DenseAV/denseav/featurizers/CAVMAE.py

import random

import numpy as np
import timm
import torch
import torch.nn as nn
import torch.nn.functional as F
import torchaudio
import torchvision.transforms as T
from PIL import Image
from timm.models.layers import to_2tuple, DropPath
from timm.models.vision_transformer import Mlp, PatchEmbed, Block
import os


class Attention(nn.Module):
    def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None, attn_drop=0., proj_drop=0.):
        super().__init__()
        self.num_heads = num_heads
        head_dim = dim // num_heads
        # NOTE scale factor was wrong in my original version, can set manually to be compat with prev weights
        self.scale = qk_scale or head_dim ** -0.5

        self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
        self.attn_drop = nn.Dropout(attn_drop)
        self.proj = nn.Linear(dim, dim)
        self.proj_drop = nn.Dropout(proj_drop)

    def forward(self, x):
        B, N, C = x.shape
        qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4)
        q, k, v = qkv[0], qkv[1], qkv[2]  # make torchscript happy (cannot use tensor as tuple)

        attn = (q @ k.transpose(-2, -1)) * self.scale
        attn = attn.softmax(dim=-1)
        attn = self.attn_drop(attn)

        x = (attn @ v).transpose(1, 2).reshape(B, N, C)
        x = self.proj(x)
        x = self.proj_drop(x)
        return x


def get_2d_sincos_pos_embed(embed_dim, grid_h_size, grid_w_size, cls_token=False):
    """

    grid_size: int of the grid height and width

    return:

    pos_embed: [grid_size*grid_size, embed_dim] or [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)

    """
    grid_h = np.arange(grid_h_size, dtype=float)
    grid_w = np.arange(grid_w_size, dtype=float)
    grid = np.meshgrid(grid_w, grid_h)  # here w goes first
    grid = np.stack(grid, axis=0)

    grid = grid.reshape([2, 1, grid_w_size, grid_h_size])
    pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
    if cls_token:
        pos_embed = np.concatenate([np.zeros([1, embed_dim]), pos_embed], axis=0)
    return pos_embed


def get_2d_sincos_pos_embed_from_grid(embed_dim, grid):
    assert embed_dim % 2 == 0

    # use half of dimensions to encode grid_h
    emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[0])  # (H*W, D/2)
    emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[1])  # (H*W, D/2)

    emb = np.concatenate([emb_h, emb_w], axis=1)  # (H*W, D)
    return emb


def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
    """

    embed_dim: output dimension for each position

    pos: a list of positions to be encoded: size (M,)

    out: (M, D)

    """
    assert embed_dim % 2 == 0
    omega = np.arange(embed_dim // 2, dtype=float)
    omega /= embed_dim / 2.
    omega = 1. / 10000 ** omega  # (D/2,)

    pos = pos.reshape(-1)  # (M,)
    out = np.einsum('m,d->md', pos, omega)  # (M, D/2), outer product

    emb_sin = np.sin(out)  # (M, D/2)
    emb_cos = np.cos(out)  # (M, D/2)

    emb = np.concatenate([emb_sin, emb_cos], axis=1)  # (M, D)
    return emb


# --------------------------------------------------------
# Interpolate position embeddings for high-resolution
# References:
# DeiT: https://github.com/facebookresearch/deit
# --------------------------------------------------------
def interpolate_pos_embed(model, checkpoint_model):
    if 'pos_embed' in checkpoint_model:
        pos_embed_checkpoint = checkpoint_model['pos_embed']
        embedding_size = pos_embed_checkpoint.shape[-1]
        num_patches = model.patch_embed.num_patches
        num_extra_tokens = model.pos_embed.shape[-2] - num_patches
        # height (== width) for the checkpoint position embedding
        orig_size = int((pos_embed_checkpoint.shape[-2] - num_extra_tokens) ** 0.5)
        # height (== width) for the new position embedding
        new_size = int(num_patches ** 0.5)
        # class_token and dist_token are kept unchanged
        if orig_size != new_size:
            print("Position interpolate from %dx%d to %dx%d" % (orig_size, orig_size, new_size, new_size))
            extra_tokens = pos_embed_checkpoint[:, :num_extra_tokens]
            # only the position tokens are interpolated
            pos_tokens = pos_embed_checkpoint[:, 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)
            new_pos_embed = torch.cat((extra_tokens, pos_tokens), dim=1)
            checkpoint_model['pos_embed'] = new_pos_embed


class PatchEmbed(nn.Module):
    def __init__(self, img_size=224, patch_size=16, in_chans=3, embed_dim=768):
        super().__init__()

        img_size = to_2tuple(img_size)
        patch_size = to_2tuple(patch_size)
        num_patches = (img_size[1] // patch_size[1]) * (img_size[0] // patch_size[0])
        self.img_size = img_size
        self.patch_size = patch_size
        self.num_patches = num_patches

        self.proj = nn.Conv2d(in_chans, embed_dim, kernel_size=patch_size, stride=patch_size)

    def forward(self, x):
        x = self.proj(x).flatten(2).transpose(1, 2)
        return x


class Block(nn.Module):
    def __init__(self, dim, num_heads, mlp_ratio=4., qkv_bias=False, qk_scale=None, drop=0., attn_drop=0.,

                 drop_path=0., act_layer=nn.GELU, norm_layer=nn.LayerNorm):
        super().__init__()
        self.norm1 = norm_layer(dim)
        self.norm1_a = norm_layer(dim)
        self.norm1_v = norm_layer(dim)
        self.attn = Attention(
            dim, num_heads=num_heads, qkv_bias=qkv_bias, qk_scale=qk_scale, attn_drop=attn_drop, proj_drop=drop)
        # NOTE: drop path for stochastic depth, we shall see if this is better than dropout here
        self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
        self.norm2 = norm_layer(dim)
        self.norm2_a = norm_layer(dim)
        self.norm2_v = norm_layer(dim)
        mlp_hidden_dim = int(dim * mlp_ratio)
        self.mlp = Mlp(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop)

