Recherche avancée

Sur d’autres sites (4338)

• How to automatically rotate video based on camera orientation while recording ?

  7 avril, par jestrabikr

  I am developing Mediasoup SFU and client web app, on the server I am recording client's stream by sending it to FFmpeg as plain RTP. FFmpeg creates HLS recording (.m3u8 and .ts files), because I need to be able to switch between WebRTC live stream and HLS recording before live stream ends.

  


  My problem is that, when I am testing the app and I rotate my phone 90 degrees, the recording's aspect ratio stays the same but the image is rotated (as shown on images 1.1, 1.2 and 1.3 below). I need for it to change aspect ratio dynamically according to camera orientation. How can I do that using FFmpeg ?

  


  On the live stream it works perfectly fine (as shown on the images - 2.1 and 2.2 below), when the phone is rotated, the aspect ration is changed and video is shown correctly. I think it works on live stream because maybe WebRTC is signaling orientation changes somehow (but it does not project to the recording).

  


  These are my ffmpeg command arguments for recording (version 6.1.1-3ubuntu5) :

  


  let commandArgs = [
      "-loglevel", "info",
      "-protocol_whitelist", "pipe,udp,rtp",
      "-fflags", "+genpts+discardcorrupt",
      "-reinit_filter", "1",
      "-strict", "-2",
      "-f", "sdp",
      "-i", "pipe:0",
      "-map", "0:v:0",
      "-c:v", "libx264",
      "-b:v", "1500k",
      "-profile:v", "high",
      "-level:v", "4.1",
      "-pix_fmt", "yuv420p",
      "-g", "30",
      "-map", "0:a:0",
      "-c:a", "aac",
      "-b:a", "128k",
      "-movflags", "+frag_keyframe+empty_moov",
      "-f", "hls",
      "-hls_time", "4",
      "-hls_list_size", "0",
      "-hls_flags", "split_by_time",
      `${filePath}.m3u8`
    ];


  


  


  • Image 1.1 - Portrait mode in recording :

    


    

    


  


  • Image 1.2 - Landscape mode in recording (rotated 90deg to my left side - front camera is on my left side) :

    


    

    


  


  • Image 1.3 - Landscape mode in recording (rotated 90deg to my right side) :

    


    

    


  


  • Image 2.1 - Portrait mode in live stream (correct behavior) :

    


    

    


  


  • Image 2.2 - Landscape mode in live stream (correct behavior) :

    


    

    


  


  


• Generate video from numpy arrays with openCV

  14 juillet 2020, par daVinci

  I am trying to use the openCV VideoWriter class to generate a video from numpy arrays. I am using the following code :

  


  import numpy as np
import cv2
size = 720*16//9, 720
duration = 2
fps = 25
out = cv2.VideoWriter('output.avi', cv2.VideoWriter_fourcc(*'X264'), fps, size)
for _ in range(fps * duration):
    data = np.random.randint(0, 256, size, dtype='uint8')
    out.write(data)
out.release()


  


  The codec seems to be installed as ffmpeg can do conversions to the x264 codec and libx264 is installed. The code runs without warnings, however the videos generated seem to contain no data since I always get the following message when trying to read them with mpv :

  


  


  [ffmpeg/demuxer] avi : Could not find codec parameters for stream 0 (Video : h264 (X264 / 0x34363258), none, 1280x720) : unspecified pixel format

  


  


  What could be the cause of this issue ?

  


• .travis.yml : Generate and validate html documentation.

  30 juillet 2019, par Ralph Giles

  .travis.yml : Generate and validate html documentation.
  Install Doxygen when running on the linux environment to test
  
  generation of the API documentation.
  Run the included static html documentation as well as the
  
  generated API documentation through xmllint to verify
  
  it conforms to the declared DTD. Since this this will be very
  
  slow or fail relying on network resources, also install
  
  the w3c-sgml library so the xhtml1 DTDs are available locally.
  We're checking the source files, not build results in the
  
  particular environment, so it's fine to run this check
  
  on only a subset of builds.
  Don't validate on CMake builds since they're not currently
  
  generating API documentation even when Doxygen is available.
  

  • [DH] .travis.yml