Adding Img2Vid support for WAN 2.1 and WAN 2.2 (#306)

* WAN Img2Vid Implementation

* Removed randn_tensor function import

* logical_axis rules and attention_sharding_uniform added in config files

* removed attn_mask from FlaxWanAttn call

* fix to prevent load_image_encoder from running for wan 2.2 iv

* boundary_ratio removed from generate_wan.py

* testing with 720p

* model restored

* attn_mask correction

* transformer corrected in wan 2.2 t2v and config files updated

* revert

* corrected

* import added in wan_checkpointer_test.py

* wan_checkpointer_test.py corrected

* wan_checkpointer_test.py corrected

* wan_checkpointer_test.py corrected

* removed redundance img attn mask

* Fix for multiple videos

* Fix for multiple videos

* Fix for multiple videos

* Fix for multiple videos

* removed redundant args

* removed redundant args

* trying dot attn fix

* reverting fix to see if that was the issue

* fix verified

* updated comments

* Added sharding

* sharding added

* ruff checks

* README updated

* sharding

* ruff check

Author: prishajain1

README.md

@@ -17,6 +17,7 @@
 [![Unit Tests](https://github.com/google/maxtext/actions/workflows/UnitTests.yml/badge.svg)](https://github.com/AI-Hypercomputer/maxdiffusion/actions/workflows/UnitTests.yml)
 
 # What's new?
+- **`2026/1/15`**: Wan2.1 and Wan2.2 Img2vid generation is now supported
 - **`2025/11/11`**: Wan2.2 txt2vid generation is now supported
 - **`2025/10/10`**: Wan2.1 txt2vid training and generation is now supported.
 - **`2025/10/14`**: NVIDIA DGX Spark Flux support.
@@ -482,19 +483,38 @@ To generate images, run the following command:
 
   Although not required, attaching an external disk is recommended as weights take up a lot of disk space. [Follow these instructions if you would like to attach an external disk](https://cloud.google.com/tpu/docs/attach-durable-block-storage).
 
+  ### Text2Vid
+
   ```bash
   HF_HUB_CACHE=/mnt/disks/external_disk/maxdiffusion_hf_cache/
   LIBTPU_INIT_ARGS="--xla_tpu_enable_async_collective_fusion=true --xla_tpu_enable_async_collective_fusion_fuse_all_reduce=true --xla_tpu_enable_async_collective_fusion_multiple_steps=true --xla_tpu_overlap_compute_collective_tc=true --xla_enable_async_all_reduce=true" HF_HUB_ENABLE_HF_TRANSFER=1 python src/maxdiffusion/generate_wan.py   src/maxdiffusion/configs/base_wan_14b.yml   attention="flash"   num_inference_steps=50   num_frames=81   width=1280   height=720   jax_cache_dir=gs://jfacevedo-maxdiffusion/jax_cache/   per_device_batch_size=.125   ici_data_parallelism=2   ici_fsdp_parallelism=2   flow_shift=5.0   enable_profiler=True   run_name=wan-inference-testing-720p   output_dir=gs:/jfacevedo-maxdiffusion   fps=16   flash_min_seq_length=0   flash_block_sizes='{"block_q" : 3024, "block_kv_compute" : 1024, "block_kv" : 2048, "block_q_dkv": 3024, "block_kv_dkv" : 2048, "block_kv_dkv_compute" : 2048, "block_q_dq" : 3024, "block_kv_dq" : 2048 }' seed=118445
   ```
+
+  ### Img2Vid
+
+   ```bash
+  HF_HUB_CACHE=/mnt/disks/external_disk/maxdiffusion_hf_cache/
+  LIBTPU_INIT_ARGS="--xla_tpu_enable_async_collective_fusion=true --xla_tpu_enable_async_collective_fusion_fuse_all_reduce=true --xla_tpu_enable_async_collective_fusion_multiple_steps=true --xla_tpu_overlap_compute_collective_tc=true --xla_enable_async_all_reduce=true" HF_HUB_ENABLE_HF_TRANSFER=1 python src/maxdiffusion/generate_wan.py   src/maxdiffusion/configs/base_wan_i2v_14b.yml   attention="flash"   num_inference_steps=30   num_frames=81   width=832   height=480   jax_cache_dir=gs://jfacevedo-maxdiffusion/jax_cache/   per_device_batch_size=.125   ici_data_parallelism=2   ici_fsdp_parallelism=2   flow_shift=3.0   enable_profiler=True   run_name=wan-i2v-inference-testing-480p   output_dir=gs:/jfacevedo-maxdiffusion   fps=16   flash_min_seq_length=0   flash_block_sizes='{"block_q" : 3024, "block_kv_compute" : 1024, "block_kv" : 2048, "block_q_dkv": 3024, "block_kv_dkv" : 2048, "block_kv_dkv_compute" : 2048, "block_q_dq" : 3024, "block_kv_dq" : 2048 }' seed=118445
+  ```
+
   ## Wan2.2
 
