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• AJAX upload file with progres + FFMPEG progress

  24 octobre 2019, par Сергей Барахтенко

  The task is to implement the following :
  1. On the page there is a form for downloading a file, the file should be loaded asynchronously, without rebooting with the help of AJAX and displaying the upload progress
  2. If the file is successfully downloaded, send a command to the server, which should check the queue, and if the queue is empty, inform the client that the processing of the file has begun, then start the processing itself
  3. If processing has begun, then show the progress of this processing

  What did you manage to implement
  File upload was successfully implemented, after a successful upload, the server issues a line with the status successfully, and the full path of the downloaded file

  Upload JS snippet

  $.ajax({
  
      url: 'api/upload/load',
  
      type: 'post',
  
      data: fd,
  
      contentType: false,
  
      processData: false,
  
      xhr: function() {
  
          var xhr = new window.XMLHttpRequest();
  
          xhr.upload.addEventListener("progress", function(evt) {
  
              if (evt.lengthComputable) {
  
                  var percent = Math.ceil((evt.loaded / evt.total) * 100);
  
                  console.log(percent) // Upload progress
  
              }
  
          }, false);
  
          return xhr;
  
      },
  
      success: function(data){
  
          var response = JSON.parse(data);
  
          if(response.status == 'success'){
  
              //if upload success, run command
  
              startConversion(response.path)
  
          }
  
      }
  
  });

  Reponse from api/upload/load

  {"status":"success","path":"<path>"}
  
  </path>

  In the AJAX script, I do a check : if the response.status == ’success’, then we call the startConversion function, which takes the full path of the newly loaded file as an argument. This function sends another AJAX request to the server, where the queue check is in progress.

  startConversion JS Snippet

  function startConversion(path){
  
      $.ajax({
  
          url: '/api/upload/conversion',
  
          type: 'POST',
  
          data: { path: path },
  
          success: function(data){
  
              var response = JSON.parse(data);
  
              // if response.status == 'start', run checkConversion function
  
          }
  
      })

  Code /api/upload/conversion

  $queue = $this->model->getQueue();
  
  if($queue < 5){
  
      // If queue is empty, notify browser
  
      $output = array('progress' => 'start');
  
      echo json_encode($output);
  
      // Then start shell_ecxec
  
      $cmd = 'some_command';
  
      shell_exec('ffmpeg.exe -i ' . $path . ' ' . $cmd . ' 1>log.txt 2>&1 ');
  
  } else {
  
      $output = array('progress' => 'waiting');
  
      echo json_encode($output);
  
  }

  Here, for some reason, a message is already not being displayed stating that processing has begun (echo before $cmd)
  
  Full link

  And here the most interesting begins. It would seem that it would be possible in the method to success call the check on the status of the processing (start, queue or an error) and if the processing began to call the third function, which, again AJAX, polls the server returns the progress of the processing

  But in reality, the following happens : as soon as the second function sends the request, nothing is returned in response, but processing is in progress, and in the console it shows the status of the request - PENDING. As soon as the server completes processing, a response is issued from the server that the queue is empty and you can start processing the progress, although the processing has already been completed

  There are suggestions that further execution of the script is blocked by the command shell_exec() until the end of her work
  Also, it is not clear to me why the response from the server is not issued when the echo is clearly registered in it, and why the browser is waiting for the complete completion of the work shel_exec() because after it, the code does not have one. What should be done, that is, as if according to the logic of things and by the code, the server should give an answer in the form of a JSON string, the browser should show that the request has completed with the status of 200, and the server, in the meantime, should start the conversion, but for some reason this does not happen...

• ffmpeg : append JPEG frames to the end of video

  5 novembre 2018, par Digital Wizard

  I need to append JPEG images to the end of existing video file using ffmpeg tool.
  Input images have same resolution as the video. No audio streams. As far as I understood from the documentation, it is possible with using a complex filter. Please help me to do it.

  For example I have :
  Input image : frame0.jpg
  Input video : slideshow.avi ; fps : 1
  Expected output video : out.avi

  And what about allocated virtual memory ? Does the output format affect required size of the RAM buffer for concatenation process ? For example if the video size is 1GB and output format is standard .avi, will it be loaded into RAM 1GB buffer entirely while processing ? What output format should I use to reduce RAM usage ? Is .flv more suitable ?

• arm : Load mb_y properly in mbtree_propagate_list_internal_neon

  26 décembre 2016, par Martin Storsjö

  arm : Load mb_y properly in mbtree_propagate_list_internal_neon
  The previous version, attempting to load two stack parameters at once,
  
  only would have worked if they were interpreted and loaded as 32 bit
  
  elements, not when loading them as 16 bit elements.
  

  • [DH] common/arm/mc-a.S