Create app.py

app.py

@@ -0,0 +1,879 @@
+import os
+from dataclasses import dataclass
+
+import gradio as gr
+import torch
+from PIL import Image
+from torchvision import transforms
+from dataclasses import dataclass
+import math
+from typing import Callable
+
+from tqdm import tqdm
+import bitsandbytes as bnb
+from bitsandbytes.nn.modules import Params4bit, QuantState
+
+
+import torch
+import random
+from einops import rearrange, repeat
+from diffusers import AutoencoderKL
+from torch import Tensor, nn
+from transformers import CLIPTextModel, CLIPTokenizer
+from transformers import T5EncoderModel, T5Tokenizer
+from safetensors.torch import load_file
+from optimum.quanto import freeze, qfloat8, quantize
+
+
+# ---------------- Encoders ----------------
+
+
+class HFEmbedder(nn.Module):
+    def __init__(self, version: str, max_length: int, **hf_kwargs):
+        super().__init__()
+        self.is_clip = version.startswith("openai")
+        self.max_length = max_length
+        self.output_key = "pooler_output" if self.is_clip else "last_hidden_state"
+
+        if self.is_clip:
+            self.tokenizer: CLIPTokenizer = CLIPTokenizer.from_pretrained(version, max_length=max_length)
+            self.hf_module: CLIPTextModel = CLIPTextModel.from_pretrained(version, **hf_kwargs)
+        else:
+            self.tokenizer: T5Tokenizer = T5Tokenizer.from_pretrained(version, max_length=max_length)
+            self.hf_module: T5EncoderModel = T5EncoderModel.from_pretrained(version, **hf_kwargs)
+
+        self.hf_module = self.hf_module.eval().requires_grad_(False)
+
+    def forward(self, text: list[str]) -> Tensor:
+        batch_encoding = self.tokenizer(
+            text,
+            truncation=True,
+            max_length=self.max_length,
+            return_length=False,
+            return_overflowing_tokens=False,
+            padding="max_length",
+            return_tensors="pt",
+        )
+
+        outputs = self.hf_module(
+            input_ids=batch_encoding["input_ids"].to(self.hf_module.device),
+            attention_mask=None,
+            output_hidden_states=False,
+        )
+        return outputs[self.output_key]
+    
+
+device = "cuda"
+t5 = HFEmbedder("google/t5-v1_1-xxl", max_length=512, torch_dtype=torch.bfloat16).to(device)
+clip = HFEmbedder("openai/clip-vit-large-patch14", max_length=77, torch_dtype=torch.bfloat16).to(device)
+ae = AutoencoderKL.from_pretrained("black-forest-labs/FLUX.1-dev", subfolder="vae", torch_dtype=torch.bfloat16).to(device)
+quantize(t5, weights=qfloat8)
+freeze(t5)
+
+
+# ---------------- NF4 ----------------
+
+
+def functional_linear_4bits(x, weight, bias):
+    out = bnb.matmul_4bit(x, weight.t(), bias=bias, quant_state=weight.quant_state)
+    out = out.to(x)
+    return out
+
+
+def copy_quant_state(state: QuantState, device: torch.device = None) -> QuantState:
+    if state is None:
+        return None
+
+    device = device or state.absmax.device
+
+    state2 = (
+        QuantState(
+            absmax=state.state2.absmax.to(device),
+            shape=state.state2.shape,
+            code=state.state2.code.to(device),
+            blocksize=state.state2.blocksize,
+            quant_type=state.state2.quant_type,
+            dtype=state.state2.dtype,
+        )
+        if state.nested
+        else None
+    )
+
+    return QuantState(
+        absmax=state.absmax.to(device),
+        shape=state.shape,
+        code=state.code.to(device),
+        blocksize=state.blocksize,
+        quant_type=state.quant_type,
+        dtype=state.dtype,
+        offset=state.offset.to(device) if state.nested else None,
+        state2=state2,
+    )
+
+
+class ForgeParams4bit(Params4bit):
+    def to(self, *args, **kwargs):
+        device, dtype, non_blocking, convert_to_format = torch._C._nn._parse_to(*args, **kwargs)
+        if device is not None and device.type == "cuda" and not self.bnb_quantized:
+            return self._quantize(device)
+        else:
+            n = ForgeParams4bit(
+                torch.nn.Parameter.to(self, device=device, dtype=dtype, non_blocking=non_blocking),
+                requires_grad=self.requires_grad,
+                quant_state=copy_quant_state(self.quant_state, device),
+                blocksize=self.blocksize,
+                compress_statistics=self.compress_statistics,
+                quant_type=self.quant_type,
+                quant_storage=self.quant_storage,
+                bnb_quantized=self.bnb_quantized,
+                module=self.module
+            )
+            self.module.quant_state = n.quant_state
+            self.data = n.data
+            self.quant_state = n.quant_state
+            return n
+
+
+class ForgeLoader4Bit(torch.nn.Module):
+    def __init__(self, *, device, dtype, quant_type, **kwargs):
