File size: 7,158 Bytes
f474836
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
import os
import torch
import einops

from diffusers import DiffusionPipeline
from transformers import CLIPTextModel, CLIPTokenizer
from huggingface_hub import snapshot_download
from diffusers_vdm.vae import VideoAutoencoderKL
from diffusers_vdm.projection import Resampler
from diffusers_vdm.unet import UNet3DModel
from diffusers_vdm.improved_clip_vision import ImprovedCLIPVisionModelWithProjection
from diffusers_vdm.dynamic_tsnr_sampler import SamplerDynamicTSNR


class LatentVideoDiffusionPipeline(DiffusionPipeline):
    def __init__(self, tokenizer, text_encoder, image_encoder, vae, image_projection, unet, fp16=True, eval=True):
        super().__init__()

        self.loading_components = dict(
            vae=vae,
            text_encoder=text_encoder,
            tokenizer=tokenizer,
            unet=unet,
            image_encoder=image_encoder,
            image_projection=image_projection
        )

        for k, v in self.loading_components.items():
            setattr(self, k, v)

        if fp16:
            self.vae.half()
            self.text_encoder.half()
            self.unet.half()
            self.image_encoder.half()
            self.image_projection.half()

        self.vae.requires_grad_(False)
        self.text_encoder.requires_grad_(False)
        self.image_encoder.requires_grad_(False)

        self.vae.eval()
        self.text_encoder.eval()
        self.image_encoder.eval()

        if eval:
            self.unet.eval()
            self.image_projection.eval()
        else:
            self.unet.train()
            self.image_projection.train()

    def to(self, *args, **kwargs):
        for k, v in self.loading_components.items():
            if hasattr(v, 'to'):
                v.to(*args, **kwargs)
        return self

    def save_pretrained(self, save_directory, **kwargs):
        for k, v in self.loading_components.items():
            folder = os.path.join(save_directory, k)
            os.makedirs(folder, exist_ok=True)
            v.save_pretrained(folder)
        return

    @classmethod
    def from_pretrained(cls, repo_id, fp16=True, eval=True, token=None):
        local_folder = snapshot_download(repo_id=repo_id, token=token)
        return cls(
            tokenizer=CLIPTokenizer.from_pretrained(os.path.join(local_folder, "tokenizer")),
            text_encoder=CLIPTextModel.from_pretrained(os.path.join(local_folder, "text_encoder")),
            image_encoder=ImprovedCLIPVisionModelWithProjection.from_pretrained(os.path.join(local_folder, "image_encoder")),
            vae=VideoAutoencoderKL.from_pretrained(os.path.join(local_folder, "vae")),
            image_projection=Resampler.from_pretrained(os.path.join(local_folder, "image_projection")),
            unet=UNet3DModel.from_pretrained(os.path.join(local_folder, "unet")),
            fp16=fp16,
            eval=eval
        )

    @torch.inference_mode()
    def encode_cropped_prompt_77tokens(self, prompt: str):
        cond_ids = self.tokenizer(prompt,
                                  padding="max_length",
                                  max_length=self.tokenizer.model_max_length,
                                  truncation=True,
                                  return_tensors="pt").input_ids.to(self.text_encoder.device)
        cond = self.text_encoder(cond_ids, attention_mask=None).last_hidden_state
        return cond

    @torch.inference_mode()
    def encode_clip_vision(self, frames):
        b, c, t, h, w = frames.shape
        frames = einops.rearrange(frames, 'b c t h w -> (b t) c h w')
        clipvision_embed = self.image_encoder(frames).last_hidden_state
        clipvision_embed = einops.rearrange(clipvision_embed, '(b t) d c -> b t d c', t=t)
        return clipvision_embed

    @torch.inference_mode()
    def encode_latents(self, videos, return_hidden_states=True):
        b, c, t, h, w = videos.shape
        x = einops.rearrange(videos, 'b c t h w -> (b t) c h w')
        encoder_posterior, hidden_states = self.vae.encode(x, return_hidden_states=return_hidden_states)
        z = encoder_posterior.mode() * self.vae.scale_factor
        z = einops.rearrange(z, '(b t) c h w -> b c t h w', b=b, t=t)

        if not return_hidden_states:
            return z

        hidden_states = [einops.rearrange(h, '(b t) c h w -> b c t h w', b=b) for h in hidden_states]
        hidden_states = [h[:, :, [0, -1], :, :] for h in hidden_states]  # only need first and last

        return z, hidden_states

    @torch.inference_mode()
    def decode_latents(self, latents, hidden_states):
        B, C, T, H, W = latents.shape
        latents = einops.rearrange(latents, 'b c t h w -> (b t) c h w')
        latents = latents.to(device=self.vae.device, dtype=self.vae.dtype) / self.vae.scale_factor
        pixels = self.vae.decode(latents, ref_context=hidden_states, timesteps=T)
        pixels = einops.rearrange(pixels, '(b t) c h w -> b c t h w', b=B, t=T)
        return pixels

    @torch.inference_mode()
    def __call__(
            self,
            batch_size: int = 1,
            steps: int = 50,
            guidance_scale: float = 5.0,
            positive_text_cond = None,
            negative_text_cond = None,
            positive_image_cond = None,
            negative_image_cond = None,
            concat_cond = None,
            fs = 3,
            progress_tqdm = None,
    ):
        unet_is_training = self.unet.training

        if unet_is_training:
            self.unet.eval()

        device = self.unet.device
        dtype = self.unet.dtype
        dynamic_tsnr_model = SamplerDynamicTSNR(self.unet)

        # Batch

        concat_cond = concat_cond.repeat(batch_size, 1, 1, 1, 1).to(device=device, dtype=dtype)  # b, c, t, h, w
        positive_text_cond = positive_text_cond.repeat(batch_size, 1, 1).to(concat_cond)  # b, f, c
        negative_text_cond = negative_text_cond.repeat(batch_size, 1, 1).to(concat_cond)  # b, f, c
        positive_image_cond = positive_image_cond.repeat(batch_size, 1, 1, 1).to(concat_cond)  # b, t, l, c
        negative_image_cond = negative_image_cond.repeat(batch_size, 1, 1, 1).to(concat_cond)

        if isinstance(fs, torch.Tensor):
            fs = fs.repeat(batch_size, ).to(dtype=torch.long, device=device)  # b
        else:
            fs = torch.tensor([fs] * batch_size, dtype=torch.long, device=device)  # b

        # Initial latents

        latent_shape = concat_cond.shape

        # Feeds

        sampler_kwargs = dict(
            cfg_scale=guidance_scale,
            positive=dict(
                context_text=positive_text_cond,
                context_img=positive_image_cond,
                fs=fs,
                concat_cond=concat_cond
            ),
            negative=dict(
                context_text=negative_text_cond,
                context_img=negative_image_cond,
                fs=fs,
                concat_cond=concat_cond
            )
        )

        # Sample

        results = dynamic_tsnr_model(latent_shape, steps, extra_args=sampler_kwargs, progress_tqdm=progress_tqdm)

        if unet_is_training:
            self.unet.train()

        return results