   Although not required, attaching an external disk is recommended as weights take up a lot of disk space. [Follow these instructions if you would like to attach an external disk](https://cloud.google.com/tpu/docs/attach-durable-block-storage).
 
+  ### Text2Vid
+
   ```bash
   HF_HUB_CACHE=/mnt/disks/external_disk/maxdiffusion_hf_cache/
   LIBTPU_INIT_ARGS="--xla_tpu_enable_async_collective_fusion=true --xla_tpu_enable_async_collective_fusion_fuse_all_reduce=true --xla_tpu_enable_async_collective_fusion_multiple_steps=true --xla_tpu_overlap_compute_collective_tc=true --xla_enable_async_all_reduce=true" HF_HUB_ENABLE_HF_TRANSFER=1 python src/maxdiffusion/generate_wan.py   src/maxdiffusion/configs/base_wan_27b.yml   attention="flash"   num_inference_steps=50   num_frames=81   width=1280   height=720   jax_cache_dir=gs://jfacevedo-maxdiffusion/jax_cache/   per_device_batch_size=.125   ici_data_parallelism=2   ici_fsdp_parallelism=2   flow_shift=5.0   enable_profiler=True   run_name=wan-inference-testing-720p   output_dir=gs:/jfacevedo-maxdiffusion   fps=16   flash_min_seq_length=0   flash_block_sizes='{"block_q" : 3024, "block_kv_compute" : 1024, "block_kv" : 2048, "block_q_dkv": 3024, "block_kv_dkv" : 2048, "block_kv_dkv_compute" : 2048, "block_q_dq" : 3024, "block_kv_dq" : 2048 }' seed=118445
   ```
 
+  ### Img2Vid
+
+  ```bash
+  HF_HUB_CACHE=/mnt/disks/external_disk/maxdiffusion_hf_cache/
+  LIBTPU_INIT_ARGS="--xla_tpu_enable_async_collective_fusion=true --xla_tpu_enable_async_collective_fusion_fuse_all_reduce=true --xla_tpu_enable_async_collective_fusion_multiple_steps=true --xla_tpu_overlap_compute_collective_tc=true --xla_enable_async_all_reduce=true" HF_HUB_ENABLE_HF_TRANSFER=1 python src/maxdiffusion/generate_wan.py   src/maxdiffusion/configs/base_wan_i2v_27b.yml   attention="flash"   num_inference_steps=30   num_frames=81   width=832   height=480   jax_cache_dir=gs://jfacevedo-maxdiffusion/jax_cache/   per_device_batch_size=.125   ici_data_parallelism=2   ici_fsdp_parallelism=2   flow_shift=3.0   enable_profiler=True   run_name=wan-i2v-inference-testing-480p   output_dir=gs:/jfacevedo-maxdiffusion   fps=16   flash_min_seq_length=0   flash_block_sizes='{"block_q" : 3024, "block_kv_compute" : 1024, "block_kv" : 2048, "block_q_dkv": 3024, "block_kv_dkv" : 2048, "block_kv_dkv_compute" : 2048, "block_q_dq" : 3024, "block_kv_dq" : 2048 }' seed=118445
+  ```
+
   ## Flux
 
