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• How to encode a series of .dpx files using X264

  4 juin 2015, par user3759710

  I am complete newbie to video encoding. I am trying to encode a series of .dpx files into one single encoded video O/P file in any of the following format. ( .mp4,.avi,.h264,.mkv etc)

  I have tried 2 different approaches. The first one works and the second one does not.
  I would like to know the difference between the two. Any help / input would be much appreciated.

  1) using FFMPEG along with x264 library and it works well. I am able to produce desired output

  ffmpeg -start_number 0 -i frame%4d.dpx -pix_fmt yuv420p -c:v libx264 -crf 28 
  
  -profile:v baseline fromdpx.h264

  2) I first try to concatenate all the dpx files into a single file using concate protocol in ffmpeg and then use x264 to encode the concatenated file.
  Here I see that the size of the concatenated file is the sum of all the files concatenated. But when I use x264 command to encode the concatenated file, I get a green screen (basically not the desired output) .

  ffmpeg -i "concat:frame0.dpx|frame01.dpx|frame2.dpx etc" -c copy output.dpx

  then

  x264 --crf 28 --profile baseline -o encoded.mp4 --input-res 1920x1080 --demuxer raw 
  
  output.dpx

  I also tried to encoded the concatenated file using ffmpeg as follows

  ffmpeg -i output.dpx -pix_fmt yuv420p -c:v libx264 -crf 28 -profile:v baseline fromdpx.h264

  This also gives me a blank video.

  Could someone please point out to me what is going on here ? Why does the first method work and the second does not ?

  Thank you.

• Can't upload folder with large amount of files to google storage. I using "@ffmpeg-installer/ffmpeg" and @google-cloud/storage

  20 juillet 2022, par Dmytro

  I upload file to google storage using "@ffmpeg-installer/ffmpeg" and @google-cloud/storage in my node.js App.
Step 1. file uploading to fs is in child processes - one process for each type of resolution (totaly six).
step 2. encription (converting to stream)
step 3. upload to google storage

  


  I use "Upload a directory to a bucket" in order to send the video from the client to the Google Cloud Storage bucket.

  


  This way is working fine only with small video.

  


  for example when I upload video with duration one hour it split on chunk and totally I get more three thousands files. But the problem occurs when there are more than 1500 files

  


  So actually i upload folder with large amount of files, but not all of this files are uploaded to cloud.

  


  maybe someone had the similar problem and helps fix it.

  


  


  


  const uploadFolder = async (bucketName, directoryPath, socketInstance) => {
    try {
      let dirCtr = 1;
      let itemCtr = 0;
      const fileList = [];

      const onComplete = async () => {
        const folderName = nanoid(46);

        await Promise.all(
          fileList.map(filePath => {
            const fileName = path.relative(directoryPath, filePath);
            const destination = `${ folderName }/${ fileName }`;

            return storage
              .bucket(bucketName)
              .upload(filePath, { destination })
              .then(
                uploadResp => ({ fileName: destination, status: uploadResp[0] }),
                err => ({ fileName: destination, response: err })
              );
          })
        );

        if (socketInstance) socketInstance.emit('uploadProgress', {
          message: `Added files to Google bucket`,
          last: false,
          part: false
        });

        return folderName;
      };

      const getFiles = async directory => {
        const items = await fs.readdir(directory);
        dirCtr--;
        itemCtr += items.length;
        for(const item of items) {
          const fullPath = path.join(directory, item);
          const stat = await fs.stat(fullPath);
          itemCtr--;
          if (stat.isFile()) {
            fileList.push(fullPath);
          } else if (stat.isDirectory()) {
            dirCtr++;
            await getFiles(fullPath);
          }
        }
      }

      await getFiles(directoryPath);

      return onComplete();
    } catch (e) {
      log.error(e.message);
      throw new Error('Can\'t store folder.');
    }
  };

  


  


  



• Mask dynamic logo using ffmpeg

  15 juin 2014, par Francesco De Pazzi

  I am trying to detect and hide a logo that dynamically positioned in a video.

  In this video the logo is positioned at the top and after a few minutes down etc.

  it’s possible to detect every time the logo when it changes place and hide it with ffmpeg ?

  I tried with delogo but I must tell the position x/y, so it is not possible in my case !

  Thank you very much !