Context Length Error

[hamza13-12]

If I reduce context length to anything under 77, I get an error:

def generate_clip_embeddings(captions, clip_model, batch_size=32):
    device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
    clip_model.to(device)

    embeddings = []
    for batch_start in range(0, len(captions), batch_size):
        batch_captions = captions[batch_start:batch_start + batch_size]
        batch_inputs = clip.tokenize(batch_captions, context_length=56, truncate=True).to(device)
        with torch.no_grad():
            batch_outputs = clip_model.encode_text(batch_inputs)
            embeddings.append(batch_outputs.cpu().numpy())

    return np.vstack(embeddings)

   RuntimeError                              Traceback (most recent call last)
Cell In[37], line 1
----> 1 clip_embeddings_train = generate_clip_embeddings(train_captions, clip_model, batch_size=128)
      2 clip_embeddings_val = generate_clip_embeddings(val_captions, clip_model, batch_size=128)

Cell In[36], line 10, in generate_clip_embeddings(captions, clip_model, batch_size)
      8     batch_inputs = clip.tokenize(batch_captions, context_length=56, truncate=True).to(device)
      9     with torch.no_grad():
---> 10         batch_outputs = clip_model.encode_text(batch_inputs)
     11         embeddings.append(batch_outputs.cpu().numpy())
     13 return np.vstack(embeddings)

File /opt/conda/lib/python3.10/site-packages/clip/model.py:346, in CLIP.encode_text(self, text)
    343 def encode_text(self, text):
    344     x = self.token_embedding(text).type(self.dtype)  # [batch_size, n_ctx, d_model]
--> 346     x = x + self.positional_embedding.type(self.dtype)
    347     x = x.permute(1, 0, 2)  # NLD -> LND
    348     x = self.transformer(x)

RuntimeError: The size of tensor a (56) must match the size of tensor b (77) at non-singleton dimension 1

Any ideas on how to resolve this?