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• configure : speed up flatten_extralibs_wrapper()

  30 juillet 2018, par Avi Halachmi (:avih)

  configure : speed up flatten_extralibs_wrapper()
  x50 - x200 faster.
  Currently configure spends 50-70% of its runtime inside a single
  
  function : flatten_extralibs[_wrapper] - which does string processing.
  During its run, nearly 20K command substitutions (subshells) are used,
  
  including its callees unique() and resolve(), which is the reason
  
  for its lengthy run.
  This commit avoids all subshells during its execution, speeding it up
  
  by about two orders of magnitude, and reducing the overall configure
  
  runtime by 50-70% .
  resolve() is rewritten to avoid subshells, and in unique() and
  
  flatten_extralibs() we "inline" the filter[_out] functionality.
  Note that logically, "unique" functionality has more than one possible
  
  output (depending on which of the recurring items is kept). As it
  
  turns out, other parts expect the last recurring item to be kept
  
  (which was the original behavior of uniqie()). This patch preservs
  
  its output order.
  Tested-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Tested-by : Helmut K. C. Tessarek <tessarek@evermeet.cx>
  
  Tested-by : Dave Yeo <daveryeo@telus.net>
  
  Tested-by : Reino Wijnsma <rwijnsma@xs4all.nl>
  
  Signed-off-by : James Almer <jamrial@gmail.com>
  

  • [DH] configure

• Loop, trim, change speed in one command

  24 avril 2020, par Nguyễn Trọng

  I am trying to cut a piece of background music and loop it into the video, while increasing the speed of the video. When I execute the command :

  



  String[] cmd = {"-y", "-i", input, "-i", shortsound,
                "-filter_complex", "[0:v]trim=0:240,setpts=1/2*(PTS-STARTPTS)[v1];" +
                "[1:a]atrim=0:6,asetpts=PTS-STARTPTS," +
                "asetrate=44100,aloop=20:size=20*44100,aformat=sample_fmts=fltp:sample_rates=44100:channel_layouts=stereo[a1];" +
                "[0:a]atrim=0:240,asetpts=PTS-STARTPTS,atempo=2.0" +
                ",aformat=sample_fmts=fltp:sample_rates=44100:channel_layouts=stereo,volume=0.5[a2];" +
                "[a1][a2]amerge=inputs=2,pan=stereo|c0code>

  



  I get a warning :

  



   [Parsed_amerge_12 @ 0xf545f660] No channel layout for input 2
   [Parsed_amerge_12 @ 0xf545f660] Input channel layouts overlap: output layout will be determined by the number of distinct input channels


  



  How to fix it ?
Thank in advance.

  


• How to speed up the process (merging audio to video) using FFmpeg in android ?

  22 octobre 2020, par RaJ

  I've add audio(mp3) to the video file(mp4) using FFmpeg library, Merging command in below

  


  String cmd = -i original.mp4 -i sample.mp3 -shortest -threads 0 -preset ultrafast -strict -2 output.mp4

  


  String[] command = cmd.split(" ") ;

  


  FFmpeg.getInstance(MainActivity.this).execute(command, new ExecuteBinaryResponseHandler()
     {
                    @Override
                    public void onFailure(String s) {
    
                    }
    
                    @Override
                    public void onSuccess(String s) {
    
                    }
    
                    @Override
                    public void onProgress(String s) {
    
                    }
                    @Override
                    public void onStart() {
    
    
                    }
    
                    @Override
                    public void onFinish() {
             
                    }
                });
            } catch (FFmpegCommandAlreadyRunningException e) {
             
            }


  


  This command working fine but it will take more time, Example I've add audio to 10second video merging time around 25-30sec.

  


  Anybody know how to increase the speed ? Please share or add your valuable information, Thanks.