   First make sure you have permissions to access the Flux repos in Huggingface.

src/maxdiffusion/checkpointing/wan_checkpointer.py

@@ -19,6 +19,8 @@
 from maxdiffusion.checkpointing.checkpointing_utils import (create_orbax_checkpoint_manager)
 from ..pipelines.wan.wan_pipeline_2_1 import WanPipeline2_1
 from ..pipelines.wan.wan_pipeline_2_2 import WanPipeline2_2
+from ..pipelines.wan.wan_pipeline_i2v_2p1 import WanPipelineI2V_2_1
+from ..pipelines.wan.wan_pipeline_i2v_2p2 import WanPipelineI2V_2_2
 from .. import max_logging, max_utils
 import orbax.checkpoint as ocp
 
@@ -59,7 +61,7 @@ def load_diffusers_checkpoint(self):
     raise NotImplementedError
 
   @abstractmethod
-  def load_checkpoint(self, step=None) -> Tuple[Optional[WanPipeline2_1 | WanPipeline2_2], Optional[dict], Optional[int]]:
+  def load_checkpoint(self, step=None) -> Tuple[Optional[WanPipeline2_1 | WanPipeline2_2 | WanPipelineI2V_2_1 | WanPipelineI2V_2_2], Optional[dict], Optional[int]]:
     raise NotImplementedError
 
   @abstractmethod

src/maxdiffusion/checkpointing/wan_checkpointer_i2v_2p1.py

@@ -0,0 +1,95 @@
+"""
+ Copyright 2025 Google LLC
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      https://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+"""
+
+import json
+import jax
+import numpy as np
+from typing import Optional, Tuple
+from ..pipelines.wan.wan_pipeline_i2v_2p1 import WanPipelineI2V_2_1
+from .. import max_logging
+import orbax.checkpoint as ocp
+from etils import epath
+from maxdiffusion.checkpointing.wan_checkpointer import WanCheckpointer
+
+class WanCheckpointerI2V_2_1(WanCheckpointer):
+
+  def load_wan_configs_from_orbax(self, step: Optional[int]) -> Tuple[Optional[dict], Optional[int]]:
+    if step is None:
+      step = self.checkpoint_manager.latest_step()
+      max_logging.log(f"Latest WAN checkpoint step: {step}")
+      if step is None:
+        max_logging.log("No WAN checkpoint found.")
+        return None, None
+    max_logging.log(f"Loading WAN checkpoint from step {step}")
+    metadatas = self.checkpoint_manager.item_metadata(step)
+    transformer_metadata = metadatas.wan_state
+    abstract_tree_structure_params = jax.tree_util.tree_map(ocp.utils.to_shape_dtype_struct, transformer_metadata)
+    params_restore = ocp.args.PyTreeRestore(
+        restore_args=jax.tree.map(
+            lambda _: ocp.RestoreArgs(restore_type=np.ndarray),
+            abstract_tree_structure_params,
+        )
+    )
+
+    max_logging.log("Restoring WAN checkpoint")
+    restored_checkpoint = self.checkpoint_manager.restore(
+        directory=epath.Path(self.config.checkpoint_dir),
+        step=step,
+        args=ocp.args.Composite(
+            wan_state=params_restore,
+            wan_config=ocp.args.JsonRestore(),
+        ),
+    )
+    max_logging.log(f"restored checkpoint {restored_checkpoint.keys()}")
+    max_logging.log(f"restored checkpoint wan_state {restored_checkpoint.wan_state.keys()}")
+    max_logging.log(f"optimizer found in checkpoint {'opt_state' in restored_checkpoint.wan_state.keys()}")
+    max_logging.log(f"optimizer state saved in attribute self.opt_state {self.opt_state}")
+    return restored_checkpoint, step
+
+  def load_diffusers_checkpoint(self):
+    pipeline = WanPipelineI2V_2_1.from_pretrained(self.config)
+    return pipeline
+
+  def load_checkpoint(self, step=None) -> Tuple[WanPipelineI2V_2_1, Optional[dict], Optional[int]]:
+    restored_checkpoint, step = self.load_wan_configs_from_orbax(step)
+    opt_state = None
+    if restored_checkpoint:
+      max_logging.log("Loading WAN pipeline from checkpoint")
+      pipeline = WanPipelineI2V_2_1.from_checkpoint(self.config, restored_checkpoint)
+      if "opt_state" in restored_checkpoint.wan_state.keys():
+        opt_state = restored_checkpoint.wan_state["opt_state"]
+    else:
+      max_logging.log("No checkpoint found, loading default pipeline.")
+      pipeline = self.load_diffusers_checkpoint()
+
+    return pipeline, opt_state, step
+
+  def save_checkpoint(self, train_step, pipeline: WanPipelineI2V_2_1, train_states: dict):
+    """Saves the training state and model configurations."""
+
+    def config_to_json(model_or_config):
+      return json.loads(model_or_config.to_json_string())
+
+    max_logging.log(f"Saving checkpoint for step {train_step}")
+    items = {
+        "wan_config": ocp.args.JsonSave(config_to_json(pipeline.transformer)),
+    }
+
+    items["wan_state"] = ocp.args.PyTreeSave(train_states)
+
+    # Save the checkpoint
+    self.checkpoint_manager.save(train_step, args=ocp.args.Composite(**items))
+    max_logging.log(f"Checkpoint for step {train_step} saved.")

