AutoencoderKLLTXVideo

The 3D variational autoencoder (VAE) model with KL loss used in LTX was introduced by Lightricks.

The model can be loaded with the following code snippet.

from mindone.diffusers import AutoencoderKLLTXVideo
import mindspore as ms

vae = AutoencoderKLLTXVideo.from_pretrained("Lightricks/LTX-Video", subfolder="vae", mindspore_dtype=ms.float32)

mindone.diffusers.AutoencoderKLLTXVideo

Bases: ModelMixin, ConfigMixin, FromOriginalModelMixin

A VAE model with KL loss for encoding images into latents and decoding latent representations into images. Used in LTX.

This model inherits from [ModelMixin]. Check the superclass documentation for it's generic methods implemented for all models (such as downloading or saving).

PARAMETER	DESCRIPTION
in_channels	Number of input channels. TYPE: `int`, defaults to `3` DEFAULT: 3
out_channels	Number of output channels. TYPE: `int`, defaults to `3` DEFAULT: 3
latent_channels	Number of latent channels. TYPE: `int`, defaults to `128` DEFAULT: 128
block_out_channels	The number of output channels for each block. TYPE: `Tuple[int, ...]`, defaults to `(128, 256, 512, 512)` DEFAULT: (128, 256, 512, 512)
spatio_temporal_scaling	Whether a block should contain spatio-temporal downscaling or not. TYPE: `Tuple[bool, ...], defaults to `(True, True, True, False)` DEFAULT: (True, True, True, False)
layers_per_block	The number of layers per block. TYPE: `Tuple[int, ...]`, defaults to `(4, 3, 3, 3, 4)` DEFAULT: (4, 3, 3, 3, 4)
patch_size	The size of spatial patches. TYPE: `int`, defaults to `4` DEFAULT: 4
patch_size_t	The size of temporal patches. TYPE: `int`, defaults to `1` DEFAULT: 1
resnet_norm_eps	Epsilon value for ResNet normalization layers. TYPE: `float`, defaults to `1e-6` DEFAULT: 1e-06
scaling_factor	The component-wise standard deviation of the trained latent space computed using the first batch of the training set. This is used to scale the latent space to have unit variance when training the diffusion model. The latents are scaled with the formula z = z * scaling_factor before being passed to the diffusion model. When decoding, the latents are scaled back to the original scale with the formula: z = 1 / scaling_factor * z. For more details, refer to sections 4.3.2 and D.1 of the High-Resolution Image Synthesis with Latent Diffusion Models paper. TYPE: `float`, *optional*, defaults to `1.0` DEFAULT: 1.0
encoder_causal	Whether the encoder should behave causally (future frames depend only on past frames) or not. TYPE: `bool`, defaults to `True` DEFAULT: True
decoder_causal	Whether the decoder should behave causally (future frames depend only on past frames) or not. TYPE: `bool`, defaults to `False` DEFAULT: False

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

class AutoencoderKLLTXVideo(ModelMixin, ConfigMixin, FromOriginalModelMixin):
    r"""
    A VAE model with KL loss for encoding images into latents and decoding latent representations into images. Used in
    [LTX](https://huggingface.co/Lightricks/LTX-Video).

    This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
    for all models (such as downloading or saving).

    Args:
        in_channels (`int`, defaults to `3`):
            Number of input channels.
        out_channels (`int`, defaults to `3`):
            Number of output channels.
        latent_channels (`int`, defaults to `128`):
            Number of latent channels.
        block_out_channels (`Tuple[int, ...]`, defaults to `(128, 256, 512, 512)`):
            The number of output channels for each block.
        spatio_temporal_scaling (`Tuple[bool, ...], defaults to `(True, True, True, False)`:
            Whether a block should contain spatio-temporal downscaling or not.
        layers_per_block (`Tuple[int, ...]`, defaults to `(4, 3, 3, 3, 4)`):
            The number of layers per block.
        patch_size (`int`, defaults to `4`):
            The size of spatial patches.
        patch_size_t (`int`, defaults to `1`):
            The size of temporal patches.
        resnet_norm_eps (`float`, defaults to `1e-6`):
            Epsilon value for ResNet normalization layers.
        scaling_factor (`float`, *optional*, defaults to `1.0`):
            The component-wise standard deviation of the trained latent space computed using the first batch of the
            training set. This is used to scale the latent space to have unit variance when training the diffusion
            model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
            diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
            / scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
            Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper.
        encoder_causal (`bool`, defaults to `True`):
            Whether the encoder should behave causally (future frames depend only on past frames) or not.
        decoder_causal (`bool`, defaults to `False`):
            Whether the decoder should behave causally (future frames depend only on past frames) or not.
    """

