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• ffmpeg copy video in video with a specific time

  13 février 2017, par Alkl

  Im new in this topic (beginner) and Im german... So it’s a bit difficult to find the correct words...

  I’ll try to explain what I’ve done and what I want to do :

  1. Extract video area from the original video converted in PRORES codec :

     ffmpeg.exe -i test.mkv -ss 00:06:21.99 -t 00:00:01.94 -async 1 -strict -2 -c:v prores_ks -pix_fmt yuva444p10le -profile:v 4444 -bits_per_mb 8000 -s 1920x1080 cut_video.mov

  2. Edit the cut in After Effects

  3. Convert the PRORES in Matroska

     ffmpeg.exe -i "C :\Users\Alex\Desktop\ffmpeg-20170202-08b0981-win64-static\bin\cut_video\cut_video.mov" -vcodec ffv1 -acodec pcm_s16le temp.mkv

  4. Replace the video area in the originale video file at the time 00:06:21.99...

  I spend 4 hours for the two commands...
  So I despair at the fourth step. Is it possible ? Can you help me ?

  I made a picture, so you can understand better what Im doing... : http://i.imgur.com/HqlNxzW.jpg

  Best regards from germany,

  Alex

• Looking for video libraries for editing video on windows/ios/azure service [on hold]

  17 juillet 2015, par sanyam

  Which library would be a good bet in terms of ...
  1. Richness in features (I want to create a video from short clips and images with effects and filters). Think auto videos created from Google Photos.
  2. Extensibility - I would prefer using similar tech on IOS and Windows apps. Might have to offload some processing to a web service on Azure (windows or linux).
  3. Programmability - An API is preferred over command line as it gives more flexibility and better error handling.

  Given all these options, what is my best bet ? I’ve only looked at ffmpeg till now, is there a better alternative ?

• 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 ?