src/maxdiffusion/checkpointing/wan_checkpointer_i2v_2p2.py

@@ -0,0 +1,114 @@
+"""
+ Copyright 2025 Google LLC
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      https://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+"""
+
+import json
+import jax
+import numpy as np
+from typing import Optional, Tuple
+from ..pipelines.wan.wan_pipeline_i2v_2p2 import WanPipelineI2V_2_2
+from .. import max_logging
+import orbax.checkpoint as ocp
+from etils import epath
+from maxdiffusion.checkpointing.wan_checkpointer import WanCheckpointer
+
+class WanCheckpointerI2V_2_2(WanCheckpointer):
+
+  def load_wan_configs_from_orbax(self, step: Optional[int]) -> Tuple[Optional[dict], Optional[int]]:
+    if step is None:
+      step = self.checkpoint_manager.latest_step()
+      max_logging.log(f"Latest WAN checkpoint step: {step}")
+      if step is None:
+        max_logging.log("No WAN checkpoint found.")
+        return None, None
+    max_logging.log(f"Loading WAN checkpoint from step {step}")
+    metadatas = self.checkpoint_manager.item_metadata(step)
+
+    # Handle low_noise_transformer
+    low_noise_transformer_metadata = metadatas.low_noise_transformer_state
+    abstract_tree_structure_low_params = jax.tree_util.tree_map(ocp.utils.to_shape_dtype_struct, low_noise_transformer_metadata)
+    low_params_restore = ocp.args.PyTreeRestore(
+        restore_args=jax.tree.map(
+            lambda _: ocp.RestoreArgs(restore_type=np.ndarray),
+            abstract_tree_structure_low_params,
+        )
+    )
+
+    # Handle high_noise_transformer
+    high_noise_transformer_metadata = metadatas.high_noise_transformer_state
+    abstract_tree_structure_high_params = jax.tree_util.tree_map(ocp.utils.to_shape_dtype_struct, high_noise_transformer_metadata)
+    high_params_restore = ocp.args.PyTreeRestore(
+        restore_args=jax.tree.map(
+            lambda _: ocp.RestoreArgs(restore_type=np.ndarray),
+            abstract_tree_structure_high_params,
+        )
+    )
+
+    max_logging.log("Restoring WAN 2.2 checkpoint")
+    restored_checkpoint = self.checkpoint_manager.restore(
+        directory=epath.Path(self.config.checkpoint_dir),
+        step=step,
+        args=ocp.args.Composite(
+            low_noise_transformer_state=low_params_restore,
+            high_noise_transformer_state=high_params_restore,
+            wan_config=ocp.args.JsonRestore(),
+        ),
+    )
+    max_logging.log(f"restored checkpoint {restored_checkpoint.keys()}")
+    max_logging.log(f"restored checkpoint low_noise_transformer_state {restored_checkpoint.low_noise_transformer_state.keys()}")
+    max_logging.log(f"restored checkpoint high_noise_transformer_state {restored_checkpoint.high_noise_transformer_state.keys()}")
+    max_logging.log(f"optimizer found in low_noise checkpoint {'opt_state' in restored_checkpoint.low_noise_transformer_state.keys()}")
