File size: 6,631 Bytes
0d95f10
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import folder_paths
import comfy.sd
import comfy.model_sampling
import torch

class LCM(comfy.model_sampling.EPS):
    def calculate_denoised(self, sigma, model_output, model_input):
        timestep = self.timestep(sigma).view(sigma.shape[:1] + (1,) * (model_output.ndim - 1))
        sigma = sigma.view(sigma.shape[:1] + (1,) * (model_output.ndim - 1))
        x0 = model_input - model_output * sigma

        sigma_data = 0.5
        scaled_timestep = timestep * 10.0 #timestep_scaling

        c_skip = sigma_data**2 / (scaled_timestep**2 + sigma_data**2)
        c_out = scaled_timestep / (scaled_timestep**2 + sigma_data**2) ** 0.5

        return c_out * x0 + c_skip * model_input

class ModelSamplingDiscreteDistilled(comfy.model_sampling.ModelSamplingDiscrete):
    original_timesteps = 50

    def __init__(self, model_config=None):
        super().__init__(model_config)

        self.skip_steps = self.num_timesteps // self.original_timesteps

        sigmas_valid = torch.zeros((self.original_timesteps), dtype=torch.float32)
        for x in range(self.original_timesteps):
            sigmas_valid[self.original_timesteps - 1 - x] = self.sigmas[self.num_timesteps - 1 - x * self.skip_steps]

        self.set_sigmas(sigmas_valid)

    def timestep(self, sigma):
        log_sigma = sigma.log()
        dists = log_sigma.to(self.log_sigmas.device) - self.log_sigmas[:, None]
        return (dists.abs().argmin(dim=0).view(sigma.shape) * self.skip_steps + (self.skip_steps - 1)).to(sigma.device)

    def sigma(self, timestep):
        t = torch.clamp(((timestep.float().to(self.log_sigmas.device) - (self.skip_steps - 1)) / self.skip_steps).float(), min=0, max=(len(self.sigmas) - 1))
        low_idx = t.floor().long()
        high_idx = t.ceil().long()
        w = t.frac()
        log_sigma = (1 - w) * self.log_sigmas[low_idx] + w * self.log_sigmas[high_idx]
        return log_sigma.exp().to(timestep.device)


def rescale_zero_terminal_snr_sigmas(sigmas):
    alphas_cumprod = 1 / ((sigmas * sigmas) + 1)
    alphas_bar_sqrt = alphas_cumprod.sqrt()

    # Store old values.
    alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
    alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()

    # Shift so the last timestep is zero.
    alphas_bar_sqrt -= (alphas_bar_sqrt_T)

    # Scale so the first timestep is back to the old value.
    alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)

    # Convert alphas_bar_sqrt to betas
    alphas_bar = alphas_bar_sqrt**2  # Revert sqrt
    alphas_bar[-1] = 4.8973451890853435e-08
    return ((1 - alphas_bar) / alphas_bar) ** 0.5

class ModelSamplingDiscrete:
    @classmethod
    def INPUT_TYPES(s):
        return {"required": { "model": ("MODEL",),
                              "sampling": (["eps", "v_prediction", "lcm"],),
                              "zsnr": ("BOOLEAN", {"default": False}),
                              }}

    RETURN_TYPES = ("MODEL",)
    FUNCTION = "patch"

    CATEGORY = "advanced/model"

    def patch(self, model, sampling, zsnr):
        m = model.clone()

        sampling_base = comfy.model_sampling.ModelSamplingDiscrete
        if sampling == "eps":
            sampling_type = comfy.model_sampling.EPS
        elif sampling == "v_prediction":
            sampling_type = comfy.model_sampling.V_PREDICTION
        elif sampling == "lcm":
            sampling_type = LCM
            sampling_base = ModelSamplingDiscreteDistilled

        class ModelSamplingAdvanced(sampling_base, sampling_type):
            pass

        model_sampling = ModelSamplingAdvanced(model.model.model_config)
        if zsnr:
            model_sampling.set_sigmas(rescale_zero_terminal_snr_sigmas(model_sampling.sigmas))

        m.add_object_patch("model_sampling", model_sampling)
        return (m, )

class ModelSamplingContinuousEDM:
    @classmethod
    def INPUT_TYPES(s):
        return {"required": { "model": ("MODEL",),
                              "sampling": (["v_prediction", "eps"],),
                              "sigma_max": ("FLOAT", {"default": 120.0, "min": 0.0, "max": 1000.0, "step":0.001, "round": False}),
                              "sigma_min": ("FLOAT", {"default": 0.002, "min": 0.0, "max": 1000.0, "step":0.001, "round": False}),
                              }}

    RETURN_TYPES = ("MODEL",)
    FUNCTION = "patch"

    CATEGORY = "advanced/model"

    def patch(self, model, sampling, sigma_max, sigma_min):
        m = model.clone()

        if sampling == "eps":
            sampling_type = comfy.model_sampling.EPS
        elif sampling == "v_prediction":
            sampling_type = comfy.model_sampling.V_PREDICTION

        class ModelSamplingAdvanced(comfy.model_sampling.ModelSamplingContinuousEDM, sampling_type):
            pass

        model_sampling = ModelSamplingAdvanced(model.model.model_config)
        model_sampling.set_sigma_range(sigma_min, sigma_max)
        m.add_object_patch("model_sampling", model_sampling)
        return (m, )

class RescaleCFG:
    @classmethod
    def INPUT_TYPES(s):
        return {"required": { "model": ("MODEL",),
                              "multiplier": ("FLOAT", {"default": 0.7, "min": 0.0, "max": 1.0, "step": 0.01}),
                              }}
    RETURN_TYPES = ("MODEL",)
    FUNCTION = "patch"

    CATEGORY = "advanced/model"

    def patch(self, model, multiplier):
        def rescale_cfg(args):
            cond = args["cond"]
            uncond = args["uncond"]
            cond_scale = args["cond_scale"]
            sigma = args["sigma"]
            sigma = sigma.view(sigma.shape[:1] + (1,) * (cond.ndim - 1))
            x_orig = args["input"]

            #rescale cfg has to be done on v-pred model output
            x = x_orig / (sigma * sigma + 1.0)
            cond = ((x - (x_orig - cond)) * (sigma ** 2 + 1.0) ** 0.5) / (sigma)
            uncond = ((x - (x_orig - uncond)) * (sigma ** 2 + 1.0) ** 0.5) / (sigma)

            #rescalecfg
            x_cfg = uncond + cond_scale * (cond - uncond)
            ro_pos = torch.std(cond, dim=(1,2,3), keepdim=True)
            ro_cfg = torch.std(x_cfg, dim=(1,2,3), keepdim=True)

            x_rescaled = x_cfg * (ro_pos / ro_cfg)
            x_final = multiplier * x_rescaled + (1.0 - multiplier) * x_cfg

            return x_orig - (x - x_final * sigma / (sigma * sigma + 1.0) ** 0.5)

        m = model.clone()
        m.set_model_sampler_cfg_function(rescale_cfg)
        return (m, )

NODE_CLASS_MAPPINGS = {
    "ModelSamplingDiscrete": ModelSamplingDiscrete,
    "ModelSamplingContinuousEDM": ModelSamplingContinuousEDM,
    "RescaleCFG": RescaleCFG,
}