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• Merge commit ’76729970049fe95659346503f7401a5d869f9959’

  13 juillet 2016, par Matthieu Bouron

  Merge commit ’76729970049fe95659346503f7401a5d869f9959’
  * commit ’76729970049fe95659346503f7401a5d869f9959’ :
  
    mov : Implement support for multiple sample description tables
  Notes :
  
    * The sc->stsc_data[index].id checks have been moved from the mov_read_stsc
  
    to mov_read_packet before the value is used in mov_change_extradata to
  
    not break playback of samples with broken stsc entries (see sample of
  
    ticket #1918).
    * sc->stsc_index is now checked against sc->stsc_count - 1 before it
  
    is incremented so it remains lesser than sc->stsc_count. Fixes a crash
  
    with :
    ./ffmpeg -i matrixbench_mpeg2.mpg -t 1 -frag_duration 200k test.mov
  
    ./ffprobe -show_packets test.mov
  Merged-by : Matthieu Bouron <matthieu.bouron@stupeflix.com>
  

  • [DH] libavformat/isom.h
  • [DH] libavformat/mov.c

• Can I use t with drawbox to simulate a playhead over a waveform in a generated video ?

  9 juillet, par terrorrussia-keeps-killing

  I want to simulate a playhead moving over a waveform, like when playing a track in an audio editor. As far as I understand, I can generate this effect if I have both the audio file and an image of the waveform.

  


  declare -r DURATION=$(ffprobe -i audio.flac -show_entries format=duration -v quiet -of csv="p=0")
ffmpeg -hide_banner -loop 1 -framerate 30 -i waveform.png -i audio.flac \
    -filter_complex "
    drawtext=text='%{pts\\:hms} -- %{n} -- %{pts\\:flt}':x=32:y=32:fontsize=24:fontcolor=black@0.75:box=1,
    drawbox=x=t*${DURATION}/iw/10000000:y=0:w=16:h=ih:color=CC1144@0.5:t=fill
    " \
    -map 1:a -shortest -t 5 -pix_fmt yuv420p playhead.mp4


  


  What it does :

  


  

  • Retrieves the duration of audio.flac.

  


  • Generates a video using waveform.png as a static background and audio.flac as the audio track. Using drawtext, I overlay time information on the video, and with drawbox I attempt to render the moving playhead. (For quicker testing, I limit the video to the first 5 seconds.)

  


  


  Note that I divide t by 10000000 just to make the box appear at all (otherwise it seems to be so big that it cannot fit the viewport). For whatever reason the box remains static, and I don't think that t even changes.

  


  What detail am I missing, and how can I at least obtain the value of t (for debug), so I can make the box move in sync with the current timestamp ?

  


• QtAV render in a widget crashes on application close

  23 novembre 2017, par user3606329

  I compiled FFmpeg statically + QtAV statically and QT statically.

  Once I add the QtAV player in a QWidget it crashes on application close. Did I miss any cleanup procdure ?

  MainWindow::MainWindow(QWidget *parent) :
  
      QMainWindow(parent),
  
      ui(new Ui::MainWindow)
  
  {
  
      ui->setupUi(this);
  
      QtAV::setLogLevel(QtAV::LogAll);
  
  
  
  
  
      AVPlayer *player = new AVPlayer();
  
      WidgetRenderer *renderer = new WidgetRenderer();
  
      renderer->show();
  
      player->addVideoRenderer(renderer);
  
      player->setFile("C:\\abc.mp4");
  
      ui->verticalLayout->addWidget(renderer->widget()); # will cause crash on exit. 
  
      player->play();
  
  
  
  }
  
  
  
  MainWindow::~MainWindow()
  
  {
  
    //  delete player; # I tried this and also the removal of the widget
  
   //   delete renderer; # It still does crash 
  
      delete ui;
  
  }

  The crash comes from

  WidgetRenderer *renderer = new WidgetRenderer();

  Once the renderer is embedded in a QWidget the application can’t exit gracefully somehow.

  I already tried to clean it up, remove the widget, delete the object, etc. but the crash still remains.

  The player works great and plays the videos ! It only gives a crash when the application is closed. (Doesn’t exit gracefully somehow).

  The QtAV log does not print anything about it.