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• Poor video quality in first few frames using video output options in gganimate

  27 January 2021, by Nautica

  I'm trying to export some animations I've made using gganimate through video format as the gifs I'm creating are quite large.

  


  Sample code:

  


  library(gganimate)

p <- ggplot(mtcars, aes(factor(cyl), mpg)) +
  theme_dark() +
  theme(panel.grid = element_line(colour = "white")) +
  geom_boxplot() +
  transition_states(
    gear,
    transition_length = 2,
    state_length = 1
  ) +
  enter_fade() +
  exit_shrink() +
  ease_aes('sine-in-out')

anim_save("example.mp4",
          animate(
            p,
            nframes = 450,
            fps = 25,
            width = 1280,
            height = 720,
            type = "cairo",
            start_pause = 50,
            end_pause = 50,
            renderer = av_renderer()
          ))


  


  Produces the video seen here: https://vimeo.com/505019987

  


  With the standard ggplot2 theme: https://vimeo.com/505020822

  


  This is another example of something I made using gganimate: https://www.youtube.com/watch?v=fHzjl_z_sSo

  


  You can see that the video quality in the first few frames are very bad. In the video with the standard ggplot2 theme and the YouTube video, the gridlines and watermark text are not visible at the start but fade in much later. I don't know much about video codecs but I assume it has something to do with the ffmpeg library the av package/av_renderer() is using. Has anyone experienced something like this?

  


• Revision de6ecc5ac3: Selective masking of split modes. Allow selective masking of individual split m

  4 October 2013, by Paul Wilkins

  Changed Paths:
   Modify /vp9/encoder/vp9_onyx_if.c

  
   Modify /vp9/encoder/vp9_onyx_int.h

  
  
  Selective masking of split modes.

  Allow selective masking of individual split modes rather than
  just a single on / off flag.

  For speed 2 recovers the large speed loss seen for some derf
  clips in change Ie6bdfa0a370148dd60bd800961077f7e97e67dd4
  and a small quality gain.

  For speed 1 10 % speed increase observed locally on some derf clips
  for minimal quality change.

  Change-Id: If86191087b93cbc05351c26c60c7933e2149e485

• From 2 videos create one split screen video, 2 separate audio streams and a thumbnail from the resultant split screen video - all in one pass

  27 April 2020, by Ben Hardy

  I'm using ffmpeg to create several single splitscreen videos out of 2 separate videos. The 2 videos have audio so I want to extract the 2 video's audio streams as 2 separate mp3s and also create a thumbnail out of the finished splitscreen video. Is it possible to do these 3 actions in one pass?
  
Here is the code I'm using to create the splitscreen and the 2 separate mp3

  



  ffmpeg -i input0.mov -i input1.mov -filter_complex "[0]scale=640x360[v0];[1]scale=640x360[v1];[v0][v1] hstack[v]" -map "[v]" output.mp4 -map 0:a audio0.mp3 -map 1:a audio1.mp3

  



  However I want to also create a thumbnail out of the resultant split screen video in the same pass, but if I add "image.jpg" at the end it only makes a thumbnail out of input1.mov not the resultant splitscreen video made from input0 and input1 and makes all the outputs only 1 frame long. Here is the code:

  



  ffmpeg -i input0.mov -i input1.mov -filter_complex "[0]scale=640x360[v0];[1]scale=640x360[v1];[v0][v1] hstack[v]" -map "[v]" output.mp4 -map 0:a audio0.mp3 -map 1:a audio1.mp3 image.jpg

  



  Is there a solution to this that will let me create all the correct outputs in one pass?