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• FFmpeg image2pipe write buffer wait until done

  20 décembre 2020, par Michael Joseph Aubry

  I'm extracting frames from an external source and passing it in as a buffer to FFMPEG using image2pipe and -i -

  


  const childProcess = spawn(ffmpeg, [
  "-y",
  "-f",
  "image2pipe",
  "-i",
  "-",
  "-vcodec",
  "libx264",
  "-pix_fmt",
  "yuv420p",
  output
]);


  


  Then I have a loop that does the job.

  


  for (let i = 0; i < 250; i++) {
  // ...await
}


  


  Inside the promise

  


  // ... do the job to get buffer

childProcess.stdin.write(frame); // frame === buffer

// frame done
resolve("success!");


  


  The problem is in some videos the frames jump and is janky. This is because FFmpeg is not fully done writing to the file before moving onto the next frame.

  


  Is there a way to write a buffer to a file through FFmpeg and make sure the frame is done writing before moving on ?

  


  Some more information

  


  Here is the source file https://s3.us-west-2.amazonaws.com/storycreator.v2.uploads/ckigi4kro00160vlfjmt74afp

  


  Here is the rendered file https://s3.us-west-2.amazonaws.com/storycreator.testing/607715f0-3ab9-11eb-a139-3bb84618c6c5.mp4?t=1607585343922

  


  Here are logs

  


  2020-12-10T07:28:48.942Z    0ae0c435-54d3-416f-9d1a-8ddf595a7e83    INFO    frame=  130 fps= 16 q=-1.0 Lsize=      83kB time=00:00:05.08 bitrate= 133.6kbits/s speed=0.641x    video:80kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.928688%


  


  2020-12-10T07:28:48.942Z    0ae0c435-54d3-416f-9d1a-8ddf595a7e83    INFO    [libx264 @ 0x640d6c0] frame I:1     Avg QP:15.47  size: 68227[libx264 @ 0x640d6c0] frame P:33    Avg QP:15.07  size:   246[libx264 @ 0x640d6c0] frame B:96    Avg QP:18.75  size:    56[libx264 @ 0x640d6c0] consecutive B-frames:  1.5%  0.0%  0.0% 98.5%


  


  2020-12-10T07:28:48.943Z    0ae0c435-54d3-416f-9d1a-8ddf595a7e83    INFO    [libx264 @ 0x640d6c0] mb I  I16..4: 24.6% 60.5% 14.9%[libx264 @ 0x640d6c0] mb P  I16..4:  0.0%  0.2%  0.0%  P16..4:  0.8%  0.0%  0.0%  0.0%  0.0%    skip:98.9%[libx264 @ 0x640d6c0] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  0.3%  0.0%  0.0%  direct: 0.0%  skip:99.7%  L0:26.7% L1:73.3% BI: 0.0%[libx264 @ 0x640d6c0] 8x8 transform intra:62.0% inter:83.6%[libx264 @ 0x640d6c0] coded y,uvDC,uvAC intra: 49.2% 44.3% 32.1% inter: 0.0% 0.2% 0.0%[libx264 @ 0x640d6c0] i16 v,h,dc,p: 53% 38%  7%  2%[libx264 @ 0x640d6c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 24% 29%  3%  3%  3%  5%  3%  4%[libx264 @ 0x640d6c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 37% 26% 14%  3%  4%  5%  4%  4%  3%[libx264 @ 0x640d6c0] i8c dc,h,v,p: 57% 27% 13%  3%[libx264 @ 0x640d6c0] Weighted P-Frames: Y:0.0% UV:0.0%[libx264 @ 0x640d6c0] ref P L0: 95.1%  1.2%  3.1%  0.6%[libx264 @ 0x640d6c0] ref B L0: 48.1% 51.3%  0.7%[libx264 @ 0x640d6c0] ref B L1: 97.3%  2.7%[libx264 @ 0x640d6c0] kb/s:125.75


  


  2020-12-10T07:28:48.944Z    0ae0c435-54d3-416f-9d1a-8ddf595a7e83    INFO    [cache @ 0x5f57940] Statistics, cache hits:0 cache misses:3551


  


• Spring content + MPD manifest and Dash.js player [closed]

  31 octobre 2024, par Iupa

  I'm total newbie to video content from web, however I was curious how those things work actually, and I found so far that for web pages there are already js libs which firstly customize the video html tag to support many features like resolution/subtitles/speed etc,secondly they work with specific manifest file as a src for video, it's *.mpd extension and xml format where is described how to play the chunks of video, now in order to generate such manifests I need another libs like ffmpeg that can generate not only manifests but the chunks as well in different resolutions and other tons of settings (kinda crazy ¯_(ツ)_/¯), anyway now I understood that in order to use spring content lib I need to generate all of those during the uploads of files, are there some tutorials/best practices for such ?

  


• FFMpeg kmsgrab record pixels wrong

  21 avril 2020, par Alex Joel

  ffmpeg -f kmsgrab -i - -framerate 60 -vf 'hwdownload,format=bgr0' -preset ultrafast out.mkv

  



  This is how a video frame should look like

This is how it is recorded by ffmpeg
https://drive.google.com/file/d/11jOUTk3ZxOfwnfd7zS4d4qBLApTS3Vmx/view?usp=sharing