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• Revision 32596 : minuscules et fin pour aujourd’hui

  1er novembre 2009, par fil@… — Log

  minuscules et fin pour aujourd’hui

• Video conversion with ffmpeg to target Android and iOS mobile devices

  17 novembre 2017, par Lee Brindley

  I’m building a react native app for both Android and IOS, the back-end API is written with NodeJS.

  Users may upload video from their phones, once uploaded the user and their friends will be able to view the video - so the videos need to be stored in a format which is playable on both Android & IOS.

  My question relates to the conversion of video, uploaded by the user. I developed a similar app a couple of years ago ; I used the repo node-fluent-ffmpeg which provides a nice API to interact with FFmpeg.

  In the previous project (which was a web app), I converted the uploaded videos into two files, one .mp4 and one .webm - if a user uploaded an mp4, then I would skip the mp4 step, likewise if they uploaded a .webm.

  This was kind of slow. Now I’ve come across the same requirement years later, after some research I think I was wrong to convert the videos to the last project.

  I’ve read that I can simply use FFmpeg to change the container format of the videos, which is a much faster process than converting them from scratch.

  The video conversion code I used last time went something along the lines of :

  var convertVideo = function (source, format, output, success, failure, progress) {
  
  
  
      var converter = ffmpeg(source);
  
  
  
      var audioCodec = "libvorbis";
  
  
  
      if (format.indexOf("mp4") != -1) {
  
          audioCodec = "aac";
  
      }
  
  
  
      converter.format(format)
  
          .withVideoBitrate(1024)
  
          .withAudioCodec(audioCodec)
  
          .on('end', success)
  
          .on('progress', progress)
  
          .on('error', failure);
  
  
  
      converter.save(output);
  
  };

  Usage :

  Convert to mp4 :

  convertVideo("PATH_TO_VIDEO", "mp4", "foo.mp4", () => {console.log("success");});

  Convert to webm :

  convertVideo("PATH_TO_VIDEO", "webm", "foo.webm", () => {console.log("success");});

  Can anyone point out a code smell here regarding the performance of this operation ? Is this code doing a lot more than it should achieve cross-platform compatibility between IOS and Android ?

  Might be worth mentioning that support for older OS versions is not such a big deal in this project.

• Continuous RTMP Streaming with FFmpeg Without Restarting the Process for New Videos

  3 avril 2024, par 刘小佳

  I'm facing a challenge with my workflow and would appreciate any guidance or solutions you might have. My business scenario involves a service that periodically generates new video files locally (e.g., 1.mp4, 2.mp4, ...). These files are then streamed to an RTMP server using FFmpeg, and clients pull the stream via HTTP-FLV for playback.

  


  My goal is to ensure continuous streaming between video files without restarting the FFmpeg process each time a new video is ready to be streamed. Restarting FFmpeg for each new file introduces a disconnect in the client playback, which I'm trying to avoid to maintain stream continuity.

  


  I've explored several approaches based on the FFmpeg Concatenate wiki (https://trac.ffmpeg.org/wiki/Concatenate), but haven't achieved the desired outcome :
  
Approach 1 :
  
Using a list.txt file with ffconcat version 1.0 and dynamically updating the file (next.mp4) being played :

  


  ffconcat version 1.0
file next.mp4
file next.mp4


  


  And then streaming with :
ffmpeg -re -stream_loop -1 -f concat -i list.txt -flush_packets 0 -f flv rtmp://xxx
  
However, when attempting to replace next.mp4 (e.g., moving 2.mp4 to next.mp4 during the streaming of 1.mp4), I encountered a "device busy" error.
  
Approach 2 :
  
Using a nested list approach where list1.txt includes 1.mp4 and list2.txt, and vice versa :

  


  // list1.txt
ffconcat version 1.0
file '1.mp4'
file 'list2.txt'
// list2.txt
ffconcat version 1.0
file '2.mp4'
file 'list1.txt'


  


  Streaming with : ffmpeg -re -stream_loop -1 -f concat -i list1.txt -flush_packets 0 -f flv rtmp://xxx
  
In this setup, I tried modifying list1.txt to replace 1.mp4 with 3.mp4 during the streaming of 2.mp4, but FFmpeg would loop back to 1.mp4 and 2.mp4 before streaming 3.mp4 in the next cycle.

  


  Am I missing something in my methods ? Does anyone have a better approach to fulfill this requirement ? Any help would be greatly appreciated !