
Recherche avancée
Médias (2)
-
Exemple de boutons d’action pour une collection collaborative
27 février 2013, par
Mis à jour : Mars 2013
Langue : français
Type : Image
-
Exemple de boutons d’action pour une collection personnelle
27 février 2013, par
Mis à jour : Février 2013
Langue : English
Type : Image
Autres articles (73)
-
Les autorisations surchargées par les plugins
27 avril 2010, parMediaspip core
autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs -
Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir -
Soumettre améliorations et plugins supplémentaires
10 avril 2011Si vous avez développé une nouvelle extension permettant d’ajouter une ou plusieurs fonctionnalités utiles à MediaSPIP, faites le nous savoir et son intégration dans la distribution officielle sera envisagée.
Vous pouvez utiliser la liste de discussion de développement afin de le faire savoir ou demander de l’aide quant à la réalisation de ce plugin. MediaSPIP étant basé sur SPIP, il est également possible d’utiliser le liste de discussion SPIP-zone de SPIP pour (...)
Sur d’autres sites (8237)
-
What is Multi-Touch Attribution ? (And How To Get Started)
2 février 2023, par Erin — Analytics Tips -
Parallelize Youtube video frame download using yt-dlp and cv2
4 mars 2023, par zulle99My task is to download multiple sequences of successive low resolution frames of Youtube videos.


I summarize the main parts of the process :


- 

- Each bag of shots have a dimension of half a second (depending on the current fps)
- In order to grab useful frames I've decided to remove the initial and final 10% of each video since it is common to have an intro and outro. Moreover
- I've made an array of pair of initial and final frame to distribute the load on multiple processes using
ProcessPoolExecutor(max_workers=multiprocessing.cpu_count())
- In case of failure/exception I completly remove the relative directory










The point is that it do not scale up, since while running I noticesd that all CPUs had always a load lower that the 20% more or less. In addition since with these shots I have to run multiple CNNs, to prevent overfitting it is suggested to have a big dataset and not a bounch of shots.


Here it is the code :


import yt_dlp
import os
from tqdm import tqdm
import cv2
import shutil
import time
import random
from concurrent.futures import ProcessPoolExecutor
import multiprocessing
import pandas as pd
import numpy as np
from pathlib import Path
import zipfile


# PARAMETERS
percentage_train_test = 50
percentage_bag_shots = 20
percentage_to_ignore = 10

zip_f_name = f'VideoClassificationDataset_{percentage_train_test}_{percentage_bag_shots}_{percentage_to_ignore}'
dataset_path = Path('/content/VideoClassificationDataset')

# DOWNOAD ZIP FILES
!wget --no-verbose https://github.com/gtoderici/sports-1m-dataset/archive/refs/heads/master.zip

# EXTRACT AND DELETE THEM
!unzip -qq -o '/content/master.zip' 
!rm '/content/master.zip'

DATA = {'train_partition.txt': {},
 'test_partition.txt': {}}

LABELS = []

train_dict = {}
test_dict = {}

path = '/content/sports-1m-dataset-master/original'

for f in os.listdir(path):
 with open(path + '/' + f) as f_txt:
 lines = f_txt.readlines()
 for line in lines:
 splitted_line = line.split(' ')
 label_indices = splitted_line[1].rstrip('\n').split(',') 
 DATA[f][splitted_line[0]] = list(map(int, label_indices))

with open('/content/sports-1m-dataset-master/labels.txt') as f_labels:
 LABELS = f_labels.read().splitlines()


TRAIN = DATA['train_partition.txt']
TEST = DATA['test_partition.txt']
print('Original Train Test length: ', len(TRAIN), len(TEST))

# sample a subset percentage_train_test
TRAIN = dict(random.sample(TRAIN.items(), (len(TRAIN)*percentage_train_test)//100))
TEST = dict(random.sample(TEST.items(), (len(TEST)*percentage_train_test)//100))

print(f'Sampled {percentage_train_test} Percentage Train Test length: ', len(TRAIN), len(TEST))


if not os.path.exists(dataset_path): os.makedirs(dataset_path)
if not os.path.exists(f'{dataset_path}/train'): os.makedirs(f'{dataset_path}/train')
if not os.path.exists(f'{dataset_path}/test'): os.makedirs(f'{dataset_path}/test')



Function to extract a sequence of continuous frames :


def extract_frames(directory, url, idx_bag, start_frame, end_frame):
 capture = cv2.VideoCapture(url)
 count = start_frame

 capture.set(cv2.CAP_PROP_POS_FRAMES, count)
 os.makedirs(f'{directory}/bag_of_shots{str(idx_bag)}')

 while count < end_frame:

 ret, frame = capture.read()

 if not ret: 
 shutil.rmtree(f'{directory}/bag_of_shots{str(idx_bag)}')
 return False

 filename = f'{directory}/bag_of_shots{str(idx_bag)}/shot{str(count - start_frame)}.png'

 cv2.imwrite(filename, frame)
 count += 1

 capture.release()
 return True



Function to spread the load along multiple processors :