+        super().__init__()
+        self.dummy = torch.nn.Parameter(torch.empty(1, device=device, dtype=dtype))
+        self.weight = None
+        self.quant_state = None
+        self.bias = None
+        self.quant_type = quant_type
+
+    def _save_to_state_dict(self, destination, prefix, keep_vars):
+        super()._save_to_state_dict(destination, prefix, keep_vars)
+        quant_state = getattr(self.weight, "quant_state", None)
+        if quant_state is not None:
+            for k, v in quant_state.as_dict(packed=True).items():
+                destination[prefix + "weight." + k] = v if keep_vars else v.detach()
+        return
+
+    def _load_from_state_dict(self, state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs):
+        quant_state_keys = {k[len(prefix + "weight."):] for k in state_dict.keys() if k.startswith(prefix + "weight.")}
+
+        if any('bitsandbytes' in k for k in quant_state_keys):
+            quant_state_dict = {k: state_dict[prefix + "weight." + k] for k in quant_state_keys}
+
+            self.weight = ForgeParams4bit.from_prequantized(
+                data=state_dict[prefix + 'weight'],
+                quantized_stats=quant_state_dict,
+                requires_grad=False,
+                device=self.dummy.device,
+                module=self
+            )
+            self.quant_state = self.weight.quant_state
+
+            if prefix + 'bias' in state_dict:
+                self.bias = torch.nn.Parameter(state_dict[prefix + 'bias'].to(self.dummy))
+
+            del self.dummy
+        elif hasattr(self, 'dummy'):
+            if prefix + 'weight' in state_dict:
+                self.weight = ForgeParams4bit(
+                    state_dict[prefix + 'weight'].to(self.dummy),
+                    requires_grad=False,
+                    compress_statistics=True,
+                    quant_type=self.quant_type,
+                    quant_storage=torch.uint8,
+                    module=self,
+                )
+                self.quant_state = self.weight.quant_state
+
+            if prefix + 'bias' in state_dict:
+                self.bias = torch.nn.Parameter(state_dict[prefix + 'bias'].to(self.dummy))
+
+            del self.dummy
+        else:
+            super()._load_from_state_dict(state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs)
+
+
+class Linear(ForgeLoader4Bit):
+    def __init__(self, *args, device=None, dtype=None, **kwargs):
+        super().__init__(device=device, dtype=dtype, quant_type='nf4')
+
+    def forward(self, x):
+        self.weight.quant_state = self.quant_state
+
+        if self.bias is not None and self.bias.dtype != x.dtype:
+            # Maybe this can also be set to all non-bnb ops since the cost is very low.
+            # And it only invokes one time, and most linear does not have bias
+            self.bias.data = self.bias.data.to(x.dtype)
+
+        return functional_linear_4bits(x, self.weight, self.bias)
+    
+
+nn.Linear = Linear
+
+
+# ---------------- Model ----------------
+
+
+def attention(q: Tensor, k: Tensor, v: Tensor, pe: Tensor) -> Tensor:
+    q, k = apply_rope(q, k, pe)
+
+    x = torch.nn.functional.scaled_dot_product_attention(q, k, v)
+    x = rearrange(x, "B H L D -> B L (H D)")
+
+    return x
+
+
+def rope(pos: Tensor, dim: int, theta: int) -> Tensor:
+    assert dim % 2 == 0
+    scale = torch.arange(0, dim, 2, dtype=torch.float64, device=pos.device) / dim
+    omega = 1.0 / (theta**scale)
+    out = torch.einsum("...n,d->...nd", pos, omega)
+    out = torch.stack([torch.cos(out), -torch.sin(out), torch.sin(out), torch.cos(out)], dim=-1)
+    out = rearrange(out, "b n d (i j) -> b n d i j", i=2, j=2)
+    return out.float()
+
+
+def apply_rope(xq: Tensor, xk: Tensor, freqs_cis: Tensor) -> tuple[Tensor, Tensor]:
+    xq_ = xq.float().reshape(*xq.shape[:-1], -1, 1, 2)
+    xk_ = xk.float().reshape(*xk.shape[:-1], -1, 1, 2)
+    xq_out = freqs_cis[..., 0] * xq_[..., 0] + freqs_cis[..., 1] * xq_[..., 1]
+    xk_out = freqs_cis[..., 0] * xk_[..., 0] + freqs_cis[..., 1] * xk_[..., 1]
+    return xq_out.reshape(*xq.shape).type_as(xq), xk_out.reshape(*xk.shape).type_as(xk)
+
+
+class EmbedND(nn.Module):
+    def __init__(self, dim: int, theta: int, axes_dim: list[int]):
+        super().__init__()
+        self.dim = dim
+        self.theta = theta
+        self.axes_dim = axes_dim
+
+    def forward(self, ids: Tensor) -> Tensor:
+        n_axes = ids.shape[-1]
+        emb = torch.cat(
+            [rope(ids[..., i], self.axes_dim[i], self.theta) for i in range(n_axes)],
+            dim=-3,
+        )
+
+        return emb.unsqueeze(1)
+
+
+def timestep_embedding(t: Tensor, dim, max_period=10000, time_factor: float = 1000.0):
+    """
+    Create sinusoidal timestep embeddings.