    _supports_gradient_checkpointing = True

    @register_to_config
    def __init__(
        self,
        in_channels: int = 3,
        out_channels: int = 3,
        latent_channels: int = 128,
        block_out_channels: Tuple[int, ...] = (128, 256, 512, 512),
        decoder_block_out_channels: Tuple[int, ...] = (128, 256, 512, 512),
        layers_per_block: Tuple[int, ...] = (4, 3, 3, 3, 4),
        decoder_layers_per_block: Tuple[int, ...] = (4, 3, 3, 3, 4),
        spatio_temporal_scaling: Tuple[bool, ...] = (True, True, True, False),
        decoder_spatio_temporal_scaling: Tuple[bool, ...] = (True, True, True, False),
        decoder_inject_noise: Tuple[bool, ...] = (False, False, False, False, False),
        upsample_residual: Tuple[bool, ...] = (False, False, False, False),
        upsample_factor: Tuple[int, ...] = (1, 1, 1, 1),
        timestep_conditioning: bool = False,
        patch_size: int = 4,
        patch_size_t: int = 1,
        resnet_norm_eps: float = 1e-6,
        scaling_factor: float = 1.0,
        encoder_causal: bool = True,
        decoder_causal: bool = False,
    ) -> None:
        super().__init__()

        self.encoder = LTXVideoEncoder3d(
            in_channels=in_channels,
            out_channels=latent_channels,
            block_out_channels=block_out_channels,
            spatio_temporal_scaling=spatio_temporal_scaling,
            layers_per_block=layers_per_block,
            patch_size=patch_size,
            patch_size_t=patch_size_t,
            resnet_norm_eps=resnet_norm_eps,
            is_causal=encoder_causal,
        )
        self.decoder = LTXVideoDecoder3d(
            in_channels=latent_channels,
            out_channels=out_channels,
            block_out_channels=decoder_block_out_channels,
            spatio_temporal_scaling=decoder_spatio_temporal_scaling,
            layers_per_block=decoder_layers_per_block,
            patch_size=patch_size,
            patch_size_t=patch_size_t,
            resnet_norm_eps=resnet_norm_eps,
            is_causal=decoder_causal,
            timestep_conditioning=timestep_conditioning,
            inject_noise=decoder_inject_noise,
            upsample_residual=upsample_residual,
            upsample_factor=upsample_factor,
        )

        self.latents_mean = ms.Parameter(ops.zeros((latent_channels,)), requires_grad=False, name="latents_mean")
        self.latents_std = ms.Parameter(ops.ones((latent_channels,)), requires_grad=False, name="latents_std")

        self.spatial_compression_ratio = patch_size * 2 ** sum(spatio_temporal_scaling)
        self.temporal_compression_ratio = patch_size_t * 2 ** sum(spatio_temporal_scaling)

        self.diag_gauss_dist = DiagonalGaussianDistribution()

        # When decoding a batch of video latents at a time, one can save memory by slicing across the batch dimension
        # to perform decoding of a single video latent at a time.
        self.use_slicing = False

        # When decoding spatially large video latents, the memory requirement is very high. By breaking the video latent
        # frames spatially into smaller tiles and performing multiple forward passes for decoding, and then blending the
        # intermediate tiles together, the memory requirement can be lowered.
        self.use_tiling = False

        # When decoding temporally long video latents, the memory requirement is very high. By decoding latent frames
        # at a fixed frame batch size (based on `self.num_latent_frames_batch_sizes`), the memory requirement can be lowered.
        self.use_framewise_encoding = False
        self.use_framewise_decoding = False

        # This can be configured based on the amount of GPU memory available.
        # `16` for sample frames and `2` for latent frames are sensible defaults for consumer GPUs.
        # Setting it to higher values results in higher memory usage.
        self.num_sample_frames_batch_size = 16
        self.num_latent_frames_batch_size = 2

        # The minimal tile height and width for spatial tiling to be used
        self.tile_sample_min_height = 512
        self.tile_sample_min_width = 512

        # The minimal distance between two spatial tiles
        self.tile_sample_stride_height = 448
        self.tile_sample_stride_width = 448

    def _set_gradient_checkpointing(self, module, value=False):
        if isinstance(module, (LTXVideoEncoder3d, LTXVideoDecoder3d)):
            module.gradient_checkpointing = value

    def enable_tiling(
        self,
        tile_sample_min_height: Optional[int] = None,
        tile_sample_min_width: Optional[int] = None,
        tile_sample_stride_height: Optional[float] = None,
        tile_sample_stride_width: Optional[float] = None,
    ) -> None:
        r"""
        Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to
        compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow
        processing larger images.

