Recherche avancée

Sur d’autres sites (6176)

• Downloading individual songs from YouTube playlist [closed]

  23 août 2024, par user26961371
  

  • I've created a custom script using yt-dlp.

  


  • The script takes a single argument, which is the actual playlist URL.

  


  • I'm using the following command :

  


  


  yt-dlp --extract-audio --audio-format mp3 --yes-playlist -o "/Users/$USER/Desktop/%(id)s.%(ext)s" --embed-chapters $1


  


  Try :
I've run the command with a valid playlist URL, but it's downloading each song from the playlist into a single MP3 file for each song. I want to download each song as an individual file, not the entire playlist in a single file 15 times.

  


  Expectation :
I expect yt-dlp to download each song from the playlist as a separate MP3 file, rather than combining all songs into a single MP3 file for each song.

  


  Context :
The issue is likely due to the use of the --yes-playlist option, which tells yt-dlp to treat the input as a playlist URL and download all songs in one go.
I've checked the official documentation for yt-dlp, but I couldn't find a solution.

  


• I created a Python code to capture live video using FFmpeg, but the output screen only shows noise

  16 octobre 2024, par chun3 hyun

  The code below is Python code that made my computer screen video capture in real time via ffmpeg.

  


  When I run the code below, it goes well until a new window named 'Captured Frame' is created. But this 'Captured Frame' window doesn't show the full screen of my computer, and the gray screen is generating a lot of noise.

  


  import cv2
import numpy as np
import subprocess

def frame_capture():
    # Set FFmpeg command (capture desired window or area)
    ffmpeg_command = [
        'ffmpeg',
        '-f', 'gdigrab',  # Windows screen capture (using gdigrab)
        '-framerate', '30',  # Setting the Frame Speed
        '-i', 'desktop',  # What to capture (for example, full screen)
        '-pix_fmt', 'bgr0',
        '-vcodec', 'rawvideo',  # Video codec settings
        '-tune', 'zerolatency',
        '-an',  # Disable audio
        '-sn',  # Disable Caption
        '-f', 'rawvideo', '-'
    ]

    # Running the FFmpeg process
    process = subprocess.Popen(ffmpeg_command, stdout=subprocess.PIPE, bufsize=10**8)

    while True:
        # Read Frame from FFmpeg (Resolution Example: 1920x1080)
        raw_frame = process.stdout.read(1920 * 1080 * 3)  # 1920x1080 resolution, BGR format
        if not raw_frame:
            break  # Shut down the loop when you can no longer receive frames

        # Converting frame data to a numpy array
        frame = np.frombuffer(raw_frame, np.uint8).reshape((1080, 1920, 3))

        # Add frame processing code here
        # Example: Showing a frame on the screen
        cv2.imshow('Captured Frame', frame)

        # Press the 'q' key to end
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break

    # End of process and release of resources
    process.stdout.close()
    process.wait()
    cv2.destroyAllWindows()
frame_capture()


  


  What could I have done wrong ? When I directly input the FFmpeg command in the Windows command prompt(knows as 'cmd') as shown below to save the video (in .mp4 format), I can see that the screen is output normally in the saved file. It seems that FFmpeg itself is installed correctly, but I don't know what the cause is.

  


  hwnd=132554 -pix_fmt yuv420p -vf "scale=iw-mod(iw\,2):ih-mod(ih\,2)" -draw_mouse 1 -t 10 output.mp4


  


  The handle number written above was the handle of the active Chrome window on my computer.

  


  My ffmpeg version is 2024-10-10-git-0f5592cfc7-full_build-www.gyan.dev My Python version is 3.12.4
My Windows version and build are as specified below.
:Windows 11 Home, 10.0.22631

  


  Capturing the computer screen with FFmpeg. I tried it, but the output screen shows only noise.

  


• Significantly different scores when calculating VMAF for the whole video vs individual frames [closed]

  24 octobre 2024, par YG1992

  Suppose i have a raw video 'encoded_raw.yuv' and 'original_raw.yuv' on YUV420p. I am getting significantly different results when im calculating VMAF using both methods

  


  Method 1

  


  $ ffmpeg -s widthxheight -pix_fmt yuv420p -i .\encoded_raw.yuv -s widthxheight -pix_fmt yuv420p -i .\original_raw.yuv -lavfi libvmaf=log_path=vmaf_logfile.json:log_fmt=json -f null -


  


  versus Method 2 : extracting the png out of a single frame and computing the VMAF score for the individual frame

  


  $ ffmpeg -video_size widthxheight -i ./encoded_raw.yuv -vf select=eq(n\,1) -vframes 1 -pix_fmt yuv420p encoded_raw_1.png
$ ffmpeg -video_size widthxheight -i ./original_raw.yuv -vf select=eq(n\,1) -vframes 1 -pix_fmt yuv420p original_raw.png
$ ffmpeg -s widthxheight -pix_fmt yuv420p -i .\encoded_raw_1.png -s widthxheight -pix_fmt yuv420p -i .\original_raw.png -lavfi libvmaf=log_path=vmaf_logfile.json:log_fmt=json -f null -`


  


  method 1 vmaf at frame 1 from json = 80

  


  method 2 vmaf = 70

  


  any reason why this is so ?

  


  Note : for moduse this is on topic as this covers
-> software tools commonly used by programmers (ie ffmpeg)