+    :param t: a 1-D Tensor of N indices, one per batch element.
+                      These may be fractional.
+    :param dim: the dimension of the output.
+    :param max_period: controls the minimum frequency of the embeddings.
+    :return: an (N, D) Tensor of positional embeddings.
+    """
+    t = time_factor * t
+    half = dim // 2
+    freqs = torch.exp(-math.log(max_period) * torch.arange(start=0, end=half, dtype=torch.float32) / half).to(
+        t.device
+    )
+
+    args = t[:, None].float() * freqs[None]
+    embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
+    if dim % 2:
+        embedding = torch.cat([embedding, torch.zeros_like(embedding[:, :1])], dim=-1)
+    if torch.is_floating_point(t):
+        embedding = embedding.to(t)
+    return embedding
+
+
+class MLPEmbedder(nn.Module):
+    def __init__(self, in_dim: int, hidden_dim: int):
+        super().__init__()
+        self.in_layer = nn.Linear(in_dim, hidden_dim, bias=True)
+        self.silu = nn.SiLU()
+        self.out_layer = nn.Linear(hidden_dim, hidden_dim, bias=True)
+
+    def forward(self, x: Tensor) -> Tensor:
+        return self.out_layer(self.silu(self.in_layer(x)))
+
+
+class RMSNorm(torch.nn.Module):
+    def __init__(self, dim: int):
+        super().__init__()
+        self.scale = nn.Parameter(torch.ones(dim))
+
+    def forward(self, x: Tensor):
+        x_dtype = x.dtype
+        x = x.float()
+        rrms = torch.rsqrt(torch.mean(x**2, dim=-1, keepdim=True) + 1e-6)
+        return (x * rrms).to(dtype=x_dtype) * self.scale
+
+
+class QKNorm(torch.nn.Module):
+    def __init__(self, dim: int):
+        super().__init__()
+        self.query_norm = RMSNorm(dim)
+        self.key_norm = RMSNorm(dim)
+
+    def forward(self, q: Tensor, k: Tensor, v: Tensor) -> tuple[Tensor, Tensor]:
+        q = self.query_norm(q)
+        k = self.key_norm(k)
+        return q.to(v), k.to(v)
+
+
+class SelfAttention(nn.Module):
+    def __init__(self, dim: int, num_heads: int = 8, qkv_bias: bool = False):
+        super().__init__()
+        self.num_heads = num_heads
+        head_dim = dim // num_heads
+
+        self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
+        self.norm = QKNorm(head_dim)
+        self.proj = nn.Linear(dim, dim)
+
+    def forward(self, x: Tensor, pe: Tensor) -> Tensor:
+        qkv = self.qkv(x)
+        q, k, v = rearrange(qkv, "B L (K H D) -> K B H L D", K=3, H=self.num_heads)
+        q, k = self.norm(q, k, v)
+        x = attention(q, k, v, pe=pe)
+        x = self.proj(x)
+        return x
+
+
+@dataclass
+class ModulationOut:
+    shift: Tensor
+    scale: Tensor
+    gate: Tensor
+
+
+class Modulation(nn.Module):
+    def __init__(self, dim: int, double: bool):
+        super().__init__()
+        self.is_double = double
+        self.multiplier = 6 if double else 3
+        self.lin = nn.Linear(dim, self.multiplier * dim, bias=True)
+
+    def forward(self, vec: Tensor) -> tuple[ModulationOut, ModulationOut | None]:
+        out = self.lin(nn.functional.silu(vec))[:, None, :].chunk(self.multiplier, dim=-1)
+
+        return (
+            ModulationOut(*out[:3]),
+            ModulationOut(*out[3:]) if self.is_double else None,
+        )
+
+
