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• Anomalie #3750 : Itérateur JSON, erreur de compilation lorsque la source contient &

  8 octobre 2018, par placido .

  J’avais fait le ticket au départ, notamment parce que le message de debug de compilation partait complètement en vrille, ce qui semble trahir un cas de remontée d’erreur pas bien géré.
  Pour le reste on a qu’à dire que cette page fera office de précis de documentation pour les urls de ressources JSON avec ’&’.

  Donc oui, on peut sans doute fermer.

• Insert still frames into H.264 video stream

  7 juillet 2021, par Bassinator

  I'm building an application that receives video packets which are encoded as H.264 from Microsoft Teams - I get one packet for each frame of video. Specifications of the packet contents are given here. For every packet I receive, I write the byte contents of the data[] buffer to a file. This resulting file is a playable H.264 encoded video.

  


  I'm trying to handle the scenario of syncing the audio and video streams from a Teams meeting, and inserting a still frame PNG as a "filler" when nobody has their camera on.

  


  I used the following FFMPEG command to generate n number of seconds of H.264 video from the filler frame :

  


  ffmpeg -loop 1 -i video_filler_frame.png -framerate 30 -c:v libx264 -t 2 -vf scale=1920:1080 C:\Code\temp\out.mp4


  


  This generates an MP4 file (H.264 encoded) - as a test in my code, I tried to read the contents of that generated file as a byte array and append them to the video file.

  


  However, this doesn't appear to work. I'm guessing this is because there is some kind of header or other metadata that prevents us from doing the simple solution of just appending the bytes of the next frame.

  


  My question is, how can I achieve what I am trying to do ? I'd like to splice in n number of frames as I am writing the individual packet contents to the file. In other words, for example, consider the following sequence :

  


  

  • Write packets of video to the file

  


  • My code determines that filler frames are needed at some point in this process

    

    • Insert needed number of filler frames to the file

    


    


  


  • Continue writing packets of video as they come in

  


  


• Using Gstreamer or ffmpeg to create rtsp client on Android

  9 décembre 2014, par Pankaj Bansal

  I want to stream a rtsp stream on android and I finally have come to
  conclusion that I can’t use android API’s MediaPlayer,Videoview etc because
  latency is big issue for me. I need an latency of <500 ms. Now I am
  planning to use Gstreamer or ffmpeg to create an android rtsp client. I just have few
  doubts

  1. Will the Gstreamer or ffmpeg client be able to provide latency <500ms. I read there are
     some parameters which I can tweak to get very low latency. Just want to
     confirm. I have very good network bandwidth. The frame size is generally
     1920X1080.

  2. I read Gstreamer is one made one level above ffmpeg and uses ffmpeg
     codecs to work. I want to know which one is easier to work with for creating an android client. Working on Gstreamer or workig directly on ffmpeg.

  3. If I use Gstreamer android client, Will I have to use the Gstreamer server as well to stream the data ? Currently I am using Live555 RTSP server to stream data