        Args:
            tile_sample_min_height (`int`, *optional*):
                The minimum height required for a sample to be separated into tiles across the height dimension.
            tile_sample_min_width (`int`, *optional*):
                The minimum width required for a sample to be separated into tiles across the width dimension.
            tile_sample_stride_height (`int`, *optional*):
                The minimum amount of overlap between two consecutive vertical tiles. This is to ensure that there are
                no tiling artifacts produced across the height dimension.
            tile_sample_stride_width (`int`, *optional*):
                The stride between two consecutive horizontal tiles. This is to ensure that there are no tiling
                artifacts produced across the width dimension.
        """
        self.use_tiling = True
        self.tile_sample_min_height = tile_sample_min_height or self.tile_sample_min_height
        self.tile_sample_min_width = tile_sample_min_width or self.tile_sample_min_width
        self.tile_sample_stride_height = tile_sample_stride_height or self.tile_sample_stride_height
        self.tile_sample_stride_width = tile_sample_stride_width or self.tile_sample_stride_width

    def disable_tiling(self) -> None:
        r"""
        Disable tiled VAE decoding. If `enable_tiling` was previously enabled, this method will go back to computing
        decoding in one step.
        """
        self.use_tiling = False

    def enable_slicing(self) -> None:
        r"""
        Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to
        compute decoding in several steps. This is useful to save some memory and allow larger batch sizes.
        """
        self.use_slicing = True

    def disable_slicing(self) -> None:
        r"""
        Disable sliced VAE decoding. If `enable_slicing` was previously enabled, this method will go back to computing
        decoding in one step.
        """
        self.use_slicing = False

    def _encode(self, x: ms.Tensor) -> ms.Tensor:
        batch_size, num_channels, num_frames, height, width = x.shape

        if self.use_tiling and (width > self.tile_sample_min_width or height > self.tile_sample_min_height):
            return self.tiled_encode(x)

        if self.use_framewise_encoding:
            # TODO(aryan): requires investigation
            raise NotImplementedError(
                "Frame-wise encoding has not been implemented for AutoencoderKLLTXVideo, at the moment, due to "
                "quality issues caused by splitting inference across frame dimension. If you believe this "
                "should be possible, please submit a PR to https://github.com/huggingface/diffusers/pulls."
            )
        else:
            enc = self.encoder(x)

        return enc

    def encode(
        self, x: ms.Tensor, return_dict: bool = False
    ) -> Union[AutoencoderKLOutput, Tuple[DiagonalGaussianDistribution]]:
        """
        Encode a batch of images into latents.

        Args:
            x (`torch.Tensor`): Input batch of images.
            return_dict (`bool`, *optional*, defaults to `False`):
                Whether to return a [`~models.autoencoder_kl.AutoencoderKLOutput`] instead of a plain tuple.

        Returns:
                The latent representations of the encoded videos. If `return_dict` is True, a
                [`~models.autoencoder_kl.AutoencoderKLOutput`] is returned, otherwise a plain `tuple` is returned.
        """
        if self.use_slicing and x.shape[0] > 1:
            encoded_slices = [self._encode(x_slice) for x_slice in x.split(1)]
            h = ops.cat(encoded_slices)
        else:
            h = self._encode(x)

        # we cannot use class in graph mode, even for jit_class or subclass of Tensor. :-(
        # posterior = DiagonalGaussianDistribution(h)

        if not return_dict:
            return (h,)
        return AutoencoderKLOutput(latent_dist=h)

    def _decode(
        self, z: ms.Tensor, temb: Optional[ms.Tensor] = None, return_dict: bool = False
    ) -> Union[DecoderOutput, ms.Tensor]:
        batch_size, num_channels, num_frames, height, width = z.shape
        tile_latent_min_height = self.tile_sample_min_height // self.spatial_compression_ratio
        tile_latent_min_width = self.tile_sample_stride_width // self.spatial_compression_ratio

        if self.use_tiling and (width > tile_latent_min_width or height > tile_latent_min_height):
            return self.tiled_decode(z, temb, return_dict=return_dict)

        if self.use_framewise_decoding:
            # TODO(aryan): requires investigation
            raise NotImplementedError(
                "Frame-wise decoding has not been implemented for AutoencoderKLLTXVideo, at the moment, due to "
                "quality issues caused by splitting inference across frame dimension. If you believe this "
                "should be possible, please submit a PR to https://github.com/huggingface/diffusers/pulls."
            )
        else:
            dec = self.decoder(z, temb)

        if not return_dict:
            return (dec,)

        return DecoderOutput(sample=dec)

    def decode(
        self, z: ms.Tensor, temb: Optional[ms.Tensor] = None, return_dict: bool = False
    ) -> Union[DecoderOutput, ms.Tensor]:
        """
        Decode a batch of images.