    def forward(self, x, modality=None):
        if modality == None:
            x = x + self.drop_path(self.attn(self.norm1(x)))
            x = x + self.drop_path(self.mlp(self.norm2(x)))
        elif modality == 'a':
            x = x + self.drop_path(self.attn(self.norm1_a(x)))
            x = x + self.drop_path(self.mlp(self.norm2_a(x)))
        elif modality == 'v':
            x = x + self.drop_path(self.attn(self.norm1_v(x)))
            x = x + self.drop_path(self.mlp(self.norm2_v(x)))
        return x


# our main proposed model, for pretraining only, for finetuning, use CAVMAEFT class
class CAVMAE(nn.Module):
    """ CAV-MAE Model

    """

    def __init__(self, img_size=224, audio_length=1024, patch_size=16, in_chans=3,

                 embed_dim=768, modality_specific_depth=11, num_heads=12,

                 decoder_embed_dim=512, decoder_depth=8, decoder_num_heads=16,

                 mlp_ratio=4., norm_layer=nn.LayerNorm, norm_pix_loss=False, tr_pos=False):
        super().__init__()
        print('A CAV-MAE Model')
        print('Use norm_pix_loss: ', norm_pix_loss)
        print('Learnable Positional Embedding: ', tr_pos)

        # the encoder part
        # overide the timm package
        timm.models.vision_transformer.PatchEmbed = PatchEmbed
        timm.models.vision_transformer.Block = Block

        self.patch_embed_a = PatchEmbed(img_size, patch_size, 1, embed_dim)
        self.patch_embed_v = PatchEmbed(img_size, patch_size, in_chans, embed_dim)

        self.patch_embed_a.num_patches = int(audio_length * 128 / 256)
        print('Number of Audio Patches: {:d}, Visual Patches: {:d}'.format(self.patch_embed_a.num_patches,
                                                                           self.patch_embed_v.num_patches))

        self.modality_a = nn.Parameter(torch.zeros(1, 1, embed_dim))
        self.modality_v = nn.Parameter(torch.zeros(1, 1, embed_dim))

        self.pos_embed_a = nn.Parameter(torch.zeros(1, self.patch_embed_a.num_patches, embed_dim),
                                        requires_grad=tr_pos)  # fixed sin-cos embedding
        self.pos_embed_v = nn.Parameter(torch.zeros(1, self.patch_embed_v.num_patches, embed_dim),
                                        requires_grad=tr_pos)  # fixed sin-cos embedding

        # audio-branch
        self.blocks_a = nn.ModuleList(
            [Block(embed_dim, num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer) for i in
             range(modality_specific_depth)])
        # visual-branch
        self.blocks_v = nn.ModuleList(
            [Block(embed_dim, num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer) for i in
             range(modality_specific_depth)])
        # unified branch
        self.blocks_u = nn.ModuleList(
            [Block(embed_dim, num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer) for i in
             range(12 - modality_specific_depth)])

        # independent normalization layer for audio, visual, and audio-visual
        self.norm_a, self.norm_v, self.norm = norm_layer(embed_dim), norm_layer(embed_dim), norm_layer(embed_dim)

        # the decoder part
        # Project to lower dimension for the decoder
        self.decoder_embed = nn.Linear(embed_dim, decoder_embed_dim, bias=True)

        # token used for masking
        self.mask_token = nn.Parameter(torch.zeros(1, 1, decoder_embed_dim))

        self.decoder_modality_a = nn.Parameter(torch.zeros(1, 1, decoder_embed_dim))
        self.decoder_modality_v = nn.Parameter(torch.zeros(1, 1, decoder_embed_dim))

        self.decoder_pos_embed_a = nn.Parameter(torch.zeros(1, self.patch_embed_a.num_patches, decoder_embed_dim),
                                                requires_grad=tr_pos)  # fixed sin-cos embedding
        self.decoder_pos_embed_v = nn.Parameter(torch.zeros(1, self.patch_embed_v.num_patches, decoder_embed_dim),
                                                requires_grad=tr_pos)  # fixed sin-cos embedding

        self.decoder_blocks = nn.ModuleList(
            [Block(decoder_embed_dim, decoder_num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer)
             for i in range(decoder_depth)])

        self.decoder_norm = norm_layer(decoder_embed_dim)

        # project channel is different for two modality, use two projection head
        self.decoder_pred_a = nn.Linear(decoder_embed_dim, patch_size ** 2 * 1, bias=True)  # decoder to patch
        self.decoder_pred_v = nn.Linear(decoder_embed_dim, patch_size ** 2 * in_chans, bias=True)  # decoder to patch

        self.norm_pix_loss = norm_pix_loss

        self.initialize_weights()

        print('Audio Positional Embedding Shape:', self.pos_embed_a.shape)
        print('Visual Positional Embedding Shape:', self.pos_embed_v.shape)

    def initialize_weights(self):
        # initialize (and freeze) pos_embed by sin-cos embedding, opt the cls token, add by myself
        pos_embed_a = get_2d_sincos_pos_embed(self.pos_embed_a.shape[-1], 8, int(self.patch_embed_a.num_patches / 8),
                                              cls_token=False)
        self.pos_embed_a.data.copy_(torch.from_numpy(pos_embed_a).float().unsqueeze(0))

