
Recherche avancée
Autres articles (40)
-
Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 septembre 2013, parCertains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;
-
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 -
Installation en mode ferme
4 février 2011, parLe mode ferme permet d’héberger plusieurs sites de type MediaSPIP en n’installant qu’une seule fois son noyau fonctionnel.
C’est la méthode que nous utilisons sur cette même plateforme.
L’utilisation en mode ferme nécessite de connaïtre un peu le mécanisme de SPIP contrairement à la version standalone qui ne nécessite pas réellement de connaissances spécifique puisque l’espace privé habituel de SPIP n’est plus utilisé.
Dans un premier temps, vous devez avoir installé les mêmes fichiers que l’installation (...)
Sur d’autres sites (4686)
-
Trying to convert code to be compatible with macOS by not using the .exe version of FFmpeg and FFmprobe. Cant open the .mp4 file when i go to run code
9 juillet 2024, par Bruno HawkinsI am attempting to edit some code in python for extracting frames from a video (using parallel processing to make it faster) a friend created that works on windows, so that it can be used on macOS. However, i am running into some issues and i am not sure what the problem is.


Essentially, when i go to run the frame extractor and try to select a video in the formats specified, it wont let me select it.


i have commented my code best i can. i am an amateur programmer so apologies if it is straightforward.


import os
import subprocess
import multiprocessing
import tkinter as tk
from tkinter import ttk, filedialog, messagebox

def extract_frames(video_path, output_folder, fps, start_time, duration, process_number):
 video_name = os.path.splitext(os.path.basename(video_path))[0]
 part_output_folder = os.path.join(output_folder, f"part_{process_number}")
 if not os.path.exists(part_output_folder):
 os.makedirs(part_output_folder)

 # Using 'ffmpeg' instead of 'ffmpeg.exe' for macOS compatibility
 ffmpeg_command = [
 'ffmpeg', '-ss', str(start_time), '-t', str(duration), '-i', video_path, '-vf', f'fps={fps}',
 os.path.join(part_output_folder, f'{video_name}_frame_%07d.png')
 ]

 print(f"Running FFmpeg command: {' '.join(ffmpeg_command)}")

 try:
 process = subprocess.run(ffmpeg_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 if process.returncode != 0:
 print(f"Cannot process the file {video_path}: {process.stderr.decode('utf-8')}")
 return part_output_folder, 0
 except Exception as e:
 print(f"Failed to run FFmpeg command: {str(e)}")
 return part_output_folder, 0

 frame_count = len([f for f in os.listdir(part_output_folder) if f.endswith('.png')])
 return part_output_folder, frame_count

def worker_function(queue, video_path, output_folder, fps, start_time, duration, process_number):
 result = extract_frames(video_path, output_folder, fps, start_time, duration, process_number)
 queue.put(result)

def parallel_frame_extraction(video_path, output_folder, fps, num_processes):
 # Use 'ffprobe' instead of 'ffprobe.exe' for macOS compatibility
 ffprobe_command = [
 'ffprobe', '-v', 'error', '-select_streams', 'v:0', '-show_entries', 'format=duration', '-of',
 'default=noprint_wrappers=1:nokey=1', video_path
 ]

 try:
 result = subprocess.run(ffprobe_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 duration = float(result.stdout.strip())
 except Exception as e:
 messagebox.showerror("Error", f"Failed to get video duration: {str(e)}")
 return

 chunk_duration = duration / num_processes
 processes = []
 manager = multiprocessing.Manager()
 queue = manager.Queue()

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

 for i in range(num_processes):
 start_time = i * chunk_duration
 p = multiprocessing.Process(target=worker_function,
 args=(queue, video_path, output_folder, fps, start_time, chunk_duration, i))
 p.start()
 processes.append(p)

 for p in processes:
 p.join()

 global_frame_offset = 0
 while not queue.empty():
 part_output_folder, frame_count = queue.get()
 frame_files = sorted([f for f in os.listdir(part_output_folder) if f.endswith('.png')])
 for i, frame_file in enumerate(frame_files):
 new_name = os.path.join(output_folder,
 f'{os.path.basename(video_path)}_frame_{global_frame_offset + i:07d}.png')
 os.rename(os.path.join(part_output_folder, frame_file), new_name)
 global_frame_offset += frame_count
 os.rmdir(part_output_folder)

 messagebox.showinfo("Complete",
 f"Frame extraction completed for {video_path}. Total frames extracted: {global_frame_offset}")

def start_frame_extraction():
 video_path = filedialog.askopenfilename(filetypes=[("Video files", "*.mp4;*.avi;*.mkv")])
 if not video_path:
 return

 output_folder = output_folder_var.get()
 if not output_folder:
 return

 fps = int(fps_var.get())
 num_processes = int(num_processes_var.get())

 parallel_frame_extraction(video_path, output_folder, fps, num_processes)

if __name__ == "__main__":
 root = tk.Tk()
 root.title("Frame Extraction")

 output_folder_var = tk.StringVar()
 fps_var = tk.StringVar(value="1")
 num_processes_var = tk.StringVar(value="4")

 def browse_output_folder():
 folder_selected = filedialog.askdirectory()
 output_folder_var.set(folder_selected)

