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• ffmpeg in PHP : Resizing image works, but getting a 404 when trying to load resized image ?

  13 décembre 2016, par Eric David Sartor

  PHP :

  if ($output = shell_exec("ffmpeg -i localhost/video/tools/poster.png -vf scale=32:32 localhost/video/tools/poster_small.png 2>&1") !== NULL)
  
      echo $output;
  
  
  
  echo "Original:<br /><img src="http://stackoverflow.com/feeds/tag/poster.png" style='max-width: 300px; max-height: 300px' /><br /><br />Resize:<br /><img src="http://stackoverflow.com/feeds/tag/poster_small.png" style='max-width: 300px; max-height: 300px' />";

  So I’m trying to have an image upload form that creates a smaller version of the uploaded image after the upload is verified. All that works fine, and when I run this command with ffmpeg, the $output is 1. That obviously means that it isn’t returning NULL, which means ffmpeg is functioning in theory...but here’s the weird part...

  I’m echoing the images out into the HTML to visually verify if they worked, and what I get (for the resized image) is a 32x32 image container, but the image doesn’t load (404 in the dev console), which to me makes no sense. If the image container is 32x32, that means that the resize must’ve worked because that’s the size I told it to be in the ffmpeg command, but if the page isn’t loading the image, how did it even get the information that the image needed to be 32x32 ? I didn’t set that in the HTML/CSS anywhere...what’s going on here ?

  I’m running this on Windows in a XAMPP server. I’ve installed ffmpeg and verified it is working in the Windows command prompt. All the files are in localhost/video/tools/, other than the ffmpeg files of course, which are in localhost/ffmpeg/.

  A screenshot of the HTML output : http://ericsartor.ca/Capture.PNG

• OpenCV accept HTTP video streaming with different endpoints

  22 juin 2019, par nabroyan

  I am writing a server, which receives live video stream over HTTP and performs some operations for different endpoints.

  I am using OpenCV for that and my basic code looks somethings like this

  void f1()
  
  {
  
      cv::VideoCapture cap("http://localhost:8080/operation1");
  
      if (!cap.isOpened())
  
          return;
  
  
  
      for (;;)
  
      {
  
          cv::Mat frame;
  
          cap >> frame;
  
  
  
          // do something
  
      }
  
  }
  
  
  
  void f2()
  
  {
  
      cv::VideoCapture cap("http://localhost:8080/operation2");
  
      if (!cap.isOpened())
  
          return;
  
  
  
      for (;;)
  
      {
  
          cv::Mat frame;
  
          cap >> frame;
  
  
  
          // do something else
  
      }
  
  }
  
  
  
  void f3() {...}

  As you see each function listens to a different HTTP endpoint and does different operation. Each function runs in a separate thread.

  The problem is that for some reason OpenCV ignores the resource part in endpoint i.e. if ip:port is correct it will accept the stream no matter it is from operation1 or operation2.

  For testing purposes I use this command as a stream generator
  ffmpeg -i sample.mp4 -listen 1 -f matroska -c:v libx264 -preset fast -tune zerolatency  http://localhost:8080/operation1

  How can I make OpenCV to differentiate between HTTP endpoints ? What am I missing ? I have no any previous experience with OpenCV and photo/video stuff.

• React Video Player failing to read RTSP stream

  20 octobre 2023, par hotmeatballsoup

  I have an RTSP server running local on localhost:8554 and can verify its up and running multiple ways. Its definitely running !

  


  I can stream/publish an MP4 file to it and make that feed available from rtsp://localhost:8554/mystream, and can read from it and do cool stuff with it via ffmpeg :

  


  # this works: it appends frames read from the RTSP server to the fp-copy-2.mp4 file
ffmpeg -rtsp_transport tcp -i rtsp://localhost:8554/mystream -c copy fp-copy-2.mp4


  


  I am now trying to play that stream/feed from inside my toy React app. I have a VideoPlayer component that looks like :

  


  import React from &#x27;react&#x27;;&#xA;import ReactPlayer from &#x27;react-player&#x27;;&#xA;&#xA;const VideoPlayer = () => {&#xA;  const rtspUrl = &#x27;rtsp://localhost:8554/mystream&#x27;;&#xA;&#xA;  return (&#xA;    <div>&#xA;      <h1>Feed</h1>&#xA;      &#xA;    </div>&#xA;  );&#xA;};&#xA;&#xA;export default VideoPlayer;&#xA;&#xA;

  


  And I am loading it on a dashboard page like so :

  


  import React from &#x27;react&#x27;;&#xA;import VideoPlayer from &#x27;../../utils/player/VideoPlayer&#x27;;&#xA;&#xA;const DashboardPage = () => {&#xA;  return (&#xA;    <div>&#xA;      <h1>Dashboard</h1>&#xA;      <videoplayer></videoplayer>      &#xA;    </div>&#xA;  );&#xA;};&#xA;&#xA;export default DashboardPage;&#xA;

  


  When I run npm start and go to the dashboard page, I see the video player loaded but it is displaying a blank screen and is not playing the content that should be available on the feed. Any ideas where I'm going awry ? Does the react-player not handle RTSP perhaps ?