File size: 16,419 Bytes
b5ce381
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
from typing import Dict, List, Optional, Tuple, Union

import math
import torch
import torch.nn as nn
from einops import rearrange, repeat
import lpips
from facenet_pytorch import InceptionResnetV1

from ...modules.autoencoding.lpips.loss.lpips import LPIPS
from ...modules.encoders.modules import GeneralConditioner, ConcatTimestepEmbedderND
from ...util import append_dims, instantiate_from_config, default
from ...modules.autoencoding.temporal_ae import VideoDecoder
from ...data.data_utils import extract_face


def logit_normal_sampler(m, s=1, beta_m=15, sample_num=1000000):
    y_samples = torch.randn(sample_num) * s + m
    x_samples = beta_m * (torch.exp(y_samples) / (1 + torch.exp(y_samples)))
    return x_samples


def mu_t(t, a=5, mu_max=1):
    t = t.to("cpu")
    return 2 * mu_max * t**a - mu_max


def get_sigma_s(t, a, beta_m):
    mu = mu_t(t, a=a)
    sigma_s = logit_normal_sampler(m=mu, sample_num=t.shape[0], beta_m=beta_m)
    return sigma_s


class StandardDiffusionLoss(nn.Module):
    def __init__(
        self,
        sigma_sampler_config: dict,
        loss_weighting_config: dict,
        loss_type: str = "l2",
        offset_noise_level: float = 0.0,
        batch2model_keys: Optional[Union[str, List[str]]] = None,
        lambda_lower: float = 1.0,
        lambda_upper: float = 1.0,
        fix_image_leak: bool = False,
        add_lpips: bool = False,
        weight_pixel: float = 0.0,
        n_frames_pixel: Optional[int] = 1,
        what_pixel_losses: Optional[List[str]] = [],
        disable_first_stage_autocast: bool = True,
    ):
        super().__init__()

        assert loss_type in ["l2", "l1", "lpips"]

        self.sigma_sampler = instantiate_from_config(sigma_sampler_config)
        self.loss_weighting = instantiate_from_config(loss_weighting_config)

        self.loss_type = loss_type
        self.offset_noise_level = offset_noise_level
        self.lambda_lower = lambda_lower
        self.lambda_upper = lambda_upper
        self.add_lpips = add_lpips
        self.weight_pixel = weight_pixel
        self.n_frames_pixel = n_frames_pixel
        self.what_pixel_losses = what_pixel_losses

        self.en_and_decode_n_samples_a_time = 1
        self.disable_first_stage_autocast = disable_first_stage_autocast

        if loss_type == "lpips":
            self.lpips = LPIPS().eval()

        if add_lpips or "lpips" in what_pixel_losses:
            self.lpips = lpips.LPIPS(net="vgg").eval()

        if "id" in what_pixel_losses or "id_mse" in what_pixel_losses:
            self.id_model = InceptionResnetV1(pretrained="vggface2").eval().cuda()
            for param in self.id_model.parameters():
                param.requires_grad = False

        if not batch2model_keys:
            batch2model_keys = []

        if isinstance(batch2model_keys, str):
            batch2model_keys = [batch2model_keys]

        self.batch2model_keys = set(batch2model_keys)

        self.fix_image_leak = fix_image_leak
        if fix_image_leak:
            self.beta_m = 15
            self.a = 5
            self.noise_encoder = ConcatTimestepEmbedderND(256)

    def get_noised_input(
        self, sigmas_bc: torch.Tensor, noise: torch.Tensor, input: torch.Tensor
    ) -> torch.Tensor:
        noised_input = input + noise * sigmas_bc
        return noised_input

    def decode_first_stage(self, z, first_stage_model):
        if len(z.shape) == 5:
            z = rearrange(z, "b c t h w -> (b t) c h w")

        z = 1.0 / 0.18215 * z
        n_samples = default(self.en_and_decode_n_samples_a_time, z.shape[0])

        n_rounds = math.ceil(z.shape[0] / n_samples)
        all_out = []
        with torch.autocast("cuda", enabled=not self.disable_first_stage_autocast):
            for n in range(n_rounds):
                if isinstance(first_stage_model.decoder, VideoDecoder):
                    kwargs = {"timesteps": len(z[n * n_samples : (n + 1) * n_samples])}
                else:
                    kwargs = {}
                out = first_stage_model.decode(
                    z[n * n_samples : (n + 1) * n_samples], **kwargs
                )
                all_out.append(out)
        out = torch.cat(all_out, dim=0)
        # out = rearrange(out, "b c h w -> b h w c")
        torch.cuda.empty_cache()
        return out.clip(-1, 1)

    def forward(
        self,
        network: nn.Module,
        denoiser: nn.Module,
        conditioner: GeneralConditioner,
        input: torch.Tensor,
        batch: Dict,
        first_stage_model: nn.Module = None,
    ) -> torch.Tensor:
        cond = conditioner(batch)
        return self._forward(network, denoiser, cond, input, batch, first_stage_model)