+    max_logging.log(f"optimizer found in high_noise checkpoint {'opt_state' in restored_checkpoint.high_noise_transformer_state.keys()}")
+    max_logging.log(f"optimizer state saved in attribute self.opt_state {self.opt_state}")
+    return restored_checkpoint, step
+
+  def load_diffusers_checkpoint(self):
+    pipeline = WanPipelineI2V_2_2.from_pretrained(self.config)
+    return pipeline
+
+  def load_checkpoint(self, step=None) -> Tuple[WanPipelineI2V_2_2, Optional[dict], Optional[int]]:
+    restored_checkpoint, step = self.load_wan_configs_from_orbax(step)
+    opt_state = None
+    if restored_checkpoint:
+      max_logging.log("Loading WAN pipeline from checkpoint")
+      pipeline = WanPipelineI2V_2_2.from_checkpoint(self.config, restored_checkpoint)
+      # Check for optimizer state in either transformer
+      if "opt_state" in restored_checkpoint.low_noise_transformer_state.keys():
+        opt_state = restored_checkpoint.low_noise_transformer_state["opt_state"]
+      elif "opt_state" in restored_checkpoint.high_noise_transformer_state.keys():
+        opt_state = restored_checkpoint.high_noise_transformer_state["opt_state"]
+    else:
+      max_logging.log("No checkpoint found, loading default pipeline.")
+      pipeline = self.load_diffusers_checkpoint()
+
+    return pipeline, opt_state, step
+
+  def save_checkpoint(self, train_step, pipeline: WanPipelineI2V_2_2, train_states: dict):
+    """Saves the training state and model configurations."""
+
+    def config_to_json(model_or_config):
+      return json.loads(model_or_config.to_json_string())
+
+    max_logging.log(f"Saving checkpoint for step {train_step}")
+    items = {
+        "wan_config": ocp.args.JsonSave(config_to_json(pipeline.low_noise_transformer)),
+    }
+
+    items["low_noise_transformer_state"] = ocp.args.PyTreeSave(train_states["low_noise_transformer"])
+    items["high_noise_transformer_state"] = ocp.args.PyTreeSave(train_states["high_noise_transformer"])
+
+    # Save the checkpoint
+    self.checkpoint_manager.save(train_step, args=ocp.args.Composite(**items))
+    max_logging.log(f"Checkpoint for step {train_step} saved.")

src/maxdiffusion/configs/base_wan_14b.yml

@@ -29,6 +29,7 @@ log_period: 100
 
 pretrained_model_name_or_path: 'Wan-AI/Wan2.1-T2V-14B-Diffusers'
 model_name: wan2.1
+model_type: 'T2V'
 
 # Overrides the transformer from pretrained_model_name_or_path
 wan_transformer_pretrained_model_name_or_path: ''

src/maxdiffusion/configs/base_wan_27b.yml

@@ -29,6 +29,7 @@ log_period: 100
 
 pretrained_model_name_or_path: 'Wan-AI/Wan2.2-T2V-A14B-Diffusers'
 model_name: wan2.2
+model_type: 'T2V'
 
 # Overrides the transformer from pretrained_model_name_or_path
 wan_transformer_pretrained_model_name_or_path: ''