def video_to_frames(video_url, labels_list, directory, dic, percentage_of_bags):
 url_id = video_url.split('=')[1]
 path_until_url_id = f'{dataset_path}/{directory}/{url_id}'
 try: 

 ydl_opts = {
 'ignoreerrors': True,
 'quiet': True,
 'nowarnings': True,
 'simulate': True,
 'ignorenoformatserror': True,
 'verbose':False,
 'cookies': '/content/all_cookies.txt',
 #https://stackoverflow.com/questions/63329412/how-can-i-solve-this-youtube-dl-429
 }
 ydl = yt_dlp.YoutubeDL(ydl_opts)
 info_dict = ydl.extract_info(video_url, download=False)

 if(info_dict is not None and info_dict['fps'] >= 20):
 # I must have a least 20 frames per seconds since I take half of second bag of shots for every video

 formats = info_dict.get('formats', None)

 # excluding the initial and final 10% of each video to avoid noise
 video_length = info_dict['duration'] * info_dict['fps']

 shots = info_dict['fps'] // 2

 to_ignore = (video_length * percentage_to_ignore) // 100
 new_len = video_length - (to_ignore * 2)
 tot_stored_bags = ((new_len // shots) * percentage_of_bags) // 100 # ((total_possbile_bags // shots) * percentage_of_bags) // 100
 if tot_stored_bags == 0: tot_stored_bags = 1 # minimum 1 bag of shots

 skip_rate_between_bags = (new_len - (tot_stored_bags * shots)) // (tot_stored_bags-1) if tot_stored_bags > 1 else 0

 chunks = [[to_ignore+(bag*(skip_rate_between_bags+shots)), to_ignore+(bag*(skip_rate_between_bags+shots))+shots] for bag in range(tot_stored_bags)]
 # sequence of [[start_frame, end_frame], [start_frame, end_frame], [start_frame, end_frame], ...]


 # ----------- For the moment I download only shots form video that has 144p resolution -----------

 res = {
 '160': '144p',
 '133': '240p',
 '134': '360p',
 '135': '360p',
 '136': '720p'
 }

 format_id = {}
 for f in formats: format_id[f['format_id']] = f
 #for res in resolution_id:
 if list(res.keys())[0] in list(format_id.keys()):
 video = format_id[list(res.keys())[0]]
 url = video.get('url', None)
 if(video.get('url', None) != video.get('manifest_url', None)):

 if not os.path.exists(path_until_url_id): os.makedirs(path_until_url_id)

 with ProcessPoolExecutor(max_workers=multiprocessing.cpu_count()) as executor:
 for idx_bag, f in enumerate(chunks): 
 res = executor.submit(
 extract_frames, directory = path_until_url_id, url = url, idx_bag = idx_bag, start_frame = f[0], end_frame = f[1])
 
 if res.result() is True: 
 l = np.zeros(len(LABELS), dtype=int) 
 for label in labels_list: l[label] = 1
 l = np.append(l, [shots]) # appending the number of shots taken in the list before adding it on the dictionary

 dic[f'{directory}/{url_id}/bag_of_shots{str(idx_bag)}'] = l.tolist()


 except Exception as e:
 shutil.rmtree(path_until_url_id)
 pass



Download of TRAIN bag of shots :


start_time = time.time()
pbar = tqdm(enumerate(TRAIN.items()), total = len(TRAIN.items()), leave=False)

for _, (url, labels_list) in pbar: video_to_frames(
 video_url = url, labels_list = labels_list, directory = 'train', dic = train_dict, percentage_of_bags = percentage_bag_shots)

print("--- %s seconds ---" % (time.time() - start_time))



Download of TEST bag of shots :


start_time = time.time()
pbar = tqdm(enumerate(TEST.items()), total = len(TEST.items()), leave=False)

for _, (url, labels_list) in pbar: video_to_frames(
 video_url = url, labels_list = labels_list, directory = 'test', dic = test_dict, percentage_of_bags = percentage_bag_shots)

print("--- %s seconds ---" % (time.time() - start_time))



Save the .csv files


train_df = pd.DataFrame.from_dict(train_dict, orient='index', dtype=int).reset_index(level=0)
train_df = train_df.rename(columns={train_df.columns[-1]: 'shots'})
train_df.to_csv('/content/VideoClassificationDataset/train.csv', index=True)

test_df = pd.DataFrame.from_dict(test_dict, orient='index', dtype=int).reset_index(level=0)
test_df = test_df.rename(columns={test_df.columns[-1]: 'shots'})
test_df.to_csv('/content/VideoClassificationDataset/test.csv', index=True)



-
How do I use ffmpeg on linux for my discord music bot ?
7 mars 2023, par DioI made a discord music bot a while back for me and my friends to use(it is minimalistic), but I recently switched from windows to Linux. I was using FFMPEG for my bot(the .exe file was in the same folder as the code).
I'll leave the Github link to my bot down here :


https://github.com/Dorian1997/Discord-Bot


Now my question is, do I have an alternative to FFMPEG on Linux ? Or how exactly should I install FFMPEG for it to work right ? I already installed it from the terminal, yet it doesn't seem to work as the bot cannot play anything.
Thank you for your time !