+class DoubleStreamBlock(nn.Module):
+    def __init__(self, hidden_size: int, num_heads: int, mlp_ratio: float, qkv_bias: bool = False):
+        super().__init__()
+
+        mlp_hidden_dim = int(hidden_size * mlp_ratio)
+        self.num_heads = num_heads
+        self.hidden_size = hidden_size
+        self.img_mod = Modulation(hidden_size, double=True)
+        self.img_norm1 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
+        self.img_attn = SelfAttention(dim=hidden_size, num_heads=num_heads, qkv_bias=qkv_bias)
+
+        self.img_norm2 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
+        self.img_mlp = nn.Sequential(
+            nn.Linear(hidden_size, mlp_hidden_dim, bias=True),
+            nn.GELU(approximate="tanh"),
+            nn.Linear(mlp_hidden_dim, hidden_size, bias=True),
+        )
+
+        self.txt_mod = Modulation(hidden_size, double=True)
+        self.txt_norm1 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
+        self.txt_attn = SelfAttention(dim=hidden_size, num_heads=num_heads, qkv_bias=qkv_bias)
+
+        self.txt_norm2 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
+        self.txt_mlp = nn.Sequential(
+            nn.Linear(hidden_size, mlp_hidden_dim, bias=True),
+            nn.GELU(approximate="tanh"),
+            nn.Linear(mlp_hidden_dim, hidden_size, bias=True),
+        )
+
+    def forward(self, img: Tensor, txt: Tensor, vec: Tensor, pe: Tensor) -> tuple[Tensor, Tensor]:
+        img_mod1, img_mod2 = self.img_mod(vec)
+        txt_mod1, txt_mod2 = self.txt_mod(vec)
+
+        # prepare image for attention
+        img_modulated = self.img_norm1(img)
+        img_modulated = (1 + img_mod1.scale) * img_modulated + img_mod1.shift
+        img_qkv = self.img_attn.qkv(img_modulated)
+        img_q, img_k, img_v = rearrange(img_qkv, "B L (K H D) -> K B H L D", K=3, H=self.num_heads)
+        img_q, img_k = self.img_attn.norm(img_q, img_k, img_v)
+
+        # prepare txt for attention
+        txt_modulated = self.txt_norm1(txt)
+        txt_modulated = (1 + txt_mod1.scale) * txt_modulated + txt_mod1.shift
+        txt_qkv = self.txt_attn.qkv(txt_modulated)
+        txt_q, txt_k, txt_v = rearrange(txt_qkv, "B L (K H D) -> K B H L D", K=3, H=self.num_heads)
+        txt_q, txt_k = self.txt_attn.norm(txt_q, txt_k, txt_v)
+
+        # run actual attention
+        q = torch.cat((txt_q, img_q), dim=2)
+        k = torch.cat((txt_k, img_k), dim=2)
+        v = torch.cat((txt_v, img_v), dim=2)
+
+        attn = attention(q, k, v, pe=pe)
+        txt_attn, img_attn = attn[:, : txt.shape[1]], attn[:, txt.shape[1] :]
+
+        # calculate the img bloks
+        img = img + img_mod1.gate * self.img_attn.proj(img_attn)
+        img = img + img_mod2.gate * self.img_mlp((1 + img_mod2.scale) * self.img_norm2(img) + img_mod2.shift)
+
+        # calculate the txt bloks
+        txt = txt + txt_mod1.gate * self.txt_attn.proj(txt_attn)
+        txt = txt + txt_mod2.gate * self.txt_mlp((1 + txt_mod2.scale) * self.txt_norm2(txt) + txt_mod2.shift)
+        return img, txt
+
+
+class SingleStreamBlock(nn.Module):
+    """
+    A DiT block with parallel linear layers as described in
+    https://arxiv.org/abs/2302.05442 and adapted modulation interface.
