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

  27 janvier 2021, par 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 ?

  


• FFMPEG stream RTSP to RTMP (Youtube) add logo

  16 juin 2017, par Māris Purviņš

  To stream video from IP cam to Youtube I’m using code (through Ubunu) :
  ffmpeg -f lavfi -i anullsrc -rtsp_transport tcp -i rtsp ://user:psw@192.168.0.100:554 -tune zerolatency -vcodec libx264 -pix_fmt + -c:v copy -c:a aac -strict experimental -f flv rtmp ://a.rtmp.youtube.com/live2/ -nostdin -nostats /dev/null 2>&1 &

  It is a bee project for school
  I have two cameras and two streams :
  https://www.youtube.com/watch?v=ws-VcLXo-hI

  Everything is ok, but... I would like to know :
  1. How to add png logo to this strem. I have tried -i /home/user/rvvg_logo_round.png -codec:v libx264 -preset ultrafast -filter_complex overlay and another methods but without a result.
  2. Sometimes there is some problem during night and video streaming stops. How to automatically check process status and restart stream.
  I have tried to create sh file as described in http://videos.cctvcamerapros.com/raspberry-pi/ip-camera-raspberry-pi-youtube-live-video-streaming-server.html and put in cron job, bet that is only to check one cam process. Is there some better idea ?

• Adobe Air , NativeProcess and ffmpeg

  18 août 2013, par Tom Lecoz

  First of all, please excuse me if my english is not perfect, I hope you could understand me...

  I discover yesterday this video tutorial about Air Native Process and FFMPEG, it shows how to create an Air app that can read every video format (avi, mkv, ...).

  http://www.youtube.com/watch?v=6N7eN9wvAGQ

  I tryed to reproduce it but obviously it didn't work...

  Then I looked for an example of it, with working source code, on the internet. I found this

  http://suzhiyam.wordpress.com/2011/05/05/as3ffmpeg-play-multi-video-formats-in-air/

  The author said it's a document class for a Flash project, it just need a button component, a text area and a video Object.

  I tryed it inside a Flash project, it didn't work...
  So, I made some adjusment to run it outside Flash (I just replaced the DisplayObject on the stage by ActionScript code), just because it easier if you want to test it.

  When I say "it didn't work", I mean my video is not read at all. The nativeProcess is working, my executable is recognize but I always get some ProgressEvent.STANDARD_ERROR_DATA and then the process stop...

  I'm working on Windows 7 64 bit.
  I tryed with FFMPEG 32 & 64 bit and get the exact same (no) result.

  You can find my code here
  pastebin.com/U3xRUKWe

  Can someone help me ?

  Please ! :)

  Thanks by advance !

  Tom