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• ffmpeg with partial motion detection

  2 mars 2021, par Silentfury

  I have video files from a static surveillance camera and I try to re-encode them using some sort of motion detection filter (keeping the movements, droping the stills) in order to save space and play time.

  


  I have successfully tried the two below filter options but it still feels not good enough. :

  


  

  • mpdecimate e.g. -vf "mpdecimate=hi=6480:lo=6420:frac=0.1,setpts=N/(15*TB)"

  


  • select (e.g. -vf "select=gt(scene,0.4)")

  


  


  The main problem is a moving bush in the camera view, that I would like to exclude from the motion detection.

  


  Is there other/better ways of applying motion detection (and stills dropping) to ffmpeg ?
Is there any way to mask areas of the video that will be ignored in the above mentioned (or any other) motion detection filter/method ?

  


  Many thanks in advance !

  


  Edit :
in the mean time I found this excellent answer from Gyan

  


  I am testing this now but would still appreciate other ideas

  


• Can't upload huge video to google storage. I using "@ffmpeg-installer/ffmpeg" and @google-cloud/storage

  20 juillet 2022, par Dmytro Petskovych

  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 file.

  


  when I upload video, actually I upload six videos, one for each type resolution

  


  for example when I upload video with duration one hour it split on chunk and totally I get more three thousands 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.');
    }
  };

  


  


  



• Android's FFmpegMediaMetadataRetriever's getFrameAtTime() returns corrupted Bitmap

  18 août 2015, par Miko Diko

  I have code that retrieves frames from a video.
  It works ok, but when it gets to the last frame of a video, it returns a Bitmap which has (width = 1 and height = 8), from a 9:16 video.

  What are the possible reasons ?