Implementation of 🦩 Flamingo, state-of-the-art few-shot visual question answering attention net out of Deepmind, in Pytorch

import torch
from flamingo_pytorch import PerceiverResampler

perceive = PerceiverResampler(
    dim = 1024,
    depth = 2,
    dim_head = 64,
    heads = 8,
    num_latents = 64,    # the number of latents to shrink your media sequence to, perceiver style
    num_time_embeds = 4  # say you have 4 images maximum in your dialogue
)

medias = torch.randn(1, 2, 256, 1024) # (batch, time, sequence length, dimension)
perceived = perceive(medias) # (1, 2, 64, 1024) - (batch, time, num latents, dimension)

import torch
from flamingo_pytorch import GatedCrossAttentionBlock

cross_attn = GatedCrossAttentionBlock(
    dim = 1024,
    dim_head = 64,
    heads = 8
)

text = torch.randn(1, 512, 1024)
perceived = torch.randn(1, 2, 64, 1024)

media_locations = torch.randint(0, 2, (1, 512)).bool()

text = cross_attn(
    text,
    perceived,
    media_locations = media_locations
)

from vit_pytorch.vit import ViT
from vit_pytorch.extractor import Extractor

vit = ViT(
    image_size = 256,
    patch_size = 32,
    num_classes = 1000,
    dim = 1024,
    depth = 6,
    heads = 16,
    mlp_dim = 2048,
    dropout = 0.1,
    emb_dropout = 0.1
)

vit = Extractor(vit, return_embeddings_only = True)

# first take your trained image encoder and wrap it in an adapter that returns the image embeddings
# here we use the ViT from the vit-pytorch library

import torch
from flamingo_pytorch import FlamingoPaLM

# a PaLM language model, the 540 billion parameter model from google that shows signs of general intelligence

flamingo_palm = FlamingoPaLM(
    num_tokens = 20000,          # number of tokens
    dim = 1024,                  # dimensions
    depth = 12,                  # depth
    heads = 8,                   # attention heads
    dim_head = 64,               # dimension per attention head
    img_encoder = vit,           # plugin your image encoder (this can be optional if you pass in the image embeddings separately, but probably want to train end to end given the perceiver resampler)
    media_token_id = 3,          # the token id representing the [media] or [image]
    cross_attn_every = 3,        # how often to cross attend
    perceiver_num_latents = 64,  # perceiver number of latents, should be smaller than the sequence length of the image tokens
    perceiver_depth = 2          # perceiver resampler depth
)

# train your PaLM as usual

text = torch.randint(0, 20000, (2, 512))

palm_logits = flamingo_palm(text)

# after much training off the regular PaLM logits
# now you are ready to train Flamingo + PaLM
# by passing in images, it automatically freezes everything but the perceiver and cross attention blocks, as in the paper

dialogue = torch.randint(0, 20000, (4, 512))
images = torch.randn(4, 2, 3, 256, 256)

flamingo_logits = flamingo_palm(dialogue, images)

# do your usual cross entropy loss