    def _forward(
        self,
        network: nn.Module,
        denoiser: nn.Module,
        cond: Dict,
        input: torch.Tensor,
        batch: Dict,
        first_stage_model: nn.Module = None,
    ) -> Tuple[torch.Tensor, Dict]:
        additional_model_inputs = {
            key: batch[key] for key in self.batch2model_keys.intersection(batch)
        }
        sigmas = self.sigma_sampler(input.shape[0]).to(input)

        noise = torch.randn_like(input)
        if self.offset_noise_level > 0.0:
            offset_shape = (
                (input.shape[0], 1, input.shape[2])
                if self.n_frames is not None
                else (input.shape[0], input.shape[1])
            )
            noise = noise + self.offset_noise_level * append_dims(
                torch.randn(offset_shape, device=input.device),
                input.ndim,
            )
        sigmas_bc = append_dims(sigmas, input.ndim)
        noised_input = self.get_noised_input(sigmas_bc, noise, input)

        if self.fix_image_leak:
            noise_aug_strength = get_sigma_s(sigmas / 700, self.a, self.beta_m)
            noise_aug = append_dims(noise_aug_strength, 4).to(input.device)
            noise = torch.randn_like(noise_aug)
            cond["concat"] = self.get_noised_input(noise_aug, noise, cond["concat"])
            noise_emb = self.noise_encoder(noise_aug_strength).to(input.device)
            # cond["vector"] = noise_emb if "vector" not in cond else torch.cat([cond["vector"], noise_emb], dim=1)
            cond["vector"] = noise_emb
            # print(cond["concat"].shape, cond["vector"].shape, noise.shape, noise_aug.shape, noise_emb.shape)

        model_output = denoiser(
            network, noised_input, sigmas, cond, **additional_model_inputs
        )
        mask = cond.get("masks", None)
        w = append_dims(self.loss_weighting(sigmas), input.ndim)
        return self.get_loss(
            model_output,
            input,
            w,
            sigmas,
            mask,
            first_stage_model,
            batch.get("original_frames", None),
            batch.get("landmarks", None),
        )

    def get_loss(
        self,
        model_output,
        target,
        w,
        sigmas,
        mask=None,
        first_stage_model=None,
        original_frames=None,
        landmarks=None,
    ):
        scaling_w = w[:, 0, 0, 0]

        T = 1
        if target.ndim == 5:
            target = rearrange(target, "b c t h w -> (b t) c h w")
            B = w.shape[0]
            T = target.shape[0] // B
            if w.shape[2] != T:
                w = repeat(w, "b () () () () -> (b t) () () ()", t=T)
            else:
                w = rearrange(w, "b c t h w -> (b t) c h w")

        or_w = w.clone()

        if self.lambda_lower != 1.0:
            weight_lower = torch.ones_like(model_output, device=w.device)
            weight_lower[:, :, model_output.shape[2] // 2 :] *= self.lambda_lower
            w = weight_lower * w

        if self.lambda_upper != 1.0:
            weight_upper = torch.ones_like(model_output, device=w.device)
            weight_upper[:, :, : model_output.shape[2] // 2] *= self.lambda_upper
            w = weight_upper * w
        loss_dict = {}

        if self.loss_type == "l2":
            loss = torch.mean(
                (w * (model_output - target) ** 2).reshape(target.shape[0], -1), 1
            )
        elif self.loss_type == "l1":
            loss = torch.mean(
                (w * (model_output - target).abs()).reshape(target.shape[0], -1), 1
            )
        elif self.loss_type == "lpips":
            loss = self.lpips(model_output, target).reshape(-1)
        else:
            raise NotImplementedError(f"Unknown loss type {self.loss_type}")

        loss_dict[self.loss_type] = loss.clone()
        loss_dict["loss"] = loss

        if self.add_lpips:
            loss_dict["lpips"] = w[:, 0, 0, 0] * self.lpips(
                (model_output[:, :3] * 0.18215).clip(-1, 1),
                (target[:, :3] * 0.18215).clip(-1, 1),
            ).reshape(-1)
            loss_dict["loss"] += loss_dict["lpips"].mean()

        if self.weight_pixel > 0.0:
            assert original_frames is not None
            # Randomly select n_frames_pixel frames
            selected_frames = torch.randperm(T)[: self.n_frames_pixel]
            selected_model_output = rearrange(
                model_output, "(b t) ... -> b t ...", t=T
            )[:, selected_frames]
            selected_model_output = rearrange(
                selected_model_output, "b t ... -> (b t) ..."
            )
            selected_original_frames = original_frames[:, :, selected_frames]
            selected_original_frames = rearrange(
                selected_original_frames, "b c t ... -> (b t) c ..."
            )
            selected_w = rearrange(or_w, "(b t) ... -> b t ...", t=T)[
                :, selected_frames
            ]
            selected_w = rearrange(selected_w, "b t ... -> (b t) ...")
            if selected_w.shape[-1] != selected_original_frames.shape[-1]:
                # Interpolate the weights to match the number of frames
                selected_w = torch.nn.functional.interpolate(
                    selected_w, size=selected_original_frames.shape[-1], mode="nearest"
                )
            decoded_frames = self.decode_first_stage(
                selected_model_output, first_stage_model
            )
            # print(decoded_frames.shape, selected_original_frames.shape, selected_w.shape)