        pos_embed_v = get_2d_sincos_pos_embed(self.pos_embed_v.shape[-1], int(self.patch_embed_v.num_patches ** .5),
                                              int(self.patch_embed_v.num_patches ** .5), cls_token=False)
        self.pos_embed_v.data.copy_(torch.from_numpy(pos_embed_v).float().unsqueeze(0))

        decoder_pos_embed_a = get_2d_sincos_pos_embed(self.decoder_pos_embed_a.shape[-1], 8,
                                                      int(self.patch_embed_a.num_patches / 8), cls_token=False)
        self.decoder_pos_embed_a.data.copy_(torch.from_numpy(decoder_pos_embed_a).float().unsqueeze(0))

        decoder_pos_embed_v = get_2d_sincos_pos_embed(self.decoder_pos_embed_v.shape[-1],
                                                      int(self.patch_embed_v.num_patches ** .5),
                                                      int(self.patch_embed_v.num_patches ** .5), cls_token=False)
        self.decoder_pos_embed_v.data.copy_(torch.from_numpy(decoder_pos_embed_v).float().unsqueeze(0))

        # initialize patch_embed like nn.Linear (instead of nn.Conv2d)
        w = self.patch_embed_a.proj.weight.data
        torch.nn.init.xavier_uniform_(w.view([w.shape[0], -1]))
        w = self.patch_embed_v.proj.weight.data
        torch.nn.init.xavier_uniform_(w.view([w.shape[0], -1]))

        # timm's trunc_normal_(std=.02) is effectively normal_(std=0.02) as cutoff is too big (2.)
        torch.nn.init.normal_(self.modality_a, std=.02)
        torch.nn.init.normal_(self.modality_v, std=.02)
        torch.nn.init.normal_(self.decoder_modality_a, std=.02)
        torch.nn.init.normal_(self.decoder_modality_v, std=.02)
        torch.nn.init.normal_(self.mask_token, std=.02)

        # initialize nn.Linear and nn.LayerNorm
        self.apply(self._init_weights)

    def _init_weights(self, m):
        if isinstance(m, nn.Linear):
            # we use xavier_uniform following official JAX ViT:
            torch.nn.init.xavier_uniform_(m.weight)
            if isinstance(m, nn.Linear) and m.bias is not None:
                nn.init.constant_(m.bias, 0)
        elif isinstance(m, nn.LayerNorm):
            nn.init.constant_(m.bias, 0)
            nn.init.constant_(m.weight, 1.0)

    def patchify(self, imgs, c, h, w, p=16):
        """

        imgs: (N, 3, H, W)

        x: (N, L, patch_size**2 *3)

        """
        x = imgs.reshape(shape=(imgs.shape[0], c, h, p, w, p))
        x = torch.einsum('nchpwq->nhwpqc', x)
        x = x.reshape(shape=(imgs.shape[0], h * w, p ** 2 * c))
        return x

    def unpatchify(self, x, c, h, w, p=16):
        """

        x: (N, L, patch_size**2 *3)

        imgs: (N, 3, H, W)

        """
        assert h * w == x.shape[1]

        x = x.reshape(shape=(x.shape[0], h, w, p, p, c))
        x = torch.einsum('nhwpqc->nchpwq', x)
        imgs = x.reshape(shape=(x.shape[0], c, h * p, w * p))
        return imgs

    def random_masking_unstructured(self, x, mask_ratio):
        """

        Perform per-sample random masking by per-sample shuffling.

        Per-sample shuffling is done by argsort random noise.

        x: [N, L, D], sequence

        """
        N, L, D = x.shape  # batch, length, dim
        len_keep = int(L * (1 - mask_ratio))

        noise = torch.rand(N, L, device=x.device)  # noise in [0, 1]

        # sort noise for each sample
        ids_shuffle = torch.argsort(noise, dim=1)  # ascend: small is keep, large is remove
        ids_restore = torch.argsort(ids_shuffle, dim=1)

        # keep the first subset
        ids_keep = ids_shuffle[:, :len_keep]
        x_masked = torch.gather(x, dim=1, index=ids_keep.unsqueeze(-1).repeat(1, 1, D))

        # generate the binary mask: 0 is keep, 1 is remove
        mask = torch.ones([N, L], device=x.device)
        mask[:, :len_keep] = 0
        # unshuffle to get the binary mask
        mask = torch.gather(mask, dim=1, index=ids_restore)

        return x_masked, mask, ids_restore

    def random_masking_structured(self, x, mask_ratio, t=64, f=8, mode='time'):
        """

        Perform per-sample random masking by per-sample shuffling.

        Per-sample shuffling is done by argsort random noise.

        x: [N, L, D], sequence

        """
        N, L, D = x.shape  # batch, length, dim
        len_keep = int(L * (1 - mask_ratio))

        noise = torch.rand(N, L, device=x.device)  # noise in [0, 1]
        assert L == f * t
        noise = noise.reshape(N, f, t)  # the audio patch is in shape [f,t], not [t,f]
        if mode == 'time':
            for i in range(N):
                mask_t_list = random.sample(range(t), int(t * mask_ratio))
                for k in mask_t_list:
                    noise[i, :, k] = 1.1  # large value will be removed
        elif mode == 'freq':
            for i in range(N):
                mask_f_list = random.sample(range(f), int(f * mask_ratio))
                for k in mask_f_list:
                    noise[i, k, :] = 1.1  # large value will be removed
        elif mode == 'tf':
            for i in range(N):
                mask_t_list = random.sample(range(t), int(t * mask_ratio * 0.7))
                for k in mask_t_list:
                    noise[i, :, k] = 1.1  # large value will be removed
            for i in range(N):
                mask_f_list = random.sample(range(f), int(f * mask_ratio * 0.7))
                for k in mask_f_list:
                    noise[i, k, :] = 1.1  # large value will be removed
        noise = noise.reshape(N, L)

