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• How to use fig.show=animate in knitr without administrator privileges

  23 mai 2013, par Stéphane Laurent

  I use Windows without administrator privileges hence I cannot set a path in the Windows PATH variable.

  The ffmpeg.exe file is in my "U:/ProgramFiles/ImageMagick-6.8.5-5/" folder.

  I have found how to use the saveVideo() function of the animate package :

  ani.options(ffmpeg = shQuote('U:/ProgramFiles/ImageMagick-6.8.5-5/ffmpeg.exe'))
  
  saveVideo({
  
    par(mar = rep(3, 4))
  
    for (i in seq(pi/2, -4/3 * pi, length = 12)) {
  
      plot(0, 0, pch = 20, ann = FALSE, axes = FALSE)
  
      arrows(0, 0, cos(i), sin(i))
  
      axis(1, 0, "VI"); axis(2, 0, "IX")
  
      axis(3, 0, "XII"); axis(4, 0, "III"); box()
  
    }
  
  },
  
          video.name="mavideo.mp4",
  
          outdir="U:/Data/Rtests/Animation")

  But I haven't find how to knit a Rmd file with the option fig.show=animate in a chunk, for instance :

  ```{r clock, fig.width=7, fig.height=6, fig.show='animate'}
  
  par(mar = rep(3, 4))
  
  for (i in seq(pi/2, -4/3 * pi, length = 12)) {
  
      plot(0, 0, pch = 20, ann = FALSE, axes = FALSE)
  
      arrows(0, 0, cos(i), sin(i))
  
      axis(1, 0, "VI"); axis(2, 0, "IX")
  
      axis(3, 0, "XII"); axis(4, 0, "III"); box()
  
  }
  
  ```

  I have tried to modifiy the hook_ffmpeg_html() function by only changing the ffmpeg.cmd variable :

  ```{r}
  
   hook_ffmpeg_html2 <- function (x, options) 
  
  { 
  
      ........ 
  
      ffmpeg.cmd = paste("-y", "-r", 1/options$interval, 
  
          "-i", fig.fname, mov.fname) 
  
      ffmpeg.cmd <-  paste('"U:/ProgramFiles/ImageMagick-6.8.5-5/ffmpeg"', ffmpeg.cmd) 
  
     ...... 
  
  } 
  
  opts_knit$set(animation.fun = hook_ffmpeg_html2) 
  
  ```

  But this chunk does not work, below is the error message :

  label: unnamed-chunk-1 
  
  Warning in block_exec(params) : 
  
    failed to tidy R code in chunk  
  
  reason: Error in base::parse(text = text, srcfile = NULL) : 
  
    21:14: unexpected symbol 
  
  20: options$out.height), if ("controls" %in% mov.opts) 
  
  21: "controls=\\"controls 

• phantomjs screenshots and ffmpeg frame missing

  20 octobre 2015, par Bussiness Way

  I have problem making video from website screenshots taken from phantomjs.

  the phantomjs did not make screenshots for all frames within the same second and even not all seconds there , there is huge missing frames .

  the result is high speed video playing with many jumps in video effects .

  test.js :

  var page = require('webpage').create(),
  
      address = 'http://raphaeljs.com/polar-clock.html',
  
      duration = 5, // duration of the video, in seconds
  
      framerate = 24, // number of frames per second. 24 is a good value.
  
      counter = 0,
  
      width = 1024,
  
      height = 786;
  
          frame = 10001;
  
  
  
  page.viewportSize = { width: width, height: height };
  
  
  
  page.open(address, function(status) {
  
      if (status !== 'success') {
  
          console.log('Unable to load the address!');
  
          phantom.exit(1);
  
      } else {
  
          window.setTimeout(function () {
  
              page.clipRect = { top: 0, left: 0, width: width, height: height };
  
  
  
              window.setInterval(function () {
  
                  counter++;
  
                  page.render('newtest/image'+(frame++)+'.png', { format: 'png' });
  
                  if (counter > duration * framerate) {
  
                      phantom.exit();
  
                  }
  
              }, 1/framerate);
  
          }, 200);
  
      }
  
  });

  this will create 120 image , this is correct count , but when you see the images one by one you will see many duplicate the same contents and many missing frames

  ffmpeg :

  fmpeg -start_number 10001 -i newtest/image%05d.png -c:v libx264 -r 24 -pix_fmt yuv420p out.mp4

  I know this script and ffmpeg command not perfect , because I did hundred of changes without lucky, and I lost the correct setting understanding .

  an anyone guide me to fix this ?.

  thank you all

• FFMPEG How to insert short video and audio in longer video in specific time, size and position

  24 novembre 2020, par Milos Dimitrijevic

  FFMPEG How to insert short video (4sec) in longer video in specific time (from 15th to 19th second) and specific size. Long video is 1920x1080px and inserted video should be 1720x820px, positioned in the middle ?

  


  file info..
Duration : 00:00:22.07, start : 0.000000, bitrate : 3982 kb/s
Stream #0:0(und) : Video : h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 3900 kb/s, 29 fps, 29 tbr, 14848 tbn, 58 tbc (default)
Metadata :
handler_name : VideoHandler
Stream #0:1(und) : Audio : aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
Metadata :
handler_name : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'short.mp4' :
Metadata :
major_brand : mp42
minor_version : 19529854
compatible_brands : mp42isom
creation_time : 2020-10-25T11:01:10.000000Z
Duration : 00:00:03.02, start : 0.000000, bitrate : 14405 kb/s
Stream #1:0(eng) : Audio : aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 319 kb/s (default)
Metadata :
creation_time : 2020-10-25T11:01:10.000000Z
handler_name : Sound Media Handler
Stream #1:1(eng) : Video : h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 14078 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
Metadata :
creation_time : 2020-10-25T11:01:10.000000Z
handler_name : Video Media Handler
encoder : AVC Coding