+    """
+
+    def __init__(
+        self,
+        hidden_size: int,
+        num_heads: int,
+        mlp_ratio: float = 4.0,
+        qk_scale: float | None = None,
+    ):
+        super().__init__()
+        self.hidden_dim = hidden_size
+        self.num_heads = num_heads
+        head_dim = hidden_size // num_heads
+        self.scale = qk_scale or head_dim**-0.5
+
+        self.mlp_hidden_dim = int(hidden_size * mlp_ratio)
+        # qkv and mlp_in
+        self.linear1 = nn.Linear(hidden_size, hidden_size * 3 + self.mlp_hidden_dim)
+        # proj and mlp_out
+        self.linear2 = nn.Linear(hidden_size + self.mlp_hidden_dim, hidden_size)
+
+        self.norm = QKNorm(head_dim)
+
+        self.hidden_size = hidden_size
+        self.pre_norm = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
+
+        self.mlp_act = nn.GELU(approximate="tanh")
+        self.modulation = Modulation(hidden_size, double=False)
+
+    def forward(self, x: Tensor, vec: Tensor, pe: Tensor) -> Tensor:
+        mod, _ = self.modulation(vec)
+        x_mod = (1 + mod.scale) * self.pre_norm(x) + mod.shift
+        qkv, mlp = torch.split(self.linear1(x_mod), [3 * self.hidden_size, self.mlp_hidden_dim], dim=-1)
+
+        q, k, v = rearrange(qkv, "B L (K H D) -> K B H L D", K=3, H=self.num_heads)
+        q, k = self.norm(q, k, v)
+
+        # compute attention
+        attn = attention(q, k, v, pe=pe)
+        # compute activation in mlp stream, cat again and run second linear layer
+        output = self.linear2(torch.cat((attn, self.mlp_act(mlp)), 2))
+        return x + mod.gate * output
+    
+
+class LastLayer(nn.Module):
+    def __init__(self, hidden_size: int, patch_size: int, out_channels: int):
+        super().__init__()
+        self.norm_final = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
+        self.linear = nn.Linear(hidden_size, patch_size * patch_size * out_channels, bias=True)
+        self.adaLN_modulation = nn.Sequential(nn.SiLU(), nn.Linear(hidden_size, 2 * hidden_size, bias=True))
+
+    def forward(self, x: Tensor, vec: Tensor) -> Tensor:
+        shift, scale = self.adaLN_modulation(vec).chunk(2, dim=1)
+        x = (1 + scale[:, None, :]) * self.norm_final(x) + shift[:, None, :]
+        x = self.linear(x)
+        return x
+   
+   
+class FluxParams:
+    in_channels: int = 64
+    vec_in_dim: int = 768
+    context_in_dim: int = 4096
+    hidden_size: int = 3072
+    mlp_ratio: float = 4.0
+    num_heads: int = 24
+    depth: int = 19
+    depth_single_blocks: int = 38
+    axes_dim: list = [16, 56, 56]
+    theta: int = 10_000
+    qkv_bias: bool = True
+    guidance_embed: bool = True
+
+
+class Flux(nn.Module):
+    """
+    Transformer model for flow matching on sequences.
+    """
+
+    def __init__(self, params = FluxParams()):
+        super().__init__()
+
+        self.params = params
+        self.in_channels = params.in_channels
+        self.out_channels = self.in_channels
+        if params.hidden_size % params.num_heads != 0:
+            raise ValueError(
+                f"Hidden size {params.hidden_size} must be divisible by num_heads {params.num_heads}"
+            )
+        pe_dim = params.hidden_size // params.num_heads
+        if sum(params.axes_dim) != pe_dim:
+            raise ValueError(f"Got {params.axes_dim} but expected positional dim {pe_dim}")
+        self.hidden_size = params.hidden_size
+        self.num_heads = params.num_heads
+        self.pe_embedder = EmbedND(dim=pe_dim, theta=params.theta, axes_dim=params.axes_dim)
+        self.img_in = nn.Linear(self.in_channels, self.hidden_size, bias=True)
+        self.time_in = MLPEmbedder(in_dim=256, hidden_dim=self.hidden_size)
+        self.vector_in = MLPEmbedder(params.vec_in_dim, self.hidden_size)
+        self.guidance_in = (
+            MLPEmbedder(in_dim=256, hidden_dim=self.hidden_size) if params.guidance_embed else nn.Identity()
+        )
+        self.txt_in = nn.Linear(params.context_in_dim, self.hidden_size)
+
+        self.double_blocks = nn.ModuleList(
+            [
+                DoubleStreamBlock(
+                    self.hidden_size,
+                    self.num_heads,
+                    mlp_ratio=params.mlp_ratio,
+                    qkv_bias=params.qkv_bias,
+                )
+                for _ in range(params.depth)
+            ]
+        )
+
+        self.single_blocks = nn.ModuleList(
+            [
+                SingleStreamBlock(self.hidden_size, self.num_heads, mlp_ratio=params.mlp_ratio)
+                for _ in range(params.depth_single_blocks)
+            ]
+        )
+
+        self.final_layer = LastLayer(self.hidden_size, 1, self.out_channels)
+
+    def forward(
+        self,
+        img: Tensor,
+        img_ids: Tensor,
+        txt: Tensor,
+        txt_ids: Tensor,
+        timesteps: Tensor,
+        y: Tensor,
+        guidance: Tensor | None = None,
+    ) -> Tensor:
+        if img.ndim != 3 or txt.ndim != 3:
+            raise ValueError("Input img and txt tensors must have 3 dimensions.")
