stable-diffusion-finetune/ldm/modules/evaluate/torch_frechet_video_distance.py

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2022-06-09 10:56:34 +02:00
# based on https://github.com/universome/fvd-comparison/blob/master/compare_models.py; huge thanks!
import os
import numpy as np
import io
import re
import requests
import html
import hashlib
import urllib
import urllib.request
import scipy.linalg
import multiprocessing as mp
import glob
from tqdm import tqdm
from typing import Any, List, Tuple, Union, Dict, Callable
from torchvision.io import read_video
import torch; torch.set_grad_enabled(False)
from einops import rearrange
from nitro.util import isvideo
def compute_frechet_distance(mu_sample,sigma_sample,mu_ref,sigma_ref) -> float:
print('Calculate frechet distance...')
m = np.square(mu_sample - mu_ref).sum()
s, _ = scipy.linalg.sqrtm(np.dot(sigma_sample, sigma_ref), disp=False) # pylint: disable=no-member
fid = np.real(m + np.trace(sigma_sample + sigma_ref - s * 2))
return float(fid)
def compute_stats(feats: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
mu = feats.mean(axis=0) # [d]
sigma = np.cov(feats, rowvar=False) # [d, d]
return mu, sigma
def open_url(url: str, num_attempts: int = 10, verbose: bool = True, return_filename: bool = False) -> Any:
"""Download the given URL and return a binary-mode file object to access the data."""
assert num_attempts >= 1
# Doesn't look like an URL scheme so interpret it as a local filename.
if not re.match('^[a-z]+://', url):
return url if return_filename else open(url, "rb")
# Handle file URLs. This code handles unusual file:// patterns that
# arise on Windows:
#
# file:///c:/foo.txt
#
# which would translate to a local '/c:/foo.txt' filename that's
# invalid. Drop the forward slash for such pathnames.
#
# If you touch this code path, you should test it on both Linux and
# Windows.
#
# Some internet resources suggest using urllib.request.url2pathname() but
# but that converts forward slashes to backslashes and this causes
# its own set of problems.
if url.startswith('file://'):
filename = urllib.parse.urlparse(url).path
if re.match(r'^/[a-zA-Z]:', filename):
filename = filename[1:]
return filename if return_filename else open(filename, "rb")
url_md5 = hashlib.md5(url.encode("utf-8")).hexdigest()
# Download.
url_name = None
url_data = None
with requests.Session() as session:
if verbose:
print("Downloading %s ..." % url, end="", flush=True)
for attempts_left in reversed(range(num_attempts)):
try:
with session.get(url) as res:
res.raise_for_status()
if len(res.content) == 0:
raise IOError("No data received")
if len(res.content) < 8192:
content_str = res.content.decode("utf-8")
if "download_warning" in res.headers.get("Set-Cookie", ""):
links = [html.unescape(link) for link in content_str.split('"') if "export=download" in link]
if len(links) == 1:
url = requests.compat.urljoin(url, links[0])
raise IOError("Google Drive virus checker nag")
if "Google Drive - Quota exceeded" in content_str:
raise IOError("Google Drive download quota exceeded -- please try again later")
match = re.search(r'filename="([^"]*)"', res.headers.get("Content-Disposition", ""))
url_name = match[1] if match else url
url_data = res.content
if verbose:
print(" done")
break
except KeyboardInterrupt:
raise
except:
if not attempts_left:
if verbose:
print(" failed")
raise
if verbose:
print(".", end="", flush=True)
# Return data as file object.
assert not return_filename
return io.BytesIO(url_data)
def load_video(ip):
vid, *_ = read_video(ip)
vid = rearrange(vid, 't h w c -> t c h w').to(torch.uint8)
return vid
def get_data_from_str(input_str,nprc = None):
assert os.path.isdir(input_str), f'Specified input folder "{input_str}" is not a directory'
vid_filelist = glob.glob(os.path.join(input_str,'*.mp4'))
print(f'Found {len(vid_filelist)} videos in dir {input_str}')
if nprc is None:
try:
nprc = mp.cpu_count()
except NotImplementedError:
print('WARNING: cpu_count() not avlailable, using only 1 cpu for video loading')
nprc = 1
pool = mp.Pool(processes=nprc)
vids = []
for v in tqdm(pool.imap_unordered(load_video,vid_filelist),total=len(vid_filelist),desc='Loading videos...'):
vids.append(v)
vids = torch.stack(vids,dim=0).float()
return vids
def get_stats(stats):
assert os.path.isfile(stats) and stats.endswith('.npz'), f'no stats found under {stats}'
print(f'Using precomputed statistics under {stats}')
stats = np.load(stats)
stats = {key: stats[key] for key in stats.files}
return stats
@torch.no_grad()
def compute_fvd(ref_input, sample_input, bs=32,
ref_stats=None,
sample_stats=None,
nprc_load=None):
calc_stats = ref_stats is None or sample_stats is None
if calc_stats:
only_ref = sample_stats is not None
only_sample = ref_stats is not None
if isinstance(ref_input,str) and not only_sample:
ref_input = get_data_from_str(ref_input,nprc_load)
if isinstance(sample_input, str) and not only_ref:
sample_input = get_data_from_str(sample_input, nprc_load)
stats = compute_statistics(sample_input,ref_input,
device='cuda' if torch.cuda.is_available() else 'cpu',
bs=bs,
only_ref=only_ref,
only_sample=only_sample)
if only_ref:
stats.update(get_stats(sample_stats))
elif only_sample:
stats.update(get_stats(ref_stats))
else:
stats = get_stats(sample_stats)
stats.update(get_stats(ref_stats))
fvd = compute_frechet_distance(**stats)
return {'FVD' : fvd,}
@torch.no_grad()
def compute_statistics(videos_fake, videos_real, device: str='cuda', bs=32, only_ref=False,only_sample=False) -> Dict:
detector_url = 'https://www.dropbox.com/s/ge9e5ujwgetktms/i3d_torchscript.pt?dl=1'
detector_kwargs = dict(rescale=True, resize=True, return_features=True) # Return raw features before the softmax layer.
