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# --------------------------------------------------------
# Based on BEiT, timm, DINO and DeiT code bases
# https://github.com/microsoft/unilm/tree/master/beit
# https://github.com/rwightman/pytorch-image-models/tree/master/timm
# https://github.com/facebookresearch/deit
# https://github.com/facebookresearch/dino
# --------------------------------------------------------'
from functools import partial
import torch
import torch.nn as nn
import torch.utils.checkpoint as cp
from .videomaev2_finetune import (
Block,
PatchEmbed,
_cfg,
get_sinusoid_encoding_table,
)
from .videomaev2_finetune import trunc_normal_ as __call_trunc_normal_
def trunc_normal_(tensor, mean=0., std=1.):
__call_trunc_normal_(tensor, mean=mean, std=std, a=-std, b=std)
class PretrainVisionTransformerEncoder(nn.Module):
""" Vision Transformer with support for patch or hybrid CNN input stage
"""
def __init__(self,
img_size=224,
patch_size=16,
in_chans=3,
num_classes=0,
embed_dim=768,
depth=12,
num_heads=12,
mlp_ratio=4.,
qkv_bias=False,
qk_scale=None,
drop_rate=0.,
attn_drop_rate=0.,
drop_path_rate=0.,
norm_layer=nn.LayerNorm,
init_values=None,
tubelet_size=2,
use_learnable_pos_emb=False,
with_cp=False,
all_frames=16,
cos_attn=False):
super().__init__()
self.num_classes = num_classes
# num_features for consistency with other models
self.num_features = self.embed_dim = embed_dim
self.patch_embed = PatchEmbed(
img_size=img_size,
patch_size=patch_size,
in_chans=in_chans,
embed_dim=embed_dim,
num_frames=all_frames,
tubelet_size=tubelet_size)
num_patches = self.patch_embed.num_patches
self.with_cp = with_cp
if use_learnable_pos_emb:
self.pos_embed = nn.Parameter(
torch.zeros(1, num_patches + 1, embed_dim))
else:
# sine-cosine positional embeddings
self.pos_embed = get_sinusoid_encoding_table(
num_patches, embed_dim)
dpr = [x.item() for x in torch.linspace(0, drop_path_rate, depth)
] # stochastic depth decay rule
self.blocks = nn.ModuleList([
Block(
dim=embed_dim,
num_heads=num_heads,
mlp_ratio=mlp_ratio,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
drop=drop_rate,
attn_drop=attn_drop_rate,
drop_path=dpr[i],
norm_layer=norm_layer,
init_values=init_values,
cos_attn=cos_attn) for i in range(depth)
])
self.norm = norm_layer(embed_dim)
self.head = nn.Linear(
embed_dim, num_classes) if num_classes > 0 else nn.Identity()
if use_learnable_pos_emb:
trunc_normal_(self.pos_embed, std=.02)
self.apply(self._init_weights)
def _init_weights(self, m):
if isinstance(m, nn.Linear):
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 get_num_layers(self):
return len(self.blocks)
@torch.jit.ignore
def no_weight_decay(self):
return {'pos_embed', 'cls_token'}
def get_classifier(self):
return self.head
def reset_classifier(self, num_classes, global_pool=''):
self.num_classes = num_classes
self.head = nn.Linear(
self.embed_dim, num_classes) if num_classes > 0 else nn.Identity()
def forward_features(self, x, mask):
x = self.patch_embed(x)
x = x + self.pos_embed.type_as(x).to(x.device).clone().detach()
B, _, C = x.shape
x_vis = x[~mask].reshape(B, -1, C) # ~mask means visible
for blk in self.blocks:
if self.with_cp:
x_vis = cp.checkpoint(blk, x_vis)
else:
x_vis = blk(x_vis)
x_vis = self.norm(x_vis)
return x_vis
def forward(self, x, mask):
x = self.forward_features(x, mask)
x = self.head(x)
return x
class PretrainVisionTransformerDecoder(nn.Module):
""" Vision Transformer with support for patch or hybrid CNN input stage
"""
def __init__(self,
patch_size=16,
num_classes=768,
embed_dim=768,
depth=12,
num_heads=12,
mlp_ratio=4.,
qkv_bias=False,
qk_scale=None,
drop_rate=0.,
attn_drop_rate=0.,
drop_path_rate=0.,
norm_layer=nn.LayerNorm,
init_values=None,
num_patches=196,
tubelet_size=2,
with_cp=False,
cos_attn=False):
super().__init__()
self.num_classes = num_classes
assert num_classes == 3 * tubelet_size * patch_size**2
# num_features for consistency with other models
self.num_features = self.embed_dim = embed_dim