        # sort noise for each sample, only need to manuplate these two ids_shuffle, ids_restore
        ids_shuffle = torch.argsort(noise, dim=1)  # ascend: small is keep, large is remove
        ids_restore = torch.argsort(ids_shuffle, dim=1)

        # keep the first subset
        ids_keep = ids_shuffle[:, :len_keep]
        x_masked = torch.gather(x, dim=1, index=ids_keep.unsqueeze(-1).repeat(1, 1, D))

        # generate the binary mask: 0 is keep, 1 is remove
        mask = torch.ones([N, L], device=x.device)
        mask[:, :len_keep] = 0
        # unshuffle to get the binary mask
        mask = torch.gather(mask, dim=1, index=ids_restore)

        return x_masked, mask, ids_restore

    def forward_encoder(self, a, v, mask_ratio_a, mask_ratio_v, mask_mode='unstructured'):
        # embed patches
        a = a.unsqueeze(1)
        a = a.transpose(2, 3)
        a = self.patch_embed_a(a)
        a = a + self.pos_embed_a
        a = a + self.modality_a

        v = self.patch_embed_v(v)
        v = v + self.pos_embed_v
        v = v + self.modality_v

        # by default, we always use unstructured masking
        if mask_mode == 'unstructured':
            a, mask_a, ids_restore_a = self.random_masking_unstructured(a, mask_ratio_a)
        # in ablation study, we tried time/freq/tf masking. mode in ['freq', 'time', 'tf']
        else:
            a, mask_a, ids_restore_a = self.random_masking_structured(a, mask_ratio_a, t=64, f=8, mode=mask_mode)

        # visual branch always use unstructured masking
        v, mask_v, ids_restore_v = self.random_masking_unstructured(v, mask_ratio_v)

        # audio and visual stream, independent blocks
        for blk in self.blocks_a:
            a = blk(a)

        for blk in self.blocks_v:
            v = blk(v)

        x = torch.cat((a, v), dim=1)

        # unified stream, shared blocks_u, but independent normalization layers
        for blk in self.blocks_u:
            x = blk(x)
        x = self.norm(x)

        for blk in self.blocks_u:
            ca = blk(a, 'a')
        ca = self.norm_a(ca)

        for blk in self.blocks_u:
            cv = blk(v, 'v')
        cv = self.norm_v(cv)

        return x, mask_a, ids_restore_a, mask_v, ids_restore_v, ca, cv

    def forward_decoder(self, x, mask_a, ids_restore_a, mask_v, ids_restore_v):

        x = self.decoder_embed(x)

        # append mask tokens to sequence
        # mask_tokens_a in shape [B, #a_mask_token, mask_token_dim], get the number of masked samples from mask_a[0], which is the first example of the batch, all samples should have same number of masked tokens
        mask_tokens_a = self.mask_token.repeat(x.shape[0], int(mask_a[0].sum()), 1)
        a_ = torch.cat([x[:, :self.patch_embed_a.num_patches - int(mask_a[0].sum()), :], mask_tokens_a],
                       dim=1)  # no cls token
        a_ = torch.gather(a_, dim=1, index=ids_restore_a.unsqueeze(-1).repeat(1, 1, x.shape[2]))  # unshuffle

        # similar for the visual modality
        mask_tokens_v = self.mask_token.repeat(x.shape[0], int(mask_v[0].sum()), 1)
        v_ = torch.cat([x[:, self.patch_embed_a.num_patches - int(mask_a[0].sum()):, :], mask_tokens_v],
                       dim=1)  # no cls token
        v_ = torch.gather(v_, dim=1, index=ids_restore_v.unsqueeze(-1).repeat(1, 1, x.shape[2]))  # unshuffle

        # concatenate audio and visual tokens
        x = torch.cat([a_, v_], dim=1)

        decoder_pos_embed = torch.cat([self.decoder_pos_embed_a, self.decoder_pos_embed_v], dim=1)
        x = x + decoder_pos_embed

        # add modality indication tokens
        x[:, 0:self.patch_embed_a.num_patches, :] = x[:, 0:self.patch_embed_a.num_patches, :] + self.decoder_modality_a
        x[:, self.patch_embed_a.num_patches:, :] = x[:, self.patch_embed_a.num_patches:, :] + self.decoder_modality_v

        # apply Transformer blocks
        for blk in self.decoder_blocks:
            x = blk(x)
        x = self.decoder_norm(x)

        # predictor projection
        x_a = self.decoder_pred_a(x[:, :self.patch_embed_a.num_patches, :])
        x_v = self.decoder_pred_v(x[:, self.patch_embed_a.num_patches:, :])

