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• How to translate bgr data to CVPixelBufferRef ?or how to play just bgr data in iOS

  4 décembre 2016, par warlock

  I have got some RGB data used live555 & FFmpeg, but how can I play it as a video ?

  I Google a lot and found that avplayer maybe help. Others I searched link me to UIImage translate to rgb...or your search returned no matches.

  This is one I searched, but it is "Create ", not "Play ".

  possible to create a video file from RGB frames using AV Foundation

  I try to use AVsampleBufferDisplayLayer, but I don’t know how to translate.

  Anyone can help ?

• Revision 4c05a051ab : Move qcoeff, dqcoeff from BLOCKD to per-plane data Start grouping data per-plan

  2 avril 2013, par John Koleszar

  Changed Paths : Modify /vp9/common/vp9_blockd.h Modify /vp9/common/vp9_invtrans.c Modify /vp9/common/vp9_mbpitch.c Modify /vp9/common/vp9_rtcd_defs.sh Modify /vp9/decoder/vp9_decodframe.c Modify /vp9/decoder/vp9_dequantize.c Modify /vp9/decoder/vp9_dequantize.h (...)

• real time video streaming in C#

  16 juin 2016, par Nuwan

  I’m developing an application for real time streaming. Two parts include for the streaming.
  I use a capture card to capture some live source and need to stream in real time.
  and also need to stream a local video file.

  To stream local video file in real time I use emgu cv to capture the video frame as bitmaps.
  To achieve this I create the bitmap list and I save captured bitmap to this list using one thread.
  and also I display those frames in a picture box. Bitmap list can store 1 second video. if frame rate is
  30 it will store 30 video frames. After filling this list I start another thread to encode that 1 second chunk
  video.

  For encoding purpose I use ffmpeg wrapper called nreco. I write that video frames to ffmpeg
  and start the ffmpeg to encode. After stopping that task I can get encoded data as byte array.

  Then I’m sending that data using UDP protocol through LAN.

  This works fine. But I cannot achieve the smooth streaming. When I received stream via VLC player there is some millisecond of delay between packets and also I noticed there a frame lost.

  private Capture _capture = null;
  
  Image frame;
  
  
  
  // Here I capture the frames and store them in a list
  
  private void ProcessFrame(object sender, EventArgs arg)
  
  {
  
       frame = _capture.QueryFrame();
  
       frameBmp = new Bitmap((int)frameWidth, (int)frameHeight, PixelFormat.Format24bppRgb);
  
       frameBmp = frame.ToBitmap(); 
  
  
  
  
  
   twoSecondVideoBitmapFramesForEncode.Add(frameBmp);
  
                          ////}
  
       if (twoSecondVideoBitmapFramesForEncode.Count == (int)FrameRate)
  
       {
  
           isInitiate = false;
  
           thread = new Thread(new ThreadStart(encodeTwoSecondVideo));
  
           thread.IsBackground = true;
  
           thread.Start();
  
       }  
  
   }
  
  
  
  public void encodeTwoSecondVideo()
  
  {
  
      List<bitmap> copyOfTwoSecondVideo = new List<bitmap>();
  
      copyOfTwoSecondVideo = twoSecondVideoBitmapFramesForEncode.ToList();
  
      twoSecondVideoBitmapFramesForEncode.Clear();
  
  
  
      int g = (int)FrameRate * 2;
  
  
  
      // create the ffmpeg task. these are the parameters i use for h264 encoding
  
  
  
          string outPutFrameSize = frameWidth.ToString() + "x" + frameHeight.ToString();
  
          //frame.ToBitmap().Save(msBit, frame.ToBitmap().RawFormat);
  
          ms = new MemoryStream();
  
          //Create video encoding task and set main parameters for the video encode
  
  
  
          ffMpegTask = ffmpegConverter.ConvertLiveMedia(
  
              Format.raw_video,
  
              ms,
  
              Format.h264,
  
              new ConvertSettings()
  
              {
  
  
  
                  CustomInputArgs = " -pix_fmt bgr24 -video_size " + frameWidth + "x" + frameHeight + " -framerate " + FrameRate + " ", // windows bitmap pixel format
  
                  CustomOutputArgs = " -threads 7 -preset ultrafast -profile:v baseline -level 3.0 -tune zerolatency -qp 0 -pix_fmt yuv420p -g " + g + " -keyint_min " + g + " -flags -global_header -sc_threshold 40 -qscale:v 1 -crf 25 -b:v 10000k -bufsize 20000k -s " + outPutFrameSize + " -r " + FrameRate + " -pass 1 -coder 1 -movflags frag_keyframe -movflags +faststart -c:a libfdk_aac -b:a 128k "
  
                  //VideoFrameSize = FrameSize.hd1080,
  
                  //VideoFrameRate = 30
  
  
  
              });
  
  
  
          ////////ffMpegTask.Start();
  
          ffMpegTask.Start();
  
  
  
  
  
        // I get the 2 second chunk video bitmap from the list and write to the ffmpeg 
  
    foreach (var item in copyOfTwoSecondVideo)
  
          {
  
              id++;
  
              byte[] buf = null;
  
              BitmapData bd = null;
  
              Bitmap frameBmp = null;
  
  
  
              Thread.Sleep((int)(1000.5 / FrameRate));
  
  
  
              bd = item.LockBits(new Rectangle(0, 0, item.Width, item.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
  
              buf = new byte[bd.Stride * item.Height];
  
              Marshal.Copy(bd.Scan0, buf, 0, buf.Length);
  
              ffMpegTask.Write(buf, 0, buf.Length);
  
              item.UnlockBits(bd);
  
          }
  
     }
  
  </bitmap></bitmap>

  This is the process I used to achieve the live streaming. But the stream is not smooth. I tried using a queue instead
  of list to reduce the the latency to fill the list. Because I thought that latency happens encoding thread encode
  and send 2 second video very quickly. But when it finishes this encoding process of bitmap list not
  completely full. So encoding thread will stop until the next 2 second video is ready.

  If any one can help me to figure this out, it is very grateful. If the way of I’m doing this is wrong, please correct me.
  Thank You !