self.patch_size = patch_size
self.with_cp = with_cp
dpr = [x.item() for x in torch.linspace(0, drop_path_rate, depth)
] # stochastic depth decay rule
self.blocks = nn.ModuleList([
Block(
dim=embed_dim,
num_heads=num_heads,
mlp_ratio=mlp_ratio,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
drop=drop_rate,
attn_drop=attn_drop_rate,
drop_path=dpr[i],
norm_layer=norm_layer,
init_values=init_values,
cos_attn=cos_attn) for i in range(depth)
])
self.norm = norm_layer(embed_dim)
self.head = nn.Linear(
embed_dim, num_classes) if num_classes > 0 else nn.Identity()
self.apply(self._init_weights)
def _init_weights(self, m):
if isinstance(m, nn.Linear):
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 get_num_layers(self):
return len(self.blocks)
@torch.jit.ignore
def no_weight_decay(self):
return {'pos_embed', 'cls_token'}
def get_classifier(self):
return self.head
def reset_classifier(self, num_classes, global_pool=''):
self.num_classes = num_classes
self.head = nn.Linear(
self.embed_dim, num_classes) if num_classes > 0 else nn.Identity()
def forward(self, x, return_token_num):
for blk in self.blocks:
if self.with_cp:
x = cp.checkpoint(blk, x)
else:
x = blk(x)
if return_token_num > 0:
# only return the mask tokens predict pixels
x = self.head(self.norm(x[:, -return_token_num:]))
else:
# [B, N, 3*16^2]
x = self.head(self.norm(x))
return x
class PretrainVisionTransformer(nn.Module):
""" Vision Transformer with support for patch or hybrid CNN input stage
"""
def __init__(
self,
img_size=224,
patch_size=16,
encoder_in_chans=3,
encoder_num_classes=0,
encoder_embed_dim=768,
encoder_depth=12,
encoder_num_heads=12,
decoder_num_classes=1536, # decoder_num_classes=768
decoder_embed_dim=512,
decoder_depth=8,
decoder_num_heads=8,
mlp_ratio=4.,
qkv_bias=False,
qk_scale=None,
drop_rate=0.,
attn_drop_rate=0.,
drop_path_rate=0.,
norm_layer=nn.LayerNorm,
init_values=0.,
use_learnable_pos_emb=False,
tubelet_size=2,
num_classes=0, # avoid the error from create_fn in timm
in_chans=0, # avoid the error from create_fn in timm
with_cp=False,
all_frames=16,
cos_attn=False,
):
super().__init__()
self.encoder = PretrainVisionTransformerEncoder(
img_size=img_size,
patch_size=patch_size,
in_chans=encoder_in_chans,
num_classes=encoder_num_classes,
embed_dim=encoder_embed_dim,
depth=encoder_depth,
num_heads=encoder_num_heads,
mlp_ratio=mlp_ratio,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
drop_rate=drop_rate,
attn_drop_rate=attn_drop_rate,
drop_path_rate=drop_path_rate,
norm_layer=norm_layer,
init_values=init_values,
tubelet_size=tubelet_size,
use_learnable_pos_emb=use_learnable_pos_emb,
with_cp=with_cp,
all_frames=all_frames,
cos_attn=cos_attn)
self.decoder = PretrainVisionTransformerDecoder(
patch_size=patch_size,
num_patches=self.encoder.patch_embed.num_patches,
num_classes=decoder_num_classes,
embed_dim=decoder_embed_dim,
depth=decoder_depth,
num_heads=decoder_num_heads,
mlp_ratio=mlp_ratio,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
drop_rate=drop_rate,
attn_drop_rate=attn_drop_rate,
drop_path_rate=drop_path_rate,
norm_layer=norm_layer,
init_values=init_values,
tubelet_size=tubelet_size,
with_cp=with_cp,
cos_attn=cos_attn)
self.encoder_to_decoder = nn.Linear(
encoder_embed_dim, decoder_embed_dim, bias=False)
self.mask_token = nn.Parameter(torch.zeros(1, 1, decoder_embed_dim))
self.pos_embed = get_sinusoid_encoding_table(
self.encoder.patch_embed.num_patches, decoder_embed_dim)
trunc_normal_(self.mask_token, std=.02)
def _init_weights(self, m):
if isinstance(m, nn.Linear):
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 get_num_layers(self):
return len(self.blocks)
@torch.jit.ignore
def no_weight_decay(self):
return {'pos_embed', 'cls_token', 'mask_token'}
def forward(self, x, mask, decode_mask=None):
decode_vis = mask if decode_mask is None else ~decode_mask
x_vis = self.encoder(x, mask) # [B, N_vis, C_e]
x_vis = self.encoder_to_decoder(x_vis) # [B, N_vis, C_d]
