def interpolate_pos_embed(pos_embed_old, pos_embed_new, num_patches_new):
    """
    Args:
        pos_embed_old: (1, L_old, d), pre-trained
        pos_embed_new: (1, L_new, d), newly initialized, to be replaced by interpolated weights
        num_patches_new:
    """
    # interpolate position embedding
    embedding_size = pos_embed_old.shape[-1]
    num_extra_tokens = pos_embed_new.shape[-2] - num_patches_new
    # height (== width) for the checkpoint position embedding
    orig_size = int((pos_embed_old.shape[-2] - num_extra_tokens) ** 0.5)
    # height (== width) for the new position embedding
    new_size = int(num_patches_new ** 0.5)

    if orig_size != new_size:
        # class_token and dist_token are kept unchanged
        # the extra tokens seems always at the beginning of the position embedding
        extra_tokens = pos_embed_old[:, :num_extra_tokens]
        # only the position tokens are interpolated
        pos_tokens = pos_embed_old[:, num_extra_tokens:]
        pos_tokens = pos_tokens.reshape(
            -1, orig_size, orig_size, embedding_size
        ).permute(0, 3, 1, 2)
        pos_tokens = torch.nn.functional.interpolate(
            pos_tokens, size=(new_size, new_size), mode="bicubic", align_corners=False
        )
        pos_tokens = pos_tokens.permute(0, 2, 3, 1).flatten(1, 2)
        interpolated_pos_embed = torch.cat((extra_tokens, pos_tokens), dim=1)
        logger.info(f"reshape position embedding from {orig_size}**2 to {new_size}**2")
        return interpolated_pos_embed
    else:
        return pos_embed_old
Args:
pos_embed_old: (1, L_old, d), pre-trained
pos_embed_new: (1, L_new, d), newly initialized, to be replaced by interpolated weights
num_patches_new:
videomamba/video_mm/models/utils.py