        Args:
            z (`torch.Tensor`): Input batch of latent vectors.
            return_dict (`bool`, *optional*, defaults to `False`):
                Whether to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.

        Returns:
            [`~models.vae.DecoderOutput`] or `tuple`:
                If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
                returned.
        """
        if self.use_slicing and z.shape[0] > 1:
            if temb is not None:
                decoded_slices = [self._decode(z_slice, t_slice)[0] for z_slice, t_slice in (z.split(1), temb.split(1))]
            else:
                decoded_slices = [self._decode(z_slice)[0] for z_slice in z.split(1)]
            decoded = ops.cat(decoded_slices)
        else:
            decoded = self._decode(z, temb)[0]

        if not return_dict:
            return (decoded,)

        return DecoderOutput(sample=decoded)

    def blend_v(self, a: ops.Tensor, b: ops.Tensor, blend_extent: int) -> ops.Tensor:
        blend_extent = min(a.shape[3], b.shape[3], blend_extent)
        for y in range(blend_extent):
            b[:, :, :, y, :] = a[:, :, :, -blend_extent + y, :] * (1 - y / blend_extent) + b[:, :, :, y, :] * (
                y / blend_extent
            )
        return b

    def blend_h(self, a: ops.Tensor, b: ops.Tensor, blend_extent: int) -> ops.Tensor:
        blend_extent = min(a.shape[4], b.shape[4], blend_extent)
        for x in range(blend_extent):
            b[:, :, :, :, x] = a[:, :, :, :, -blend_extent + x] * (1 - x / blend_extent) + b[:, :, :, :, x] * (
                x / blend_extent
            )
        return b

    def tiled_encode(self, x: ops.Tensor) -> ops.Tensor:
        r"""Encode a batch of images using a tiled encoder.

        Args:
            x (`torch.Tensor`): Input batch of videos.

        Returns:
            `torch.Tensor`:
                The latent representation of the encoded videos.
        """
        batch_size, num_channels, num_frames, height, width = x.shape
        latent_height = height // self.spatial_compression_ratio
        latent_width = width // self.spatial_compression_ratio

        tile_latent_min_height = self.tile_sample_min_height // self.spatial_compression_ratio
        tile_latent_min_width = self.tile_sample_min_width // self.spatial_compression_ratio
        tile_latent_stride_height = self.tile_sample_stride_height // self.spatial_compression_ratio
        tile_latent_stride_width = self.tile_sample_stride_width // self.spatial_compression_ratio

        blend_height = tile_latent_min_height - tile_latent_stride_height
        blend_width = tile_latent_min_width - tile_latent_stride_width

        # Split x into overlapping tiles and encode them separately.
        # The tiles have an overlap to avoid seams between tiles.
        rows = []
        for i in range(0, height, self.tile_sample_stride_height):
            row = []
            for j in range(0, width, self.tile_sample_stride_width):
                if self.use_framewise_encoding:
                    # TODO(aryan): requires investigation
                    raise NotImplementedError(
                        "Frame-wise encoding has not been implemented for AutoencoderKLLTXVideo, at the moment, due to "
                        "quality issues caused by splitting inference across frame dimension. If you believe this "
                        "should be possible, please submit a PR to https://github.com/huggingface/diffusers/pulls."
                    )
                else:
                    time = self.encoder(
                        x[:, :, :, i : i + self.tile_sample_min_height, j : j + self.tile_sample_min_width]
                    )

                row.append(time)
            rows.append(row)

        result_rows = []
        for i, row in enumerate(rows):
            result_row = []
            for j, tile in enumerate(row):
                # blend the above tile and the left tile
                # to the current tile and add the current tile to the result row
                if i > 0:
                    tile = self.blend_v(rows[i - 1][j], tile, blend_height)
                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(ops.cat(result_row, axis=4))

        enc = ops.cat(result_rows, axis=3)[:, :, :, :latent_height, :latent_width]
        return enc

    def tiled_decode(
        self, z: ms.Tensor, temb: Optional[ms.Tensor], return_dict: bool = False
    ) -> Union[DecoderOutput, ms.Tensor]:
        r"""
        Decode a batch of images using a tiled decoder.

