Recherche avancée

Sur d’autres sites (7078)

• ffmpeg record screen file formats

  3 avril 2020, par New_Dev

  Good day,
I'm currently writing a bash script which records the screen under certain conditions. The problem is that only avi works as a file extension for recording the screen. This script is going to be used on an Raspberry Pi and currently I get on a decent virtual machine only 10-20 fps (goal would be around 30 fps). I think .avi is not suited for my project. But .mpeg and .mp4 are not working for recording. I tried recording with .avi and then converting it in .mp4, but I have limited memory and .avi ist just too big in size. I use currently the following command :

  



  ffmpeg -f x11grab -y -r 30 -s 960x750 -i :0.0+0,100 -vcodec huffyuv ./Videos/out_$now.avi
//$now is the current date and time


  



  So I wanted to know if I need some special packages from ffmpeg to record with for example .mp4 or if there are other file formats available for ffmpeg screen recording.

  



  Edit :
I found that the codec libx264 for mp4 works, but the fps drop until they hit5 fps, which is definetly too low. The recorded video appeared like being a fast forward version of the recorded screen.

  



  With mpeg4 for mpeg I reached over 30 fps, but the video qualitywas very bad.

  



  It appears that even my big avi-files look like being played fast forward. Is there something I do wrong ?

  



  Is there a good middle way, where I get a decend video quality, good fps (20+) and a file which isn't too big ?

  



  Edit 2 :
I tried recording it with .avi and converting it afterwards. Just converting with ffmpeg -i test.avi -c:a aac -b:a 128k -c:v libx264 -crf 23 output.mp4 
resulted in the same framedrops as if I was recording with .mp4. But when I cut a littlebit of the beginning of the video and named the outputfile .mp4, the size became much smaller. But when I started the cutting at 0:00:00 (so tried just converting), it just changed the file format without converting it (so the size stayed the same). Any ideas ?

  


• fixed - ffmpeg output file is too large

  14 mai 2017, par David Page

  I want to burn a subtitle file(.srt) to a mp4 video.My command is :

  ffmpeg -i input.mp4 -c:v mpeg4 -q:v 1 -vf subtitles=input.srt out.mp4

  It output a video with a good quality,but its size is 1.12GB while the input file is 213MB.

  I think the problem is kbps of output file is too high.the bitrate of input file is 568 kb/s but the output file is 3154 kb/s.

  So I want to set the kps,now here is my code :

  ffmpeg -i input.mp4 -b:v 569k -minrate 568k -maxrate 570k -c:v mpeg4 -q:v 1 -vf subtitles=input.srt out.mp4

  Although the output file become smaller(538MB),the video’s quality is awful(Compare with input file)...
  So how to make the output file smaller and in good quality ?Thanks.

• ffmpeg output file is too large

  1er janvier 2016, par David Page

  I want to burn a subtitle file(.srt) to a mp4 video.My command is :

  ffmpeg -i input.mp4 -c:v mpeg4 -q:v 1 -vf subtitles=input.srt out.mp4

  It output a video with a good quality,but its size is 1.12GB while the input file is 213MB.

  I think the problem is kbps of output file is too high.the bitrate of input file is 568 kb/s but the output file is 3154 kb/s.

  So I want to set the kps,now here is my code :

  ffmpeg -i input.mp4 -b:v 569k -minrate 568k -maxrate 570k -c:v mpeg4 -q:v 1 -vf subtitles=input.srt out.mp4

  Although the output file become smaller(538MB),the video’s quality is awful(Compare with input file)...
  So how to make the output file smaller and in good quality ?Thanks.