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• ffmpeg record pulseaudio has some crackles

  8 janvier 2021, par boygiandi

  I'm trying to record audio from pulseaudio (on Centos 7), using ffmpeg. But the audio is not smooth, it has some crackles, noise after few seconds
Please check this video link : https://www.facebook.com/watch/live/?v=692754594726722&ref=watch_permalink

  


  The ffmpeg command looks like this

  


  ffmpeg -fflags +igndts -framerate 30 -s 1920x1130 -draw_mouse 0 -f x11grab -i :1085.0+nomouse -f pulse -i sinkgstvDViJbLFIaUBLdTxTeLtr.monitor -c:v libx264 -filter:v crop=1920:1080:0:50 -g 60 -r 30 -bufsize 2M -b:v 7M -vbsf h264_mp4toannexb -pix_fmt yuv420p -strict experimental -preset ultrafast -c:a aac -async 1 -vsync 1 -b:a 128k -bsf:a aac_adtstoasc -metadata comment=gstvDViJbLFIaUBLdTxTeLtr -f flv "rtmps://live-api-s.facebook.com:443/rtmp/4248189238527878?s_bl=1&s_psm=1&s_sc=4248189291861206&s_sw=0&s_vt=api-s&a=Abx_pMiM4_ccqBcS"


  


  I found this article but it didn't fix my problem https://forum.level1techs.com/t/improving-linux-audio-updated/134511 .
Please help

  


• Color spot in FFmpeg output

  2 juin 2022, par Fabian Garcia

  I work in a company that serves multimedia content to different clients and one of these requests that the videos contain the following specifications :

  


  

  • Codec : H264 High@4.0

  


  • Mode : CBR 1 pass

  


  • Window Buffer : 5 secs

  


  • Frame Rate : 29.97/23.97

  


  • Key Frame Interval : 2 secs

  


  • Bitrate : 4000 Kbps

  


  • Size : 1920x1080

  


  • Window Buffer : 5 secs

  


  • GOP : closed

  


  • GOP size : fixed (no scene change detection)

  


  • Window Buffer : 5 secs

  


  • B Frames : As needed

  


  


  For the above, i build following script :

  


  ffmpeg -hide_banner -nostats -loglevel error -y
-init_hw_device cuda=cuda -hwaccel cuda -hwaccel_device cuda
-i 'video_source.mxf' -filter_hw_device cuda
-filter_complex '[0:v]format=nv12,hwupload,yadif_cuda,scale_cuda=1920:1080[v0]'
-map '[v0]' -c:v h264_nvenc -rc cbr -b:v 4M -bufsize 8M -x264-params "keyint=60:min-keyint=48:no-scenecut" -r '30000/1001' -profile:v high -level:v 4
-map 0:1 -c:a libfdk_aac -b:a 96k -ar 44100 -ac 2 -sample_fmt s16
'output.mp4'


  


  The inconvenience is that the generated output presents some color spots in the scene changes (it's a fade) as can be seen in the attached image.

  


  I could notice that in the output video, the time does not match the input precisely, the output is a few milliseconds ahead, I think that the color spot corresponds to the image that should be shown at that moment in the original video.

  


  Can you see something wrong in script ? Or maybe some concept that i don't know is causing a conflict with the output (This is my first time using ffmpeg).

  


  Thank for your help !

  


  

  


• libfdk-aacdec : Clean up properly if the init fails

  14 août 2015, par Martin Storsjö

  libfdk-aacdec : Clean up properly if the init fails
  Previously most of the error paths leaked.
  Also add FF_CODEC_CAP_INIT_THREADSAFE while adding caps_internal ;
  
  this decoder wrapper doesn’t have any static data that is initialized.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavcodec/libfdk-aacdec.c