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• How to automatically remove black bars using ffmpeg and powershell ?

  7 avril 2020, par timlwsk

  Thanks to the help of the user mklement0 I got this script to automatically convert all files in the folder "video_old" and move them into "video_new", all while keeping the original filename. Original Post.

  



  Now I want to remove the black bars in the container. I know that there is "cropdetect" but AFAIK you have to manually parse the the value into the script manually. How can I automate this process using PowerShell ?

  



  Get-ChildItem .\video_old -Filter *.mkv | ForEach-Object {
  .\ffmpeg.exe -i $_.FullName -c:v libx265 -crf 18 ".\video_new\$($_.Name)"
}


  


• Revision e88a280573 : Enable more precise background detection for partition decision This commit com

  15 avril 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_encodeframe.c

  
  
  Enable more precise background detection for partition decision

  This commit compares the current original frame to the previous
  original frame at 64x64 block level and decides if the entire
  block belongs to background area. If it is in the background area,
  skip non-RD partition search and copy the partition types of the
  collocated block in the previous frame.

  For vidyo1 in the rtc set, this makes the speed -5 coding speed
  about 8% faster. The overall compression performance is down by
  1.37% for rtc set.

  Change-Id : Iccf920562fcc88f21d377fb6a44c547c8689b7ea

• convert video without losing frames and have same fps and tbr using ffmpeg

  15 août 2021, par srinivast6

  My original video "test1.mp4" has following properties

  


  Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 283 kb/s, 34.55 fps, 50 tbr, 50k tbn, 50 tbc (default).


  


  I got it from running ffmpeg -i test1.mp4.

  


  I had to change the video codec to h264. So I converted the above video using below command

  


  ffmpeg -i test1.mp4 test1.mp4.

  


  However the props of the converted video has changed. fps is 50 and tbr is 50. And also frame count has increased compared to original video.

  


   Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 114 kb/s, 50 fps, 50 tbr, 12800 tbn, 100 tbc (default)


  


  After following this link https://superuser.com/questions/1307863/why-is-ffmpeg-changing-framerate-from-60-to-120, I found that ffmpeg uses tbr values instead of fps while converting in order to not to lose any frames but at the cost of duplicate frames. As suggested in the link above I used vsync 0 option while converting video.

  


  ffmpeg -i test1.mp4 -vsync 0 test1_sync.mp4.


  


  Now the Frame count is same as the input video (checked using ffprobe). But the fps is still little different from the original video.

  


   Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 61 kb/s, 12.88 fps, 50 tbr, 12800 tbn, 100 tbc (default).


  


  How come frame count remains same even when fps is different ?

  


  To my use case I need the converted video to have same number of frames at the same timestamps as the original video, i just need the codec to be changed to h264. I dont want duplicate or losing frames.

  


  How can I achieve this ?