        Args:
            z (`torch.Tensor`): Input batch of latent vectors.
            return_dict (`bool`, *optional*, defaults to `False`):
                Whether or not to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.

        Returns:
            [`~models.vae.DecoderOutput`] or `tuple`:
                If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
                returned.
        """

        batch_size, num_channels, num_frames, height, width = z.shape
        sample_height = height * self.spatial_compression_ratio
        sample_width = width * self.spatial_compression_ratio

        tile_latent_min_height = self.tile_sample_min_height // self.spatial_compression_ratio
        tile_latent_min_width = self.tile_sample_min_width // self.spatial_compression_ratio
        tile_latent_stride_height = self.tile_sample_stride_height // self.spatial_compression_ratio
        tile_latent_stride_width = self.tile_sample_stride_width // self.spatial_compression_ratio

        blend_height = self.tile_sample_min_height - self.tile_sample_stride_height
        blend_width = self.tile_sample_min_width - self.tile_sample_stride_width

        # Split z into overlapping tiles and decode them separately.
        # The tiles have an overlap to avoid seams between tiles.
        rows = []
        for i in range(0, height, tile_latent_stride_height):
            row = []
            for j in range(0, width, tile_latent_stride_width):
                if self.use_framewise_decoding:
                    # TODO(aryan): requires investigation
                    raise NotImplementedError(
                        "Frame-wise decoding has not been implemented for AutoencoderKLLTXVideo, at the moment, due to "
                        "quality issues caused by splitting inference across frame dimension. If you believe this "
                        "should be possible, please submit a PR to https://github.com/huggingface/diffusers/pulls."
                    )
                else:
                    time = self.decoder(z[:, :, :, i : i + tile_latent_min_height, j : j + tile_latent_min_width], temb)

                row.append(time)
            rows.append(row)

        result_rows = []
        for i, row in enumerate(rows):
            result_row = []
            for j, tile in enumerate(row):
                # blend the above tile and the left tile
                # to the current tile and add the current tile to the result row
                if i > 0:
                    tile = self.blend_v(rows[i - 1][j], tile, blend_height)
                if j > 0:
                    tile = self.blend_h(row[j - 1], tile, blend_width)
                result_row.append(tile[:, :, :, : self.tile_sample_stride_height, : self.tile_sample_stride_width])
            result_rows.append(ops.cat(result_row, axis=4))

        dec = ops.cat(result_rows, axis=3)[:, :, :, :sample_height, :sample_width]

        if not return_dict:
            return (dec,)

        return DecoderOutput(sample=dec)

    def construct(
        self,
        sample: ms.Tensor,
        temb: Optional[ms.Tensor] = None,
        sample_posterior: bool = False,
        return_dict: bool = False,
        generator: Optional[np.random.Generator] = None,
    ) -> Union[ms.Tensor, ms.Tensor]:
        x = sample
        posterior = self.encode(x)[0]
        if sample_posterior:
            z = self.diag_gauss_dist.sample(posterior, generator=generator)
        else:
            z = self.diag_gauss_dist.mode(posterior)
        dec = self.decode(z, temb)[0]
        if not return_dict:
            return (dec,)
        return dec

mindone.diffusers.AutoencoderKLLTXVideo.decode(z, temb=None, return_dict=False)

Decode a batch of images.

PARAMETER	DESCRIPTION
z	Input batch of latent vectors. TYPE: `torch.Tensor`
return_dict	Whether to return a [~models.vae.DecoderOutput] instead of a plain tuple. TYPE: `bool`, *optional*, defaults to `False` DEFAULT: False

RETURNS	DESCRIPTION
Union[DecoderOutput, Tensor]	[~models.vae.DecoderOutput] or tuple: If return_dict is True, a [~models.vae.DecoderOutput] is returned, otherwise a plain tuple is returned.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def decode(
    self, z: ms.Tensor, temb: Optional[ms.Tensor] = None, return_dict: bool = False
) -> Union[DecoderOutput, ms.Tensor]:
    """
    Decode a batch of images.

    Args:
        z (`torch.Tensor`): Input batch of latent vectors.
        return_dict (`bool`, *optional*, defaults to `False`):
            Whether to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.

