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• lavfi : addroi filter

  7 juillet 2019, par Mark Thompson

  lavfi : addroi filter
  This can be used to add region of interest side data to video frames.
  

  • [DH] doc/filters.texi
  • [DH] libavfilter/Makefile
  • [DH] libavfilter/allfilters.c
  • [DH] libavfilter/vf_addroi.c

• Combine multiple videos into one

  10 janvier 2012, par StackedCrooked

  I have three videos :

  • a lecture that was filmed with a video camera
  • a video of the desktop capture of the computer used in the lecture
  • and the video of the whiteboard

  I want to create a final video with those three components taking up a certain region of the screen.

  Is open-source software that would allow me to do this (mencoder, ffmpeg, virtualdub..) ? Which do you recommend ?

  Or is there a C/C++ API that would enable me to create something like that programmatically ?

  Edit
  There will be multiple recorded lectures in the future. This means that I need a generic/automated solution.

  I'm currently checking out if I could write an application with GStreamer to do this job. Any comments on that ?

  Solved !
  I succeeded in doing this with GStreamer's videomixer element. I use the gst-launch syntax to create a pipeline and then load it with gst_parse_launch. It's a really productive way to implement complex pipelines.

  Here's a pipeline that takes two incoming video streams and a logo image, blends them into one stream and the duplicates it so that it simultaneously displayed and saved to disk.

    desktop. ! queue
  
             ! ffmpegcolorspace
  
             ! videoscale
  
             ! video/x-raw-yuv,width=640,height=480
  
             ! videobox right=-320
  
             ! ffmpegcolorspace
  
             ! vmix.sink_0
  
    webcam. ! queue
  
            ! ffmpegcolorspace
  
            ! videoscale
  
            ! video/x-raw-yuv,width=320,height=240
  
            ! vmix.sink_1
  
    logo. ! queue
  
          ! jpegdec
  
          ! ffmpegcolorspace
  
          ! videoscale
  
          ! video/x-raw-yuv,width=320,height=240
  
          ! vmix.sink_2
  
    vmix. ! t.
  
    t. ! queue
  
       ! ffmpegcolorspace
  
       ! ffenc_mpeg2video
  
       ! filesink location="recording.mpg"
  
    t. ! queue
  
       ! ffmpegcolorspace
  
       ! dshowvideosink
  
    videotestsrc name="desktop"
  
    videotestsrc name="webcam"
  
    multifilesrc name="logo" location="logo.jpg"
  
    videomixer name=vmix
  
               sink_0::xpos=0 sink_0::ypos=0 sink_0::zorder=0
  
               sink_1::xpos=640 sink_1::ypos=0 sink_1::zorder=1
  
               sink_2::xpos=640 sink_2::ypos=240 sink_2::zorder=2
  
    tee name="t"

• ASP.NET MVC - Converting Video Format From Email Attachment Scanner

  24 juillet 2018, par BenHayward

  We have a Quartz scheduler that scans the company email account every 60 seconds, and will process those emails accordingly. Any attachments are stored in a byte array.

  Video attachments need to be converted to an MP4 and then back to a byte array to be stored in the DB ; I am trying to use FFMPEG (fflib) to complete this, however I’m having trouble figuring out how it can be done with a byte array as the source - the company have stated that this conversion must be done before it enters the database.

  Is the conversion of a byte array possible using the Process Class to access the FFMPEG CLI ?

  Here is the code I currently have, just using local file locations (using fflib ffmpeg library).

   public IList<documentstoreattachment> AddDocumentsToDocumentStore(IList<fileattachment> documentsToStore, Guid personId, IList<documentattributedto> documentAttributes)
  
          {
  
              var storedDocuments = new List<documentstoreattachment>();
  
  
  
              foreach (var documentToStore in documentsToStore)
  
              {
  
                  try
  
                  {
  
                      if (IsExtensionAllowed(documentToStore.AttachmentName))
  
                      {
  
  
  
                          if (documentToStore.MimeType == "mpeg")
  
                          {
  
                              Job2Convert job = new Job2Convert()
  
                              {
  
                                  pszSrcFile = @"..\..\Amigo Loans 2018 Advert MPG.mpg",
  
                                  pszDstFile = @"C:\Users\ben.hayward\Desktop\Amigo Loans 2018 Advert MPG.mp4",
  
  
  
                                  pszDstFormat = "mp4",
  
                                  pszAudioCodec = "aac",
  
  
  
                                  nAudioChannels = 2,
  
                                  nAudioBitrate = -1,
  
                                  nAudioRate = -1,
  
  
  
                                  pszVideoCodec = "h264",
  
  
  
                                  nVideoBitrate = -1,
  
                                  nVideoFrameRate = -1,
  
                                  nVideoFrameWidth = -1,
  
                                  nVideoFrameHeight = -1
  
  
  
                              };
  
  
  
                              _sut.ConvertFile(job);
  
  
  
                          }
  
  
  
                          storedDocuments.Add(AddDocumentToDocumentStore(documentToStore.AttachmentName, documentToStore.ByteArray, documentToStore.MimeType, personId, documentAttributes));
  
                      }
  
                      else
  
                      {
  
                          Logger.WarnFormat("AddDocumentsToDocumentStore: File extension not allowed for file name: {0}, person id: {1}", documentToStore.AttachmentName, personId);
  
                      }
  
                  }
  
                  catch (Exception e)
  
                  {
  
                      #region Error
  
  
  
                      Logger.Error(String.Format("There was a problem saving the document to the document store. The file name was {0}, person id: {1}",
  
                          documentToStore.AttachmentName, personId), e);
  
  
  
                      #endregion
  
                  }
  
              }
  
  
  
              return storedDocuments;
  
          }
  
  </documentstoreattachment></documentattributedto></fileattachment></documentstoreattachment>

  Thank you in advance.