        # return audio and video tokens
        return x_a, x_v

    def forward_contrastive(self, audio_rep, video_rep, bidirect_contrast=False):
        # calculate nce loss for mean-visual representation and mean-audio representation

        audio_rep = torch.nn.functional.normalize(audio_rep, dim=-1)
        video_rep = torch.nn.functional.normalize(video_rep, dim=-1)

        total = torch.mm(audio_rep, torch.transpose(video_rep, 0, 1)) / 0.05

        # by default we use single directional
        if bidirect_contrast == False:
            nce = -torch.mean(torch.diag(torch.nn.functional.log_softmax(total, dim=0)))
            c_acc = torch.sum(torch.eq(torch.argmax(torch.nn.functional.softmax(total, dim=0), dim=0),
                                       torch.arange(0, total.shape[0], device=audio_rep.device))) / total.shape[0]
            return nce, c_acc
        else:
            nce_1 = -torch.mean(torch.diag(torch.nn.functional.log_softmax(total, dim=0)))
            nce_2 = -torch.mean(torch.diag(torch.nn.functional.log_softmax(total.t(), dim=0)))
            c_acc_1 = torch.sum(torch.eq(torch.argmax(torch.nn.functional.softmax(total, dim=0), dim=0),
                                         torch.arange(0, total.shape[0], device=audio_rep.device))) / total.shape[0]
            c_acc_2 = torch.sum(torch.eq(torch.argmax(torch.nn.functional.softmax(total.t(), dim=0), dim=0),
                                         torch.arange(0, total.shape[0], device=audio_rep.device))) / total.shape[0]
            nce = (nce_1 + nce_2) / 2
            c_acc = (c_acc_1 + c_acc_2) / 2
            return nce, c_acc

    def forward_mae_loss(self, input, pred, mask, modality):
        if modality == 'a':
            # for audio, need to adjust the shape
            input = input.unsqueeze(1)
            input = input.transpose(2, 3)
            target = self.patchify(input, 1, int(input.shape[2] / self.patch_embed_a.patch_size[0]),
                                   int(input.shape[3] / self.patch_embed_a.patch_size[1]), 16)
        elif modality == 'v':
            target = self.patchify(input, 3, int(input.shape[2] / self.patch_embed_v.patch_size[0]),
                                   int(input.shape[3] / self.patch_embed_v.patch_size[1]), 16)

        # patch-wise normalization might minorly improve the classification performance, but will make the model lose inpainting function
        if self.norm_pix_loss:
            mean = target.mean(dim=-1, keepdim=True)
            var = target.var(dim=-1, keepdim=True)
            target = (target - mean) / (var + 1.e-6) ** .5

        loss = (pred - target) ** 2
        loss = loss.mean(dim=-1)  # [N, L], mean loss per patch

        loss = (loss * mask).sum() / mask.sum()  # mean loss on removed patches
        return loss

    def forward(self, audio, imgs, mask_ratio_a=0.75, mask_ratio_v=0.75, mae_loss_weight=1., contrast_loss_weight=0.01,

                mask_mode='unstructured'):
        # latent is used for reconstruction (mae), latent_c_{a,v} are used for contrastive learning
        latent, mask_a, ids_restore_a, mask_v, ids_restore_v, latent_c_a, latent_c_v = self.forward_encoder(audio, imgs,
                                                                                                            mask_ratio_a,
                                                                                                            mask_ratio_v,
                                                                                                            mask_mode=mask_mode)
        # if mae loss is used
        if mae_loss_weight != 0:
            pred_a, pred_v = self.forward_decoder(latent, mask_a, ids_restore_a, mask_v, ids_restore_v)
            loss_mae_a = self.forward_mae_loss(audio, pred_a, mask_a, 'a')
            loss_mae_v = self.forward_mae_loss(imgs, pred_v, mask_v, 'v')
            loss_mae = mae_loss_weight * (loss_mae_a + loss_mae_v)
        else:
            loss_mae_a, loss_mae_v, loss_mae = torch.tensor(0.0, device=audio.device), torch.tensor(0.0,
                                                                                                    device=audio.device), torch.tensor(
                0.0, device=audio.device)

        # if contrastive loss is used
        if contrast_loss_weight != 0:
            # note this is single directional
            loss_c, c_acc = self.forward_contrastive(latent_c_a.mean(dim=1), latent_c_v.mean(dim=1))
            loss_c = contrast_loss_weight * loss_c
        else:
            loss_c, c_acc = torch.tensor(0.0, device=audio.device), torch.tensor(0.0, device=audio.device)

        loss = loss_mae + loss_c

        return loss, loss_mae, loss_mae_a, loss_mae_v, loss_c, mask_a, mask_v, c_acc

    # used only for inpainting, ignore if inpainting is not of interest
    def forward_inpaint(self, audio, imgs, mask_ratio_a=0.75, mask_ratio_v=0.75, mask_mode='unstructured'):
        latent, mask_a, ids_restore_a, mask_v, ids_restore_v, latent_c_a, latent_c_v = self.forward_encoder(audio, imgs,
                                                                                                            mask_ratio_a,
                                                                                                            mask_ratio_v,
                                                                                                            mask_mode=mask_mode)
        pred_a, pred_v = self.forward_decoder(latent, mask_a, ids_restore_a, mask_v, ids_restore_v)  # [N, L, p*p*3]
        loss_pixel_a = self.forward_mae_loss(audio, pred_a, mask_a, 'a')
        loss_pixel_v = self.forward_mae_loss(imgs, pred_v, mask_v, 'v')
        return pred_a, pred_v, mask_a, mask_v, loss_pixel_a, loss_pixel_v

    # used for retrieval, ignore if retrieval is not of interest
    def forward_feat(self, a, v):
        # embed patches
        a = a.unsqueeze(1)
        a = a.transpose(2, 3)
        a = self.patch_embed_a(a)
        a = a + self.pos_embed_a
        a = a + self.modality_a

        v = self.patch_embed_v(v)
        v = v + self.pos_embed_v
        v = v + self.modality_v

        # the modality-specific stream
        for blk in self.blocks_a:
            a = blk(a)

        for blk in self.blocks_v:
            v = blk(v)

