# Model input shape doesnt match
**URL:**
**Author:**  [@LukasUni](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2FLukasUni)%5C
**Post date:** [April 12, 2025, 10:22am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Fmodel-input-shape-doesnt-match%2F150085%2F1 "2025-04-12T10:22:19Z")
Hello,
with the following Code
```auto
from diffusers import UNet1DModel
import torch
import torch.nn as nn
class ClassConditionedUned(nn.Module):
def __init__ (self, num_ela=8, class_emb_size=4):
super(). __init__ ()
self.class_emb = nn.Sequential(
nn.Linear(num_ela, 32),
nn.ReLU(),
nn.Linear(32, class_emb_size)
)
self.model = UNet1DModel(
sample_size=512,
in_channels=1+class_emb_size,
out_channels=1,
layers_per_block=1,
block_out_channels = (32, 32, 64),
down_block_types = ("DownBlock1DNoSkip", "DownBlock1D", "AttnDownBlock1D"),
up_block_types = ("AttnUpBlock1D", "UpBlock1D", "UpBlock1DNoSkip"),
)
def forward(self, x, t, ela_vec):
bs, ch, h = x.shape
class_cond = self.class_emb(ela_vec) # Map to embedding dimension
class_cond = class_cond.view(bs, -1, 1).expand(-1, -1, h)
net_input = torch.cat((x, class_cond), 1)
print(net_input.shape)
return self.model(net_input, t).sample
model = ClassConditionedUned()
x = torch.randn(1, 1, 512)
t = torch.randint(0, 1000, (1,))
ela_vec = torch.rand(1, 8) # normalisierte ELA-Vektoren
with torch.no_grad():
out = model(x, t, ela_vec)
```
i get this error:
out = model(x, t, ela\_vec)
^^^^^^^^^^^^^^^^^^^^
RuntimeError: Given groups=1, weight of size [32, 5, 1], expected input[1, 21, 512] to have 5 channels, but got 21 channels instead
What am i doing wrong?
Thank you in advance
---
**Author:**  [@LukasUni](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2FLukasUni)%5C
**Post date:** [April 12, 2025, 11:04am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Fmodel-input-shape-doesnt-match%2F150085%2F2 "2025-04-12T11:04:39Z")
this solvers my issue: [https://github.com/huggingface/diffusers/issues/2967#issuecomment-1500800012](https://github.com/huggingface/diffusers/issues/2967#issuecomment-1500800012)
i had to add 16 to the input channels
---
**Author:**  [@system](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fsystem)%5C
**Post date:** [April 12, 2025, 11:05pm UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Fmodel-input-shape-doesnt-match%2F150085%2F3 "2025-04-12T23:05:32Z")
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