            for loss_name in self.what_pixel_losses:
                if loss_name == "l2":
                    # print(selected_w.shape, decoded_frames.shape, selected_original_frames.shape)
                    loss_pixel = torch.mean(
                        (
                            selected_w
                            * (decoded_frames - selected_original_frames) ** 2
                        ).reshape(selected_original_frames.shape[0], -1),
                        1,
                    )
                    loss_dict["pixel_l2"] = self.weight_pixel * loss_pixel.mean()
                    loss += self.weight_pixel * loss_pixel.mean()
                elif loss_name == "lpips":
                    loss_pixel = (
                        self.lpips(decoded_frames, selected_original_frames).reshape(-1)
                        * scaling_w
                    )
                    loss_dict["pixel_lpips"] = loss_pixel.mean()
                    loss += self.weight_pixel * loss_pixel.mean()
                elif loss_name == "l1":
                    loss_pixel = torch.mean(
                        (
                            selected_w
                            * (decoded_frames - selected_original_frames).abs()
                        ).reshape(selected_original_frames.shape[0], -1),
                        1,
                    )
                    loss_dict["pixel_l1"] = self.weight_pixel * loss_pixel.mean()
                    loss += self.weight_pixel * loss_pixel.mean()
                elif loss_name == "id":
                    landmarks = landmarks[:, selected_frames]
                    cat_id_input = (
                        (
                            torch.cat([decoded_frames, selected_original_frames], dim=0)
                            + 1
                        )
                        / 2
                    ) * 255
                    cat_id_landmarks = torch.cat([landmarks, landmarks], dim=0)
                    cat_id_landmarks = (
                        rearrange(cat_id_landmarks, "b t ... -> (b t) ...")
                        .cpu()
                        .numpy()
                    )
                    try:
                        cropped_decoded_frames = extract_face(
                            rearrange(cat_id_input, "b c h w -> b h w c"),
                            cat_id_landmarks,
                            margin=30,
                            postprocess=True,
                        )
                        # Save first frame to debug
                        n = cat_id_input.shape[0] // 2

                        id_embeddings = self.id_model(
                            rearrange(cropped_decoded_frames, "b h w c -> b c h w")
                        )
                        pred_embeddings, target_embeddings = (
                            id_embeddings[:n],
                            id_embeddings[n:],
                        )
                        # Cosine similarity loss (1 - cos_sim to make it a loss that should be minimized)
                        id_w = scaling_w
                        loss_pixel = (
                            id_w
                            * (
                                1
                                - torch.nn.functional.cosine_similarity(
                                    pred_embeddings, target_embeddings
                                )
                            )
                        ).mean()
                        loss_dict["pixel_id"] = self.weight_pixel * loss_pixel
                        loss += self.weight_pixel * loss_pixel
                    except RuntimeError as e:
                        if "adaptive_avg_pool2d()" in str(e):
                            print(
                                "Warning: Invalid face crop dimensions, skipping ID loss for this batch"
                            )
                            loss_dict["pixel_id"] = torch.tensor(
                                0.0, device=cat_id_input.device
                            )
                            continue
                        else:
                            raise  # Re-raise other RuntimeErrors
                elif loss_name == "id_mse":
                    landmarks = landmarks[:, selected_frames]
                    cat_id_input = (
                        (
                            torch.cat([decoded_frames, selected_original_frames], dim=0)
                            + 1
                        )
                        / 2
                    ) * 255
                    cat_id_landmarks = torch.cat([landmarks, landmarks], dim=0)
                    cat_id_landmarks = (
                        rearrange(cat_id_landmarks, "b t ... -> (b t) ...")
                        .cpu()
                        .numpy()
                    )
                    cropped_decoded_frames = extract_face(
                        rearrange(cat_id_input, "b c h w -> b h w c"),
                        cat_id_landmarks,
                        margin=30,
                        postprocess=True,
                    )
                    # Save first frame to debug
                    n = cat_id_input.shape[0] // 2

                    id_embeddings = self.id_model(
                        rearrange(cropped_decoded_frames, "b h w c -> b c h w")
                    )

                    pred_embeddings, target_embeddings = (
                        id_embeddings[:n],
                        id_embeddings[n:],
                    )
                    # Cosine similarity loss (1 - cos_sim to make it a loss that should be minimized)
                    id_w = append_dims(
                        self.loss_weighting(sigmas), pred_embeddings.ndim
                    )
                    loss_pixel = (
                        id_w * ((pred_embeddings - target_embeddings) ** 2)
                    ).mean()
                    loss_dict["pixel_id_mse"] = self.weight_pixel * loss_pixel
                    loss += self.weight_pixel * loss_pixel

                else:
                    raise NotImplementedError(f"Unknown pixel loss type {loss_name}")

        return loss_dict