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• dnn/vf_dnn_detect.c : add tensorflow output parse support

  6 mai 2021, par Ting Fu

  dnn/vf_dnn_detect.c : add tensorflow output parse support
  Testing model is tensorflow offical model in github repo, please refer
  
  https://github.com/tensorflow/models/blob/master/research/object_detection/g3doc/tf2_detection_zoo.md
  
  to download the detect model as you need.
  
  For example, local testing was carried on with 'ssd_mobilenet_v2_coco_2018_03_29.tar.gz', and
  
  used one image of dog in
  
  https://github.com/tensorflow/models/blob/master/research/object_detection/test_images/image1.jpg
  Testing command is :
  
  ./ffmpeg -i image1.jpg -vf dnn_detect=dnn_backend=tensorflow:input=image_tensor:output=\
  
  "num_detections&detection_scores&detection_classes&detection_boxes":model=ssd_mobilenet_v2_coco.pb,\
  
  showinfo -f null -
  We will see the result similar as below :
  
  [Parsed_showinfo_1 @ 0x33e65f0]   side data - detection bounding boxes :
  
  [Parsed_showinfo_1 @ 0x33e65f0] source : ssd_mobilenet_v2_coco.pb
  
  [Parsed_showinfo_1 @ 0x33e65f0] index : 0,       region : (382, 60) -> (1005, 593), label : 18, confidence : 9834/10000.
  
  [Parsed_showinfo_1 @ 0x33e65f0] index : 1,       region : (12, 8) -> (328, 549), label : 18, confidence : 8555/10000.
  
  [Parsed_showinfo_1 @ 0x33e65f0] index : 2,       region : (293, 7) -> (682, 458), label : 1, confidence : 8033/10000.
  
  [Parsed_showinfo_1 @ 0x33e65f0] index : 3,       region : (342, 0) -> (690, 325), label : 1, confidence : 5878/10000.
  There are two boxes of dog with cores 94.05% & 93.45% and two boxes of person with scores 80.33% & 58.78%.
  Signed-off-by : Ting Fu <ting.fu@intel.com>
  
  Signed-off-by : Guo, Yejun <yejun.guo@intel.com>
  

  • [DH] libavfilter/vf_dnn_detect.c

• How do i compress a video file in c# (Xamarin android)

  1er août 2016, par stackOverNo

  I’m currently working on a xamarin.android project, and am attempting to upload a video to an aws server, and then also be able to play it back. The upload is working correctly as far as I can tell.

  I’m retrieving the file from the user’s phone, turning it into a byte array, and uploading that. This is the code to upload :

  if (isImageAttached || isVideoAttached)
  
              {
  
                  //upload the file 
  
                  byte[] fileInfo = System.IO.File.ReadAllBytes(filePath);
  
                  Task<media> task = client.SaveMediaAsync(fileInfo, nameOfFile);
  
                  mediaObj = await task;
  
  
  
                  //other code below is irrelevant to example
  
              }
  
  </media>

  and SaveMediaAsync is a function I wrote in a PCL :

  public async Task<media> SaveMediaAsync(byte[] fileInfo, string fName)
  
      {        
  
          Media a = new Media();
  
          var uri = new Uri(RestUrl);
  
  
  
          try
  
          {
  
  
  
              MultipartFormDataContent form = new MultipartFormDataContent();
  
              form.Add(new StreamContent(new MemoryStream(fileInfo)), "file", fName);  //add file
  
  
  
              var response = await client.PostAsync(uri, form);            //post the form   client is an httpclient object
  
              string info = await response.Content.ReadAsStringAsync();
  
  
  
      //save info to media object
  
              string[] parts = info.Split('\"');
  
              a.Name = parts[3];
  
              a.Path = parts[7];
  
              a.Size = Int32.Parse(parts[10]);
  
  
  
          }
  
          catch(Exception ex)
  
          {
  
      //handle exception
  
          }
  
  
  
          return a;
  
  
  
      }
  
  </media>

  After uploading the video like that, I’m able to view it in a browser using the public url. The quality is the same, and there is no issue with lag or load time. However when I try to play back the video using the same public url on my app on an android device, it takes an unbelievably long time to load the video. Even once it is loaded, it plays less than a second of it, and then seems to start loading the video again(the part of the progress bar that shows how much of the video has loaded jumps back to the current position and starts loading again).

   VideoView myVideo = FindViewById<videoview>(Resource.Id.TestVideo);
  
  
  
   myVideo.SetVideoURI(Android.Net.Uri.Parse(url));
  
  
  
   //add media controller
  
   MediaController cont = new MediaController(this);
  
   cont.SetAnchorView(myVideo);
  
   myVideo.SetMediaController(cont);
  
  
  
   //start video
  
   myVideo.Start();
  
  </videoview>

  Now I’m trying to play a 15 second video that is 5.9mb. When I try to play a 5 second video that’s 375kb it plays with no issue. This leads me to believe I need to make the video file smaller before playing it back, but I’m not sure how to do that. I’m trying to allow the user to upload their own videos, so I’ll have all different file formats and sizes.

  I’ve seen some people suggesting ffmpeg for a c# library to alter video files, but I’m not quite sure what it is I need to do to the video file. Can anyone fill in the gaps in my knowledge here ?

  Thanks for your time, it’s greatly appreciated !

• Xuggler encoding and muxing

  18 décembre 2012, par HeineyBehinds

  I'm trying to use Xuggler (which I believe uses ffmpeg under the hood) to do the following :

  • Accept a raw MPJPEG video bitstream (from a small TTL serial camera) and encode/transcode it to h.264 ; and
  • Accept a raw audio bitsream (from a microphone) and encode it to AAC ; then
  • Mux the two (audio and video) bitsreams together into a MPEG-TS container

  I've watched/read some of their excellent tutorials, and so far here's what I've got :

  // I'll worry about implementing this functionality later, but
  
  // involves querying native device drivers.
  
  byte[] nextMjpeg = getNextMjpegFromSerialPort();
  
  
  
  // I'll also worry about implementing this functionality as well;
  
  // I'm simply providing these for thoroughness.
  
  BufferedImage mjpeg = MjpegFactory.newMjpeg(nextMjpeg);
  
  
  
  // Specify a h.264 video stream (how?)
  
  String h264Stream = "???";
  
  
  
  IMediaWriter writer = ToolFactory.makeWriter(h264Stream);
  
  writer.addVideoStream(0, 0, ICodec.ID.CODEC_ID_H264);
  
  writer.encodeVideo(0, mjpeg);

  For one, I think I'm close here, but it's still not correct ; and I've only gotten this far by reading the video code examples (not the audio - I can't find any good audio examples).

  Literally, I'll be getting byte-level access to the raw video and audio feeds coming into my Xuggler implementation. But for the life of me I can't figure out how to get them into an h.264/AAC/MPEG-TS format. Thanks in advance for any help here.