+
+        # running on sequences img
+        img = self.img_in(img)
+        vec = self.time_in(timestep_embedding(timesteps, 256))
+        if self.params.guidance_embed:
+            if guidance is None:
+                raise ValueError("Didn't get guidance strength for guidance distilled model.")
+            vec = vec + self.guidance_in(timestep_embedding(guidance, 256))
+        vec = vec + self.vector_in(y)
+        txt = self.txt_in(txt)
+
+        ids = torch.cat((txt_ids, img_ids), dim=1)
+        pe = self.pe_embedder(ids)
+
+        for block in self.double_blocks:
+            img, txt = block(img=img, txt=txt, vec=vec, pe=pe)
+
+        img = torch.cat((txt, img), 1)
+        for block in self.single_blocks:
+            img = block(img, vec=vec, pe=pe)
+        img = img[:, txt.shape[1] :, ...]
+
+        img = self.final_layer(img, vec)  # (N, T, patch_size ** 2 * out_channels)
+        return img
+
+
+def prepare(t5: HFEmbedder, clip: HFEmbedder, img: Tensor, prompt: str | list[str]) -> dict[str, Tensor]:
+    bs, c, h, w = img.shape
+    if bs == 1 and not isinstance(prompt, str):
+        bs = len(prompt)
+
+    img = rearrange(img, "b c (h ph) (w pw) -> b (h w) (c ph pw)", ph=2, pw=2)
+    if img.shape[0] == 1 and bs > 1:
+        img = repeat(img, "1 ... -> bs ...", bs=bs)
+
+    img_ids = torch.zeros(h // 2, w // 2, 3)
+    img_ids[..., 1] = img_ids[..., 1] + torch.arange(h // 2)[:, None]
+    img_ids[..., 2] = img_ids[..., 2] + torch.arange(w // 2)[None, :]
+    img_ids = repeat(img_ids, "h w c -> b (h w) c", b=bs)
+
+    if isinstance(prompt, str):
+        prompt = [prompt]
+    txt = t5(prompt)
+    if txt.shape[0] == 1 and bs > 1:
+        txt = repeat(txt, "1 ... -> bs ...", bs=bs)
+    txt_ids = torch.zeros(bs, txt.shape[1], 3)
+
+    vec = clip(prompt)
+    if vec.shape[0] == 1 and bs > 1:
+        vec = repeat(vec, "1 ... -> bs ...", bs=bs)
+
+    return {
+        "img": img,
+        "img_ids": img_ids.to(img.device),
+        "txt": txt.to(img.device),
+        "txt_ids": txt_ids.to(img.device),
+        "vec": vec.to(img.device),
+    }
+
+
+def time_shift(mu: float, sigma: float, t: Tensor):
+    return math.exp(mu) / (math.exp(mu) + (1 / t - 1) ** sigma)
+
+
+def get_lin_function(
+    x1: float = 256, y1: float = 0.5, x2: float = 4096, y2: float = 1.15
+) -> Callable[[float], float]:
+    m = (y2 - y1) / (x2 - x1)
+    b = y1 - m * x1
+    return lambda x: m * x + b
+
+
+def get_schedule(
+    num_steps: int,
+    image_seq_len: int,
+    base_shift: float = 0.5,
+    max_shift: float = 1.15,
+    shift: bool = True,
+) -> list[float]:
+    # extra step for zero
+    timesteps = torch.linspace(1, 0, num_steps + 1)
+
+    # shifting the schedule to favor high timesteps for higher signal images
+    if shift:
+        # eastimate mu based on linear estimation between two points
+        mu = get_lin_function(y1=base_shift, y2=max_shift)(image_seq_len)
+        timesteps = time_shift(mu, 1.0, timesteps)
+
+    return timesteps.tolist()
+
+
+def denoise(
+    model: Flux,
+    # model input
+    img: Tensor,
+    img_ids: Tensor,
+    txt: Tensor,
+    txt_ids: Tensor,
+    vec: Tensor,
+    # sampling parameters
+    timesteps: list[float],
+    guidance: float = 4.0,
+):
+    # this is ignored for schnell
+    guidance_vec = torch.full((img.shape[0],), guidance, device=img.device, dtype=img.dtype)
+    for t_curr, t_prev in tqdm(zip(timesteps[:-1], timesteps[1:]), total=len(timesteps) - 1):
+        t_vec = torch.full((img.shape[0],), t_curr, dtype=img.dtype, device=img.device)
+        pred = model(
+            img=img,
+            img_ids=img_ids,
+            txt=txt,
+            txt_ids=txt_ids,
+            y=vec,
+            timesteps=t_vec,
+            guidance=guidance_vec,
+        )
+
+        img = img + (t_prev - t_curr) * pred
+
+    return img
+
+
+def unpack(x: Tensor, height: int, width: int) -> Tensor:
+    return rearrange(
+        x,
+        "b (h w) (c ph pw) -> b c (h ph) (w pw)",
+        h=math.ceil(height / 16),
+        w=math.ceil(width / 16),
+        ph=2,
+        pw=2,
+    )
+
+@dataclass
+class SamplingOptions:
+    prompt: str
+    width: int
+    height: int
+    guidance: float
+    seed: int | None
+    
+
+def get_image(image) -> torch.Tensor | None:
+    if image is None:
+        return None
+    image = Image.fromarray(image).convert("RGB")
+
+    transform = transforms.Compose([
+        transforms.ToTensor(),
+        transforms.Lambda(lambda x: 2.0 * x - 1.0),
+    ])
+    img: torch.Tensor = transform(image)
+    return img[None, ...]