        # use modality specific normalization,
        for blk in self.blocks_u:
            a = blk(a, 'a')
        a = self.norm_a(a)

        for blk in self.blocks_u:
            v = blk(v, 'v')
        v = self.norm_v(v)
        return a, v

    def forward_audio(self, a):
        # embed patches
        a = a.unsqueeze(1)
        a = a.transpose(2, 3)
        a = self.patch_embed_a(a)
        a = a + self.pos_embed_a
        a = a + self.modality_a

        # the modality-specific stream
        for blk in self.blocks_a:
            a = blk(a)

        # use modality specific normalization,
        for blk in self.blocks_u:
            a = blk(a, 'a')
        a = self.norm_a(a)

        return a.reshape(a.shape[0], 128 // 16, 1024 // 16, 768).permute(0, 3, 1, 2)

    def forward_video(self, v):
        v = self.patch_embed_v(v)
        v = v + self.pos_embed_v
        v = v + self.modality_v

        for blk in self.blocks_v:
            v = blk(v)

        for blk in self.blocks_u:
            v = blk(v, 'v')
        v = self.norm_v(v)
        return v.reshape(v.shape[0], 224 // 16, 224 // 16, 768).permute(0, 3, 1, 2)


# the finetuned CAV-MAE model
class CAVMAEFT(nn.Module):
    def __init__(self, label_dim, img_size=224, audio_length=1024, patch_size=16, in_chans=3,

                 embed_dim=768, modality_specific_depth=11, num_heads=12, mlp_ratio=4., norm_layer=nn.LayerNorm,

                 norm_pix_loss=False, tr_pos=True):
        super().__init__()
        timm.models.vision_transformer.Block = Block
        print('Use norm_pix_loss: ', norm_pix_loss)

        timm.models.vision_transformer.PatchEmbed = PatchEmbed
        timm.models.vision_transformer.Block = Block

        self.patch_embed_a = PatchEmbed(img_size, patch_size, 1, embed_dim)
        self.patch_embed_v = PatchEmbed(img_size, patch_size, in_chans, embed_dim)

        self.patch_embed_a.num_patches = int(audio_length * 128 / 256)
        print('Number of Audio Patches: {:d}, Visual Patches: {:d}'.format(self.patch_embed_a.num_patches,
                                                                           self.patch_embed_v.num_patches))

        self.modality_a = nn.Parameter(torch.zeros(1, 1, embed_dim))
        self.modality_v = nn.Parameter(torch.zeros(1, 1, embed_dim))

        self.pos_embed_a = nn.Parameter(torch.zeros(1, self.patch_embed_a.num_patches, embed_dim),
                                        requires_grad=tr_pos)  # fixed sin-cos embedding
        self.pos_embed_v = nn.Parameter(torch.zeros(1, self.patch_embed_v.num_patches, embed_dim),
                                        requires_grad=tr_pos)  # fixed sin-cos embedding

        self.blocks_a = nn.ModuleList(
            [Block(embed_dim, num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer) for i in
             range(modality_specific_depth)])
        self.blocks_v = nn.ModuleList(
            [Block(embed_dim, num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer) for i in
             range(modality_specific_depth)])
        self.blocks_u = nn.ModuleList(
            [Block(embed_dim, num_heads, mlp_ratio, qkv_bias=True, qk_scale=None, norm_layer=norm_layer) for i in
             range(12 - modality_specific_depth)])

        self.norm_a = norm_layer(embed_dim)
        self.norm_v = norm_layer(embed_dim)
        self.norm = norm_layer(embed_dim)

        self.mlp_head = nn.Sequential(nn.LayerNorm(embed_dim), nn.Linear(embed_dim, label_dim))

        self.initialize_weights()

        print('Audio Positional Embedding Shape:', self.pos_embed_a.shape)
        print('Visual Positional Embedding Shape:', self.pos_embed_v.shape)

    def get_patch_num(self, input_shape, stride):
        test_input = torch.zeros(1, 1, input_shape[0], input_shape[1])
        test_proj = torch.nn.Conv2d(1, 4, kernel_size=(16, 16), stride=(stride, stride))
        test_output = test_proj(test_input)
        print(test_output.shape)
        return test_output.shape[2], test_output[3], test_output[2] * test_output[2]

    def initialize_weights(self):
        pos_embed_a = get_2d_sincos_pos_embed(self.pos_embed_a.shape[-1], 8, int(self.patch_embed_a.num_patches / 8),
                                              cls_token=False)
        self.pos_embed_a.data.copy_(torch.from_numpy(pos_embed_a).float().unsqueeze(0))

        pos_embed_v = get_2d_sincos_pos_embed(self.pos_embed_v.shape[-1], int(self.patch_embed_v.num_patches ** .5),
                                              int(self.patch_embed_v.num_patches ** .5), cls_token=False)
        self.pos_embed_v.data.copy_(torch.from_numpy(pos_embed_v).float().unsqueeze(0))

        w = self.patch_embed_a.proj.weight.data
        torch.nn.init.xavier_uniform_(w.view([w.shape[0], -1]))
        w = self.patch_embed_v.proj.weight.data
        torch.nn.init.xavier_uniform_(w.view([w.shape[0], -1]))

        torch.nn.init.normal_(self.modality_a, std=.02)
        torch.nn.init.normal_(self.modality_v, std=.02)

        self.apply(self._init_weights)

    def _init_weights(self, m):
        if isinstance(m, nn.Linear):
            # we use xavier_uniform following official JAX ViT:
            torch.nn.init.xavier_uniform_(m.weight)
            if isinstance(m, nn.Linear) and m.bias is not None:
                nn.init.constant_(m.bias, 0)
        elif isinstance(m, nn.LayerNorm):
            nn.init.constant_(m.bias, 0)
            nn.init.constant_(m.weight, 1.0)