B, N_vis, C = x_vis.shape
# we don't unshuffle the correct visible token order,
# but shuffle the pos embedding accorddingly.
expand_pos_embed = self.pos_embed.expand(B, -1, -1).type_as(x).to(
x.device).clone().detach()
pos_emd_vis = expand_pos_embed[~mask].reshape(B, -1, C)
pos_emd_mask = expand_pos_embed[decode_vis].reshape(B, -1, C)
# [B, N, C_d]
x_full = torch.cat(
[x_vis + pos_emd_vis, self.mask_token + pos_emd_mask], dim=1)
# NOTE: if N_mask==0, the shape of x is [B, N_mask, 3 * 16 * 16]
x = self.decoder(x_full, pos_emd_mask.shape[1])
return x
def pretrain_videomae_small_patch16_224(pretrained=False, **kwargs):
model = PretrainVisionTransformer(
img_size=224,
patch_size=16,
encoder_embed_dim=384,
encoder_depth=12,
encoder_num_heads=6,
encoder_num_classes=0,
decoder_num_classes=1536, # 16 * 16 * 3 * 2
decoder_embed_dim=192,
decoder_num_heads=3,
mlp_ratio=4,
qkv_bias=True,
norm_layer=partial(nn.LayerNorm, eps=1e-6),
**kwargs)
model.default_cfg = _cfg()
if pretrained:
checkpoint = torch.load(kwargs["init_ckpt"], map_location="cpu")
model.load_state_dict(checkpoint["model"])
return model
def pretrain_videomae_base_patch16_224(pretrained=False, **kwargs):
model = PretrainVisionTransformer(
img_size=224,
patch_size=16,
encoder_embed_dim=768,
encoder_depth=12,
encoder_num_heads=12,
encoder_num_classes=0,
decoder_num_classes=1536, # 16 * 16 * 3 * 2
decoder_embed_dim=384,
decoder_num_heads=6,
mlp_ratio=4,
qkv_bias=True,
norm_layer=partial(nn.LayerNorm, eps=1e-6),
**kwargs)
model.default_cfg = _cfg()
if pretrained:
checkpoint = torch.load(kwargs["init_ckpt"], map_location="cpu")
model.load_state_dict(checkpoint["model"])
return model
def pretrain_videomae_large_patch16_224(pretrained=False, **kwargs):
model = PretrainVisionTransformer(
img_size=224,
patch_size=16,
encoder_embed_dim=1024,
encoder_depth=24,
encoder_num_heads=16,
encoder_num_classes=0,
decoder_num_classes=1536, # 16 * 16 * 3 * 2
decoder_embed_dim=512,
decoder_num_heads=8,
mlp_ratio=4,
qkv_bias=True,
norm_layer=partial(nn.LayerNorm, eps=1e-6),
**kwargs)
model.default_cfg = _cfg()
if pretrained:
checkpoint = torch.load(kwargs["init_ckpt"], map_location="cpu")
model.load_state_dict(checkpoint["model"])
return model
def pretrain_videomae_huge_patch16_224(pretrained=False, **kwargs):
model = PretrainVisionTransformer(
img_size=224,
patch_size=16,
encoder_embed_dim=1280,
encoder_depth=32,
encoder_num_heads=16,
encoder_num_classes=0,
decoder_num_classes=1536, # 16 * 16 * 3 * 2
decoder_embed_dim=512,
decoder_num_heads=8,
mlp_ratio=4,
qkv_bias=True,
norm_layer=partial(nn.LayerNorm, eps=1e-6),
**kwargs)
model.default_cfg = _cfg()
if pretrained:
checkpoint = torch.load(kwargs["init_ckpt"], map_location="cpu")
model.load_state_dict(checkpoint["model"])
return model
def pretrain_videomae_giant_patch14_224(pretrained=False, **kwargs):
model = PretrainVisionTransformer(
img_size=224,
patch_size=14,
encoder_embed_dim=1408,
encoder_depth=40,
encoder_num_heads=16,
encoder_num_classes=0,
decoder_num_classes=1176, # 14 * 14 * 3 * 2,
decoder_embed_dim=512,
decoder_num_heads=8,
mlp_ratio=48 / 11,
qkv_bias=True,
norm_layer=partial(nn.LayerNorm, eps=1e-6),
**kwargs)
model.default_cfg = _cfg()
if pretrained:
checkpoint = torch.load(kwargs["init_ckpt"], map_location="cpu")
model.load_state_dict(checkpoint["model"])
return model