    Returns:
        [`~models.vae.DecoderOutput`] or `tuple`:
            If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
            returned.
    """
    if self.use_slicing and z.shape[0] > 1:
        if temb is not None:
            decoded_slices = [self._decode(z_slice, t_slice)[0] for z_slice, t_slice in (z.split(1), temb.split(1))]
        else:
            decoded_slices = [self._decode(z_slice)[0] for z_slice in z.split(1)]
        decoded = ops.cat(decoded_slices)
    else:
        decoded = self._decode(z, temb)[0]

    if not return_dict:
        return (decoded,)

    return DecoderOutput(sample=decoded)

mindone.diffusers.AutoencoderKLLTXVideo.disable_slicing()

Disable sliced VAE decoding. If enable_slicing was previously enabled, this method will go back to computing decoding in one step.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def disable_slicing(self) -> None:
    r"""
    Disable sliced VAE decoding. If `enable_slicing` was previously enabled, this method will go back to computing
    decoding in one step.
    """
    self.use_slicing = False

mindone.diffusers.AutoencoderKLLTXVideo.disable_tiling()

Disable tiled VAE decoding. If enable_tiling was previously enabled, this method will go back to computing decoding in one step.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def disable_tiling(self) -> None:
    r"""
    Disable tiled VAE decoding. If `enable_tiling` was previously enabled, this method will go back to computing
    decoding in one step.
    """
    self.use_tiling = False

mindone.diffusers.AutoencoderKLLTXVideo.enable_slicing()

Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to compute decoding in several steps. This is useful to save some memory and allow larger batch sizes.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def enable_slicing(self) -> None:
    r"""
    Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to
    compute decoding in several steps. This is useful to save some memory and allow larger batch sizes.
    """
    self.use_slicing = True

mindone.diffusers.AutoencoderKLLTXVideo.enable_tiling(tile_sample_min_height=None, tile_sample_min_width=None, tile_sample_stride_height=None, tile_sample_stride_width=None)

Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow processing larger images.

PARAMETER	DESCRIPTION
tile_sample_min_height	The minimum height required for a sample to be separated into tiles across the height dimension. TYPE: `int`, *optional* DEFAULT: None
tile_sample_min_width	The minimum width required for a sample to be separated into tiles across the width dimension. TYPE: `int`, *optional* DEFAULT: None
tile_sample_stride_height	The minimum amount of overlap between two consecutive vertical tiles. This is to ensure that there are no tiling artifacts produced across the height dimension. TYPE: `int`, *optional* DEFAULT: None
tile_sample_stride_width	The stride between two consecutive horizontal tiles. This is to ensure that there are no tiling artifacts produced across the width dimension. TYPE: `int`, *optional* DEFAULT: None

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def enable_tiling(
    self,
    tile_sample_min_height: Optional[int] = None,
    tile_sample_min_width: Optional[int] = None,
    tile_sample_stride_height: Optional[float] = None,
    tile_sample_stride_width: Optional[float] = None,
) -> None:
    r"""
    Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to
    compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow
    processing larger images.

    Args:
        tile_sample_min_height (`int`, *optional*):
            The minimum height required for a sample to be separated into tiles across the height dimension.
        tile_sample_min_width (`int`, *optional*):
            The minimum width required for a sample to be separated into tiles across the width dimension.
        tile_sample_stride_height (`int`, *optional*):
            The minimum amount of overlap between two consecutive vertical tiles. This is to ensure that there are
            no tiling artifacts produced across the height dimension.
        tile_sample_stride_width (`int`, *optional*):
            The stride between two consecutive horizontal tiles. This is to ensure that there are no tiling
            artifacts produced across the width dimension.
    """
    self.use_tiling = True
    self.tile_sample_min_height = tile_sample_min_height or self.tile_sample_min_height
    self.tile_sample_min_width = tile_sample_min_width or self.tile_sample_min_width
    self.tile_sample_stride_height = tile_sample_stride_height or self.tile_sample_stride_height
    self.tile_sample_stride_width = tile_sample_stride_width or self.tile_sample_stride_width

mindone.diffusers.AutoencoderKLLTXVideo.encode(x, return_dict=False)

Encode a batch of images into latents.

PARAMETER	DESCRIPTION
x	Input batch of images. TYPE: `torch.Tensor`
return_dict	Whether to return a [~models.autoencoder_kl.AutoencoderKLOutput] instead of a plain tuple. TYPE: `bool`, *optional*, defaults to `False` DEFAULT: False

RETURNS	DESCRIPTION
Union[AutoencoderKLOutput, Tuple[DiagonalGaussianDistribution]]	The latent representations of the encoded videos. If return_dict is True, a
Union[AutoencoderKLOutput, Tuple[DiagonalGaussianDistribution]]	[~models.autoencoder_kl.AutoencoderKLOutput] is returned, otherwise a plain tuple is returned.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def encode(
    self, x: ms.Tensor, return_dict: bool = False
) -> Union[AutoencoderKLOutput, Tuple[DiagonalGaussianDistribution]]:
    """
    Encode a batch of images into latents.

