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• Problems accessing codecs with ggplot and gganimate

  19 décembre 2016, par noLongerRandom

  Using gganimate. Can’t figure out how to properly access functionality of ffmpeg, specifically I want to change the codec I’m using in the video file I’m outputting.

  # load packages
  
  library(ggplot)
  
  library(animation)
  
  library(gganimate)
  
  
  
  # Here's my data.frame
  
  myDf <- data.frame(
  
      year = c(1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014), 
  
      bottom50 = c(0.195, 0.191, 0.187, 0.192, 0.196, 0.205, 0.207, 0.210, 0.209, 0.204, 0.203, 0.204, 0.205, 0.203, 0.202, 0.200, 0.200, 0.201, 0.199, 0.195, 0.190, 0.183, 0.179, 0.179, 0.177, 0.172, 0.169, 0.169, 0.168, 0.166, 0.158, 0.159, 0.158, 0.154, 0.151, 0.148, 0.149, 0.148, 0.146, 0.149, 0.148, 0.145, 0.142, 0.138, 0.135, 0.137, 0.137, 0.136, 0.130, 0.127, 0.123, 0.127, 0.125), top1 = c(0.126, 0.127, 0.129, 0.128, 0.126, 0.123, 0.122, 0.115, 0.110, 0.111, 0.111, 0.109, 0.106, 0.105, 0.105, 0.107, 0.108, 0.111, 0.107, 0.110, 0.112, 0.115, 0.125, 0.125, 0.122, 0.133, 0.149, 0.145, 0.145, 0.139, 0.150, 0.146, 0.147, 0.153, 0.160, 0.166, 0.169, 0.177, 0.183, 0.173, 0.171, 0.172, 0.183, 0.194, 0.201, 0.199, 0.195, 0.185, 0.198, 0.196, 0.208, 0.196, 0.202)
  
  )
  
  
  
  #Basic plot
  
  p <- ggplot(myDf, aes(x = year, y = bottom50, frame = year)) + 
  
      geom_line(color = "dodgerblue") + 
  
      geom_line(aes(y = top1), color = "darkred")

  The non-animated version gets me what I want :

  

  And I get an animation version output to video with :

  gganimate(p, interval = .1, title_frame = FALSE, "income.mp4")

  That’s fine, but I want to change some the output parameters, specifically : alter the dimensions, the frame rate, and use a different codec.

  # change some of the options
  
  ani.options(ani.height = 1080, ani.width = 1920, 
  
              interval = 0.04166667, other.opts = "-vcodec qtrle -f mov")
  
  # re-animate
  
  gganimate(p, title_frame = FALSE, "income.mov")

  That gives me the following error :

  Error in animation_saver(saver, filename) : 
  
    Don't know how to save animation of type mov

  I’m using ’.mov’ as my file extension because I’m trying to change to the Animation codec (so it’s no longer a .mp4 wrapper). I’ve got ffmpeg installed, so this is probably a syntax issue. But the documentation isn’t very clear here ; gganimate doesn’t have any documentation on changing codecs (or outputting any video besides an mp4), and the animation package is light on specifics as well.

• Converting mp4 audio to webm with ffmpeg - unable to find suitable output for webm

  13 janvier 2015, par JDStraughan

  I have a custom heroku buildpack that is installing ffmpeg, libvorbis, etc.

  When I run ffmpeg I get the following output :

  FFmpeg version SVN-r0.5.9-4:0.5.9-0ubuntu0.10.04.3, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  
  
  
  configuration: --extra-version=4:0.5.9-0ubuntu0.10.04.3 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --disable-vhook --enable-runtime-cpudetect --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static
  
    libavutil     49.15. 0 / 49.15. 0
  
    libavcodec    52.20. 1 / 52.20. 1
  
    libavformat   52.31. 0 / 52.31. 0
  
    libavdevice   52. 1. 0 / 52. 1. 0
  
    libavfilter    0. 4. 0 /  0. 4. 0
  
    libswscale     0. 7. 1 /  0. 7. 1
  
    libpostproc   51. 2. 0 / 51. 2. 0
  
    built on Jan 24 2013 19:42:59, gcc: 4.4.3
  
  At least one output file must be specified

  I’m trying to convert mp4 audio to webm audio.

  Here is the command I am using :

  ~/public/audio $ ffmpeg -i sample.mp3 sample.webm

  And the output :

  FFmpeg version SVN-r0.5.9-4:0.5.9-0ubuntu0.10.04.3, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  
    configuration: --extra-version=4:0.5.9-0ubuntu0.10.04.3 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --disable-vhook --enable-runtime-cpudetect --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static
  
    libavutil     49.15. 0 / 49.15. 0
  
    libavcodec    52.20. 1 / 52.20. 1
  
    libavformat   52.31. 0 / 52.31. 0
  
    libavdevice   52. 1. 0 / 52. 1. 0
  
    libavfilter    0. 4. 0 /  0. 4. 0
  
    libswscale     0. 7. 1 /  0. 7. 1
  
    libpostproc   51. 2. 0 / 51. 2. 0
  
    built on Jan 24 2013 19:42:59, gcc: 4.4.3
  
  Input #0, mp3, from 'sample.mp3':
  
    Duration: 00:00:01.56, start: 0.000000, bitrate: 76 kb/s
  
      Stream #0.0: Audio: mp3, 24000 Hz, stereo, s16, 64 kb/s
  
  Unable to find a suitable output format for 'sample.webm'

  This works fine on my OSX install, but on Ubuntu 14.04 I’m getting these errors.

  What do I need to do so .webm files can be the destination ?

• Algorithm to draw waveform from audio

  27 février 2016, par yayuj

  I’m trying to draw a waveform from a raw audio file. I demuxed/decoded an audio file using FFmpeg and I have those informations : samples buffer, the size of the samples buffer, the duration of the audio file (in seconds), sample rate (44100, 48000, etc), sample size, sample format (uint8, int16, int32, float, double), and the raw audio data itself.

  Digging on the Internet I found this algorithm (more here) :

  White Noise :

  

  The Algorithm

  All you need to do is randomize every sample from –amplitude to
  amplitude. We don’t care about the number of channels in most cases so
  we just fill every sample with a new random number.

  Random rnd = new Random();
  
  short randomValue = 0;
  
  
  
  for (int i = 0; i < numSamples; i++)
  
  {
  
      randomValue = Convert.ToInt16(rnd.Next(-amplitude, amplitude));
  
      data.shortArray[i] = randomValue;
  
  }

  It’s really good but I don’t want to draw that way, but this way :

  

  Is there any algorithm or idea of how I can be drawing using the informations that I have ?