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• How to get a loading return value

  5 septembre 2011, par anthonypliu

  I am trying to create a loading progress bar for my function :

  private string ConvertToFLV(string phyicalFilePath)
  
          {
  
              if (Path.GetExtension(phyicalFilePath).Equals(".flv")) return phyicalFilePath;
  
  
  
                  var argument = string.Format(@"-i ""{0}"" -vcodec flv -f flv -r 29.97 -s 320x240 -aspect 4:3 -b 300k -g 160 -cmp dct  -subcmp dct  -mbd 2 -flags +aic+cbp+mv0+mv4 -trellis 1 -ac 1 -ar 22050 -ab 56k ""{1}""", phyicalFilePath, Path.ChangeExtension(phyicalFilePath, "flv"));
  
                 // var argument = string.Format("-i {0} -crf 35.0 -vcodec libx264 -acodec libfaac -ar 48000 -ab 128k -coder 1 -flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -me_method hex -subq 6 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -b_strategy 1 -threads 0 {1}", phyicalFilePath, Path.ChangeExtension(phyicalFilePath, "mp4"));
  
                  File.Delete(Path.ChangeExtension(phyicalFilePath, "flv"));
  
  
  
                  ProcessStartInfo process = new ProcessStartInfo(ffmpegPhysicalPath, argument);
  
                  Process proc = new Process();
  
                  proc.StartInfo = process;
  
                  proc.Start();
  
                  proc.WaitForExit();
  
  
  
                  return Path.ChangeExtension(phyicalFilePath, "flv");
  
  
  
  
  
  
  
          }

  Whent he command "proc.WaitForExit()" is invoked, I want to be able to return some type of load percentage. In the frontend I just have a gif loading image, but I want to be able to show progress on this, is there a way to do this ?

• Decode h264 video

  29 août 2011, par john bowring

  I am looking for a way to decode h264 (or indeed any video format) using c#. The ultimate goal is to be able to decode the images and very strictly control the playback in real time. The project I am working on is a non-linear video art piece where the HD footage is required to loop and edit itself on the fly, playing back certain frame ranges and then jumping to the next randomly selected frame range seamlessly.

  I have created an app which reads image files (jpegs) in from the disk and plays them on screen in order, I have total control over which frame is loaded and when it is displayed but at full HD res it takes slightly longer than I want to load the images from hard drive (which are about 500k each), I am thinking that using a compressed video format would be smaller and therefore faster to read and decode into a particular frame however I cannot find any readily available way to do this.

  Are there any libraries which can do this ? i.e. extract an arbitrary frame from a video file and serve it to my app in less time than it takes to show the frame (running at 25fps), I have looked into the vlc libraries and wrappers for ffmpeg but I don't know which would be better or if there would be another even better option. Also I don't know which codec would be the best choice as some are key frame based making arbitrary frame extraction probably very difficult.

  Any advice welcome, thanks

• playing http video url using ffmpeg

  17 mai 2012, par Ranjith

  I am using libavcodec of ffmpeg to play a http video stream in my application.
  I have implemented my own video player for this.This player is working fine.

  Now, I want to show buffering status of video (what percentage of video is downloaded by ffmpeg). But I could not find any api or event for this.