,14 +149,16 @@ def __init__(self,
                                                 config.vocab_size, logit_scale)
         self.sampler = Sampler()
 
-    def _validate_image_data(self, data: torch.Tensor) -> torch.Tensor:
-        if list(data.shape)[1:] != [
-                3, self.config.vision_config.image_size,
-                self.config.vision_config.image_size
-        ]:
+    def _validate_pixel_values(self, data: torch.Tensor) -> torch.Tensor:
+        h = w = self.config.vision_config.image_size
+        expected_dims = (3, h, w)
+        actual_dims = tuple(data.shape[1:])
+
+        if actual_dims != expected_dims:
+            expected_expr = ("batch_size", *map(str, expected_dims))
             raise ValueError(
-                "The expected image tensor shape is batch dimension plus "
-                "channel, height and width.")
+                f"The expected shape of pixel values is {expected_expr}. "
+                f"You supplied {tuple(data.shape)}.")
 
         return data
 
@@ -173,7 +175,7 @@ def _parse_and_validate_image_input(
 
         return LlavaImagePixelInputs(
             type="pixel_values",
-            data=self._validate_image_data(pixel_values),
+            data=self._validate_pixel_values(pixel_values),
         )
 
     def _select_image_features(self, image_features: torch.Tensor, *,
@@ -226,18 +228,25 @@ def forward(
 
         One key thing to understand is the `input_ids` already accounts for the
         positions of the to-be-inserted image embeddings.
+
         Concretely, consider a text prompt:
-        "<image>\nUSER: What's the content of the image?\nASSISTANT:".
+        `"USER: <image>\\nWhat's the content of the image?\\nASSISTANT:"`.
+
         Tokenizer outputs:
-        [1, 32000, 29871, 13, 11889, 29901, 1724, 29915, 29879, 278,
-        2793, 310, 278, 1967, 29973, 13, 22933, 9047, 13566, 29901].
-        The to-be-inserted image has a size of 576 (24 * 24) along the context
-        length dimension.
-        `input_ids` is thus [1, 32000, ..., 32000, 29871, 13, 11889, 29901,
-        1724, 29915, 29879, 278, 2793, 310, 278, 1967, 29973, 13, 22933,
-        9047, 13566, 29901].
-        There will be 576 `32000` in the `input_ids`.
-        (32000 is the token id for `<image>`.)
+        `[1, 3148, 1001, 29901, 29871, 32000, 29871, 13, 5618, 29915, 29879,
+        278, 2793, 310, 278, 1967, 29973, 13, 22933, 9047, 13566, 29901]`.
+
+        To reserve space in KV cache, we have to insert placeholder tokens
+        before they are inputted to the model, so the input processor prepends 
+        additional image tokens (denoted as `32000`), resulting in:
+        `[1, 3148, 1001, 29901, 29871, 32000, ..., 32000, 29871, 13, 5618,
+        29915, 29879, 278, 2793, 310, 278, 1967, 29973, 13, 22933, 9047, 13566,
+        29901]`.
+
+        We insert 575 tokens so that including the original image token in the
+        input, there are a total of 576 (24 * 24) image tokens, which
+        corresponds to the number of image tokens inputted to the language
+        model, i.e. the number of image tokens outputted by the visual encoder.
 
         This way, the `positions` and `attn_metadata` are consistent
         with the `input_ids`.
@@ -246,6 +255,9 @@ def forward(
             input_ids: Flattened (concatenated) input_ids corresponding to a
                 batch.
             pixel_values: The pixels in each input image.
+        
+        See also:
+            :class:`LlavaImageInputs`
         """
         image_input = self._parse_and_validate_image_input(**kwargs)
 

vllm/model_executor/models/llava_next.py

@@ -47,7 +47,8 @@ class LlavaNextImagePixelInputs(TypedDict):
     """
     Shape: `(batch_size, 1 + num_patches, num_channels, height, width)`
 
