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• How to plot animated time series in R ?

  28 août 2016, par pOrlando

  I am trying use the ’animation’ package in R to plot an animated time series.

  My dataset consists of a time vector and a value vector, each with 1800 rows.

  I keep getting an error message after running the loop which reads :

  Error in jpeg(gname[i]) : unable to start jpeg() device
  
  In addition: Warning messages:
  
  1: In jpeg(gname[i]) : unable to open file 'g11:30:00.jpg' for writing
  
  2: In jpeg(gname[i]) : opening device failed

  Here’s the source code

  timemax<-1800
  
  setwd("~/Documents/Animation/")
  
  graphdata<-read.csv("filling_line_data_construction_v2.csv")
  
  attach(graphdata)
  
  gname<-paste("g",time, ".jpg", sep="")
  
  for (i in 1:timemax){
  
      jpeg(gname[i])
  
      plot(time[1],value[1],type="l",ylim=c(0,35), xlim=c(0,100),
  
        ylim = c(0, 35),ylab = "", xlab="time")
  
      lines(time[1:i],value[1:i])
  
      dev.off(dev.cur())
  
  }

  The end goal is to string together these 1800 plots as a stop animation video by calling the ffmpeg shell :

  shell("C:/ffmpeg/bin/ffmpeg.exe -report -i g%d.jpg -b:v 2048k fillin_lineR.mpg",mustWork=FALSE)

  This is code that I’ve been trying to adapt from http://www.animatedgraphs.co.uk/LondonR.html#slide-30, but this example uses a .tif file instead of .jpg, and my computer gives me 1800 error messages when trying to make a video from .tif files...

  Thanks in advance !

• Write a function to run through a series of commands, zsh

  8 septembre 2016, par Ali Samii

  I am trying to write a function to run through a series of commands, but I have no idea where to start.

  This is the series of commands I want to run.

  find ./ -name '*.mp4' -exec bash -c 'ffmpeg -i "$0" -vcodec libx264 -vf scale=854:480 -cpu-used 5 -threads 8 "${0%%.mp4}-copy.mp4"' {} \;
  
  touch -r video.mp4 video-copy.mp4
  
  rm -rf video.mp4
  
  mv video-copy.mp4 video.mp4
  
  find ./ -name '*.mp4' -exec bash -c 'qt-faststart "$0" "${0%%.mp4}-fs.mp4"' {} \;
  
  touch -r video.mp4 video-fs.mp4
  
  rm -rf video.mp4
  
  mv video-fs.mp4 video.mp4
  
  find ./ -name '*.mp4' -exec bash -c 'ffmpeg -i "$0" -vcodec libvpx -acodec libvorbis -vf scale=-1:480 -cpu-used 5 -threads 8 "${0%%.mp4}.webm"' {} \;
  
  touch -r video.mp4 video.webm
  
  find ./ -name '*.mp4' -exec bash -c 'ffmpeg -i "$0" -ss 00:00:10 -vframes 1 -r 1 -vf scale=-1:480 -f image2 "${0%%.mp4}.jpg"' {} \;
  
  touch -r video.mp4 video.jpg
  
  mv video.jpg thumbnail.jpg

  Can someone help me please.

• Android Create MP4 with bitmap series and mp3 by FFmpeg (i need minimal ffmpeg config for build)

  29 septembre 2017, par grizzly

  i’m building ffmpeg for android. my target is only create mp4 video with series of bitmap image and merge mp3 audio. i want use ffmpeg only only for this target. So i need optimized config for this target. i try find in google and find not bad config list. but i need full optimize config for reduce size of ffmpeg in android app. can you suggest me best config for this target ?

  i find this :

  Minimal configuration for mp4 files

  how do i modify this ffmpeg build script for minimal binary size output

  but is not complete optimized.

  please suggest me full optimize config for my target. thanks