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• FFMPEG color range cropped to 15-235 in RGB

  20 décembre 2017, par Some1Else

  I have a series of BMPs (or PNG) images that I want to convert to XVID and MP5 movie formats.

  Encoding works but the resulting movie has a washed out color look to it and the blacks are somehow moved to RGB 16 and the brightest 255 values are moved down to 235. I want the output movie to use the same 0 to 255 colors as the source frames.

  Now there are all sorts of conflicting doco out there for FFMPEG so I am hopinbg someone has an example command line that does what I need. I have tried all sorts of pix_fmt flags but none of them get the output movie in the full color range.

  For XVID

  ffmpeg.exe -framerate 60 -i "D:\SRC%05d.BMP"  -c:v mpeg4 -vtag xvid -qscale 1 -y "D:\OUTPUT.AVI""

  For H265

  ffmpeg.exe -framerate 60 -i "D:\SRC%05d.BMP" -c:v libx265 -x265-params lossless=1 -s 3840x2160 -pix_fmt yuvj420p -an -y "D:\OUTPUT.MP4""

  The yuvj420p is supposed to give the full color range but ffmpeg complains "Incompatible pixel format ’yuvj420p’ for codec ’libx265’, auto-selecting format ’yuv420p’"

  So, are there any FFMPEG gurus out there that can give me the magic switches to get my output movies with black blacks and colors that maintain the original frame files 0-255 RGB values.

• FFMPEG spawn promise not resolving

  24 décembre 2020, par fitzmode

  I have a problem where running ffmpeg with spawn using the event listener API for close or exit events works fine but when I try to convert spawn into a Promise it does not resolve.

  


  I'm

  


  This works fine

  


   const ls = spawn(ffmpeg_static.path,`-i movie.mov movie.mp4`.split(" ");

    //Listen for processing close
  ls.on("close", (code) => {
        console.log(`child process exited with code ${code}`);
        
     });



  


  function pspawn(args) {
 
  // *** Return the promise
  return new Promise(function (resolve, reject) {
 
    const process = spawn(ffmpeg_static.path, args);
//Listen for close and resolve.
    process.on("close", function (code) {
    
      resolve("Complete");
    });
    process.on("error", function (err) {
       // *** Process creation failed
       reject(err);
    });
  });
}

... 

async function run () {
await pspawn(['-i', 'movie.mov','movie.mp4'])
}


  


  I might be missing something simple but can't seem to figure out what it is.

  


• Grab frame without downloading whole file ?

  12 janvier 2012, par Writecoder

  Is this possible using php + ffmpeg ?

  ffmpeg-php has the ability to :

  Ability to grab frames from movie files and return them as images that
  can be manipulated using PHP's built-in image functions. This is great
  for automatically creating thumbnails for movie files.

  I just don't want to download the whole file before doing so.
  So lets say i want to grab a frame @ 10% of the movie :

  First lets get the size of remote file :

  $ch = curl_init(); 
  
  curl_setopt($ch, CURLOPT_HEADER, true); 
  
  curl_setopt($ch, CURLOPT_NOBODY, true);
  
  curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); 
  
  curl_setopt($ch, CURLOPT_URL, $url); //specify the url
  
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE); 
  
  $head = curl_exec($ch);
  
  
  
  $size = curl_getinfo($ch,CURLINFO_CONTENT_LENGTH_DOWNLOAD);

  Then it's quite easy to download only 10% of the .flv or .mov file using curl.

  But the framegrab trick using ffmpeg-php probably won't work because the file probably is corrupted ?

  Any other ideas ?