[diffusion] feat: support multi-frame image output (#15878)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

python/sglang/multimodal_gen/test/server/perf_baselines.json

@@ -788,6 +788,69 @@
             "expected_avg_denoise_ms": 1267.96,
             "expected_median_denoise_ms": 1273.46
         },
+        "qwen_image_layered_i2i": {
+            "stages_ms": {
+                "QwenImageLayeredBeforeDenoisingStage": 3240.24,
+                "TimestepPreparationStage": 3.14,
+                "DenoisingStage": 41551.18,
+                "DecodingStage": 312.93
+            },
+            "denoise_step_ms": {
+                "0": 809.93,
+                "1": 836.69,
+                "2": 834.98,
+                "3": 826.84,
+                "4": 827.15,
+                "5": 827.28,
+                "6": 830.97,
+                "7": 827.7,
+                "8": 829.4,
+                "9": 832.14,
+                "10": 825.99,
+                "11": 831.65,
+                "12": 829.31,
+                "13": 829.46,
+                "14": 828.33,
+                "15": 831.14,
+                "16": 830.44,
+                "17": 831.6,
+                "18": 829.18,
+                "19": 831.64,
+                "20": 828.21,
+                "21": 831.02,
+                "22": 831.39,
+                "23": 830.16,
+                "24": 832.21,
+                "25": 831.04,
+                "26": 830.48,
+                "27": 831.88,
+                "28": 833.5,
+                "29": 837.31,
+                "30": 828.16,
+                "31": 832.24,
+                "32": 833.56,
+                "33": 829.08,
+                "34": 833.11,
+                "35": 831.07,
+                "36": 832.71,
+                "37": 833.12,
+                "38": 830.65,
+                "39": 831.59,
+                "40": 833.24,
+                "41": 831.92,
+                "42": 832.77,
+                "43": 830.88,
+                "44": 833.75,
+                "45": 831.29,
+                "46": 834.48,
+                "47": 832.6,
+                "48": 835.24,
+                "49": 832.49
+            },
+            "expected_e2e_ms": 45109.63,
+            "expected_avg_denoise_ms": 830.86,
+            "expected_median_denoise_ms": 831.34
+        },
         "fastwan2_2_ti2v_5b": {
             "stages_ms": {
                 "InputValidationStage": 88.86,

python/sglang/multimodal_gen/test/server/test_server_common.py

@@ -103,6 +103,7 @@ def diffusion_server(case: DiffusionTestCase) -> ServerContext:
             model=server_args.model_path,
             prompt=sampling_params.prompt or "A colorful raccoon icon",
             output_size=output_size,
+            output_format=sampling_params.output_format,
         )
         warmup.run_text_warmups(server_args.warmup_text)
 

python/sglang/multimodal_gen/test/server/test_server_utils.py

@@ -455,6 +455,7 @@ class WarmupRunner:
         model: str,
         prompt: str,
         output_size: str,
+        output_format: str = None,
     ):
         self.client = OpenAI(
             api_key="sglang-anything",
@@ -463,6 +464,7 @@ class WarmupRunner:
         self.model = model
         self.prompt = prompt
         self.output_size = output_size
+        self.output_format = output_format
 
     def run_text_warmups(self, count: int) -> None:
         """Run text-to-image warmup requests."""
@@ -511,6 +513,7 @@ class WarmupRunner:
                     n=1,
                     size=self.output_size,
                     response_format="b64_json",
+                    output_format=self.output_format,
                 )
             finally:
                 for img in images:
@@ -898,7 +901,9 @@ def get_generate_fn(
         image_paths = new_image_paths
 
         # Request parameters that affect output format
-        req_output_format = None  # Not specified in current request
+        req_output_format = (
+            sampling_params.output_format
+        )  # Not specified in current request
         req_background = None  # Not specified in current request
 
         images = [open(image_path, "rb") for image_path in image_paths]
@@ -910,6 +915,8 @@ def get_generate_fn(
                 n=n,
                 size=output_size,
                 response_format="b64_json",
+                output_format=req_output_format,
+                extra_body={"num_frames": sampling_params.num_frames},
             )
         finally:
             for img in images:
@@ -954,7 +961,6 @@ def get_generate_fn(
         """TI2I: Text + Image ? Image edit using direct URL transfer (no pre-download)."""
         if not sampling_params.prompt or not sampling_params.image_path:
             pytest.skip(f"{id}: no edit config")
-
         # Handle both single URL and list of URLs
         image_urls = sampling_params.image_path
         if not isinstance(image_urls, list):
@@ -968,7 +974,9 @@ def get_generate_fn(
                 )
 
         # Request parameters that affect output format
-        req_output_format = None  # Not specified in current request
+        req_output_format = (
+            sampling_params.output_format
+        )  # Not specified in current request
         req_background = None  # Not specified in current request
 
         response = client.images.with_raw_response.edit(
@@ -978,7 +986,8 @@ def get_generate_fn(
             n=n,
             size=sampling_params.output_size,
             response_format="b64_json",
-            extra_body={"url": image_urls},
+            output_format=req_output_format,
+            extra_body={"url": image_urls, "num_frames": sampling_params.num_frames},
         )
 
         result = response.parse()

python/sglang/multimodal_gen/test/server/testcase_configs.py

@@ -173,6 +173,9 @@ class DiffusionSamplingParams:
     # URL direct test flag - if True, don't pre-download URL images
     direct_url_test: bool = False
 
+    # output format
+    output_format: str | None = None  # "png", "jpeg", "mp4", etc.
+
     num_outputs_per_prompt: int = 1
 
 
@@ -269,6 +272,15 @@ MULTI_IMAGE_TI2I_sampling_params = DiffusionSamplingParams(
     ],
     direct_url_test=True,
 )
+MULTI_FRAME_I2I_sampling_params = DiffusionSamplingParams(
+    prompt="a high quality, cute halloween themed illustration, consistent style and lighting",
+    image_path=[
+        "https://raw.githubusercontent.com/QwenLM/Qwen-Image-Layered/main/assets/test_images/4.png"
+    ],
+    num_frames=4,
+    direct_url_test=True,
+    output_format="png",
+)
 
 T2V_PROMPT = "A curious raccoon"
 
@@ -356,6 +368,16 @@ ONE_GPU_CASES_A: list[DiffusionTestCase] = [
         ),
         MULTI_IMAGE_TI2I_sampling_params,
     ),
+    DiffusionTestCase(
+        "qwen_image_layered_i2i",
+        DiffusionServerArgs(
+            model_path="Qwen/Qwen-Image-Layered",
+            modality="image",
+            warmup_text=0,
+            warmup_edit=1,
+        ),
+        MULTI_FRAME_I2I_sampling_params,
+    ),
 ]
 
 ONE_GPU_CASES_B: list[DiffusionTestCase] = [