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• Add support for building fuzzer tools for an individual demuxer

  10 octobre 2020, par Michael Niedermayer

  Add support for building fuzzer tools for an individual demuxer
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] Makefile
  • [DH] tools/Makefile
  • [DH] tools/target_dem_fuzzer.c

• How to generate a GIF thumbnail from a video without saving individual frames to disk ?

  12 mars 2023, par Rabie Daddi

  I have a Node.js script that uses fluent-FFmpeg to generate a GIF thumbnail from a video for the first 4 seconds. Currently, the script saves individual frames as PNG images to disk, and then reads them back in to generate the GIF. However, this creates a lot of unnecessary I/O.

  


  Is there a way to modify the script to generate the GIF directly from the video frames, without saving them to disk first ? Ideally, I would like to do this while still using FFmpeg for the processing.

  


  Here's the current code for generating the frames and the GIF :

  


  function generateFrames(videoUrl) {
  return new Promise((resolve, reject) => {
    ffmpeg(videoUrl)
      .setStartTime(0) // start at 0 seconds
      .setDuration(4) // cut 4 seconds
      .videoFilters('scale=if(gte(iw\\,ih)\\,min(600\\,iw)\\,-2):if(lt(iw\\,ih)\\,min(600\\,ih)\\,-2)')
      .fps(4)
      .output('output/img%04d.png') // output file pattern with %04d indicating a sequence number with four digits
      .on('end', () => {
        console.log('GIF generated successfully!');
        resolve()
      })
      .on('error', (err) => {
        console.log('Error generating GIF: ' + err.message);
        reject()
      })
      .run();
  });
}

function generateGif() {
  const inputPattern = 'output/img%04d.png';
  const outputFilename = 'output/output2.gif';

  ffmpeg(inputPattern)
    .inputFPS(9)
    .output(outputFilename)
    .on('error', (err) => {
      console.log('Error generating GIF: ' + err.message);
    })
    .run();
}


execute = async () => {
  await generateFrames('video.mp4')
  generateGif()
}

execute()


  


  Any help or suggestions would be greatly appreciated. Thank you !

  


• Strange error [adding watermark to flv video with ffmpeg on linux centos 6]

  20 juillet 2012, par igor

  I have tried to do the job with following code :

  ffmpeg -i /home/igordr/video.flv -vf "movie=/home/igordr/wm.jpg [watermark]; [in][watermark] overlay=main_w/2-overlay_w/2:main_h/2-overlay_h/2 [out]" /home/igordr/outputvideo.flv

  Also tried :

  ffmpeg -i /home/igordr/video.flv -b:a 300k -ar 22050 -t 10 -f flv -s 352x288 -vf "movie = /home/igordr/wm.png [watermark]; [in][watermark] overlay =0:0 [out]" /home/igordr/out.flv

  I get errors :

  Unrecognized option 'vf'
  
  
  
  Unrecognized option 'b:a'

  Also, I am interested, how I can add just one big image, before video starts, without watermark, and does it possible ?

  How can i check ffmpeg version, and install new one if it's old ?