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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.

• gstreamer h264 multicast missing SPS/PPS information

  6 mars 2015, par RBI

  I have two video streaming units capable of streaming live video inputs :

  • AXIS Q7424-R Video Encoder
  • EPIPHAN VGADVI Broadcaster 99460 -

  I am using gstreamer to view these streams on client terminals running linux. I am interested in the h264, rtp multicast streams (which both units support).

  I can stream the Epiphan video using the following gstreamer pipeline :

  gst-launch-0.10 udpsrc multicast-group=ADDRESS port=PORT caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtph264depay ! ffdec_h254 ! autovideosink

  However, this pipeline does not work for the Axis unit as I get the following error repeatedly :

  ffmpeg:0:: non-existing PPS referenced
  
  ffmpeg:0:: non-existing PPS 0 referenced
  
  ffmpeg:0:: decode_slice_header error
  
  ffmpeg:0:: no frame!
  
  ffdec_h264: decoding error (len:-1, have_data: 0)

  I have read that this error means that the ffmpeg decoder is missing the SPS/PPS information provided by a keyframe. The axis unit has a GOV parameter which is the interval at which i-frames are sent ; it is set to 32.

  Note that I can view both units’ rtp streams in unicast with the following :

  gst-launch-0.10 rtspsrc location=rtsp://ADDRESS:PORT/... latency=100 ! rtph264depay ! ffdec_h264 ! autovideosink

  Since unicast works and the unicast and multicast pipelines are the same (except for the source), my guess is either :

  • My udpsrc caps are simply incorrect for the axis stream (and I don’t really know where/how to verify it)

  • or, the axis multicast format/encoding is different and requires a modification to the pipeline (I find this unlikely since unicast is working and I don’t understand why the encoding would change between unicast/multicast).

  Any suggestions are appreciated as I am limited by my knowledge of gstreamer and media formats in terms of what to try next.

• Merge remote-tracking branch ’cus/stable’

  10 février 2015, par Michael Niedermayer

  Merge remote-tracking branch ’cus/stable’
  * cus/stable :
  
    ffplay : factorize thread starting and stopping code into decoder
  
    ffplay : make eof part of videostate and signal it when opening a stream
  
    ffplay : update frame timer based on last updated clock time when toggling pause
  Merged-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] ffplay.c