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• Save frame as image during video stream using ffmpeg, in C

  30 avril 2017, par George T.

  I’m using the Parrot SDK3 to retrieve the video stream from a Bebop2 drone. From it I need to "extract" a frame and save it as an image.

  The whole code can be found here, but I shall try to include the (what I understand as) important parts here.

  Where the video is sent to mplayer. I assume from this that the video format is h624.

  if (videoOut != NULL)
  
  {
  
      if (codec.type == ARCONTROLLER_STREAM_CODEC_TYPE_H264)
  
      {
  
          if (DISPLAY_WITH_MPLAYER)
  
          {
  
              fwrite(codec.parameters.h264parameters.spsBuffer, codec.parameters.h264parameters.spsSize, 1, videoOut);
  
              fwrite(codec.parameters.h264parameters.ppsBuffer, codec.parameters.h264parameters.ppsSize, 1, videoOut);
  
  
  
              fflush (videoOut);
  
          }
  
      }
  
  }

  Where the frame is received and written to videoOut, to be displayed

  eARCONTROLLER_ERROR didReceiveFrameCallback (ARCONTROLLER_Frame_t *frame, void *customData)
  
  {
  
      if (videoOut != NULL)
  
      {
  
          if (frame != NULL)
  
          {
  
              if (DISPLAY_WITH_MPLAYER)
  
              {
  
                  fwrite(frame->data, frame->used, 1, videoOut);
  
  
  
                  fflush (videoOut);
  
              }
  
          }
  
      }
  
      return ARCONTROLLER_OK;
  
  }

  The idea I had in mind is to fwrite(frame->data, frame->used, 1, videoOut); to a different file but that just creates a corrupted file, probably because of encoding. In what way can I get this frame and store it to a separate image ? The preferable image filetype .png, .jpg or .gif

  Any help will be greatly appreciated ! Thanks in advance !

• Slicing an AVI file

  7 novembre 2014, par Peter Lur

  I am trying to upload only a certain part of an AVI file on the server without having to upload the whole file first.

  If I set the slice to the beginning (byte : 0), I can read the resulting file no problem even if I slice it in any size. However if the slice start anywhere but not at byte 0, the file become unreadable. I guess this has something to do with the avi header/index being messed up. I was wondering maybe I could use ffmpeg to move the header or something ?

  HTML Source

      
  
          
  
          <code class="echappe-js">&lt;script type=&quot;text/javascript&quot;&gt;<br />
  
  <br />
  
              window.BlobBuilder = window.MozBlobBuilder || window.WebKitBlobBuilder || window.BlobBuilder;<br />
  
  <br />
  
              function sendRequest() {<br />
  
                  var blob = document.getElementById('fileToUpload').files[0];<br />
  
  <br />
  
  <br />
  
                  //Slicing parameters<br />
  
  <br />
  
  <br />
  
                  //#1: Starting at byte:0 = WORKING WELL<br />
  
                  var start = 0;<br />
  
                  var end = 1048576;  // 1MB chunk sizes.<br />
  
  <br />
  
  <br />
  
                  //#2: Slicing the video file somewhere else (FAIL)<br />
  
  <br />
  
                  /*<br />
  
                  var start = 1048576*3;<br />
  
                  var end = 1048576*4;<br />
  
                  */<br />
  
  <br />
  
  <br />
  
                  var chunk = blob.slice(start, end, 'video/avi');<br />
  
                  uploadFile(chunk);<br />
  
  <br />
  
              }<br />
  
  <br />
  
              function fileSelected() {<br />
  
                  var file = document.getElementById('fileToUpload').files[0];<br />
  
                  if (file) {<br />
  
                      var fileSize = 0;<br />
  
                      if (file.size &gt; 1024 * 1024)<br />
  
                          fileSize = (Math.round(file.size * 100 / (1024 * 1024)) / 100).toString() + 'MB';<br />
  