-    Note that `num_patches` may be different for each batch.
+    Note that `num_patches` may be different for each batch, in which case
+    the data is passed as a list instead of a batched tensor.
     """
 
     image_sizes: NotRequired[torch.Tensor]
@@ -255,40 +256,20 @@ def _validate_pixel_values(
         self, data: Union[torch.Tensor, List[torch.Tensor]]
     ) -> Union[torch.Tensor, List[torch.Tensor]]:
 
-        def _validate_shape(data: torch.Tensor):
-
-            dim = data.dim()
-            height = width = self.config.vision_config.image_size
-            # All 4d image tensors have the same number of patches,
-            # so data is a 5d batch of these tensors
-            if dim == 5:
-                if list(data.shape)[2:] != [
-                        3, self.config.vision_config.image_size,
-                        self.config.vision_config.image_size
-                ]:
-                    raise ValueError(
-                        "Expected pixel value tensor in shape of: (batch size, "
-                        f"patch number, 3, {height}, {width}), got {data.shape}"
-                    )
-
-            # 4d image tensors have different number of patches,
-            # so data is each individual tensor.
-            elif dim == 4:
-                if list(data.shape)[1:] != [
-                        3, self.config.vision_config.image_size,
-                        self.config.vision_config.image_size
-                ]:
-                    raise ValueError(
-                        "Expected pixel value tensor in shape of: (patch "
-                        f"number, 3, {height}, {width}), got {data.shape}")
-            else:
+        h = w = self.config.vision_config.image_size
+        expected_dims = (3, h, w)
+
+        def _validate_shape(d: torch.Tensor):
+            actual_dims = tuple(d.shape[1:])
+
+            if actual_dims != expected_dims:
+                expected_expr = ("num_patches", *map(str, expected_dims))
                 raise ValueError(
-                    f"Invalid pixel value tensor of shape {data.shape}")
+                    "The expected shape of pixel values in each batch element "
+                    f"is {expected_expr}. You supplied {tuple(d.shape)}.")
 
-        if isinstance(data, torch.Tensor):
-            _validate_shape(data)
-        else:
-            [_validate_shape(d) for d in data]
+        for d in data:
+            _validate_shape(d)
 
         return data
 
@@ -464,18 +445,33 @@ def forward(
 
         One key thing to understand is the `input_ids` already accounts for the
         positions of the to-be-inserted image embeddings.
+
         Concretely, consider a text prompt:
-        "<image>\nUSER: What's the content of the image?\nASSISTANT:".
+        `"A chat between a curious human and an artificial intelligence
+        assistant. The assistant gives helpful, detailed, and polite answers to
+        the human's questions.
+        USER: <image>\\nWhat is shown in this image? ASSISTANT:"`.
+
         Tokenizer outputs:
-        [1, 32000, 29871, 13, 11889, 29901, 1724, 29915, 29879, 278,
-        2793, 310, 278, 1967, 29973, 13, 22933, 9047, 13566, 29901].
-        The to-be-inserted image has a size of 576 (24 * 24) along the context
-        length dimension.
-        `input_ids` is thus [1, 32000, ..., 32000, 29871, 13, 11889, 29901,
-        1724, 29915, 29879, 278, 2793, 310, 278, 1967, 29973, 13, 22933,
-        9047, 13566, 29901].
-        There will be 576 `32000` in the `input_ids`.
-        (32000 is the token id for `<image>`.)
+        `[1, 319, 13563, 1546, 263, 12758, 5199, 322, 385, 23116, 21082, 20255,
+        29889, 450, 20255, 4076, 8444, 29892, 13173, 29892, 322, 1248, 568,
+        6089, 304, 278, 5199, 29915, 29879, 5155, 29889, 3148, 1001, 29901,
+        29871, 32000, 13, 5618, 338, 4318, 297, 445, 1967, 29973, 319, 1799,
+        9047, 13566, 29901]`.
+
+        To reserve space in KV cache, we have to insert placeholder tokens
+        before they are inputted to the model, so the input processor prepends 
+        additional image tokens (denoted as `32000`), resulting in:
+        `[1, 319, 13563, 1546, 263, 12758, 5199, 322, 385, 23116, 21082, 20255,
+        29889, 450, 20255, 4076, 8444, 29892, 13173, 29892, 322, 1248, 568,
+        6089, 304, 278, 5199, 29915, 29879, 5155, 29889, 3148, 1001, 29901,
+        29871, 32000, ..., 32000, 13, 5618, 338, 4318, 297, 445, 1967, 29973,
+        319, 1799, 9047, 13566, 29901]`.
+
+        Unlike in LLaVA-1.5, the number of image tokens inputted to the language
+        model depends on the original size of the input image. Including the
+        original image token in the input, the required number of image tokens
+        is given by :func:`get_llava_next_image_feature_size`.
 