    def forward(self, a, v, mode):
        # multi-modal fine-tuning, our default method for fine-tuning
        if mode == 'multimodal':
            a = a.unsqueeze(1)
            a = a.transpose(2, 3)
            a = self.patch_embed_a(a)
            a = a + self.pos_embed_a
            a = a + self.modality_a

            v = self.patch_embed_v(v)
            v = v + self.pos_embed_v
            v = v + self.modality_v

            for blk in self.blocks_a:
                a = blk(a)

            for blk in self.blocks_v:
                v = blk(v)

            x = torch.cat((a, v), dim=1)

            for blk in self.blocks_u:
                x = blk(x)
            x = self.norm(x)

            x = x.mean(dim=1)
            x = self.mlp_head(x)
            return x

        # finetune with only audio (and inference with only audio when the model is finetuned with only audio)
        elif mode == 'audioonly':
            a = a.unsqueeze(1)
            a = a.transpose(2, 3)
            a = self.patch_embed_a(a)
            a = a + self.pos_embed_a
            a = a + self.modality_a

            for blk in self.blocks_a:
                a = blk(a)

            # note here uses the 'a' normalization, it is used in both training and inference, so it is fine
            for blk in self.blocks_u:
                a = blk(a, 'a')
            a = self.norm_a(a)
            x = a.mean(dim=1)
            x = self.mlp_head(x)
            return x

        # finetune with only image (and inference with only audio when the model is finetuned with only image)
        elif mode == 'videoonly':
            v = self.patch_embed_v(v)
            v = v + self.pos_embed_v
            v = v + self.modality_v

            for blk in self.blocks_v:
                v = blk(v)

            # note here uses the 'v' normalization, it is used in both training and inference, so it is fine
            for blk in self.blocks_u:
                v = blk(v, 'v')
            v = self.norm_v(v)
            x = v.mean(dim=1)
            x = self.mlp_head(x)
            return x

        # used in case that the model is finetuned with both modality, but in inference only audio is given
        elif mode == 'missingaudioonly':
            a = a.unsqueeze(1)
            a = a.transpose(2, 3)
            a = self.patch_embed_a(a)
            a = a + self.pos_embed_a
            a = a + self.modality_a

            for blk in self.blocks_a:
                a = blk(a)

            # two forward passes to the block_u, one with modality-specific normalization, another with unified normalization
            u = a
            for blk in self.blocks_u:
                u = blk(u)  # note here use unified normalization
            u = self.norm(u)
            u = u.mean(dim=1)

            for blk in self.blocks_u:
                a = blk(a, 'a')  # note here use modality-specific normalization
            a = self.norm_a(a)
            a = a.mean(dim=1)

            # average the output of the two forward passes
            x = (u + a) / 2
            x = self.mlp_head(x)
            return x

        # used in case that the model is fine-tuned with both modality, but in inference only image is given
        elif mode == 'missingvideoonly':
            v = self.patch_embed_v(v)
            v = v + self.pos_embed_v
            v = v + self.modality_v

            for blk in self.blocks_v:
                v = blk(v)

            # two forward passes to the block_u, one with modality-specific normalization, another with unified normalization
            u = v
            for blk in self.blocks_u:
                u = blk(u)  # note here use unified normalization
            u = self.norm(u)
            u = u.mean(dim=1)

            for blk in self.blocks_u:
                v = blk(v, 'v')  # note here use modality-specific normalization
            v = self.norm_v(v)
            v = v.mean(dim=1)

            # average the output of the two forward passes
            x = (u + v) / 2
            x = self.mlp_head(x)
            return x

    # for retrieval
    def forward_feat(self, a, v, mode='av'):
        # return both audio and visual
        if mode == 'av':
            a = a.unsqueeze(1)
            a = a.transpose(2, 3)
            a = self.patch_embed_a(a)
            a = a + self.pos_embed_a
            a = a + self.modality_a

            v = self.patch_embed_v(v)
            v = v + self.pos_embed_v
            v = v + self.modality_v

            for blk in self.blocks_a:
                a = blk(a)

            for blk in self.blocks_v:
                v = blk(v)

            for blk in self.blocks_u:
                a = blk(a, 'a')
            a = self.norm_a(a)

            for blk in self.blocks_u:
                v = blk(v, 'v')

            v = self.norm_v(v)
            return a, v

        # return only audio
        if mode == 'a':
            a = a.unsqueeze(1)
            a = a.transpose(2, 3)
            a = self.patch_embed_a(a)
            a = a + self.pos_embed_a
            a = a + self.modality_a

            for blk in self.blocks_a:
                a = blk(a)

            for blk in self.blocks_u:
                a = blk(a, 'a')

            a = self.norm_a(a)
            return a


def _wav2fbank(filename):
    waveform, sr = torchaudio.load(filename)
    waveform = torchaudio.functional.resample(
        waveform, orig_freq=sr, new_freq=16000
    )

    waveform = waveform - waveform.mean()
    waveform
    print(sr)

    fbank = torchaudio.compliance.kaldi.fbank(
        waveform,
        htk_compat=True,
        sample_frequency=sr,
        use_energy=False,
        window_type='hanning',
        num_mel_bins=128,
        dither=0.0,
        frame_shift=10)

    target_length = 1024
    n_frames = fbank.shape[0]

    p = target_length - n_frames

    # cut and pad
    if p > 0:
        m = torch.nn.ZeroPad2d((0, 0, 0, p))
        fbank = m(fbank)
    elif p < 0:
        fbank = fbank[0:target_length, :]

    return fbank


def pca(image_feats_list, dim=3, fit_pca=None):
    from sklearn.decomposition import PCA

