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• creating a video from images

  12 septembre 2022, par ALAEDDIN

  My goal is to create a video from images using videoshow : a utility for node/io.js to create straightforward video slideshows based on images using FFmpeg.

  


  The problem i have is when i add more images like 3 with a display resolution of 1024x instead of 640x as in default the program/virtual machine (aws - t3.micro) freezes..until i force a restart in the console.. , but with 2 images the video is rendered just fine..

  


  I guess it's related to the memory.. how i can solve the issue and where i can see the logs ?

  


• Normalize audio, then reduce the volume in ffmpeg

  27 octobre 2014, par Steve Sheldon

  I have a question relating to ffmpeg. First here is the scenario, I am working on a project where I need to have some audio with a presenter talking and then potentially some background music. I also have the requirement to normalize the audio. I would like to do this without presenting a bunch of options to the user.

  For normalization I use something similar to this post :

  How to normalize audio with ffmpeg.

  In short, I get a volume adjustment which I then apply to ffmpeg like this :

  ffmpeg -i <input /> -af "volume=xxxdB" <output>
  
  </output>

  So far so good. Now let’s consider the backing track, it doesn’t want to be the same volume as the presenters voice, this would be really distracting, so I want to lower that by some percentage. I can also do this with ffmpeg, I could do it like this (example would set volume to 50%) :

  ffmpeg -i <input /> -af "volume=0.5" <output>
  
  </output>

  Using these two commands back to back, I can get the desired result.

  My question has two parts :

  1. Is there a way to do this in one step ?
  2. Is there any benefit to doing it in one step ?

  Thanks for any help !

• moov atom not found (Extracting unique faces from youtube video)

  10 avril 2023, par Tochukwu

  I got the error below

  


  Saved 0 unique faces
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000024f505224c0] moov atom not found


  


  Trying to extract unique faces from a YouTube video with the code below which is designed to download the YouTube video and extract unique faces into a folder named faces. I got an empty video and folder. Please do check the Python code below

  


  import os
import urllib.request
import cv2
import face_recognition
import numpy as np

# Step 1: Download the YouTube video
video_url = "https://www.youtube.com/watch?v=JriaiYZZhbY&t=4s"
urllib.request.urlretrieve(video_url, "video.mp4")

# Step 2: Extract frames from the video
cap = cv2.VideoCapture("video.mp4")
frame_count = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
frames = []
for i in range(frame_count):
    cap.set(cv2.CAP_PROP_POS_FRAMES, i)
    ret, frame = cap.read()
    if ret:
        frames.append(frame)
cap.release()

# Step 3: Detect faces in the frames
detected_faces = []
for i, frame in enumerate(frames):
    face_locations = face_recognition.face_locations(frame)
    for j, location in enumerate(face_locations):
        top, right, bottom, left = location
        face_image = frame[top:bottom, left:right]
        cv2.imwrite(f"detected_{i}_{j}.jpg", face_image)
        detected_faces.append(face_image)

# Step 4: Save the faces as separate images
if not os.path.exists("faces"):
    os.makedirs("faces")
known_faces = []
for i in range(len(detected_faces)):
    face_image = detected_faces[i]
    face_encoding = face_recognition.face_encodings(face_image)[0]
    known_faces.append(face_encoding)
    cv2.imwrite(f"faces/face_{i}.jpg", face_image)
print("Saved", len(known_faces), "unique faces")