         This way, the `positions` and `attn_metadata` are consistent
         with the `input_ids`.
@@ -484,15 +480,10 @@ def forward(
             input_ids: Flattened (concatenated) input_ids corresponding to a
                 batch.
             pixel_values: The pixels in each grid patch for each input image.
-                Expects a batch with shape `[1, num_patches, 3, h, w]`.
             image_sizes: The original `(height, width)` for each input image.
-                Expects a batch with shape `[1, 2]`.
-
+        
         See also:
-            Each input maps to huggingface implementation, as follows:
-
-            - `pixel_values`: https://github.com/huggingface/transformers/blob/v4.41.1/src/transformers/models/llava_next/modeling_llava_next.py#L690
-            - `image_sizes`: https://github.com/huggingface/transformers/blob/v4.41.1/src/transformers/models/llava_next/modeling_llava_next.py#L691
+            :class:`LlavaNextImageInputs`
         """
         image_input = self._parse_and_validate_image_input(**kwargs)
 

vllm/model_executor/models/phi3v.py

@@ -263,7 +263,8 @@ class Phi3VImagePixelInputs(TypedDict):
     """
     Shape: `(batch_size, 1 + num_patches, num_channels, height, width)`
 
-    Note that `num_patches` may be different for each batch.
+    Note that `num_patches` may be different for each batch, in which case
+    the data is passed as a list instead of a batched tensor.
     """
 
     image_sizes: torch.Tensor
@@ -466,28 +467,29 @@ def __init__(self,
     def _validate_image_sizes(self, data: torch.Tensor) -> torch.Tensor:
         if list(data.shape[1:]) != [2]:
             raise ValueError(
-                f"The expected image sizes shape is batch dimension plus "
-                f"{[2]}. You supplied {data.shape}.")
+                f"The expected shape of image sizes is batch dimension plus "
+                f"{[2]}. You supplied {tuple(data.shape)}.")
 
         return data
 
     def _validate_pixel_values(
         self, data: Union[torch.Tensor, List[torch.Tensor]]
     ) -> Union[torch.Tensor, List[torch.Tensor]]:
 
-        def _validate_shape(data: torch.Tensor):
-            if list(data.shape)[2:] != [
-                    3, CLIP_VIT_LARGE_PATCH14_336_CONFIG.image_size,
-                    CLIP_VIT_LARGE_PATCH14_336_CONFIG.image_size
-            ]:
+        h = w = CLIP_VIT_LARGE_PATCH14_336_CONFIG.image_size
+        expected_dims = (3, h, w)
+
+        def _validate_shape(d: torch.Tensor):
+            actual_dims = tuple(d.shape[1:])
+
+            if actual_dims != expected_dims:
+                expected_expr = ("num_patches", *map(str, expected_dims))
                 raise ValueError(
-                    "The expected pixel value tensor shape is batch dimension "
-                    "plus patch number, channel, height and width.")
+                    "The expected shape of pixel values in each batch element "
+                    f"is {expected_expr}. You supplied {tuple(d.shape)}.")
 
-        if isinstance(data, torch.Tensor):
-            _validate_shape(data)
-        else:
-            [_validate_shape(d) for d in data]
+        for d in data:
+            _validate_shape(d)
 
         return data