Sur d’autres sites (7084)

• How to increase speed of ffmpeg stream when running in cli assuming streaming over network

  28 juin 2020, par VRu11ra

  I'd like to increase the speed of playback so that I can catch up to whatever the newest available audio packet is. Using PulseAudio on archlinux for server, client uses windows although that really shouldn't matter.

  


  Server commands issued :

  


  pactl load-module module-null-sink sink_name=remote
ffmpeg -f pulse -i "remote.monitor" -ac 2 -acodec pcm_s16le -ar 48000 -f s16le "udp://{LAN_IP_OF_CLIENT}:{PORT}"


  


  Client command issued :

  


  ffplay.exe -nodisp -ac 2 -acodec pcm_s16le -ar 48000 -analyzeduration 0 -probesize 32 -f u8 -i udp://0.0.0.0:{PORT}


  


  Current setup is using pavucontrol to put the audio output to the pactl sink from firefox and just keeping the cli application running somewhere. Often times the network is slow, and the audio will grow an increasingly noticable lag behind whatever is onscreen. When I re-execute the commands on both server and client it catches up. If possible I'd like to keep up with whatever's being broadcast- I figure the simplest solution is to nudge the playback speed a little faster than audio is being sent over so that in the mid-long term it will fix itself.

  


  If there's just a way to discard audio packets that aren't the newest ones and jump ahead when possible I'd prefer that as a solution- I know too little about ffmpeg to know if that's possible to do easily.

  


• Stream RTSP to HTML5 Video - which is the best approach ?

  13 janvier 2020, par Daniel

  As this task is very complicated I’ve created two approaches and I’d like to know which is the better approach for my purpose.

  Approach 1 :

  H264 frames are grabbed out of RTSP stream on the server (i.e. by ffmpeg), then they are put into a websocket and sent to the client. Client uses mp4box.js to fragment the h264 and then HTML5 video can render it with MSE.

  Approach 2 :

  H264 frames are grabbed out of RTSP stream and also fragmented on the server (i.e. by ffmpeg), then they are transferred directly to the client’s HTML5 video to render it with MSE.
  Here is an example for this approach.

  If we consider today’s client devices (modern phones, notebooks), we can state approach1 would be a better solution because it would prevent the central load on the server.

  However I have not really found any good resource or material on how to use approach1, hence I could not yet tried it out.

  I would like to know if approach1 is really better than approach2 ?

  because maybe grabbing and fragmenting would not put much higher load on the server than grabbing only

  (why I’m asking this ? because for approach2 I’ve a concrete example, whereas for approach1 I don’t. If approach1 is really better, I’ll go for it and implement the whole thing.)

  To put it more exact : does ffmpeg stress the server more if it grabs and fragments an rtsp-h264 stream to fmp4 than when it only grabs the frames from rtsp-h264 stream ?

• Ffmpeg speed up image extractio from higher quality video [closed]

  29 octobre 2020, par Expressingx

  I'm using ffmpeg and mage to create thumbnails for our web client. This is current fastest implementation I've found. However if the video quality is higher (e.g. full hd) it still takes a lot of time for 15 min video duration.

  


  Mage is used to create sprite image from the generate images and the .vtt file is manually created from the code. Those 2 are fast, so I have no concerns with them.

  


  Ffmpeg command

  


  ffmpeg.exe -loglevel panic -i video.mp4 -q:v 8 -vf "select=not(mod(n\,30)),scale=120:80" -vsync 0 -frame_pts 1 .\test\frame-%d.jpg


  


  I'm generating the jpegs with their frame time as name so I can parse and correctly display them in the client.

  


  Is there a way to make it faster ?