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• openCV VideoCapture doesn't work with gstreamer x264

  18 juin 2014, par nschoe

  I’d like to display a rtp / vp8 video stream that comes from gstreamer, in openCV.

  I have already a working solution which is implemented like this :

  gst-launch-0.10 udpsrc port=6666 ! "application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)VP8-DRAFT-IETF-01,payload=(int)120" ! rtpvp8depay ! vp8dec ! ffmpegcolorspace ! ffenc_mpeg4 ! filesink location=videoStream

  Basically it grabs incoming data from a UDP socket, depacketize rtp, decode vp8, pass to ffmpegcolorspace (I still don’t understand what this is for, I see it everywhere in gstreamer).

  The videoStream is a pipe I created with mkfifo. On the side, I have my openCV code that does :

  VideoCapture cap("videoStream");

  and uses cap.read() to push into a Mat.

  My main concern is that I use ffenc_mpeg4 here and I believe this alters my video quality. I tried using x264enc in place of ffenc_mpeg4 but I have no output : openCV doesn’t react, neither does gstreamer, and after a couple of seconds, gst-launch just stops.

  Any idea what I could use instead of ffenc_mpeg4 ? I looked for "lossless codec" on the net, but it seems I am confusing things such as codec, contains, format, compression and encoding ; so any help would be (greatly) appreciated !

  Thanks in advance !

• Need help working ffmpeg in php

  15 mars 2015, par Lukas Kane

  I am working on a video uploading site. I have never converted videos from other users though. All signs point towards using ffmpeg, but I am honestly lost. I have installed it properly within my htdocs folder in my xampp folder, and I have the upload file php setup correctly, because it does upload the video file and moves the file to the right folder. I do have what I would think to be working ffmpeg code within the php code, but it is not working. I need to make all the files .mp4 no matter what the input file format is. I would appreciate someone helping to figure out my problem so much.

  "htdocs\new-video\upload\index.php" is where I have the code for ffmpeg and uploading the file. The htdocs\phpffmpeg\ folder is just the regular structure of phpffmpeg and ffmpeg installation.

  This is the code for the uploading and ffmpeg exec.

          $name = $_FILES["file"]["name"];
  
          $temp = explode(".", $_FILES["file"]["name"]);
  
          $extension = end($temp);
  
  
  
          move_uploaded_file($_FILES["file"]["tmp_name"],
  
          "(my file location that I move the file to)" . $_FILES["file"]["name"]);
  
  
  
          shell_exec("ffmpeg -i $name.$extension -b 1500k -vcodec libx264 -vpre slow -vpre baseline -g 30 $name.mp4");

  Like I said, the uploading and moving to folder works just fine. It is the not converting that is the problem. All links, tips, and information are greatly appreciated. Hope everyone has a great day.

• Embedding SMPTE 336M KLV data into video

  8 décembre 2023, par Mateo

  I have a drone video in .MP4 format, and an accompanying log file containing various timecoded data, e.g. GPS location, altitude.

  



  I need to embed the data into the video in the SMPTE 336M (KLV Data Encoding Protocol Using Key-Length-Value) standard format.

  



  I've successfully extracted KLV data from a MPEG2-TS file using FFMPEG and a parser in Node.

  



  Now I need to go the other way : to generate KLV data from my log file and insert it into the relevant video. How this is done ?