Recherche avancée

Sur d’autres sites (12217)

• The GStreamer custom plugin's _transform_frame_ip function is not working [closed]

  28 octobre 2024, par Amiya

  I have created a custom GStreamer plugin named brightness I checked it with the gst-inspect-1.0 and gst-launch-1.0 commands and am able to get video output. I used the following command :

  


  gst-launch-1.0 filesrc location=sample-15s.mp4 ! decodebin ! videoconvert ! video/x-raw,format=RGB ! brightness brightness=1.0 ! videoconvert ! vp8enc ! webmmux ! filesink location=capture1.webm


  


  Codebaselink : link

  


  In the codebase, I am setting all data to 0, so I expect a black video in the output file, capture1.webm. However, I'm getting the same video as the input. I also added a print statement after setting the data to 0, and it printed 0 as expected. I'm not sure why the output is not as expected.

  


  _transform_frame_ip function details :

  


  static GstFlowReturn gst_brightness_transform_frame_ip(GstVideoFilter *filter, GstVideoFrame *frame) {
    GstBrightness *brightness = GST_BRIGHTNESS(filter);
    guint8 *data = GST_VIDEO_FRAME_PLANE_DATA(frame, 0);
    gsize size = GST_VIDEO_FRAME_COMP_PSTRIDE(frame, 0) * GST_VIDEO_FRAME_HEIGHT(frame);

    printf("frame received:%f\n", brightness->brightness);
    for (gsize i = 0; i < size; i++) {
        gint pixel = data[i] + (gint)(brightness->brightness * 255.0);
        data[i] = 0; //CLAMP(pixel, 0, 255);
    }

    return GST_FLOW_OK;
}


  


  I am expecting black video in the output file.

  


• FFmpeg insufficient thread locking only when deploying application using homebrew

  20 décembre 2012, par Kikohs

  I have the strangest bug of my life.
  I have installed ffmpeg using homebrew. I use it from a dll.
  I have set a lock manager because I use ffmpeg from multiple threads.

  In Engine.h :

  class EXPORT_LIB Engine
  
  {
  
  public:
  
      static int initEngine();    
  
      static int closeEngine();
  
  };

  In Engine.cpp :

  static int ff_lockmgr(void **mutex, enum AVLockOp op)
  
  {
  
  if (NULL == mutex)
  
      return -1;
  
  
  
  switch(op)
  
  {
  
  case AV_LOCK_CREATE:
  
  {
  
      *mutex = NULL;
  
      boost::mutex * m = new boost::mutex();
  
      *mutex = static_cast(m);
  
      break;
  
  }
  
  case AV_LOCK_OBTAIN:
  
  {
  
      boost::mutex * m =  static_cast(*mutex);
  
      m->lock();
  
      break;
  
  }
  
  case AV_LOCK_RELEASE:
  
  {
  
      boost::mutex * m = static_cast(*mutex);
  
      m->unlock();
  
      break;
  
  }
  
  case AV_LOCK_DESTROY:
  
  {
  
      boost::mutex * m = static_cast(*mutex);
  
      delete m;
  
      break;
  
  }
  
  default:
  
      break;
  
  }
  
  return 0;
  
  }
  
  
  
  
  
  int Engine::initEngine()
  
  {
  
      int res = -1;
  
      res = av_lockmgr_register(&ff_lockmgr);
  
      av_register_all();
  
      av_log_set_level(AV_LOG_QUIET); // ERROR, PANIC
  
      // Av lock manager success
  
      if( res == 0 ) {
  
          res = MULTITHREAD;
  
      }
  
      else {
  
          res = SINGLETHREAD;
  
      }
  
      return res;
  
  }
  
  
  
  int Engine::closeEngine()
  
  {
  
      int res = 0;
  
      res = av_lockmgr_register(NULL);
  
      return res;
  
  }

  So far so good, everything works as expected.

  When I deploy my app using CMake fix_bundle. I have an error message

  insufficient thread locking around avcodec_open/close()

  If I compile ffmpeg by hand in a custom location, when I deploy the app everything works as expected. What is wrong with homebrew ?

• FFMpeg HLS Video Transcoding Generating Partial Playlist

  26 avril 2021, par moberemk

  I'm trying to convert a basic mp4 video into an HLS video using ffmpeg (running on OSX) using the following command :

  



  ffmpeg -i SampleVideo_1280x720_10mb.mp4 -codec:v libx264 -codec:a aac -strict experimental -start_number 1 out.m3u8


  



  It does manage to generate all of the .ts segment files, but the resulting .m3u8 playlist file only lists the final four segment files, cutting out any earlier segments. Help ?