    Args:
        x (`torch.Tensor`): Input batch of images.
        return_dict (`bool`, *optional*, defaults to `False`):
            Whether to return a [`~models.autoencoder_kl.AutoencoderKLOutput`] instead of a plain tuple.

    Returns:
            The latent representations of the encoded videos. If `return_dict` is True, a
            [`~models.autoencoder_kl.AutoencoderKLOutput`] is returned, otherwise a plain `tuple` is returned.
    """
    if self.use_slicing and x.shape[0] > 1:
        encoded_slices = [self._encode(x_slice) for x_slice in x.split(1)]
        h = ops.cat(encoded_slices)
    else:
        h = self._encode(x)

    # we cannot use class in graph mode, even for jit_class or subclass of Tensor. :-(
    # posterior = DiagonalGaussianDistribution(h)

    if not return_dict:
        return (h,)
    return AutoencoderKLOutput(latent_dist=h)

mindone.diffusers.AutoencoderKLLTXVideo.tiled_decode(z, temb, return_dict=False)

Decode a batch of images using a tiled decoder.

PARAMETER	DESCRIPTION
z	Input batch of latent vectors. TYPE: `torch.Tensor`
return_dict	Whether or not to return a [~models.vae.DecoderOutput] instead of a plain tuple. TYPE: `bool`, *optional*, defaults to `False` DEFAULT: False

RETURNS	DESCRIPTION
Union[DecoderOutput, Tensor]	[~models.vae.DecoderOutput] or tuple: If return_dict is True, a [~models.vae.DecoderOutput] is returned, otherwise a plain tuple is returned.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def tiled_decode(
    self, z: ms.Tensor, temb: Optional[ms.Tensor], return_dict: bool = False
) -> Union[DecoderOutput, ms.Tensor]:
    r"""
    Decode a batch of images using a tiled decoder.

    Args:
        z (`torch.Tensor`): Input batch of latent vectors.
        return_dict (`bool`, *optional*, defaults to `False`):
            Whether or not to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.

    Returns:
        [`~models.vae.DecoderOutput`] or `tuple`:
            If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
            returned.
    """

    batch_size, num_channels, num_frames, height, width = z.shape
    sample_height = height * self.spatial_compression_ratio
    sample_width = width * self.spatial_compression_ratio

    tile_latent_min_height = self.tile_sample_min_height // self.spatial_compression_ratio
    tile_latent_min_width = self.tile_sample_min_width // self.spatial_compression_ratio
    tile_latent_stride_height = self.tile_sample_stride_height // self.spatial_compression_ratio
    tile_latent_stride_width = self.tile_sample_stride_width // self.spatial_compression_ratio

    blend_height = self.tile_sample_min_height - self.tile_sample_stride_height
    blend_width = self.tile_sample_min_width - self.tile_sample_stride_width

    # Split z into overlapping tiles and decode them separately.
    # The tiles have an overlap to avoid seams between tiles.
    rows = []
    for i in range(0, height, tile_latent_stride_height):
        row = []
        for j in range(0, width, tile_latent_stride_width):
            if self.use_framewise_decoding:
                # TODO(aryan): requires investigation
                raise NotImplementedError(
                    "Frame-wise decoding has not been implemented for AutoencoderKLLTXVideo, at the moment, due to "
                    "quality issues caused by splitting inference across frame dimension. If you believe this "
                    "should be possible, please submit a PR to https://github.com/huggingface/diffusers/pulls."
                )
            else:
                time = self.decoder(z[:, :, :, i : i + tile_latent_min_height, j : j + tile_latent_min_width], temb)

            row.append(time)
        rows.append(row)

    result_rows = []
    for i, row in enumerate(rows):
        result_row = []
        for j, tile in enumerate(row):
            # blend the above tile and the left tile
            # to the current tile and add the current tile to the result row
            if i > 0:
                tile = self.blend_v(rows[i - 1][j], tile, blend_height)
            if j > 0:
                tile = self.blend_h(row[j - 1], tile, blend_width)
            result_row.append(tile[:, :, :, : self.tile_sample_stride_height, : self.tile_sample_stride_width])
        result_rows.append(ops.cat(result_row, axis=4))

    dec = ops.cat(result_rows, axis=3)[:, :, :, :sample_height, :sample_width]

    if not return_dict:
        return (dec,)

    return DecoderOutput(sample=dec)

mindone.diffusers.AutoencoderKLLTXVideo.tiled_encode(x)

Encode a batch of images using a tiled encoder.

