Hunyuan VAE tiling fixes and transformer docs

src/diffusers/models/autoencoders/autoencoder_kl_hunyuan_video.py

@@ -792,12 +792,12 @@ def __init__(
         # The minimal tile height and width for spatial tiling to be used
         self.tile_sample_min_height = 256
         self.tile_sample_min_width = 256
-        self.tile_sample_min_num_frames = 64
+        self.tile_sample_min_num_frames = 16
 
         # The minimal distance between two spatial tiles
         self.tile_sample_stride_height = 192
         self.tile_sample_stride_width = 192
-        self.tile_sample_stride_num_frames = 48
+        self.tile_sample_stride_num_frames = 12
 
     def _set_gradient_checkpointing(self, module, value=False):
         if isinstance(module, (HunyuanVideoEncoder3D, HunyuanVideoDecoder3D)):
@@ -1003,7 +1003,7 @@ def tiled_encode(self, x: torch.Tensor) -> AutoencoderKLOutput:
         for i in range(0, height, self.tile_sample_stride_height):
             row = []
             for j in range(0, width, self.tile_sample_stride_width):
-                tile = x[:, :, :, i : i + self.tile_sample_min_size, j : j + self.tile_sample_min_size]
+                tile = x[:, :, :, i : i + self.tile_sample_min_height, j : j + self.tile_sample_min_width]
                 tile = self.encoder(tile)
                 tile = self.quant_conv(tile)
                 row.append(tile)
@@ -1020,7 +1020,7 @@ def tiled_encode(self, x: torch.Tensor) -> AutoencoderKLOutput:
                 if j > 0:
                     tile = self.blend_h(row[j - 1], tile, blend_width)
                 result_row.append(tile[:, :, :, :tile_latent_stride_height, :tile_latent_stride_width])
-            result_rows.append(torch.cat(result_row, dim=-1))
+            result_rows.append(torch.cat(result_row, dim=4))
 
         enc = torch.cat(result_rows, dim=3)[:, :, :, :latent_height, :latent_width]
         return enc

src/diffusers/models/transformers/transformer_hunyuan_video.py

@@ -497,6 +497,46 @@ def forward(
 
 
 class HunyuanVideoTransformer3DModel(ModelMixin, ConfigMixin):
+    r"""
+    A Transformer model for video-like data used in [HunyuanVideo](https://huggingface.co/tencent/HunyuanVideo).
+
+    Args:
+        in_channels (`int`, defaults to `16`):
+            The number of channels in the input.
+        out_channels (`int`, defaults to `16`):
+            The number of channels in the output.
+        num_attention_heads (`int`, defaults to `24`):
+            The number of heads to use for multi-head attention.
+        attention_head_dim (`int`, defaults to `128`):
+            The number of channels in each head.
+        num_layers (`int`, defaults to `20`):
+            The number of layers of dual-stream blocks to use.
+        num_single_layers (`int`, defaults to `40`):
+            The number of layers of single-stream blocks to use.
+        num_refiner_layers (`int`, defaults to `2`):
+            The number of layers of refiner blocks to use.
+        mlp_ratio (`float`, defaults to `4.0`):
+            The ratio of the hidden layer size to the input size in the feedforward network.
+        patch_size (`int`, defaults to `2`):
+            The size of the spatial patches to use in the patch embedding layer.
+        patch_size_t (`int`, defaults to `1`):
+            The size of the tmeporal patches to use in the patch embedding layer.
+        qk_norm (`str`, defaults to `rms_norm`):
+            The normalization to use for the query and key projections in the attention layers.
+        guidance_embeds (`bool`, defaults to `True`):
+            Whether to use guidance embeddings in the model.
+        text_embed_dim (`int`, defaults to `4096`):
+            Input dimension of text embeddings from the text encoder.
+        pooled_projection_dim (`int`, defaults to `768`):
+            The dimension of the pooled projection of the text embeddings.
+        rope_theta (`float`, defaults to `256.0`):
+            The value of theta to use in the RoPE layer.
+        rope_axes_dim (`Tuple[int]`, defaults to `(16, 56, 56)`):
+            The dimensions of the axes to use in the RoPE layer.
+    """
+
+    _supports_gradient_checkpointing = True
+
     @register_to_config
     def __init__(
         self,