Recherche avancée

Sur d’autres sites (11097)

• Node.js Live Streaming : Avoid buffering

  27 octobre 2012, par Shirish Kamath

  I've written a small nodeJS server that outputs system audio captured by ffmpeg on Windows (using DirectShow) to the browser as a streaming MP3 file. The audio needs to be as live as possible, with minimum/no buffering, and a "skipping" effect in the audio is perfectly acceptable.

  When I play the audio in Chrome using the HTML5 audio tag, there's a delay of about 8-10 secs over a low-latency LAN connection. I suspected this to be a client-side buffer, and used a Flash MP3 player on the client-side, which brought down the delay to 2-3 secs.

  Now, the buffering seems to taking place on the server-side. The documentation for NodeJS's response.write mentions that the data is written kernel buffers. How do I go about avoiding any buffering altogether or at least getting around it, so that the client always gets the latest audio data ? Strategies for handling 'drain' events to always push live data ?

  On the request object, I've used setNoDelay(true) to avoid the use of Nagle's algorithm. Following is a snippet of how data is written when the spawned ffmpeg process emits data.

  var clients = []; //List of client connections currently being served
  
  ffmpeg.stdout.on('data', function(data) {
  
      for(var i = 0; i < clients.length; i++){
  
          clients[i].res.write(data);
  
      }
  
  });

• Why do I get a black box when I tile pictures with -filter_complex tile=2x1 in FFmpeg ?

  19 juin 2016, par Mateusz Piotrowski

  As I was trying to write a script (which attempts to join two pictures eventually) using FFmpeg I came across a very weird behaviour.

  I’ve found a command in an accepted answer for the very same problem I had (How to join two image into one by ffmpeg ?) :

  ffmpeg -i a.jpg -i b.jpg -filter_complex scale=120:-1,tile=2x1 output.jpg

  • Input : a.jpg, b.jpg

    

  • Output : output.jpg

    

  What happened to the B cat ? Why is it missing from the output image ? I couldn’t find any information why tile=2x1 behaves like this.

• FFmpeg : How to convert vertical/horizontal video (any size) with black sides, to 1080x1350 vertical video with blurred background sides/bottom-top

  12 octobre 2023, par devweb

  i've been trying to make a ffmpeg 'filter_complex' code to make what i need but i can't, i've used some codes here on stack but non works for what i need, each is like for a different size/dimension.
I'm trying to make videos like Instagram posts (tallest allowed) : 1080 x 1350

  


  Bassically, horizontal videos with blurred sides or bottom-top.

  


  Any help will be awesome, thanks !

  


  This is the principal which i tried

  


  Something like this :

  


  Example 1
Example 2

  


  Here some codes i tried to worked with and changing stuff :
filter_complex='[0:v]scale=1080*2:1350*2,boxblur=luma_radius=min(h\\,w)/20:luma_power=1:chroma_radius=min(cw\\,ch)/20:chroma_power=1[bg];[0:v]scale=-1:1080[ov];[bg][ov]overlay=(W-w)/2:(H-h)/2,crop=w=1080:h=1350'

  


  filter_complex='[0:v]scale=ih*5/4:-1,crop=h=iw*4/5,gblur=sigma=20[blurred];[blurred][0:v]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2'

  


  filter_complex='[0:v]scale=1080:1350,setsar=1,gblur=sigma=20[blurred];[blurred][0:v]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2'