+
+
+# ---------------- Demo ----------------
+
+
+from pathlib import Path
+
+if not Path("flux1-dev-bnb-nf4.safetensors").exists():
+    torch.hub.download_url_to_file("https://huggingface.co/lllyasviel/flux1-dev-bnb-nf4/resolve/main/flux1-dev-bnb-nf4.safetensors", "flux1-dev-bnb-nf4.safetensors")
+    
+sd = load_file("flux1-dev-bnb-nf4.safetensors")
+sd = {k.replace("model.diffusion_model.", ""): v for k, v in sd.items() if "model.diffusion_model" in k}
+model = Flux().to(dtype=torch.float16, device="cuda")
+result = model.load_state_dict(sd)
+print(result)
+
+# model = Flux().to(dtype=torch.bfloat16, device="cuda")
+# result = model.load_state_dict(load_file("/storage/dev/nyanko/flux-dev/flux1-dev.sft"))
+
+@torch.inference_mode()
+def generate_image(
+    prompt, width, height, guidance, seed,
+    do_img2img, init_image, image2image_strength, resize_img,
+    progress=gr.Progress(track_tqdm=True),
+):
+    if seed == 0:
+        seed = int(random.random() * 1000000)
+        
+    device = "cuda" if torch.cuda.is_available() else "cpu"
+    torch_device = torch.device(device)
+
+    if do_img2img and init_image is not None:
+        init_image = get_image(init_image)
+        if resize_img:
+            init_image = torch.nn.functional.interpolate(init_image, (height, width))
+        else:
+            h, w = init_image.shape[-2:]
+            init_image = init_image[..., : 16 * (h // 16), : 16 * (w // 16)]
+            height = init_image.shape[-2]
+            width = init_image.shape[-1]
+        init_image = ae.encode(init_image.to(torch_device))
+
+    generator = torch.Generator(device=device).manual_seed(seed)
+    x = torch.randn(1, 16, 2 * math.ceil(height / 16), 2 * math.ceil(width / 16), device=device, dtype=torch.bfloat16, generator=generator) 
+    
+    num_steps = 25
+    timesteps = get_schedule(num_steps, (x.shape[-1] * x.shape[-2]) // 4, shift=True)
+
+    if do_img2img and init_image is not None:
+        t_idx = int((1 - image2image_strength) * num_steps)
+        t = timesteps[t_idx]
+        timesteps = timesteps[t_idx:]
+        x = t * x + (1.0 - t) * init_image.to(x.dtype)
+
+    inp = prepare(t5=t5, clip=clip, img=x, prompt=prompt)
+    x = denoise(model, **inp, timesteps=timesteps, guidance=guidance)
+    x = unpack(x.float(), height, width)
+    with torch.autocast(device_type=torch_device.type, dtype=torch.bfloat16):
+        x = x = (x / ae.config.scaling_factor) + ae.config.shift_factor 
+        x = ae.decode(x).sample
+
+    x = x.clamp(-1, 1)
+    x = rearrange(x[0], "c h w -> h w c")
+    img = Image.fromarray((127.5 * (x + 1.0)).cpu().byte().numpy())
+
+    return img, seed
+
+def create_demo():
+    with gr.Blocks(theme="bethecloud/storj_theme") as demo:
+        gr.HTML(
+            """
+                <div style="text-align: center; margin: 0 auto;">
+                <div
+                    style="
+                    display: inline-flex;
+                    align-items: center;
+                    gap: 0.8rem;
+                    font-size: 1.75rem;
+                    "
+                >
+                    <svg
+                    width="0.65em"
+                    height="0.65em"
+                    viewBox="0 0 115 115"
+                    fill="none"
+                    xmlns="http://www.w3.org/2000/svg"
+                    >
+                    <rect width="23" height="23" fill="white"></rect>
+                    <rect y="69" width="23" height="23" fill="white"></rect>
+                    <rect x="23" width="23" height="23" fill="#AEAEAE"></rect>
+                    <rect x="23" y="69" width="23" height="23" fill="#AEAEAE"></rect>
+                    <rect x="46" width="23" height="23" fill="white"></rect>
+                    <rect x="46" y="69" width="23" height="23" fill="white"></rect>
+                    <rect x="69" width="23" height="23" fill="black"></rect>
+                    <rect x="69" y="69" width="23" height="23" fill="black"></rect>
+                    <rect x="92" width="23" height="23" fill="#D9D9D9"></rect>
+                    <rect x="92" y="69" width="23" height="23" fill="#AEAEAE"></rect>
