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• Possible bug in latest google chrome (v62) ?

  21 novembre 2017, par Jalal El-Shaer

  The following demo was working perfectly :

  http://jsfiddle.net/r6wz0nz6/2/

  The following is a sample of ’video-preview’ class in action :

  <a href="https://www.youtube.com/watch?v=v1uyQZNg2vE" target="_blank" class="video-preview" data-frames="100" data-source="http://i.imgur.com/BX0pV4J.jpg">
  
  </a>

  Now, if you use your mouse to scroll from left-to-right, somehow it is not working (shows thumbnail instead of current image position). This was working perfectly before v62. While, from right-to-left, it works normally.

  Updated Please watch how this looks here : https://www.youtube.com/watch?v=HvDP-YXJgOk

  Question : How can I overcome this bug/issue ?

  P.S. the demo is based on this blog post (https://www.binpress.com/tutorial/how-to-generate-video-previews-with-ffmpeg/138)

  Update 2
  Interesting, in the following part :

  elm.mousemove(function(e) {
  
  var left = e.clientX - elm.position().left;
  
  slider.show().css('left', left -1); // <<---------------------- this line
  
  img.css('left', -Math.floor((left / width) * frames) * width);

  if I remove the ’-1’ like so :
  slider.show().css('left', left);
  It works from Left-To-Right, but now from Right-To-Left is showing same bug !!

  Proposed Workaround by @A. Wollf
  Change the "mouseout" to "mouseleave" and it seems to fix it : http://jsfiddle.net/r6wz0nz6/388

• What are the gotchas of using statically linked libraries in serverless platforms such as Google Cloud Functions ?

  5 septembre 2017, par Dzh

  Libraries such as ffmpeg-static upload statically linked binaries onto container.

  I wonder what are the drawbacks of using this approach ?

  Does the library size counts against your memory use (it’s billed by GCloud) ?

  Does it slow down the container ? Perhaps some future-proofing issues ?

  Edit : Found something of a related (I wanted to setup OpenCV) on AWS blog. It doesn’t explain drawbacks, just shows how to do it exactly.

• Direct Show Video capture performance

  23 mai 2019, par Barry Andrews

  I originally started out looking for an example of how I can use FFMPEG in c++ builder to create an application to record from usb capture device and playback video because of apparrent poor performance

  I tried Mitov components, Datastead, FFMPEGVCL and winsoft camera which use directshow but their capture performance seemed poor.

  I need to capture 1920x1080 at up to 60fps into a compressed format and play this back later at both normal speed and slow speed.

  What I found was that DirectShow itself has a number of limitations which can be improved by adding things like FFMPEG, but ultimately PC hardware, in particular the HDD and processor limit capture capability.

  1920x1080 60fps is basically the upper end for DirectShow so you need to have best performing hardware in order to achieve this sort of performance @Spektre kindly gave me examples of DirectShow using the API direct which were good for comparison with the purchased components.

  Using this and comparing to the components I found that MITOV has a major issue with regards the larger video sizes and frame rates. Using this 1920x108 30fps and 60fps can be previewed but they have a massive delay between video feed and preview (5 or 6 seconds). The other components performed similar to the API direct method with only minor variations in performance. None were able to capture and record 1920x108 60fps with any sort of compression filter without large frame drops and very jerky preview.