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• Why when creating a video file from images using ffmpeg when playing the video file the quality is bad and the video is running too fast ?

  27 avril 2016, par Daniel Voit

   public void Start(string pathFileName, int BitmapRate)
  
          {
  
              try
  
              {
  
  
  
                  string outPath = pathFileName;
  
                  p = new NamedPipeServerStream(pipename, PipeDirection.Out, 1, PipeTransmissionMode.Byte);
  
                  ProcessStartInfo psi = new ProcessStartInfo();
  
                  psi.WindowStyle = ProcessWindowStyle.Hidden;
  
                  psi.UseShellExecute = false;
  
                  psi.CreateNoWindow = false;
  
                  psi.FileName = ffmpegFileName;
  
                  psi.WorkingDirectory = workingDirectory;
  
                  psi.Arguments = @"-f rawvideo -pix_fmt bgra -video_size 1920x1080 -i \\.\pipe\mytestpipe -c:v libx264 -crf 20 -r " + BitmapRate + " " + outPath;
  
                      //@"-f rawvideo -pix_fmt bgra -video_size 1920x1080 -i \\.\pipe\mytestpipe -c:v mpeg2video -crf 20 -r " + BitmapRate + " " + outPath;
  
  
  
                  process = Process.Start(psi);
  
                  process.EnableRaisingEvents = false;
  
                  psi.RedirectStandardError = true;
  
                  p.WaitForConnection();
  
              }
  
              catch (Exception err)
  
              {
  
                  Logger.Write("Exception Error: " + err.ToString());
  
              }
  
          }

  I tried to use either the first or second line.
  BitmapRate is set to 25
  I tried to change both 20 to 10 and also the BitmapRate to 10 or to 17. but the video on hard disk when playing it it’s only 3-4 seconds bad quality.
  I see all the images but too fast it’s like running I forward mode.

  Each file size is 8MB on hard disk.
  55 Bitmap files.
  The video file is 1072 KB

  Tried to google but I didn’t find any googd example to fix it.
  It’s not that it’s not creating the video file it does but with bad quality and running too fast.

  It’s strange why the created video file is so small if every file is 8MB and why so bad quality.

  The video

  video

• How to not add AdaptationSet for audio in cmd file if audio stream is not present in input video file

  15 juin 2019, par Saurabh

  I am using ffmpeg-dash to create mpd files. I am using following command to generate the same :

  ffmpeg -i input/video.mov \
  
          -map 0:v:0 -map 0:v:0 -map 0:v:0 -map 0:a\?:0 \
  
          -b:v:0 350k -c:v:0 libx264 -filter:v:0 "scale=320:-1" \
  
          -b:v:1 1000k -c:v:1 libx264 -filter:v:1 "scale=640:-1" \
  
          -b:v:2 3000k -c:v:2 libx264 -filter:v:2 "scale=1280:-1" \
  
          -use_timeline 1 -use_template 1 -window_size 6  -adaptation_sets "id=0,streams=v id=1,streams=a"  \
  
          -seg_duration 2 -threads 16 -hls_playlist true -f dash output/ffmpeg/output.mpd

  This works with video which has audio streams, but for the case there is no audio stream in the video file, I get empty entry for audio in mpd files like following, which is not valid and fails while playing in Exo Player in Android.

  <adaptationset contenttype="audio" segmentalignment="true" bitstreamswitching="true">
  
  </adaptationset>

  I tried adding ? in option adaptation_sets like : id=0,streams=v id=1,streams=a?, however that also adds above line.

  One solution is to run different commands for different videos by first checking whether there is audio stream or not, but would be better if there is some option which add audio adaptationSet only if audio stream is present in the input file.

• I want the mp4 file shooting date to be the xml file name

  21 novembre 2019, par re6

  In Windows 10 environment, I would like to change the name of both “file with extension mp4” and “file with extension xml” to the shooting date of mp4 file.

  C0001.MP4
  
  C0001M01.XML
  
  C0002.MP4
  
  C0002M01.XML

  Specifically, I want to change the file name as follows.

  2019-10-23_13-10-32.MP4
  
  2019-10-23_13-10-32.XML
  
  2019-10-23_13-10-49.MP4
  
  2019-10-23_13-10-49.XML

  ---

  I tried to think that using the ext option would give me the expected result, but I didn’t get the expected result.

  First time

  C:\Users\user>exiftool "-FileNamehoge/C0001M01.XML
  
  Warning: No writable tags set from C:/hoge/C0001M01.XML
  
  Warning: [minor] Error 3 placing ::NonRealTimeMetaAudioFormatAudioRecPortTrackDst in structure or list - C:/hoge/C0002M01.XML
  
  Warning: No writable tags set from C:/hoge/C0002M01.XML
  
      1 directories scanned
  
      0 image files updated
  
      2 image files unchanged

  Second time

  C:\Users\user>exiftool "-FileNamehoge/C0001.MP4
  
  Warning: [minor] Error 3 placing ::NonRealTimeMetaLtcChangeTableLtcChangeStatus in structure or list - C:/hoge/C0001M01.XML
  
  Warning: No writable tags set from C:/hoge/C0001M01.XML
  
  Warning: [minor] The ExtractEmbedded option may find more tags in the movie data - C:/hoge/C0002.MP4
  
  Warning: [minor] Error 3 placing ::NonRealTimeMetaAudioFormatAudioRecPortPort in structure or list - C:/hoge/C0002M01.XML
  
  Warning: No writable tags set from C:/hoge/C0002M01.XML
  
      1 directories scanned
  
      2 image files updated
  
      2 image files unchanged