Recherche avancée

Sur d’autres sites (5106)

• Video Seek Scroll (60FPS)

  9 avril 2022, par Enijar

  Trying to achieve an effect of seeking through a video when the page is scrolled. This has been achieved by exporting all frames of the video to JPEG images, pre-loading the images, and rendering them to a canvas. However, this approach uses a lot of bandwidth and takes a long time to load on slow networks.

  


  Trying to achieve the same effect by rendering a video to a canvas does not play as smoothly as the image-based approach.

  


  Here is a working demo with the video-based approach :

  


  https://codesandbox.io/s/infallible-chaum-grvi0r?file=/index.html

  


  Since HTMLMediaElement.fastSeek() doesn't have widespread browser coverage, how can one achieve a realtime playback rate of 30-60 FPS ?

  


  Here is the relevant code for the effect (see CSB link above for the full code) :

  


  const video = document.querySelector("video");
const canvas = document.querySelector("canvas");
const ctx = canvas.getContext("2d");

(function tick() {
  requestAnimationFrame(tick);

  const { scrollHeight, clientHeight, scrollTop } = document.body;
  const maxScroll = scrollHeight - clientHeight;
  const scrollProgress = scrollTop / maxScroll;

  canvas.width = document.body.clientWidth;
  canvas.height = document.body.clientHeight;

  // This is the line that causes the issue
  video.currentTime = video.duration * scrollProgress;

  ctx.clearRect(0, 0, canvas.width, canvas.height);
  ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
})();


  


• How can I combine these three ffmpeg commands ?

  16 mai 2022, par Anuj Saxena

  I want to combine the following three commands into one command, if possible.

  


  a = f'''ffmpeg -i {footage} -vcodec libx264 -acodec aac {mov_path}'''
b = f'''ffmpeg -i {mov_path} -vf "drawtext=text=' {hostname}\n {socket.gethostbyname(hostname)}\n {getpass.getuser()}':x=10:y=H-th-10:fontfile=KhmerOS.ttf:fontsize=50:fontcolor=black:shadowcolor=black:shadowx=2:shadowy=2" {watermark_path}'''
c = f'''ffmpeg -i {watermark_path} -vf "drawtext=fontfile=KhmerOS.ttf: text='%{{frame_num}}': start_number=1: x=(w-tw)/2: y=h-(2*lh): fontcolor=black: fontsize=50: box=1: boxcolor=white: boxborderw=5" -c:a copy {current_frame} '''


  


  I want a single output video because I don't want to use unnecessary variables like b,c,watermark_path, and current_frame I want only one resultant video with mov_path

  


• sppedUp FFmpegKit overlay Flutter

  17 septembre 2023, par mlika

  I'm using FFmpegKit to overlay text on video :
I'm coding it for macos app, I double checked the CPU usage,it's using only 20%
I have MAC M1 PRO

  


    String drawtextFilter = 'drawtext=fontfile=\'$_fontPath\':'
          'textfile=\'${segments[i].textFilePath}\':'
          'x=(w-text_w)/2:y=(h-text_h)/2:'
          'fontsize=65:fontcolor=white@0.8:' // @0.8 sets the opacity
          'bordercolor=black:borderw=9:'
          'shadowcolor=black:shadowx=5:shadowy=5:' // Adding shadow
          'box=1:boxcolor=black@0.1:boxborderw=20:' // Adding background box
          'fix_bounds=1:'
          'line_spacing=10:'
          'enable=\'between(t,0,${segments[i].duration})\'';
  String command =
          '-i "${segments[i].videoPath}" -vf "$drawtextFilter" -c:v h264_videotoolbox -threads 0 -y "$outputPath"';



  


  The problem is it's taking too long to finish the speed is around 0.6
Is there a solution or alternative as, I'm converting 1hour+ videos and it's taking too much time.
Thanks

  


  

  • I tried compute and Isolate to run multiple ffmpeg but it still very slow