PARAMETER	DESCRIPTION
x	Input batch of videos. TYPE: `torch.Tensor`

RETURNS	DESCRIPTION
Tensor	torch.Tensor: The latent representation of the encoded videos.

Source code in mindone/diffusers/models/autoencoders/autoencoder_kl_ltx.py

def tiled_encode(self, x: ops.Tensor) -> ops.Tensor:
    r"""Encode a batch of images using a tiled encoder.

    Args:
        x (`torch.Tensor`): Input batch of videos.

    Returns:
        `torch.Tensor`:
            The latent representation of the encoded videos.
    """
    batch_size, num_channels, num_frames, height, width = x.shape
    latent_height = height // self.spatial_compression_ratio
    latent_width = width // self.spatial_compression_ratio

    tile_latent_min_height = self.tile_sample_min_height // self.spatial_compression_ratio
    tile_latent_min_width = self.tile_sample_min_width // self.spatial_compression_ratio
    tile_latent_stride_height = self.tile_sample_stride_height // self.spatial_compression_ratio
    tile_latent_stride_width = self.tile_sample_stride_width // self.spatial_compression_ratio

    blend_height = tile_latent_min_height - tile_latent_stride_height
    blend_width = tile_latent_min_width - tile_latent_stride_width

    # Split x into overlapping tiles and encode them separately.
    # The tiles have an overlap to avoid seams between tiles.
    rows = []
    for i in range(0, height, self.tile_sample_stride_height):
        row = []
        for j in range(0, width, self.tile_sample_stride_width):
            if self.use_framewise_encoding:
                # TODO(aryan): requires investigation
                raise NotImplementedError(
                    "Frame-wise encoding has not been implemented for AutoencoderKLLTXVideo, at the moment, due to "
                    "quality issues caused by splitting inference across frame dimension. If you believe this "
                    "should be possible, please submit a PR to https://github.com/huggingface/diffusers/pulls."
                )
            else:
                time = self.encoder(
                    x[:, :, :, i : i + self.tile_sample_min_height, j : j + self.tile_sample_min_width]
                )

            row.append(time)
        rows.append(row)

    result_rows = []
    for i, row in enumerate(rows):
        result_row = []
        for j, tile in enumerate(row):
            # blend the above tile and the left tile
            # to the current tile and add the current tile to the result row
            if i > 0:
                tile = self.blend_v(rows[i - 1][j], tile, blend_height)
            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(ops.cat(result_row, axis=4))

    enc = ops.cat(result_rows, axis=3)[:, :, :, :latent_height, :latent_width]
    return enc

mindone.diffusers.models.autoencoders.autoencoder_kl.AutoencoderKLOutput dataclass

Bases: BaseOutput

Output of AutoencoderKL encoding method.

PARAMETER	DESCRIPTION
latent	Encoded outputs of Encoder represented as the mean and logvar of DiagonalGaussianDistribution. DiagonalGaussianDistribution allows for sampling latents from the distribution. TYPE: `ms.Tensor`

Source code in mindone/diffusers/models/modeling_outputs.py

@dataclass
class AutoencoderKLOutput(BaseOutput):
    """
    Output of AutoencoderKL encoding method.

    Args:
        latent (`ms.Tensor`):
            Encoded outputs of `Encoder` represented as the mean and logvar of `DiagonalGaussianDistribution`.
            `DiagonalGaussianDistribution` allows for sampling latents from the distribution.
    """

    latent: ms.Tensor

mindone.diffusers.models.autoencoders.vae.DecoderOutput dataclass

Bases: BaseOutput

Output of decoding method.

PARAMETER	DESCRIPTION
sample	The decoded output sample from the last layer of the model. TYPE: `ms.Tensor` of shape `(batch_size, num_channels, height, width)`

Source code in mindone/diffusers/models/autoencoders/vae.py

@dataclass
class DecoderOutput(BaseOutput):
    r"""
    Output of decoding method.

    Args:
        sample (`ms.Tensor` of shape `(batch_size, num_channels, height, width)`):
            The decoded output sample from the last layer of the model.
    """

    sample: ms.Tensor
    commit_loss: Optional[ms.Tensor] = None