                      else<br />
  
                          fileSize = (Math.round(file.size * 100 / 1024) / 100).toString() + 'KB';<br />
  
  <br />
  
                      document.getElementById('fileName').innerHTML = 'Name: ' + file.name;<br />
  
                      document.getElementById('fileSize').innerHTML = 'Size: ' + fileSize;<br />
  
                      document.getElementById('fileType').innerHTML = 'Type: ' + file.type;<br />
  
                  }<br />
  
              }<br />
  
  <br />
  
              function uploadFile(blobFile) {<br />
  
                  //var file = document.getElementById('fileToUpload').files[0];  <br />
  
                  var fd = new FormData();<br />
  
                  fd.append(&quot;fileToUpload&quot;, blobFile);<br />
  
  <br />
  
                  var xhr = new XMLHttpRequest();<br />
  
                  xhr.upload.addEventListener(&quot;progress&quot;, uploadProgress, false);<br />
  
                  xhr.addEventListener(&quot;load&quot;, uploadComplete, false);<br />
  
                  xhr.addEventListener(&quot;error&quot;, uploadFailed, false);<br />
  
                  xhr.addEventListener(&quot;abort&quot;, uploadCanceled, false);<br />
  
                  xhr.open(&quot;POST&quot;, &quot;upload.php&quot;);<br />
  
                  xhr.onload = function(e) {<br />
  
                    //alert(&quot;loaded!&quot;);<br />
  
                    };<br />
  
  <br />
  
                  xhr.send(fd);<br />
  
                  //alert(&quot;oen over&quot;);<br />
  
              }<br />
  
  <br />
  
              function uploadProgress(evt) {<br />
  
                  if (evt.lengthComputable) {<br />
  
                      var percentComplete = Math.round(evt.loaded * 100 / evt.total);<br />
  
                      document.getElementById('progressNumber').innerHTML = percentComplete.toString() + '%';<br />
  
                  }<br />
  
                  else {<br />
  
                      document.getElementById('progressNumber').innerHTML = 'unable to compute';<br />
  
                  }<br />
  
              }<br />
  
  <br />
  
              function uploadComplete(evt) {<br />
  
                  /* This event is raised when the server send back a response */<br />
  
                  //alert(evt.target.responseText);<br />
  
              }<br />
  
  <br />
  
              function uploadFailed(evt) {<br />
  
                  alert(&quot;There was an error attempting to upload the file.&quot;);<br />
  
              }<br />
  
  <br />
  
              function uploadCanceled(evt) {<br />
  
                  xhr.abort();<br />
  
                  xhr = null;<br />
  
                  //alert(&quot;The upload has been canceled by the user or the browser dropped the connection.&quot;);<br />
  
              }<br />
  
          &lt;/script&gt;
  
              
  
                  Select a File to Upload
  
                  
                  
              
              
  
              
  
              
  
              
  
                  
              
              
  
          
  

  PHP Source (upload.php)

  <?php
  
  
  
  $tmp_name = $_FILES['fileToUpload']['tmp_name'];
  
  $size = $_FILES['fileToUpload']['size'];
  
  $name = $_FILES['fileToUpload']['name'];
  
  
  
  $target_file = basename($name);
  
  
  
  $complete = "complete.avi";
  
  $com = fopen($complete, "ab");
  
  
  
  // Open temp file
  
  $out = fopen($target_file, "wb");
  
  
  
  if ( $out ) {
  
      // Read binary input stream and append it to temp file
  
      $in = fopen($tmp_name, "rb");
  
      if ( $in ) {
  
          while ( $buff = fread( $in, 1048576 ) ) {
  
              fwrite($out, $buff);
  
              fwrite($com, $buff);
  
          }   
  
      }
  
      fclose($in);
  
      fclose($out);
  
  }
  
  fclose($com);
  
  
  
  ?>

• Relative Path for React-Native-ffmpeg ?

  27 juillet 2023, par christen03

  I'm using react-native-ffmpeg and I'm trying to add some text and an image to my videos. I'm trying to get use a font file through a relative path, but I'm having some issues. Everything is executing correctly, but my video is saved using some default font instead of the font I want it to use.

  


  This is the code I'm trying, these two lines to set the fontDirectory/path,

  


      await FFmpegKitConfig.setFontDirectory("../fonts");
    const fontFilePath = "../fonts/Montserrat-Medium.ttf";



  


  then the command that I execute.
-y -i ${inputFilePath} -i ${randomImage} -filter_complex "[0:v][1:v] overlay=${imgWidthScale * windowWidth}:${imgHeightScale * windowHeight}, drawtext=fontfile=${fontFilePath}:text=@${selfUser.username}:fontsize=${fontSize}:fontcolor=white:x=${textWidthScale * windowWidth}:y=${textHeightScale * windowHeight}" -codec:a copy ${outputPath}

  


  I'm sure my font file is insde the fonts directory and that this path is correct. However, this is the error I'm getting in my terminal :

  


  [AVFilterGraph @ 0x2877c2fa0] Error initializing filter 'drawtext'
 LOG  [AVFilterGraph @ 0x2877c2fa0]  with args 'fontfile=../fonts/Montserrat-Medium.ttf:text=@chris:fontsize=36:fontcolor=white...


  


  Which I'm not too sure about, but looks like the colon delimiter is not working ? However it seems to be reading all my other arguments fine as my text, fontsize, color, and position work with no issues.

  


  Is there something I'm doing wrong in my command ? Or setting up my font directory ? Or does ffmpeg not work with relative paths ? I appreciate any help :)