 tk.Label(root, text="Output Folder:").grid(row=0, column=0, padx=10, pady=10)
 tk.Entry(root, textvariable=output_folder_var, width=50).grid(row=0, column=1, padx=10, pady=10)
 tk.Button(root, text="Browse", command=browse_output_folder).grid(row=0, column=2, padx=10, pady=10)

 tk.Label(root, text="FPS:").grid(row=1, column=0, padx=10, pady=10)
 tk.Entry(root, textvariable=fps_var, width=10).grid(row=1, column=1, padx=10, pady=10)

 tk.Label(root, text="Number of Processes:").grid(row=2, column=0, padx=10, pady=10)
 tk.Entry(root, textvariable=num_processes_var, width=10).grid(row=2, column=1, padx=10, pady=10)

 tk.Button(root, text="Start Frame Extraction", command=start_frame_extraction).grid(row=3, column=0, columnspan=3,
 padx=10, pady=20)

 root.mainloop()



I tried changing the FFmpeg and FFmprobe path formats from


ffmpeg_path = os.path.join(os.path.dirname(__file__), 'ffmpeg-7.0.1-essentials_build', 'bin', 'ffmpeg.exe')
ffprobe_path = os.path.join(os.path.dirname(__file__), 'ffmpeg-7.0.1-essentials_build', 'bin', 'ffprobe.exe')




to


ffmpeg_command = [
 'ffmpeg', '-ss', str(start_time), '-t', str(duration), '-i', video_path, '-vf', f'fps={fps}',
 os.path.join(part_output_folder, f'{video_name}_frame_%07d.png')
]

ffprobe_command = [
 'ffprobe', '-v', 'error', '-select_streams', 'v:0', '-show_entries', 'format=duration', '-of',
 'default=noprint_wrappers=1:nokey=1', video_path
]




I found this online so im not sure if it is the correct thing to do.


Thanks for any help.


-
Qt 5.2 / OpenCV 2.4.8 - Can’t open video files via VideoCapture
4 août 2015, par ZamahraI have a big problem that i can’t solve by myself. OpenCV itself works fine, but i’m not able to load videos. Here’s my code :
PRO- File
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = videoredux
TEMPLATE = app
INCLUDEPATH += C:/OpenCV/opencv_bin/install/include
LIBS += -LC:\\OpenCV\\opencv_bin\\bin \
libopencv_core248d \
libopencv_highgui248d \
libopencv_imgproc248d \
libopencv_features2d248d \
libopencv_calib3d248d \
libopencv_video248d \
SOURCES += main.cpp\
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.uiand the MainWindow Class :
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <qfiledialog>
#include <iostream>
#include
#include <opencv2></opencv2>core/core.hpp>
#include <opencv2></opencv2>highgui/highgui.hpp>
#include <opencv2></opencv2>imgproc/imgproc.hpp>
#include <opencv></opencv>cv.h>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
ui->videoStatusLabel->setText("Kein Video geladen.");
// SIGNALS & SLOTS
QObject::connect(ui->chooseVideoButton,SIGNAL(clicked()),
this,SLOT(chooseVideo()));
QObject::connect(ui->startButton,SIGNAL(clicked()),
this,SLOT(startProcess()));
}
void MainWindow::chooseVideo(){
QString fileName = QFileDialog::getOpenFileName(this,
tr("Open Video"), "/home", tr("Video Files (*.avi *.mp4 *.mpeg *.mpg)"));
qDebug() << "Path:" << fileName;
ui->videoStatusLabel->setText(fileName);
}
void MainWindow::startProcess(){
QString videoPath = ui->videoStatusLabel->text();
QFileInfo video(videoPath);
if(video.exists()){
const std::string path = videoPath.toUtf8().constData();
cv::VideoCapture capture(path);
cv::Mat frame;
if(!capture.isOpened()){
qDebug() << "Error, video not loaded";
}
cv::namedWindow("window",1);
while(true)
{
bool success = capture.read(frame);
if(success == false){
break;
}
cv::imshow("window",frame);
cv::waitKey(20);
}
cv::waitKey(0);
}
else{
qDebug() << "Error, File doesn't exist";
}
}
</iostream></qfiledialog>The paths are correct, I tried many different video formats but he never loads the videos. I’m running Qt on a Windows 8 machine and i have “K-Lite Codec Pack 10.2.0 Basic” and ffmpeg installed. The videos are playing properly with my video players. I also tried to copy the .dll to the working directory, searched for opencv dll’s in the system32 directory and rebuild OpenCV with mingw on this computer. I know that many people have the same problems, but none of their suggestions solved it. Does anyone know how to solve this problem ?
Thank you very much !
Nadine
----UPDATE---- I still can’t open video files, so I programmed the application on a Windows7 64-Bit system. It worked fine, but when I try to open the application on a Windows8 computer it still can’t open the file. It doesn’t matter which codecs are installed, because it generally runs on every Windows7 computer and fails on every Windows8 computer.. The same for older OpenCV-Versions. Is there a general problem with OpenCV and Windows8 ?
-
Open Banking Security 101 : Is open banking safe ?
3 décembre 2024, par Daniel Crough — Banking and Financial Services