with open_url(detector_url, verbose=False) as f:
detector = torch.jit.load(f).eval().to(device)
assert not (only_sample and only_ref), 'only_ref and only_sample arguments are mutually exclusive'
ref_embed, sample_embed = [], []
info = f'Computing I3D activations for FVD score with batch size {bs}'
if only_ref:
if not isvideo(videos_real):
# if not is video we assume to have numpy arrays pf shape (n_vids, t, h, w, c) in range [0,255]
videos_real = torch.from_numpy(videos_real).permute(0, 4, 1, 2, 3).float()
print(videos_real.shape)
if videos_real.shape[0] % bs == 0:
n_secs = videos_real.shape[0] // bs
else:
n_secs = videos_real.shape[0] // bs + 1
videos_real = torch.tensor_split(videos_real, n_secs, dim=0)
for ref_v in tqdm(videos_real, total=len(videos_real),desc=info):
feats_ref = detector(ref_v.to(device).contiguous(), **detector_kwargs).cpu().numpy()
ref_embed.append(feats_ref)
elif only_sample:
if not isvideo(videos_fake):
# if not is video we assume to have numpy arrays pf shape (n_vids, t, h, w, c) in range [0,255]
videos_fake = torch.from_numpy(videos_fake).permute(0, 4, 1, 2, 3).float()
print(videos_fake.shape)
if videos_fake.shape[0] % bs == 0:
n_secs = videos_fake.shape[0] // bs
else:
n_secs = videos_fake.shape[0] // bs + 1
videos_real = torch.tensor_split(videos_real, n_secs, dim=0)
for sample_v in tqdm(videos_fake, total=len(videos_real),desc=info):
feats_sample = detector(sample_v.to(device).contiguous(), **detector_kwargs).cpu().numpy()
sample_embed.append(feats_sample)
else:
if not isvideo(videos_real):
# if not is video we assume to have numpy arrays pf shape (n_vids, t, h, w, c) in range [0,255]
videos_real = torch.from_numpy(videos_real).permute(0, 4, 1, 2, 3).float()
if not isvideo(videos_fake):
videos_fake = torch.from_numpy(videos_fake).permute(0, 4, 1, 2, 3).float()
if videos_fake.shape[0] % bs == 0:
n_secs = videos_fake.shape[0] // bs
else:
n_secs = videos_fake.shape[0] // bs + 1
videos_real = torch.tensor_split(videos_real, n_secs, dim=0)
videos_fake = torch.tensor_split(videos_fake, n_secs, dim=0)
for ref_v, sample_v in tqdm(zip(videos_real,videos_fake),total=len(videos_fake),desc=info):
# print(ref_v.shape)
# ref_v = torch.nn.functional.interpolate(ref_v, size=(sample_v.shape[2], 256, 256), mode='trilinear', align_corners=False)
# sample_v = torch.nn.functional.interpolate(sample_v, size=(sample_v.shape[2], 256, 256), mode='trilinear', align_corners=False)
feats_sample = detector(sample_v.to(device).contiguous(), **detector_kwargs).cpu().numpy()
feats_ref = detector(ref_v.to(device).contiguous(), **detector_kwargs).cpu().numpy()
sample_embed.append(feats_sample)
ref_embed.append(feats_ref)
out = dict()
if len(sample_embed) > 0:
sample_embed = np.concatenate(sample_embed,axis=0)
mu_sample, sigma_sample = compute_stats(sample_embed)
out.update({'mu_sample': mu_sample,
'sigma_sample': sigma_sample})
if len(ref_embed) > 0:
ref_embed = np.concatenate(ref_embed,axis=0)
mu_ref, sigma_ref = compute_stats(ref_embed)
out.update({'mu_ref': mu_ref,
'sigma_ref': sigma_ref})
return out