+                    <rect x="115" y="46" width="23" height="23" fill="white"></rect>
+                    <rect x="115" y="115" width="23" height="23" fill="white"></rect>
+                    <rect x="115" y="69" width="23" height="23" fill="#D9D9D9"></rect>
+                    <rect x="92" y="46" width="23" height="23" fill="#AEAEAE"></rect>
+                    <rect x="92" y="115" width="23" height="23" fill="#AEAEAE"></rect>
+                    <rect x="92" y="69" width="23" height="23" fill="white"></rect>
+                    <rect x="69" y="46" width="23" height="23" fill="white"></rect>
+                    <rect x="69" y="115" width="23" height="23" fill="white"></rect>
+                    <rect x="69" y="69" width="23" height="23" fill="#D9D9D9"></rect>
+                    <rect x="46" y="46" width="23" height="23" fill="black"></rect>
+                    <rect x="46" y="115" width="23" height="23" fill="black"></rect>
+                    <rect x="46" y="69" width="23" height="23" fill="black"></rect>
+                    <rect x="23" y="46" width="23" height="23" fill="#D9D9D9"></rect>
+                    <rect x="23" y="115" width="23" height="23" fill="#AEAEAE"></rect>
+                    <rect x="23" y="69" width="23" height="23" fill="black"></rect>
+                    </svg>
+                    <h1 style="font-weight: 900; margin-bottom: 7px;margin-top:5px">
+                    FLUX.1 dev NF4 Quantized Demo
+                    </h1>
+                </div>
+                <p style="margin-bottom: 20px; font-size: 94%; line-height: 23px;">
+                    12B param rectified flow transformer guidance-distilled from <a href="https://blackforestlabs.ai/">FLUX.1 [pro]</a>
+                    <a href="https://huggingface.co/black-forest-labs/FLUX.1-dev/blob/main/LICENSE.md">[non-commercial license]</a> <a href="https://blackforestlabs.ai/announcing-black-forest-labs/">[blog]</a> <a href="https://huggingface.co/black-forest-labs/FLUX.1-dev">[model]</a>
+                </p>
+                </div>
+            """
+        )
+        with gr.Row():
+            with gr.Column():
+                prompt = gr.Textbox(label="Prompt", value="a photo of a forest with mist swirling around the tree trunks. The word 'FLUX' is painted over it in big, red brush strokes with visible texture")
+                
+                width = gr.Slider(minimum=128, maximum=2048, step=64, label="Width", value=1360)
+                height = gr.Slider(minimum=128, maximum=2048, step=64, label="Height", value=768)
+                guidance = gr.Slider(minimum=1.0, maximum=5.0, step=0.1, label="Guidance", value=3.5)
+                seed = gr.Number(label="Seed", precision=-1)
+                do_img2img = gr.Checkbox(label="Image to Image", value=False)
+                init_image = gr.Image(label="Input Image", visible=False)
+                image2image_strength = gr.Slider(minimum=0.0, maximum=1.0, step=0.01, label="Noising strength", value=0.8, visible=False)
+                resize_img = gr.Checkbox(label="Resize image", value=True, visible=False)
+                generate_button = gr.Button("Generate")
+            
+            with gr.Column():
+                output_image = gr.Image(label="Generated Image")
+                output_seed = gr.Number(label="Used Seed", precision=0)
+
+        do_img2img.change(
+            fn=lambda x: [gr.update(visible=x), gr.update(visible=x), gr.update(visible=x)],
+            inputs=[do_img2img],
+            outputs=[init_image, image2image_strength, resize_img]
+        )
+
+        generate_button.click(
+            fn=generate_image,
+            inputs=[prompt, width, height, guidance, seed, do_img2img, init_image, image2image_strength, resize_img],
+            outputs=[output_image, output_seed]
+        )
+        
+        examples = [
+            "a tiny astronaut hatching from an egg on the moon",
+            "a cat holding a sign that says hello world",
+            "an anime illustration of a wiener schnitzel",
+        ]
+
+    return demo
+
+if __name__ == "__main__":
+    demo = create_demo()
+    demo.launch()