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• Storing high quality video stream (from IP Action Camera) continuously to a Storage Device and issues around Write-Speed bottlenecks

  21 mai 2017, par Aldo

  I am looking to get an Action Camera (Eken H8R, or a GoPro) for a project. Let me explain the scenario I have :

  I will obtain a live stream from the camera on to a Raspberry Pi (over WiFi) as shown here. Next, I want to continuously segment this live stream into 10-15 minute video clips and store them in an external Hard Drive (which is connected to the RPi). I am considering this thread, and the avconvcommand mentioned in the answer by Alexander.

  Now, my concern is write-speed limitations. The video stream would probably have a high bitrate, and might be 4k30fps, in which case file sizes would be huge. Would write speed to disk be a bottleneck ? If so, how will the Pi maintain a buffer to achieve this ? Could I run out of space as the memory stick on the Pi would only be around 8 gigs ? If so, what’s a better alternative ? Please correct me if I’m wrong on these as I’m only a beginner.

• ffmpeg v4l2 taking 100% cpu usage

  16 novembre 2022, par didentifier

  I am on Fedora 37, version is irrelevant as I had same issue on Fedora 36.

  


  I am using the following command to send video from my usb video card to v4l2loopback and the CPU usage goes to 100% and I can't do much more on my computer (i5-8600k, nvidia 2060 rtx, 16GB ram).

  


  ffmpeg -nostdin -threads 1 -f video4linux2 -video_size 1920x1080 -input_format mjpeg -i /dev/video1 -f v4l2 -preset fast -c:v copy /dev/video0

  


  previously the command was like that and the rest of the arguments was added to see if it makes any difference, it seems it doesn't change much

  


  ffmpeg -f video4linux2 -video_size 1920x1080 -input_format mjpeg -i /dev/video1 -f v4l2 -c copy /dev/video0

  


  To be honest I don't know much about ffmpeg or video in general, I was using the same command a few months ago on the same hardware with almost 0 impact to my performance, I could play games and watch videos at the same time while now I get 15 FPS in my games while I am using ffmpeg. Did anything change in ffmpeg ? Any improvements to my ffmpeg command ? Shouldn't ffmpeg not encode anything if I am using pixelformat and frame rate supported by my usb video card and if that is true shouldn't be super light ?

  


• How to rename the .wav file which is going to download using the below program ?

  29 avril 2020, par Y V Sravan Kumar Reddy

  from __future__ import unicode_literals
import youtube_dl

ydl_opts = {
    'format': 'bestaudio/best',
    'postprocessors': [{
        'key': 'FFmpegExtractAudio',
        'preferredcodec': 'wav',
        'preferredquality': '192'
    }],
    'postprocessor_args': [
        '-ar', '16000'
    ],
    'prefer_ffmpeg': True,
    'keepvideo': True
}

with youtube_dl.YoutubeDL(ydl_opts) as ydl:
    ydl.download(['https://www.youtube.com/watch?v=JpjEwIceVIo'])


  



  ---

  



  Output :

  



  [youtube] JpjEwIceVIo: Downloading webpage
[download] Speech on Importance of Education in English for Higher Secondary students by Smile Please World-JpjEwIceVIo.webm has already been downloaded
[download] 100% of 1.69MiB
[ffmpeg] Destination: Speech on Importance of Education in English for Higher Secondary students by Smile Please World-JpjEwIceVIo.wav


  



  ---

  



  I want to change the filename to audio1.wav instead of Speech on Importance of Education in English for Higher Secondary students by Smile Please World-JpjEwIceVIo.wav. Please help me with this problem.