    device = image_feats_list[0].device

    def flatten(tensor, target_size=None):
        if target_size is not None and fit_pca is None:
            F.interpolate(tensor, (target_size, target_size), mode="bilinear")
        B, C, H, W = tensor.shape
        return feats.permute(1, 0, 2, 3).reshape(C, B * H * W).permute(1, 0).detach().cpu()

    if len(image_feats_list) > 1 and fit_pca is None:
        target_size = image_feats_list[0].shape[2]
    else:
        target_size = None

    flattened_feats = []
    for feats in image_feats_list:
        flattened_feats.append(flatten(feats, target_size))
    x = torch.cat(flattened_feats, dim=0)

    if fit_pca is None:
        fit_pca = PCA(n_components=dim).fit(x)

    reduced_feats = []
    for feats in image_feats_list:
        x_red = torch.from_numpy(fit_pca.transform(flatten(feats)))
        x_red -= x_red.min(dim=0, keepdim=True).values
        x_red /= x_red.max(dim=0, keepdim=True).values
        B, C, H, W = feats.shape
        reduced_feats.append(x_red.reshape(B, H, W, dim).permute(0, 3, 1, 2).to(device))

    return reduced_feats, fit_pca


class CAVMAEAudioFeaturizer(nn.Module):

    def __init__(self, output_path, model_name="base", model=None):
        super().__init__()
        if model is not None:
            self.model = model
        else:
            if model_name == "base":
                model_path = os.path.join(output_path, 'models/audio_model.21.pth')
            else:
                raise ValueError(f"Unknown model type {model_name}")

            audio_model = CAVMAE(
                audio_length=1024,
                modality_specific_depth=11,
                norm_pix_loss=True,
                tr_pos=False)
            device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
            mdl_weight = torch.load(model_path, map_location=device)
            audio_model = torch.nn.DataParallel(audio_model)
            audio_model.load_state_dict(mdl_weight, strict=True)
            self.model = audio_model.module.cuda()

    def forward(self, audio, include_cls):
        cls_token = None
        patch_tokens = self.model.forward_audio(audio.squeeze(1))

        if include_cls:
            return patch_tokens, cls_token
        else:
            return patch_tokens


class CAVMAEImageFeaturizer(nn.Module):

    def __init__(self, output_path, model=None, model_name="base"):
        super().__init__()
        if model is not None:
            self.model: CAVMAE = model
        else:
            if model_name == "base":
                model_path = os.path.join(output_path, 'models/audio_model.21.pth')
            else:
                raise ValueError(f"Unknown model type {model_name}")

            audio_model = CAVMAE(
                audio_length=1024,
                modality_specific_depth=11,
                norm_pix_loss=True,
                tr_pos=False)
            device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
            mdl_weight = torch.load(model_path, map_location=device)
            audio_model = torch.nn.DataParallel(audio_model)
            audio_model.load_state_dict(mdl_weight, strict=True)
            self.model: CAVMAE = audio_model.module.cuda()

    def forward(self, image, include_cls):
        cls_token = None
        patch_tokens = self.model.forward_video(image)

        if include_cls:
            return patch_tokens, cls_token
        else:
            return patch_tokens


if __name__ == "__main__":
    model_path = os.path.join("../../", 'models/audio_model.21.pth')
    audio_model = CAVMAE(
        audio_length=1024,
        modality_specific_depth=11,
        norm_pix_loss=True,
        tr_pos=False)
    device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
    mdl_weight = torch.load(model_path, map_location=device)
    audio_model = torch.nn.DataParallel(audio_model)
    audio_model.load_state_dict(mdl_weight, strict=True)
    model: CAVMAE = audio_model.module.cuda()

    image_paths = ["../../samples/dog_image.jpg", "../../samples/car_image.jpg", "../../samples/bird_image.jpg"]
    audio_paths = ["../../samples/dog_audio.wav", "../../samples/car_audio.wav", "../../samples/bird_audio.wav"]

    images = []
    audios = []

    for image_path in image_paths:
        image = Image.open(image_path).convert("RGB")
        preprocess = T.Compose([
            T.Resize(224, interpolation=Image.BICUBIC),
            T.CenterCrop(224),
            T.ToTensor(),
            T.Normalize(
                mean=[0.4850, 0.4560, 0.4060],
                std=[0.2290, 0.2240, 0.2250]
            )])
        images.append(preprocess(image).unsqueeze(0).cuda())

    for audio_path in audio_paths:
        a = _wav2fbank(audio_path).cuda().unsqueeze(0)
        a = (a + 5.081) / (4.4849)
        audios.append(a)

    audio_feats, image_feats = model.forward_feat(
        torch.cat(audios, dim=0), torch.cat(images, dim=0))

    audio_feats = F.normalize(audio_feats.mean(1), dim=1)
    image_feats = F.normalize(image_feats.mean(1), dim=1)

    sims = torch.einsum("bc,dc->bd", image_feats, audio_feats)
    print(sims)

    print("here")

    # a_feat = F.normalize(a_feat, dim=1)
    # v_feat = F.normalize(v_feat, dim=1)

    # [red_v_feat, red_a_feat], fit_pca = pca([v_feat, a_feat])
    #
    # [red_v_feat], fit_pca = pca([v_feat])
    # [red_a_feat], fit_pca = pca([a_feat])
    #
    # import matplotlib.pyplot as plt
    #
    # fig, ax = plt.subplots(1, 2, figsize=(2 * 5, 5))
    # ax[0].imshow(red_v_feat[0].permute(1, 2, 0).cpu())
    # ax[1].imshow(red_a_feat[0].permute(1, 2, 0).cpu())
    # plt.tight_layout()
    # plt.show()
    # print("here")