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• Show first and last frame longer in ffmpeg

  3 novembre 2014, par Gert Gottschalk

  I am building a time-lapse animation from single frames and would like to show the first and last frames longer than the prescribe frame rate. My initial ffmpeg call looks like this and works quite well. It creates the basic time-lapse animation from single frames.

  ffmpeg -r 16  -threads 0 -f image2 -pattern_type glob -i './sofi_20141022/octave2reg/IMG_*_cent.png' -c:v libx264 -s 1440x1080 -crf 24 ./Video/20141022_Partial_Solar_Eclipse_crf24_16fps.mp4

  But how do I add controls to have the first and last frame show longer (i.e for sec) ??

  Thanks,
  Gert

• 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 

• Revision 99a132f561 : Add a seg map preservation test vector. Add a test vector to show the cases whe

  13 octobre 2014, par Alex Converse

  Changed Paths :
   Modify /test/test-data.mk

  
   Modify /test/test-data.sha1

  
   Modify /test/test_vectors.cc

  
  
  Add a seg map preservation test vector.

  Add a test vector to show the cases where segmentation map is preserved
  from frome to frame as outlined in the inquiry in issue 761.

  Change-Id : I630c6aba27d0d0b109cc7fd7c6fcd008222a0cf3